Bug Summary

File:include/llvm/Support/Error.h
Warning:line 201, column 5
Potential leak of memory pointed to by 'Payload._M_t._M_head_impl'

Annotated Source Code

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clang -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name InputSection.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -mrelocation-model pic -pic-level 2 -mthread-model posix -fmath-errno -masm-verbose -mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu x86-64 -dwarf-column-info -debugger-tuning=gdb -momit-leaf-frame-pointer -ffunction-sections -fdata-sections -resource-dir /usr/lib/llvm-8/lib/clang/8.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-8~svn345461/build-llvm/tools/lld/ELF -I /build/llvm-toolchain-snapshot-8~svn345461/tools/lld/ELF -I /build/llvm-toolchain-snapshot-8~svn345461/tools/lld/include -I /build/llvm-toolchain-snapshot-8~svn345461/build-llvm/tools/lld/include -I /build/llvm-toolchain-snapshot-8~svn345461/build-llvm/include -I /build/llvm-toolchain-snapshot-8~svn345461/include -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0/backward -internal-isystem /usr/include/clang/8.0.0/include/ -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-8/lib/clang/8.0.0/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-comment -std=c++11 -fdeprecated-macro -fdebug-compilation-dir /build/llvm-toolchain-snapshot-8~svn345461/build-llvm/tools/lld/ELF -ferror-limit 19 -fmessage-length 0 -fvisibility-inlines-hidden -fobjc-runtime=gcc -fdiagnostics-show-option -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -o /tmp/scan-build-2018-10-27-211344-32123-1 -x c++ /build/llvm-toolchain-snapshot-8~svn345461/tools/lld/ELF/InputSection.cpp -faddrsig

/build/llvm-toolchain-snapshot-8~svn345461/tools/lld/ELF/InputSection.cpp

1//===- InputSection.cpp ---------------------------------------------------===//
2//
3// The LLVM Linker
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9
10#include "InputSection.h"
11#include "Config.h"
12#include "EhFrame.h"
13#include "InputFiles.h"
14#include "LinkerScript.h"
15#include "OutputSections.h"
16#include "Relocations.h"
17#include "SymbolTable.h"
18#include "Symbols.h"
19#include "SyntheticSections.h"
20#include "Target.h"
21#include "Thunks.h"
22#include "lld/Common/ErrorHandler.h"
23#include "lld/Common/Memory.h"
24#include "llvm/Support/Compiler.h"
25#include "llvm/Support/Compression.h"
26#include "llvm/Support/Endian.h"
27#include "llvm/Support/Threading.h"
28#include "llvm/Support/xxhash.h"
29#include <algorithm>
30#include <mutex>
31#include <set>
32#include <vector>
33
34using namespace llvm;
35using namespace llvm::ELF;
36using namespace llvm::object;
37using namespace llvm::support;
38using namespace llvm::support::endian;
39using namespace llvm::sys;
40
41using namespace lld;
42using namespace lld::elf;
43
44std::vector<InputSectionBase *> elf::InputSections;
45
46// Returns a string to construct an error message.
47std::string lld::toString(const InputSectionBase *Sec) {
48 return (toString(Sec->File) + ":(" + Sec->Name + ")").str();
49}
50
51template <class ELFT>
52static ArrayRef<uint8_t> getSectionContents(ObjFile<ELFT> &File,
53 const typename ELFT::Shdr &Hdr) {
54 if (Hdr.sh_type == SHT_NOBITS)
3
Assuming the condition is false
4
Taking false branch
55 return makeArrayRef<uint8_t>(nullptr, Hdr.sh_size);
56 return check(File.getObj().getSectionContents(&Hdr));
5
Calling 'ELFFileBase::getObj'
57}
58
59InputSectionBase::InputSectionBase(InputFile *File, uint64_t Flags,
60 uint32_t Type, uint64_t Entsize,
61 uint32_t Link, uint32_t Info,
62 uint32_t Alignment, ArrayRef<uint8_t> Data,
63 StringRef Name, Kind SectionKind)
64 : SectionBase(SectionKind, Name, Flags, Entsize, Alignment, Type, Info,
65 Link),
66 File(File), RawData(Data) {
67 // In order to reduce memory allocation, we assume that mergeable
68 // sections are smaller than 4 GiB, which is not an unreasonable
69 // assumption as of 2017.
70 if (SectionKind == SectionBase::Merge && RawData.size() > UINT32_MAX(4294967295U))
71 error(toString(this) + ": section too large");
72
73 NumRelocations = 0;
74 AreRelocsRela = false;
75
76 // The ELF spec states that a value of 0 means the section has
77 // no alignment constraits.
78 uint32_t V = std::max<uint64_t>(Alignment, 1);
79 if (!isPowerOf2_64(V))
80 fatal(toString(File) + ": section sh_addralign is not a power of 2");
81 this->Alignment = V;
82
83 // In ELF, each section can be compressed by zlib, and if compressed,
84 // section name may be mangled by appending "z" (e.g. ".zdebug_info").
85 // If that's the case, demangle section name so that we can handle a
86 // section as if it weren't compressed.
87 if ((Flags & SHF_COMPRESSED) || Name.startswith(".zdebug")) {
88 if (!zlib::isAvailable())
89 error(toString(File) + ": contains a compressed section, " +
90 "but zlib is not available");
91 parseCompressedHeader();
92 }
93}
94
95// Drop SHF_GROUP bit unless we are producing a re-linkable object file.
96// SHF_GROUP is a marker that a section belongs to some comdat group.
97// That flag doesn't make sense in an executable.
98static uint64_t getFlags(uint64_t Flags) {
99 Flags &= ~(uint64_t)SHF_INFO_LINK;
100 if (!Config->Relocatable)
101 Flags &= ~(uint64_t)SHF_GROUP;
102 return Flags;
103}
104
105// GNU assembler 2.24 and LLVM 4.0.0's MC (the newest release as of
106// March 2017) fail to infer section types for sections starting with
107// ".init_array." or ".fini_array.". They set SHT_PROGBITS instead of
108// SHF_INIT_ARRAY. As a result, the following assembler directive
109// creates ".init_array.100" with SHT_PROGBITS, for example.
110//
111// .section .init_array.100, "aw"
112//
113// This function forces SHT_{INIT,FINI}_ARRAY so that we can handle
114// incorrect inputs as if they were correct from the beginning.
115static uint64_t getType(uint64_t Type, StringRef Name) {
116 if (Type == SHT_PROGBITS && Name.startswith(".init_array."))
117 return SHT_INIT_ARRAY;
118 if (Type == SHT_PROGBITS && Name.startswith(".fini_array."))
119 return SHT_FINI_ARRAY;
120 return Type;
121}
122
123template <class ELFT>
124InputSectionBase::InputSectionBase(ObjFile<ELFT> &File,
125 const typename ELFT::Shdr &Hdr,
126 StringRef Name, Kind SectionKind)
127 : InputSectionBase(&File, getFlags(Hdr.sh_flags),
128 getType(Hdr.sh_type, Name), Hdr.sh_entsize, Hdr.sh_link,
129 Hdr.sh_info, Hdr.sh_addralign,
130 getSectionContents(File, Hdr), Name, SectionKind) {
2
Calling 'getSectionContents<llvm::object::ELFType<llvm::support::big, true>>'
131 // We reject object files having insanely large alignments even though
132 // they are allowed by the spec. I think 4GB is a reasonable limitation.
133 // We might want to relax this in the future.
134 if (Hdr.sh_addralign > UINT32_MAX(4294967295U))
135 fatal(toString(&File) + ": section sh_addralign is too large");
136}
137
138size_t InputSectionBase::getSize() const {
139 if (auto *S = dyn_cast<SyntheticSection>(this))
140 return S->getSize();
141 if (UncompressedSize >= 0)
142 return UncompressedSize;
143 return RawData.size();
144}
145
146void InputSectionBase::uncompress() const {
147 size_t Size = UncompressedSize;
148 UncompressedBuf.reset(new char[Size]);
149
150 if (Error E =
151 zlib::uncompress(toStringRef(RawData), UncompressedBuf.get(), Size))
152 fatal(toString(this) +
153 ": uncompress failed: " + llvm::toString(std::move(E)));
154 RawData = makeArrayRef((uint8_t *)UncompressedBuf.get(), Size);
155}
156
157uint64_t InputSectionBase::getOffsetInFile() const {
158 const uint8_t *FileStart = (const uint8_t *)File->MB.getBufferStart();
159 const uint8_t *SecStart = data().begin();
160 return SecStart - FileStart;
161}
162
163uint64_t SectionBase::getOffset(uint64_t Offset) const {
164 switch (kind()) {
165 case Output: {
166 auto *OS = cast<OutputSection>(this);
167 // For output sections we treat offset -1 as the end of the section.
168 return Offset == uint64_t(-1) ? OS->Size : Offset;
169 }
170 case Regular:
171 case Synthetic:
172 return cast<InputSection>(this)->getOffset(Offset);
173 case EHFrame:
174 // The file crtbeginT.o has relocations pointing to the start of an empty
175 // .eh_frame that is known to be the first in the link. It does that to
176 // identify the start of the output .eh_frame.
177 return Offset;
178 case Merge:
179 const MergeInputSection *MS = cast<MergeInputSection>(this);
180 if (InputSection *IS = MS->getParent())
181 return IS->getOffset(MS->getParentOffset(Offset));
182 return MS->getParentOffset(Offset);
183 }
184 llvm_unreachable("invalid section kind")::llvm::llvm_unreachable_internal("invalid section kind", "/build/llvm-toolchain-snapshot-8~svn345461/tools/lld/ELF/InputSection.cpp"
, 184)
;
185}
186
187uint64_t SectionBase::getVA(uint64_t Offset) const {
188 const OutputSection *Out = getOutputSection();
189 return (Out ? Out->Addr : 0) + getOffset(Offset);
190}
191
192OutputSection *SectionBase::getOutputSection() {
193 InputSection *Sec;
194 if (auto *IS = dyn_cast<InputSection>(this))
195 Sec = IS;
196 else if (auto *MS = dyn_cast<MergeInputSection>(this))
197 Sec = MS->getParent();
198 else if (auto *EH = dyn_cast<EhInputSection>(this))
199 Sec = EH->getParent();
200 else
201 return cast<OutputSection>(this);
202 return Sec ? Sec->getParent() : nullptr;
203}
204
205// When a section is compressed, `RawData` consists with a header followed
206// by zlib-compressed data. This function parses a header to initialize
207// `UncompressedSize` member and remove the header from `RawData`.
208void InputSectionBase::parseCompressedHeader() {
209 typedef typename ELF64LE::Chdr Chdr64;
210 typedef typename ELF32LE::Chdr Chdr32;
211
212 // Old-style header
213 if (Name.startswith(".zdebug")) {
214 if (!toStringRef(RawData).startswith("ZLIB")) {
215 error(toString(this) + ": corrupted compressed section header");
216 return;
217 }
218 RawData = RawData.slice(4);
219
220 if (RawData.size() < 8) {
221 error(toString(this) + ": corrupted compressed section header");
222 return;
223 }
224
225 UncompressedSize = read64be(RawData.data());
226 RawData = RawData.slice(8);
227
228 // Restore the original section name.
229 // (e.g. ".zdebug_info" -> ".debug_info")
230 Name = Saver.save("." + Name.substr(2));
231 return;
232 }
233
234 assert(Flags & SHF_COMPRESSED)((Flags & SHF_COMPRESSED) ? static_cast<void> (0) :
__assert_fail ("Flags & SHF_COMPRESSED", "/build/llvm-toolchain-snapshot-8~svn345461/tools/lld/ELF/InputSection.cpp"
, 234, __PRETTY_FUNCTION__))
;
235 Flags &= ~(uint64_t)SHF_COMPRESSED;
236
237 // New-style 64-bit header
238 if (Config->Is64) {
239 if (RawData.size() < sizeof(Chdr64)) {
240 error(toString(this) + ": corrupted compressed section");
241 return;
242 }
243
244 auto *Hdr = reinterpret_cast<const Chdr64 *>(RawData.data());
245 if (Hdr->ch_type != ELFCOMPRESS_ZLIB) {
246 error(toString(this) + ": unsupported compression type");
247 return;
248 }
249
250 UncompressedSize = Hdr->ch_size;
251 RawData = RawData.slice(sizeof(*Hdr));
252 return;
253 }
254
255 // New-style 32-bit header
256 if (RawData.size() < sizeof(Chdr32)) {
257 error(toString(this) + ": corrupted compressed section");
258 return;
259 }
260
261 auto *Hdr = reinterpret_cast<const Chdr32 *>(RawData.data());
262 if (Hdr->ch_type != ELFCOMPRESS_ZLIB) {
263 error(toString(this) + ": unsupported compression type");
264 return;
265 }
266
267 UncompressedSize = Hdr->ch_size;
268 RawData = RawData.slice(sizeof(*Hdr));
269}
270
271InputSection *InputSectionBase::getLinkOrderDep() const {
272 assert(Link)((Link) ? static_cast<void> (0) : __assert_fail ("Link"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/lld/ELF/InputSection.cpp"
, 272, __PRETTY_FUNCTION__))
;
273 assert(Flags & SHF_LINK_ORDER)((Flags & SHF_LINK_ORDER) ? static_cast<void> (0) :
__assert_fail ("Flags & SHF_LINK_ORDER", "/build/llvm-toolchain-snapshot-8~svn345461/tools/lld/ELF/InputSection.cpp"
, 273, __PRETTY_FUNCTION__))
;
274 return cast<InputSection>(File->getSections()[Link]);
275}
276
277// Find a function symbol that encloses a given location.
278template <class ELFT>
279Defined *InputSectionBase::getEnclosingFunction(uint64_t Offset) {
280 for (Symbol *B : File->getSymbols())
281 if (Defined *D = dyn_cast<Defined>(B))
282 if (D->Section == this && D->Type == STT_FUNC && D->Value <= Offset &&
283 Offset < D->Value + D->Size)
284 return D;
285 return nullptr;
286}
287
288// Returns a source location string. Used to construct an error message.
289template <class ELFT>
290std::string InputSectionBase::getLocation(uint64_t Offset) {
291 // We don't have file for synthetic sections.
292 if (getFile<ELFT>() == nullptr)
293 return (Config->OutputFile + ":(" + Name + "+0x" + utohexstr(Offset) + ")")
294 .str();
295
296 // First check if we can get desired values from debugging information.
297 if (Optional<DILineInfo> Info = getFile<ELFT>()->getDILineInfo(this, Offset))
298 return Info->FileName + ":" + std::to_string(Info->Line);
299
300 // File->SourceFile contains STT_FILE symbol that contains a
301 // source file name. If it's missing, we use an object file name.
302 std::string SrcFile = getFile<ELFT>()->SourceFile;
303 if (SrcFile.empty())
304 SrcFile = toString(File);
305
306 if (Defined *D = getEnclosingFunction<ELFT>(Offset))
307 return SrcFile + ":(function " + toString(*D) + ")";
308
309 // If there's no symbol, print out the offset in the section.
310 return (SrcFile + ":(" + Name + "+0x" + utohexstr(Offset) + ")").str();
311}
312
313// This function is intended to be used for constructing an error message.
314// The returned message looks like this:
315//
316// foo.c:42 (/home/alice/possibly/very/long/path/foo.c:42)
317//
318// Returns an empty string if there's no way to get line info.
319std::string InputSectionBase::getSrcMsg(const Symbol &Sym, uint64_t Offset) {
320 return File->getSrcMsg(Sym, *this, Offset);
321}
322
323// Returns a filename string along with an optional section name. This
324// function is intended to be used for constructing an error
325// message. The returned message looks like this:
326//
327// path/to/foo.o:(function bar)
328//
329// or
330//
331// path/to/foo.o:(function bar) in archive path/to/bar.a
332std::string InputSectionBase::getObjMsg(uint64_t Off) {
333 std::string Filename = File->getName();
334
335 std::string Archive;
336 if (!File->ArchiveName.empty())
337 Archive = " in archive " + File->ArchiveName;
338
339 // Find a symbol that encloses a given location.
340 for (Symbol *B : File->getSymbols())
341 if (auto *D = dyn_cast<Defined>(B))
342 if (D->Section == this && D->Value <= Off && Off < D->Value + D->Size)
343 return Filename + ":(" + toString(*D) + ")" + Archive;
344
345 // If there's no symbol, print out the offset in the section.
346 return (Filename + ":(" + Name + "+0x" + utohexstr(Off) + ")" + Archive)
347 .str();
348}
349
350InputSection InputSection::Discarded(nullptr, 0, 0, 0, ArrayRef<uint8_t>(), "");
351
352InputSection::InputSection(InputFile *F, uint64_t Flags, uint32_t Type,
353 uint32_t Alignment, ArrayRef<uint8_t> Data,
354 StringRef Name, Kind K)
355 : InputSectionBase(F, Flags, Type,
356 /*Entsize*/ 0, /*Link*/ 0, /*Info*/ 0, Alignment, Data,
357 Name, K) {}
358
359template <class ELFT>
360InputSection::InputSection(ObjFile<ELFT> &F, const typename ELFT::Shdr &Header,
361 StringRef Name)
362 : InputSectionBase(F, Header, Name, InputSectionBase::Regular) {}
363
364bool InputSection::classof(const SectionBase *S) {
365 return S->kind() == SectionBase::Regular ||
366 S->kind() == SectionBase::Synthetic;
367}
368
369OutputSection *InputSection::getParent() const {
370 return cast_or_null<OutputSection>(Parent);
371}
372
373// Copy SHT_GROUP section contents. Used only for the -r option.
374template <class ELFT> void InputSection::copyShtGroup(uint8_t *Buf) {
375 // ELFT::Word is the 32-bit integral type in the target endianness.
376 typedef typename ELFT::Word u32;
377 ArrayRef<u32> From = getDataAs<u32>();
378 auto *To = reinterpret_cast<u32 *>(Buf);
379
380 // The first entry is not a section number but a flag.
381 *To++ = From[0];
382
383 // Adjust section numbers because section numbers in an input object
384 // files are different in the output.
385 ArrayRef<InputSectionBase *> Sections = File->getSections();
386 for (uint32_t Idx : From.slice(1))
387 *To++ = Sections[Idx]->getOutputSection()->SectionIndex;
388}
389
390InputSectionBase *InputSection::getRelocatedSection() const {
391 if (!File || (Type != SHT_RELA && Type != SHT_REL))
392 return nullptr;
393 ArrayRef<InputSectionBase *> Sections = File->getSections();
394 return Sections[Info];
395}
396
397// This is used for -r and --emit-relocs. We can't use memcpy to copy
398// relocations because we need to update symbol table offset and section index
399// for each relocation. So we copy relocations one by one.
400template <class ELFT, class RelTy>
401void InputSection::copyRelocations(uint8_t *Buf, ArrayRef<RelTy> Rels) {
402 InputSectionBase *Sec = getRelocatedSection();
403
404 for (const RelTy &Rel : Rels) {
405 RelType Type = Rel.getType(Config->IsMips64EL);
406 Symbol &Sym = getFile<ELFT>()->getRelocTargetSym(Rel);
407
408 auto *P = reinterpret_cast<typename ELFT::Rela *>(Buf);
409 Buf += sizeof(RelTy);
410
411 if (RelTy::IsRela)
412 P->r_addend = getAddend<ELFT>(Rel);
413
414 // Output section VA is zero for -r, so r_offset is an offset within the
415 // section, but for --emit-relocs it is an virtual address.
416 P->r_offset = Sec->getVA(Rel.r_offset);
417 P->setSymbolAndType(In.SymTab->getSymbolIndex(&Sym), Type,
418 Config->IsMips64EL);
419
420 if (Sym.Type == STT_SECTION) {
421 // We combine multiple section symbols into only one per
422 // section. This means we have to update the addend. That is
423 // trivial for Elf_Rela, but for Elf_Rel we have to write to the
424 // section data. We do that by adding to the Relocation vector.
425
426 // .eh_frame is horribly special and can reference discarded sections. To
427 // avoid having to parse and recreate .eh_frame, we just replace any
428 // relocation in it pointing to discarded sections with R_*_NONE, which
429 // hopefully creates a frame that is ignored at runtime.
430 auto *D = dyn_cast<Defined>(&Sym);
431 if (!D) {
432 error("STT_SECTION symbol should be defined");
433 continue;
434 }
435 SectionBase *Section = D->Section;
436 if (Section == &InputSection::Discarded) {
437 P->setSymbolAndType(0, 0, false);
438 continue;
439 }
440
441 int64_t Addend = getAddend<ELFT>(Rel);
442 const uint8_t *BufLoc = Sec->data().begin() + Rel.r_offset;
443 if (!RelTy::IsRela)
444 Addend = Target->getImplicitAddend(BufLoc, Type);
445
446 if (Config->EMachine == EM_MIPS && Config->Relocatable &&
447 Target->getRelExpr(Type, Sym, BufLoc) == R_MIPS_GOTREL) {
448 // Some MIPS relocations depend on "gp" value. By default,
449 // this value has 0x7ff0 offset from a .got section. But
450 // relocatable files produced by a complier or a linker
451 // might redefine this default value and we must use it
452 // for a calculation of the relocation result. When we
453 // generate EXE or DSO it's trivial. Generating a relocatable
454 // output is more difficult case because the linker does
455 // not calculate relocations in this mode and loses
456 // individual "gp" values used by each input object file.
457 // As a workaround we add the "gp" value to the relocation
458 // addend and save it back to the file.
459 Addend += Sec->getFile<ELFT>()->MipsGp0;
460 }
461
462 if (RelTy::IsRela)
463 P->r_addend = Sym.getVA(Addend) - Section->Repl->getOutputSection()->Addr;
464 else if (Config->Relocatable)
465 Sec->Relocations.push_back({R_ABS, Type, Rel.r_offset, Addend, &Sym});
466 }
467 }
468}
469
470// The ARM and AArch64 ABI handle pc-relative relocations to undefined weak
471// references specially. The general rule is that the value of the symbol in
472// this context is the address of the place P. A further special case is that
473// branch relocations to an undefined weak reference resolve to the next
474// instruction.
475static uint32_t getARMUndefinedRelativeWeakVA(RelType Type, uint32_t A,
476 uint32_t P) {
477 switch (Type) {
478 // Unresolved branch relocations to weak references resolve to next
479 // instruction, this will be either 2 or 4 bytes on from P.
480 case R_ARM_THM_JUMP11:
481 return P + 2 + A;
482 case R_ARM_CALL:
483 case R_ARM_JUMP24:
484 case R_ARM_PC24:
485 case R_ARM_PLT32:
486 case R_ARM_PREL31:
487 case R_ARM_THM_JUMP19:
488 case R_ARM_THM_JUMP24:
489 return P + 4 + A;
490 case R_ARM_THM_CALL:
491 // We don't want an interworking BLX to ARM
492 return P + 5 + A;
493 // Unresolved non branch pc-relative relocations
494 // R_ARM_TARGET2 which can be resolved relatively is not present as it never
495 // targets a weak-reference.
496 case R_ARM_MOVW_PREL_NC:
497 case R_ARM_MOVT_PREL:
498 case R_ARM_REL32:
499 case R_ARM_THM_MOVW_PREL_NC:
500 case R_ARM_THM_MOVT_PREL:
501 return P + A;
502 }
503 llvm_unreachable("ARM pc-relative relocation expected\n")::llvm::llvm_unreachable_internal("ARM pc-relative relocation expected\n"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/lld/ELF/InputSection.cpp"
, 503)
;
504}
505
506// The comment above getARMUndefinedRelativeWeakVA applies to this function.
507static uint64_t getAArch64UndefinedRelativeWeakVA(uint64_t Type, uint64_t A,
508 uint64_t P) {
509 switch (Type) {
510 // Unresolved branch relocations to weak references resolve to next
511 // instruction, this is 4 bytes on from P.
512 case R_AARCH64_CALL26:
513 case R_AARCH64_CONDBR19:
514 case R_AARCH64_JUMP26:
515 case R_AARCH64_TSTBR14:
516 return P + 4 + A;
517 // Unresolved non branch pc-relative relocations
518 case R_AARCH64_PREL16:
519 case R_AARCH64_PREL32:
520 case R_AARCH64_PREL64:
521 case R_AARCH64_ADR_PREL_LO21:
522 case R_AARCH64_LD_PREL_LO19:
523 return P + A;
524 }
525 llvm_unreachable("AArch64 pc-relative relocation expected\n")::llvm::llvm_unreachable_internal("AArch64 pc-relative relocation expected\n"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/lld/ELF/InputSection.cpp"
, 525)
;
526}
527
528// ARM SBREL relocations are of the form S + A - B where B is the static base
529// The ARM ABI defines base to be "addressing origin of the output segment
530// defining the symbol S". We defined the "addressing origin"/static base to be
531// the base of the PT_LOAD segment containing the Sym.
532// The procedure call standard only defines a Read Write Position Independent
533// RWPI variant so in practice we should expect the static base to be the base
534// of the RW segment.
535static uint64_t getARMStaticBase(const Symbol &Sym) {
536 OutputSection *OS = Sym.getOutputSection();
537 if (!OS || !OS->PtLoad || !OS->PtLoad->FirstSec)
538 fatal("SBREL relocation to " + Sym.getName() + " without static base");
539 return OS->PtLoad->FirstSec->Addr;
540}
541
542// For R_RISCV_PC_INDIRECT (R_RISCV_PCREL_LO12_{I,S}), the symbol actually
543// points the corresponding R_RISCV_PCREL_HI20 relocation, and the target VA
544// is calculated using PCREL_HI20's symbol.
545//
546// This function returns the R_RISCV_PCREL_HI20 relocation from
547// R_RISCV_PCREL_LO12's symbol and addend.
548Relocation *lld::elf::getRISCVPCRelHi20(const Symbol *Sym, uint64_t Addend) {
549 const Defined *D = cast<Defined>(Sym);
550 InputSection *IS = cast<InputSection>(D->Section);
551
552 if (Addend != 0)
553 warn("Non-zero addend in R_RISCV_PCREL_LO12 relocation to " +
554 IS->getObjMsg(D->Value) + " is ignored");
555
556 // Relocations are sorted by offset, so we can use std::equal_range to do
557 // binary search.
558 auto Range = std::equal_range(IS->Relocations.begin(), IS->Relocations.end(),
559 D->Value, RelocationOffsetComparator{});
560 for (auto It = std::get<0>(Range); It != std::get<1>(Range); ++It)
561 if (isRelExprOneOf<R_PC>(It->Expr))
562 return &*It;
563
564 error("R_RISCV_PCREL_LO12 relocation points to " + IS->getObjMsg(D->Value) +
565 " without an associated R_RISCV_PCREL_HI20 relocation");
566 return nullptr;
567}
568
569static uint64_t getRelocTargetVA(const InputFile *File, RelType Type, int64_t A,
570 uint64_t P, const Symbol &Sym, RelExpr Expr) {
571 switch (Expr) {
572 case R_INVALID:
573 return 0;
574 case R_ABS:
575 case R_RELAX_TLS_LD_TO_LE_ABS:
576 case R_RELAX_GOT_PC_NOPIC:
577 return Sym.getVA(A);
578 case R_ADDEND:
579 return A;
580 case R_ARM_SBREL:
581 return Sym.getVA(A) - getARMStaticBase(Sym);
582 case R_GOT:
583 case R_RELAX_TLS_GD_TO_IE_ABS:
584 return Sym.getGotVA() + A;
585 case R_GOTONLY_PC:
586 return In.Got->getVA() + A - P;
587 case R_GOTONLY_PC_FROM_END:
588 return In.Got->getVA() + A - P + In.Got->getSize();
589 case R_GOTREL:
590 return Sym.getVA(A) - In.Got->getVA();
591 case R_GOTREL_FROM_END:
592 return Sym.getVA(A) - In.Got->getVA() - In.Got->getSize();
593 case R_GOT_FROM_END:
594 case R_RELAX_TLS_GD_TO_IE_END:
595 return Sym.getGotOffset() + A - In.Got->getSize();
596 case R_TLSLD_GOT_OFF:
597 case R_GOT_OFF:
598 case R_RELAX_TLS_GD_TO_IE_GOT_OFF:
599 return Sym.getGotOffset() + A;
600 case R_GOT_PAGE_PC:
601 case R_RELAX_TLS_GD_TO_IE_PAGE_PC:
602 return getAArch64Page(Sym.getGotVA() + A) - getAArch64Page(P);
603 case R_GOT_PC:
604 case R_RELAX_TLS_GD_TO_IE:
605 return Sym.getGotVA() + A - P;
606 case R_HEXAGON_GOT:
607 return Sym.getGotVA() - In.GotPlt->getVA();
608 case R_MIPS_GOTREL:
609 return Sym.getVA(A) - In.MipsGot->getGp(File);
610 case R_MIPS_GOT_GP:
611 return In.MipsGot->getGp(File) + A;
612 case R_MIPS_GOT_GP_PC: {
613 // R_MIPS_LO16 expression has R_MIPS_GOT_GP_PC type iif the target
614 // is _gp_disp symbol. In that case we should use the following
615 // formula for calculation "AHL + GP - P + 4". For details see p. 4-19 at
616 // ftp://www.linux-mips.org/pub/linux/mips/doc/ABI/mipsabi.pdf
617 // microMIPS variants of these relocations use slightly different
618 // expressions: AHL + GP - P + 3 for %lo() and AHL + GP - P - 1 for %hi()
619 // to correctly handle less-sugnificant bit of the microMIPS symbol.
620 uint64_t V = In.MipsGot->getGp(File) + A - P;
621 if (Type == R_MIPS_LO16 || Type == R_MICROMIPS_LO16)
622 V += 4;
623 if (Type == R_MICROMIPS_LO16 || Type == R_MICROMIPS_HI16)
624 V -= 1;
625 return V;
626 }
627 case R_MIPS_GOT_LOCAL_PAGE:
628 // If relocation against MIPS local symbol requires GOT entry, this entry
629 // should be initialized by 'page address'. This address is high 16-bits
630 // of sum the symbol's value and the addend.
631 return In.MipsGot->getVA() + In.MipsGot->getPageEntryOffset(File, Sym, A) -
632 In.MipsGot->getGp(File);
633 case R_MIPS_GOT_OFF:
634 case R_MIPS_GOT_OFF32:
635 // In case of MIPS if a GOT relocation has non-zero addend this addend
636 // should be applied to the GOT entry content not to the GOT entry offset.
637 // That is why we use separate expression type.
638 return In.MipsGot->getVA() + In.MipsGot->getSymEntryOffset(File, Sym, A) -
639 In.MipsGot->getGp(File);
640 case R_MIPS_TLSGD:
641 return In.MipsGot->getVA() + In.MipsGot->getGlobalDynOffset(File, Sym) -
642 In.MipsGot->getGp(File);
643 case R_MIPS_TLSLD:
644 return In.MipsGot->getVA() + In.MipsGot->getTlsIndexOffset(File) -
645 In.MipsGot->getGp(File);
646 case R_PAGE_PC:
647 case R_PLT_PAGE_PC: {
648 uint64_t Dest;
649 if (Sym.isUndefWeak())
650 Dest = getAArch64Page(A);
651 else
652 Dest = getAArch64Page(Sym.getVA(A));
653 return Dest - getAArch64Page(P);
654 }
655 case R_RISCV_PC_INDIRECT: {
656 const Relocation *HiRel = getRISCVPCRelHi20(&Sym, A);
657 if (!HiRel)
658 return 0;
659 return getRelocTargetVA(File, HiRel->Type, HiRel->Addend, Sym.getVA(),
660 *HiRel->Sym, HiRel->Expr);
661 }
662 case R_PC: {
663 uint64_t Dest;
664 if (Sym.isUndefWeak()) {
665 // On ARM and AArch64 a branch to an undefined weak resolves to the
666 // next instruction, otherwise the place.
667 if (Config->EMachine == EM_ARM)
668 Dest = getARMUndefinedRelativeWeakVA(Type, A, P);
669 else if (Config->EMachine == EM_AARCH64)
670 Dest = getAArch64UndefinedRelativeWeakVA(Type, A, P);
671 else
672 Dest = Sym.getVA(A);
673 } else {
674 Dest = Sym.getVA(A);
675 }
676 return Dest - P;
677 }
678 case R_PLT:
679 return Sym.getPltVA() + A;
680 case R_PLT_PC:
681 case R_PPC_CALL_PLT:
682 return Sym.getPltVA() + A - P;
683 case R_PPC_CALL: {
684 uint64_t SymVA = Sym.getVA(A);
685 // If we have an undefined weak symbol, we might get here with a symbol
686 // address of zero. That could overflow, but the code must be unreachable,
687 // so don't bother doing anything at all.
688 if (!SymVA)
689 return 0;
690
691 // PPC64 V2 ABI describes two entry points to a function. The global entry
692 // point is used for calls where the caller and callee (may) have different
693 // TOC base pointers and r2 needs to be modified to hold the TOC base for
694 // the callee. For local calls the caller and callee share the same
695 // TOC base and so the TOC pointer initialization code should be skipped by
696 // branching to the local entry point.
697 return SymVA - P + getPPC64GlobalEntryToLocalEntryOffset(Sym.StOther);
698 }
699 case R_PPC_TOC:
700 return getPPC64TocBase() + A;
701 case R_RELAX_GOT_PC:
702 return Sym.getVA(A) - P;
703 case R_RELAX_TLS_GD_TO_LE:
704 case R_RELAX_TLS_IE_TO_LE:
705 case R_RELAX_TLS_LD_TO_LE:
706 case R_TLS:
707 // A weak undefined TLS symbol resolves to the base of the TLS
708 // block, i.e. gets a value of zero. If we pass --gc-sections to
709 // lld and .tbss is not referenced, it gets reclaimed and we don't
710 // create a TLS program header. Therefore, we resolve this
711 // statically to zero.
712 if (Sym.isTls() && Sym.isUndefWeak())
713 return 0;
714
715 // For TLS variant 1 the TCB is a fixed size, whereas for TLS variant 2 the
716 // TCB is on unspecified size and content. Targets that implement variant 1
717 // should set TcbSize.
718 if (Target->TcbSize) {
719 // PPC64 V2 ABI has the thread pointer offset into the middle of the TLS
720 // storage area by TlsTpOffset for efficient addressing TCB and up to
721 // 4KB – 8 B of other thread library information (placed before the TCB).
722 // Subtracting this offset will get the address of the first TLS block.
723 if (Target->TlsTpOffset)
724 return Sym.getVA(A) - Target->TlsTpOffset;
725
726 // If thread pointer is not offset into the middle, the first thing in the
727 // TLS storage area is the TCB. Add the TcbSize to get the address of the
728 // first TLS block.
729 return Sym.getVA(A) + alignTo(Target->TcbSize, Out::TlsPhdr->p_align);
730 }
731 return Sym.getVA(A) - Out::TlsPhdr->p_memsz;
732 case R_RELAX_TLS_GD_TO_LE_NEG:
733 case R_NEG_TLS:
734 return Out::TlsPhdr->p_memsz - Sym.getVA(A);
735 case R_SIZE:
736 return Sym.getSize() + A;
737 case R_TLSDESC:
738 return In.Got->getGlobalDynAddr(Sym) + A;
739 case R_TLSDESC_PAGE:
740 return getAArch64Page(In.Got->getGlobalDynAddr(Sym) + A) -
741 getAArch64Page(P);
742 case R_TLSGD_GOT:
743 return In.Got->getGlobalDynOffset(Sym) + A;
744 case R_TLSGD_GOT_FROM_END:
745 return In.Got->getGlobalDynOffset(Sym) + A - In.Got->getSize();
746 case R_TLSGD_PC:
747 return In.Got->getGlobalDynAddr(Sym) + A - P;
748 case R_TLSLD_GOT_FROM_END:
749 return In.Got->getTlsIndexOff() + A - In.Got->getSize();
750 case R_TLSLD_GOT:
751 return In.Got->getTlsIndexOff() + A;
752 case R_TLSLD_PC:
753 return In.Got->getTlsIndexVA() + A - P;
754 default:
755 llvm_unreachable("invalid expression")::llvm::llvm_unreachable_internal("invalid expression", "/build/llvm-toolchain-snapshot-8~svn345461/tools/lld/ELF/InputSection.cpp"
, 755)
;
756 }
757}
758
759// This function applies relocations to sections without SHF_ALLOC bit.
760// Such sections are never mapped to memory at runtime. Debug sections are
761// an example. Relocations in non-alloc sections are much easier to
762// handle than in allocated sections because it will never need complex
763// treatement such as GOT or PLT (because at runtime no one refers them).
764// So, we handle relocations for non-alloc sections directly in this
765// function as a performance optimization.
766template <class ELFT, class RelTy>
767void InputSection::relocateNonAlloc(uint8_t *Buf, ArrayRef<RelTy> Rels) {
768 const unsigned Bits = sizeof(typename ELFT::uint) * 8;
769
770 for (const RelTy &Rel : Rels) {
771 RelType Type = Rel.getType(Config->IsMips64EL);
772
773 // GCC 8.0 or earlier have a bug that they emit R_386_GOTPC relocations
774 // against _GLOBAL_OFFSET_TABLE_ for .debug_info. The bug has been fixed
775 // in 2017 (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82630), but we
776 // need to keep this bug-compatible code for a while.
777 if (Config->EMachine == EM_386 && Type == R_386_GOTPC)
778 continue;
779
780 uint64_t Offset = getOffset(Rel.r_offset);
781 uint8_t *BufLoc = Buf + Offset;
782 int64_t Addend = getAddend<ELFT>(Rel);
783 if (!RelTy::IsRela)
784 Addend += Target->getImplicitAddend(BufLoc, Type);
785
786 Symbol &Sym = getFile<ELFT>()->getRelocTargetSym(Rel);
787 RelExpr Expr = Target->getRelExpr(Type, Sym, BufLoc);
788 if (Expr == R_NONE)
789 continue;
790
791 if (Expr != R_ABS) {
792 std::string Msg = getLocation<ELFT>(Offset) +
793 ": has non-ABS relocation " + toString(Type) +
794 " against symbol '" + toString(Sym) + "'";
795 if (Expr != R_PC) {
796 error(Msg);
797 return;
798 }
799
800 // If the control reaches here, we found a PC-relative relocation in a
801 // non-ALLOC section. Since non-ALLOC section is not loaded into memory
802 // at runtime, the notion of PC-relative doesn't make sense here. So,
803 // this is a usage error. However, GNU linkers historically accept such
804 // relocations without any errors and relocate them as if they were at
805 // address 0. For bug-compatibilty, we accept them with warnings. We
806 // know Steel Bank Common Lisp as of 2018 have this bug.
807 warn(Msg);
808 Target->relocateOne(BufLoc, Type,
809 SignExtend64<Bits>(Sym.getVA(Addend - Offset)));
810 continue;
811 }
812
813 if (Sym.isTls() && !Out::TlsPhdr)
814 Target->relocateOne(BufLoc, Type, 0);
815 else
816 Target->relocateOne(BufLoc, Type, SignExtend64<Bits>(Sym.getVA(Addend)));
817 }
818}
819
820// This is used when '-r' is given.
821// For REL targets, InputSection::copyRelocations() may store artificial
822// relocations aimed to update addends. They are handled in relocateAlloc()
823// for allocatable sections, and this function does the same for
824// non-allocatable sections, such as sections with debug information.
825static void relocateNonAllocForRelocatable(InputSection *Sec, uint8_t *Buf) {
826 const unsigned Bits = Config->Is64 ? 64 : 32;
827
828 for (const Relocation &Rel : Sec->Relocations) {
829 // InputSection::copyRelocations() adds only R_ABS relocations.
830 assert(Rel.Expr == R_ABS)((Rel.Expr == R_ABS) ? static_cast<void> (0) : __assert_fail
("Rel.Expr == R_ABS", "/build/llvm-toolchain-snapshot-8~svn345461/tools/lld/ELF/InputSection.cpp"
, 830, __PRETTY_FUNCTION__))
;
831 uint8_t *BufLoc = Buf + Rel.Offset + Sec->OutSecOff;
832 uint64_t TargetVA = SignExtend64(Rel.Sym->getVA(Rel.Addend), Bits);
833 Target->relocateOne(BufLoc, Rel.Type, TargetVA);
834 }
835}
836
837template <class ELFT>
838void InputSectionBase::relocate(uint8_t *Buf, uint8_t *BufEnd) {
839 if (Flags & SHF_EXECINSTR)
840 adjustSplitStackFunctionPrologues<ELFT>(Buf, BufEnd);
841
842 if (Flags & SHF_ALLOC) {
843 relocateAlloc(Buf, BufEnd);
844 return;
845 }
846
847 auto *Sec = cast<InputSection>(this);
848 if (Config->Relocatable)
849 relocateNonAllocForRelocatable(Sec, Buf);
850 else if (Sec->AreRelocsRela)
851 Sec->relocateNonAlloc<ELFT>(Buf, Sec->template relas<ELFT>());
852 else
853 Sec->relocateNonAlloc<ELFT>(Buf, Sec->template rels<ELFT>());
854}
855
856void InputSectionBase::relocateAlloc(uint8_t *Buf, uint8_t *BufEnd) {
857 assert(Flags & SHF_ALLOC)((Flags & SHF_ALLOC) ? static_cast<void> (0) : __assert_fail
("Flags & SHF_ALLOC", "/build/llvm-toolchain-snapshot-8~svn345461/tools/lld/ELF/InputSection.cpp"
, 857, __PRETTY_FUNCTION__))
;
858 const unsigned Bits = Config->Wordsize * 8;
859
860 for (const Relocation &Rel : Relocations) {
861 uint64_t Offset = Rel.Offset;
862 if (auto *Sec = dyn_cast<InputSection>(this))
863 Offset += Sec->OutSecOff;
864 uint8_t *BufLoc = Buf + Offset;
865 RelType Type = Rel.Type;
866
867 uint64_t AddrLoc = getOutputSection()->Addr + Offset;
868 RelExpr Expr = Rel.Expr;
869 uint64_t TargetVA = SignExtend64(
870 getRelocTargetVA(File, Type, Rel.Addend, AddrLoc, *Rel.Sym, Expr),
871 Bits);
872
873 switch (Expr) {
874 case R_RELAX_GOT_PC:
875 case R_RELAX_GOT_PC_NOPIC:
876 Target->relaxGot(BufLoc, TargetVA);
877 break;
878 case R_RELAX_TLS_IE_TO_LE:
879 Target->relaxTlsIeToLe(BufLoc, Type, TargetVA);
880 break;
881 case R_RELAX_TLS_LD_TO_LE:
882 case R_RELAX_TLS_LD_TO_LE_ABS:
883 Target->relaxTlsLdToLe(BufLoc, Type, TargetVA);
884 break;
885 case R_RELAX_TLS_GD_TO_LE:
886 case R_RELAX_TLS_GD_TO_LE_NEG:
887 Target->relaxTlsGdToLe(BufLoc, Type, TargetVA);
888 break;
889 case R_RELAX_TLS_GD_TO_IE:
890 case R_RELAX_TLS_GD_TO_IE_ABS:
891 case R_RELAX_TLS_GD_TO_IE_GOT_OFF:
892 case R_RELAX_TLS_GD_TO_IE_PAGE_PC:
893 case R_RELAX_TLS_GD_TO_IE_END:
894 Target->relaxTlsGdToIe(BufLoc, Type, TargetVA);
895 break;
896 case R_PPC_CALL:
897 // If this is a call to __tls_get_addr, it may be part of a TLS
898 // sequence that has been relaxed and turned into a nop. In this
899 // case, we don't want to handle it as a call.
900 if (read32(BufLoc) == 0x60000000) // nop
901 break;
902
903 // Patch a nop (0x60000000) to a ld.
904 if (Rel.Sym->NeedsTocRestore) {
905 if (BufLoc + 8 > BufEnd || read32(BufLoc + 4) != 0x60000000) {
906 error(getErrorLocation(BufLoc) + "call lacks nop, can't restore toc");
907 break;
908 }
909 write32(BufLoc + 4, 0xe8410018); // ld %r2, 24(%r1)
910 }
911 Target->relocateOne(BufLoc, Type, TargetVA);
912 break;
913 default:
914 Target->relocateOne(BufLoc, Type, TargetVA);
915 break;
916 }
917 }
918}
919
920// For each function-defining prologue, find any calls to __morestack,
921// and replace them with calls to __morestack_non_split.
922static void switchMorestackCallsToMorestackNonSplit(
923 DenseSet<Defined *> &Prologues, std::vector<Relocation *> &MorestackCalls) {
924
925 // If the target adjusted a function's prologue, all calls to
926 // __morestack inside that function should be switched to
927 // __morestack_non_split.
928 Symbol *MoreStackNonSplit = Symtab->find("__morestack_non_split");
929 if (!MoreStackNonSplit) {
930 error("Mixing split-stack objects requires a definition of "
931 "__morestack_non_split");
932 return;
933 }
934
935 // Sort both collections to compare addresses efficiently.
936 llvm::sort(MorestackCalls, [](const Relocation *L, const Relocation *R) {
937 return L->Offset < R->Offset;
938 });
939 std::vector<Defined *> Functions(Prologues.begin(), Prologues.end());
940 llvm::sort(Functions, [](const Defined *L, const Defined *R) {
941 return L->Value < R->Value;
942 });
943
944 auto It = MorestackCalls.begin();
945 for (Defined *F : Functions) {
946 // Find the first call to __morestack within the function.
947 while (It != MorestackCalls.end() && (*It)->Offset < F->Value)
948 ++It;
949 // Adjust all calls inside the function.
950 while (It != MorestackCalls.end() && (*It)->Offset < F->Value + F->Size) {
951 (*It)->Sym = MoreStackNonSplit;
952 ++It;
953 }
954 }
955}
956
957static bool enclosingPrologueAttempted(uint64_t Offset,
958 const DenseSet<Defined *> &Prologues) {
959 for (Defined *F : Prologues)
960 if (F->Value <= Offset && Offset < F->Value + F->Size)
961 return true;
962 return false;
963}
964
965// If a function compiled for split stack calls a function not
966// compiled for split stack, then the caller needs its prologue
967// adjusted to ensure that the called function will have enough stack
968// available. Find those functions, and adjust their prologues.
969template <class ELFT>
970void InputSectionBase::adjustSplitStackFunctionPrologues(uint8_t *Buf,
971 uint8_t *End) {
972 if (!getFile<ELFT>()->SplitStack)
973 return;
974 DenseSet<Defined *> Prologues;
975 std::vector<Relocation *> MorestackCalls;
976
977 for (Relocation &Rel : Relocations) {
978 // Local symbols can't possibly be cross-calls, and should have been
979 // resolved long before this line.
980 if (Rel.Sym->isLocal())
981 continue;
982
983 // Ignore calls into the split-stack api.
984 if (Rel.Sym->getName().startswith("__morestack")) {
985 if (Rel.Sym->getName().equals("__morestack"))
986 MorestackCalls.push_back(&Rel);
987 continue;
988 }
989
990 // A relocation to non-function isn't relevant. Sometimes
991 // __morestack is not marked as a function, so this check comes
992 // after the name check.
993 if (Rel.Sym->Type != STT_FUNC)
994 continue;
995
996 // If the callee's-file was compiled with split stack, nothing to do. In
997 // this context, a "Defined" symbol is one "defined by the binary currently
998 // being produced". So an "undefined" symbol might be provided by a shared
999 // library. It is not possible to tell how such symbols were compiled, so be
1000 // conservative.
1001 if (Defined *D = dyn_cast<Defined>(Rel.Sym))
1002 if (InputSection *IS = cast_or_null<InputSection>(D->Section))
1003 if (!IS || !IS->getFile<ELFT>() || IS->getFile<ELFT>()->SplitStack)
1004 continue;
1005
1006 if (enclosingPrologueAttempted(Rel.Offset, Prologues))
1007 continue;
1008
1009 if (Defined *F = getEnclosingFunction<ELFT>(Rel.Offset)) {
1010 Prologues.insert(F);
1011 if (Target->adjustPrologueForCrossSplitStack(Buf + getOffset(F->Value),
1012 End, F->StOther))
1013 continue;
1014 if (!getFile<ELFT>()->SomeNoSplitStack)
1015 error(lld::toString(this) + ": " + F->getName() +
1016 " (with -fsplit-stack) calls " + Rel.Sym->getName() +
1017 " (without -fsplit-stack), but couldn't adjust its prologue");
1018 }
1019 }
1020
1021 if (Target->NeedsMoreStackNonSplit)
1022 switchMorestackCallsToMorestackNonSplit(Prologues, MorestackCalls);
1023}
1024
1025template <class ELFT> void InputSection::writeTo(uint8_t *Buf) {
1026 if (Type == SHT_NOBITS)
1027 return;
1028
1029 if (auto *S = dyn_cast<SyntheticSection>(this)) {
1030 S->writeTo(Buf + OutSecOff);
1031 return;
1032 }
1033
1034 // If -r or --emit-relocs is given, then an InputSection
1035 // may be a relocation section.
1036 if (Type == SHT_RELA) {
1037 copyRelocations<ELFT>(Buf + OutSecOff, getDataAs<typename ELFT::Rela>());
1038 return;
1039 }
1040 if (Type == SHT_REL) {
1041 copyRelocations<ELFT>(Buf + OutSecOff, getDataAs<typename ELFT::Rel>());
1042 return;
1043 }
1044
1045 // If -r is given, we may have a SHT_GROUP section.
1046 if (Type == SHT_GROUP) {
1047 copyShtGroup<ELFT>(Buf + OutSecOff);
1048 return;
1049 }
1050
1051 // If this is a compressed section, uncompress section contents directly
1052 // to the buffer.
1053 if (UncompressedSize >= 0 && !UncompressedBuf) {
1054 size_t Size = UncompressedSize;
1055 if (Error E = zlib::uncompress(toStringRef(RawData),
1056 (char *)(Buf + OutSecOff), Size))
1057 fatal(toString(this) +
1058 ": uncompress failed: " + llvm::toString(std::move(E)));
1059 uint8_t *BufEnd = Buf + OutSecOff + Size;
1060 relocate<ELFT>(Buf, BufEnd);
1061 return;
1062 }
1063
1064 // Copy section contents from source object file to output file
1065 // and then apply relocations.
1066 memcpy(Buf + OutSecOff, data().data(), data().size());
1067 uint8_t *BufEnd = Buf + OutSecOff + data().size();
1068 relocate<ELFT>(Buf, BufEnd);
1069}
1070
1071void InputSection::replace(InputSection *Other) {
1072 Alignment = std::max(Alignment, Other->Alignment);
1073 Other->Repl = Repl;
1074 Other->Live = false;
1075}
1076
1077template <class ELFT>
1078EhInputSection::EhInputSection(ObjFile<ELFT> &F,
1079 const typename ELFT::Shdr &Header,
1080 StringRef Name)
1081 : InputSectionBase(F, Header, Name, InputSectionBase::EHFrame) {}
1
Calling constructor for 'InputSectionBase'
1082
1083SyntheticSection *EhInputSection::getParent() const {
1084 return cast_or_null<SyntheticSection>(Parent);
1085}
1086
1087// Returns the index of the first relocation that points to a region between
1088// Begin and Begin+Size.
1089template <class IntTy, class RelTy>
1090static unsigned getReloc(IntTy Begin, IntTy Size, const ArrayRef<RelTy> &Rels,
1091 unsigned &RelocI) {
1092 // Start search from RelocI for fast access. That works because the
1093 // relocations are sorted in .eh_frame.
1094 for (unsigned N = Rels.size(); RelocI < N; ++RelocI) {
1095 const RelTy &Rel = Rels[RelocI];
1096 if (Rel.r_offset < Begin)
1097 continue;
1098
1099 if (Rel.r_offset < Begin + Size)
1100 return RelocI;
1101 return -1;
1102 }
1103 return -1;
1104}
1105
1106// .eh_frame is a sequence of CIE or FDE records.
1107// This function splits an input section into records and returns them.
1108template <class ELFT> void EhInputSection::split() {
1109 if (AreRelocsRela)
1110 split<ELFT>(relas<ELFT>());
1111 else
1112 split<ELFT>(rels<ELFT>());
1113}
1114
1115template <class ELFT, class RelTy>
1116void EhInputSection::split(ArrayRef<RelTy> Rels) {
1117 unsigned RelI = 0;
1118 for (size_t Off = 0, End = data().size(); Off != End;) {
1119 size_t Size = readEhRecordSize(this, Off);
1120 Pieces.emplace_back(Off, this, Size, getReloc(Off, Size, Rels, RelI));
1121 // The empty record is the end marker.
1122 if (Size == 4)
1123 break;
1124 Off += Size;
1125 }
1126}
1127
1128static size_t findNull(StringRef S, size_t EntSize) {
1129 // Optimize the common case.
1130 if (EntSize == 1)
1131 return S.find(0);
1132
1133 for (unsigned I = 0, N = S.size(); I != N; I += EntSize) {
1134 const char *B = S.begin() + I;
1135 if (std::all_of(B, B + EntSize, [](char C) { return C == 0; }))
1136 return I;
1137 }
1138 return StringRef::npos;
1139}
1140
1141SyntheticSection *MergeInputSection::getParent() const {
1142 return cast_or_null<SyntheticSection>(Parent);
1143}
1144
1145// Split SHF_STRINGS section. Such section is a sequence of
1146// null-terminated strings.
1147void MergeInputSection::splitStrings(ArrayRef<uint8_t> Data, size_t EntSize) {
1148 size_t Off = 0;
1149 bool IsAlloc = Flags & SHF_ALLOC;
1150 StringRef S = toStringRef(Data);
1151
1152 while (!S.empty()) {
1153 size_t End = findNull(S, EntSize);
1154 if (End == StringRef::npos)
1155 fatal(toString(this) + ": string is not null terminated");
1156 size_t Size = End + EntSize;
1157
1158 Pieces.emplace_back(Off, xxHash64(S.substr(0, Size)), !IsAlloc);
1159 S = S.substr(Size);
1160 Off += Size;
1161 }
1162}
1163
1164// Split non-SHF_STRINGS section. Such section is a sequence of
1165// fixed size records.
1166void MergeInputSection::splitNonStrings(ArrayRef<uint8_t> Data,
1167 size_t EntSize) {
1168 size_t Size = Data.size();
1169 assert((Size % EntSize) == 0)(((Size % EntSize) == 0) ? static_cast<void> (0) : __assert_fail
("(Size % EntSize) == 0", "/build/llvm-toolchain-snapshot-8~svn345461/tools/lld/ELF/InputSection.cpp"
, 1169, __PRETTY_FUNCTION__))
;
1170 bool IsAlloc = Flags & SHF_ALLOC;
1171
1172 for (size_t I = 0; I != Size; I += EntSize)
1173 Pieces.emplace_back(I, xxHash64(Data.slice(I, EntSize)), !IsAlloc);
1174}
1175
1176template <class ELFT>
1177MergeInputSection::MergeInputSection(ObjFile<ELFT> &F,
1178 const typename ELFT::Shdr &Header,
1179 StringRef Name)
1180 : InputSectionBase(F, Header, Name, InputSectionBase::Merge) {}
1181
1182MergeInputSection::MergeInputSection(uint64_t Flags, uint32_t Type,
1183 uint64_t Entsize, ArrayRef<uint8_t> Data,
1184 StringRef Name)
1185 : InputSectionBase(nullptr, Flags, Type, Entsize, /*Link*/ 0, /*Info*/ 0,
1186 /*Alignment*/ Entsize, Data, Name, SectionBase::Merge) {}
1187
1188// This function is called after we obtain a complete list of input sections
1189// that need to be linked. This is responsible to split section contents
1190// into small chunks for further processing.
1191//
1192// Note that this function is called from parallelForEach. This must be
1193// thread-safe (i.e. no memory allocation from the pools).
1194void MergeInputSection::splitIntoPieces() {
1195 assert(Pieces.empty())((Pieces.empty()) ? static_cast<void> (0) : __assert_fail
("Pieces.empty()", "/build/llvm-toolchain-snapshot-8~svn345461/tools/lld/ELF/InputSection.cpp"
, 1195, __PRETTY_FUNCTION__))
;
1196
1197 if (Flags & SHF_STRINGS)
1198 splitStrings(data(), Entsize);
1199 else
1200 splitNonStrings(data(), Entsize);
1201
1202 OffsetMap.reserve(Pieces.size());
1203 for (size_t I = 0, E = Pieces.size(); I != E; ++I)
1204 OffsetMap[Pieces[I].InputOff] = I;
1205}
1206
1207template <class It, class T, class Compare>
1208static It fastUpperBound(It First, It Last, const T &Value, Compare Comp) {
1209 size_t Size = std::distance(First, Last);
1210 assert(Size != 0)((Size != 0) ? static_cast<void> (0) : __assert_fail ("Size != 0"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/lld/ELF/InputSection.cpp"
, 1210, __PRETTY_FUNCTION__))
;
1211 while (Size != 1) {
1212 size_t H = Size / 2;
1213 const It MI = First + H;
1214 Size -= H;
1215 First = Comp(Value, *MI) ? First : First + H;
1216 }
1217 return Comp(Value, *First) ? First : First + 1;
1218}
1219
1220SectionPiece *MergeInputSection::getSectionPiece(uint64_t Offset) {
1221 if (this->data().size() <= Offset)
1222 fatal(toString(this) + ": offset is outside the section");
1223
1224 // Find a piece starting at a given offset.
1225 auto It = OffsetMap.find(Offset);
1226 if (It != OffsetMap.end())
1227 return &Pieces[It->second];
1228
1229 // If Offset is not at beginning of a section piece, it is not in the map.
1230 // In that case we need to do a binary search of the original section piece vector.
1231 auto I = fastUpperBound(
1232 Pieces.begin(), Pieces.end(), Offset,
1233 [](const uint64_t &A, const SectionPiece &B) { return A < B.InputOff; });
1234 --I;
1235 return &*I;
1236}
1237
1238// Returns the offset in an output section for a given input offset.
1239// Because contents of a mergeable section is not contiguous in output,
1240// it is not just an addition to a base output offset.
1241uint64_t MergeInputSection::getParentOffset(uint64_t Offset) const {
1242 // If Offset is not at beginning of a section piece, it is not in the map.
1243 // In that case we need to search from the original section piece vector.
1244 const SectionPiece &Piece =
1245 *(const_cast<MergeInputSection *>(this)->getSectionPiece (Offset));
1246 uint64_t Addend = Offset - Piece.InputOff;
1247 return Piece.OutputOff + Addend;
1248}
1249
1250template InputSection::InputSection(ObjFile<ELF32LE> &, const ELF32LE::Shdr &,
1251 StringRef);
1252template InputSection::InputSection(ObjFile<ELF32BE> &, const ELF32BE::Shdr &,
1253 StringRef);
1254template InputSection::InputSection(ObjFile<ELF64LE> &, const ELF64LE::Shdr &,
1255 StringRef);
1256template InputSection::InputSection(ObjFile<ELF64BE> &, const ELF64BE::Shdr &,
1257 StringRef);
1258
1259template std::string InputSectionBase::getLocation<ELF32LE>(uint64_t);
1260template std::string InputSectionBase::getLocation<ELF32BE>(uint64_t);
1261template std::string InputSectionBase::getLocation<ELF64LE>(uint64_t);
1262template std::string InputSectionBase::getLocation<ELF64BE>(uint64_t);
1263
1264template void InputSection::writeTo<ELF32LE>(uint8_t *);
1265template void InputSection::writeTo<ELF32BE>(uint8_t *);
1266template void InputSection::writeTo<ELF64LE>(uint8_t *);
1267template void InputSection::writeTo<ELF64BE>(uint8_t *);
1268
1269template MergeInputSection::MergeInputSection(ObjFile<ELF32LE> &,
1270 const ELF32LE::Shdr &, StringRef);
1271template MergeInputSection::MergeInputSection(ObjFile<ELF32BE> &,
1272 const ELF32BE::Shdr &, StringRef);
1273template MergeInputSection::MergeInputSection(ObjFile<ELF64LE> &,
1274 const ELF64LE::Shdr &, StringRef);
1275template MergeInputSection::MergeInputSection(ObjFile<ELF64BE> &,
1276 const ELF64BE::Shdr &, StringRef);
1277
1278template EhInputSection::EhInputSection(ObjFile<ELF32LE> &,
1279 const ELF32LE::Shdr &, StringRef);
1280template EhInputSection::EhInputSection(ObjFile<ELF32BE> &,
1281 const ELF32BE::Shdr &, StringRef);
1282template EhInputSection::EhInputSection(ObjFile<ELF64LE> &,
1283 const ELF64LE::Shdr &, StringRef);
1284template EhInputSection::EhInputSection(ObjFile<ELF64BE> &,
1285 const ELF64BE::Shdr &, StringRef);
1286
1287template void EhInputSection::split<ELF32LE>();
1288template void EhInputSection::split<ELF32BE>();
1289template void EhInputSection::split<ELF64LE>();
1290template void EhInputSection::split<ELF64BE>();

/build/llvm-toolchain-snapshot-8~svn345461/tools/lld/ELF/InputFiles.h

1//===- InputFiles.h ---------------------------------------------*- C++ -*-===//
2//
3// The LLVM Linker
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9
10#ifndef LLD_ELF_INPUT_FILES_H
11#define LLD_ELF_INPUT_FILES_H
12
13#include "Config.h"
14#include "lld/Common/ErrorHandler.h"
15#include "lld/Common/LLVM.h"
16#include "lld/Common/Reproduce.h"
17#include "llvm/ADT/CachedHashString.h"
18#include "llvm/ADT/DenseSet.h"
19#include "llvm/ADT/STLExtras.h"
20#include "llvm/DebugInfo/DWARF/DWARFDebugLine.h"
21#include "llvm/IR/Comdat.h"
22#include "llvm/Object/Archive.h"
23#include "llvm/Object/ELF.h"
24#include "llvm/Object/IRObjectFile.h"
25#include "llvm/Support/Threading.h"
26#include <map>
27
28namespace llvm {
29class TarWriter;
30struct DILineInfo;
31namespace lto {
32class InputFile;
33}
34} // namespace llvm
35
36namespace lld {
37namespace elf {
38class InputFile;
39class InputSectionBase;
40}
41
42// Returns "<internal>", "foo.a(bar.o)" or "baz.o".
43std::string toString(const elf::InputFile *F);
44
45namespace elf {
46
47using llvm::object::Archive;
48
49class Symbol;
50
51// If -reproduce option is given, all input files are written
52// to this tar archive.
53extern llvm::TarWriter *Tar;
54
55// Opens a given file.
56llvm::Optional<MemoryBufferRef> readFile(StringRef Path);
57
58// The root class of input files.
59class InputFile {
60public:
61 enum Kind {
62 ObjKind,
63 SharedKind,
64 LazyObjKind,
65 ArchiveKind,
66 BitcodeKind,
67 BinaryKind,
68 };
69
70 Kind kind() const { return FileKind; }
71
72 bool isElf() const {
73 Kind K = kind();
74 return K == ObjKind || K == SharedKind;
75 }
76
77 StringRef getName() const { return MB.getBufferIdentifier(); }
78 MemoryBufferRef MB;
79
80 // Returns sections. It is a runtime error to call this function
81 // on files that don't have the notion of sections.
82 ArrayRef<InputSectionBase *> getSections() const {
83 assert(FileKind == ObjKind || FileKind == BinaryKind)((FileKind == ObjKind || FileKind == BinaryKind) ? static_cast
<void> (0) : __assert_fail ("FileKind == ObjKind || FileKind == BinaryKind"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/lld/ELF/InputFiles.h"
, 83, __PRETTY_FUNCTION__))
;
84 return Sections;
85 }
86
87 // Returns object file symbols. It is a runtime error to call this
88 // function on files of other types.
89 ArrayRef<Symbol *> getSymbols() { return getMutableSymbols(); }
90
91 std::vector<Symbol *> &getMutableSymbols() {
92 assert(FileKind == BinaryKind || FileKind == ObjKind ||((FileKind == BinaryKind || FileKind == ObjKind || FileKind ==
BitcodeKind) ? static_cast<void> (0) : __assert_fail (
"FileKind == BinaryKind || FileKind == ObjKind || FileKind == BitcodeKind"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/lld/ELF/InputFiles.h"
, 93, __PRETTY_FUNCTION__))
93 FileKind == BitcodeKind)((FileKind == BinaryKind || FileKind == ObjKind || FileKind ==
BitcodeKind) ? static_cast<void> (0) : __assert_fail (
"FileKind == BinaryKind || FileKind == ObjKind || FileKind == BitcodeKind"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/lld/ELF/InputFiles.h"
, 93, __PRETTY_FUNCTION__))
;
94 return Symbols;
95 }
96
97 // Filename of .a which contained this file. If this file was
98 // not in an archive file, it is the empty string. We use this
99 // string for creating error messages.
100 std::string ArchiveName;
101
102 // If this is an architecture-specific file, the following members
103 // have ELF type (i.e. ELF{32,64}{LE,BE}) and target machine type.
104 ELFKind EKind = ELFNoneKind;
105 uint16_t EMachine = llvm::ELF::EM_NONE;
106 uint8_t OSABI = 0;
107
108 // Cache for toString(). Only toString() should use this member.
109 mutable std::string ToStringCache;
110
111 std::string getSrcMsg(const Symbol &Sym, InputSectionBase &Sec,
112 uint64_t Offset);
113
114 // True if this is an argument for --just-symbols. Usually false.
115 bool JustSymbols = false;
116
117 // GroupId is used for --warn-backrefs which is an optional error
118 // checking feature. All files within the same --{start,end}-group or
119 // --{start,end}-lib get the same group ID. Otherwise, each file gets a new
120 // group ID. For more info, see checkDependency() in SymbolTable.cpp.
121 uint32_t GroupId;
122 static bool IsInGroup;
123 static uint32_t NextGroupId;
124
125 // Index of MIPS GOT built for this file.
126 llvm::Optional<size_t> MipsGotIndex;
127
128protected:
129 InputFile(Kind K, MemoryBufferRef M);
130 std::vector<InputSectionBase *> Sections;
131 std::vector<Symbol *> Symbols;
132
133private:
134 const Kind FileKind;
135};
136
137template <typename ELFT> class ELFFileBase : public InputFile {
138public:
139 typedef typename ELFT::Shdr Elf_Shdr;
140 typedef typename ELFT::Sym Elf_Sym;
141 typedef typename ELFT::Word Elf_Word;
142 typedef typename ELFT::SymRange Elf_Sym_Range;
143
144 ELFFileBase(Kind K, MemoryBufferRef M);
145 static bool classof(const InputFile *F) { return F->isElf(); }
146
147 llvm::object::ELFFile<ELFT> getObj() const {
148 return check(llvm::object::ELFFile<ELFT>::create(MB.getBuffer()));
6
Calling 'ELFFile::create'
149 }
150
151 StringRef getStringTable() const { return StringTable; }
152
153 uint32_t getSectionIndex(const Elf_Sym &Sym) const;
154
155 Elf_Sym_Range getGlobalELFSyms();
156 Elf_Sym_Range getELFSyms() const { return ELFSyms; }
157
158protected:
159 ArrayRef<Elf_Sym> ELFSyms;
160 uint32_t FirstGlobal = 0;
161 ArrayRef<Elf_Word> SymtabSHNDX;
162 StringRef StringTable;
163 void initSymtab(ArrayRef<Elf_Shdr> Sections, const Elf_Shdr *Symtab);
164};
165
166// .o file.
167template <class ELFT> class ObjFile : public ELFFileBase<ELFT> {
168 typedef ELFFileBase<ELFT> Base;
169 typedef typename ELFT::Rel Elf_Rel;
170 typedef typename ELFT::Rela Elf_Rela;
171 typedef typename ELFT::Sym Elf_Sym;
172 typedef typename ELFT::Shdr Elf_Shdr;
173 typedef typename ELFT::Word Elf_Word;
174 typedef typename ELFT::CGProfile Elf_CGProfile;
175
176 StringRef getShtGroupSignature(ArrayRef<Elf_Shdr> Sections,
177 const Elf_Shdr &Sec);
178 ArrayRef<Elf_Word> getShtGroupEntries(const Elf_Shdr &Sec);
179
180public:
181 static bool classof(const InputFile *F) { return F->kind() == Base::ObjKind; }
182
183 ArrayRef<Symbol *> getLocalSymbols();
184 ArrayRef<Symbol *> getGlobalSymbols();
185
186 ObjFile(MemoryBufferRef M, StringRef ArchiveName);
187 void parse(llvm::DenseSet<llvm::CachedHashStringRef> &ComdatGroups);
188
189 Symbol &getSymbol(uint32_t SymbolIndex) const {
190 if (SymbolIndex >= this->Symbols.size())
191 fatal(toString(this) + ": invalid symbol index");
192 return *this->Symbols[SymbolIndex];
193 }
194
195 template <typename RelT> Symbol &getRelocTargetSym(const RelT &Rel) const {
196 uint32_t SymIndex = Rel.getSymbol(Config->IsMips64EL);
197 return getSymbol(SymIndex);
198 }
199
200 llvm::Optional<llvm::DILineInfo> getDILineInfo(InputSectionBase *, uint64_t);
201 llvm::Optional<std::pair<std::string, unsigned>> getVariableLoc(StringRef Name);
202
203 // MIPS GP0 value defined by this file. This value represents the gp value
204 // used to create the relocatable object and required to support
205 // R_MIPS_GPREL16 / R_MIPS_GPREL32 relocations.
206 uint32_t MipsGp0 = 0;
207
208 // Name of source file obtained from STT_FILE symbol value,
209 // or empty string if there is no such symbol in object file
210 // symbol table.
211 StringRef SourceFile;
212
213 // True if the file defines functions compiled with
214 // -fsplit-stack. Usually false.
215 bool SplitStack = false;
216
217 // True if the file defines functions compiled with -fsplit-stack,
218 // but had one or more functions with the no_split_stack attribute.
219 bool SomeNoSplitStack = false;
220
221 // Pointer to this input file's .llvm_addrsig section, if it has one.
222 const Elf_Shdr *AddrsigSec = nullptr;
223
224 // SHT_LLVM_CALL_GRAPH_PROFILE table
225 ArrayRef<Elf_CGProfile> CGProfile;
226
227private:
228 void
229 initializeSections(llvm::DenseSet<llvm::CachedHashStringRef> &ComdatGroups);
230 void initializeSymbols();
231 void initializeJustSymbols();
232 void initializeDwarf();
233 InputSectionBase *getRelocTarget(const Elf_Shdr &Sec);
234 InputSectionBase *createInputSection(const Elf_Shdr &Sec);
235 StringRef getSectionName(const Elf_Shdr &Sec);
236
237 bool shouldMerge(const Elf_Shdr &Sec);
238 Symbol *createSymbol(const Elf_Sym *Sym);
239
240 // .shstrtab contents.
241 StringRef SectionStringTable;
242
243 // Debugging information to retrieve source file and line for error
244 // reporting. Linker may find reasonable number of errors in a
245 // single object file, so we cache debugging information in order to
246 // parse it only once for each object file we link.
247 std::unique_ptr<llvm::DWARFContext> Dwarf;
248 std::vector<const llvm::DWARFDebugLine::LineTable *> LineTables;
249 struct VarLoc {
250 const llvm::DWARFDebugLine::LineTable *LT;
251 unsigned File;
252 unsigned Line;
253 };
254 llvm::DenseMap<StringRef, VarLoc> VariableLoc;
255 llvm::once_flag InitDwarfLine;
256};
257
258// LazyObjFile is analogous to ArchiveFile in the sense that
259// the file contains lazy symbols. The difference is that
260// LazyObjFile wraps a single file instead of multiple files.
261//
262// This class is used for --start-lib and --end-lib options which
263// instruct the linker to link object files between them with the
264// archive file semantics.
265class LazyObjFile : public InputFile {
266public:
267 LazyObjFile(MemoryBufferRef M, StringRef ArchiveName,
268 uint64_t OffsetInArchive)
269 : InputFile(LazyObjKind, M), OffsetInArchive(OffsetInArchive) {
270 this->ArchiveName = ArchiveName;
271 }
272
273 static bool classof(const InputFile *F) { return F->kind() == LazyObjKind; }
274
275 template <class ELFT> void parse();
276 MemoryBufferRef getBuffer();
277 InputFile *fetch();
278 bool AddedToLink = false;
279
280private:
281 uint64_t OffsetInArchive;
282};
283
284// An ArchiveFile object represents a .a file.
285class ArchiveFile : public InputFile {
286public:
287 explicit ArchiveFile(std::unique_ptr<Archive> &&File);
288 static bool classof(const InputFile *F) { return F->kind() == ArchiveKind; }
289 template <class ELFT> void parse();
290
291 // Pulls out an object file that contains a definition for Sym and
292 // returns it. If the same file was instantiated before, this
293 // function returns a nullptr (so we don't instantiate the same file
294 // more than once.)
295 InputFile *fetch(const Archive::Symbol &Sym);
296
297private:
298 std::unique_ptr<Archive> File;
299 llvm::DenseSet<uint64_t> Seen;
300};
301
302class BitcodeFile : public InputFile {
303public:
304 BitcodeFile(MemoryBufferRef M, StringRef ArchiveName,
305 uint64_t OffsetInArchive);
306 static bool classof(const InputFile *F) { return F->kind() == BitcodeKind; }
307 template <class ELFT>
308 void parse(llvm::DenseSet<llvm::CachedHashStringRef> &ComdatGroups);
309 std::unique_ptr<llvm::lto::InputFile> Obj;
310};
311
312// .so file.
313template <class ELFT> class SharedFile : public ELFFileBase<ELFT> {
314 typedef ELFFileBase<ELFT> Base;
315 typedef typename ELFT::Dyn Elf_Dyn;
316 typedef typename ELFT::Shdr Elf_Shdr;
317 typedef typename ELFT::Sym Elf_Sym;
318 typedef typename ELFT::SymRange Elf_Sym_Range;
319 typedef typename ELFT::Verdef Elf_Verdef;
320 typedef typename ELFT::Versym Elf_Versym;
321
322 const Elf_Shdr *VersymSec = nullptr;
323 const Elf_Shdr *VerdefSec = nullptr;
324
325public:
326 std::vector<const Elf_Verdef *> Verdefs;
327 std::string SoName;
328
329 static bool classof(const InputFile *F) {
330 return F->kind() == Base::SharedKind;
331 }
332
333 SharedFile(MemoryBufferRef M, StringRef DefaultSoName);
334
335 void parseSoName();
336 void parseRest();
337 uint32_t getAlignment(ArrayRef<Elf_Shdr> Sections, const Elf_Sym &Sym);
338 std::vector<const Elf_Verdef *> parseVerdefs();
339 std::vector<uint32_t> parseVersyms();
340
341 struct NeededVer {
342 // The string table offset of the version name in the output file.
343 size_t StrTab;
344
345 // The version identifier for this version name.
346 uint16_t Index;
347 };
348
349 // Mapping from Elf_Verdef data structures to information about Elf_Vernaux
350 // data structures in the output file.
351 std::map<const Elf_Verdef *, NeededVer> VerdefMap;
352
353 // Used for --as-needed
354 bool IsNeeded;
355};
356
357class BinaryFile : public InputFile {
358public:
359 explicit BinaryFile(MemoryBufferRef M) : InputFile(BinaryKind, M) {}
360 static bool classof(const InputFile *F) { return F->kind() == BinaryKind; }
361 void parse();
362};
363
364InputFile *createObjectFile(MemoryBufferRef MB, StringRef ArchiveName = "",
365 uint64_t OffsetInArchive = 0);
366InputFile *createSharedFile(MemoryBufferRef MB, StringRef DefaultSoName);
367
368inline bool isBitcode(MemoryBufferRef MB) {
369 return identify_magic(MB.getBuffer()) == llvm::file_magic::bitcode;
370}
371
372std::string replaceThinLTOSuffix(StringRef Path);
373
374extern std::vector<BinaryFile *> BinaryFiles;
375extern std::vector<BitcodeFile *> BitcodeFiles;
376extern std::vector<LazyObjFile *> LazyObjFiles;
377extern std::vector<InputFile *> ObjectFiles;
378extern std::vector<InputFile *> SharedFiles;
379
380} // namespace elf
381} // namespace lld
382
383#endif

/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Object/ELF.h

1//===- ELF.h - ELF object file implementation -------------------*- C++ -*-===//
2//
3// The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file declares the ELFFile template class.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_OBJECT_ELF_H
15#define LLVM_OBJECT_ELF_H
16
17#include "llvm/ADT/ArrayRef.h"
18#include "llvm/ADT/SmallVector.h"
19#include "llvm/ADT/StringRef.h"
20#include "llvm/BinaryFormat/ELF.h"
21#include "llvm/Object/ELFTypes.h"
22#include "llvm/Object/Error.h"
23#include "llvm/Support/Endian.h"
24#include "llvm/Support/Error.h"
25#include <cassert>
26#include <cstddef>
27#include <cstdint>
28#include <limits>
29#include <utility>
30
31namespace llvm {
32namespace object {
33
34StringRef getELFRelocationTypeName(uint32_t Machine, uint32_t Type);
35uint32_t getELFRelrRelocationType(uint32_t Machine);
36StringRef getELFSectionTypeName(uint32_t Machine, uint32_t Type);
37
38// Subclasses of ELFFile may need this for template instantiation
39inline std::pair<unsigned char, unsigned char>
40getElfArchType(StringRef Object) {
41 if (Object.size() < ELF::EI_NIDENT)
42 return std::make_pair((uint8_t)ELF::ELFCLASSNONE,
43 (uint8_t)ELF::ELFDATANONE);
44 return std::make_pair((uint8_t)Object[ELF::EI_CLASS],
45 (uint8_t)Object[ELF::EI_DATA]);
46}
47
48static inline Error createError(StringRef Err) {
49 return make_error<StringError>(Err, object_error::parse_failed);
10
Calling 'make_error<llvm::StringError, llvm::StringRef &, llvm::object::object_error>'
50}
51
52template <class ELFT>
53class ELFFile {
54public:
55 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT)using Elf_Addr = typename ELFT::Addr; using Elf_Off = typename
ELFT::Off; using Elf_Half = typename ELFT::Half; using Elf_Word
= typename ELFT::Word; using Elf_Sword = typename ELFT::Sword
; using Elf_Xword = typename ELFT::Xword; using Elf_Sxword = typename
ELFT::Sxword;
56 using uintX_t = typename ELFT::uint;
57 using Elf_Ehdr = typename ELFT::Ehdr;
58 using Elf_Shdr = typename ELFT::Shdr;
59 using Elf_Sym = typename ELFT::Sym;
60 using Elf_Dyn = typename ELFT::Dyn;
61 using Elf_Phdr = typename ELFT::Phdr;
62 using Elf_Rel = typename ELFT::Rel;
63 using Elf_Rela = typename ELFT::Rela;
64 using Elf_Relr = typename ELFT::Relr;
65 using Elf_Verdef = typename ELFT::Verdef;
66 using Elf_Verdaux = typename ELFT::Verdaux;
67 using Elf_Verneed = typename ELFT::Verneed;
68 using Elf_Vernaux = typename ELFT::Vernaux;
69 using Elf_Versym = typename ELFT::Versym;
70 using Elf_Hash = typename ELFT::Hash;
71 using Elf_GnuHash = typename ELFT::GnuHash;
72 using Elf_Nhdr = typename ELFT::Nhdr;
73 using Elf_Note = typename ELFT::Note;
74 using Elf_Note_Iterator = typename ELFT::NoteIterator;
75 using Elf_Dyn_Range = typename ELFT::DynRange;
76 using Elf_Shdr_Range = typename ELFT::ShdrRange;
77 using Elf_Sym_Range = typename ELFT::SymRange;
78 using Elf_Rel_Range = typename ELFT::RelRange;
79 using Elf_Rela_Range = typename ELFT::RelaRange;
80 using Elf_Relr_Range = typename ELFT::RelrRange;
81 using Elf_Phdr_Range = typename ELFT::PhdrRange;
82
83 const uint8_t *base() const {
84 return reinterpret_cast<const uint8_t *>(Buf.data());
85 }
86
87 size_t getBufSize() const { return Buf.size(); }
88
89private:
90 StringRef Buf;
91
92 ELFFile(StringRef Object);
93
94public:
95 const Elf_Ehdr *getHeader() const {
96 return reinterpret_cast<const Elf_Ehdr *>(base());
97 }
98
99 template <typename T>
100 Expected<const T *> getEntry(uint32_t Section, uint32_t Entry) const;
101 template <typename T>
102 Expected<const T *> getEntry(const Elf_Shdr *Section, uint32_t Entry) const;
103
104 Expected<StringRef> getStringTable(const Elf_Shdr *Section) const;
105 Expected<StringRef> getStringTableForSymtab(const Elf_Shdr &Section) const;
106 Expected<StringRef> getStringTableForSymtab(const Elf_Shdr &Section,
107 Elf_Shdr_Range Sections) const;
108
109 Expected<ArrayRef<Elf_Word>> getSHNDXTable(const Elf_Shdr &Section) const;
110 Expected<ArrayRef<Elf_Word>> getSHNDXTable(const Elf_Shdr &Section,
111 Elf_Shdr_Range Sections) const;
112
113 StringRef getRelocationTypeName(uint32_t Type) const;
114 void getRelocationTypeName(uint32_t Type,
115 SmallVectorImpl<char> &Result) const;
116 uint32_t getRelrRelocationType() const;
117
118 const char *getDynamicTagAsString(unsigned Arch, uint64_t Type) const;
119 const char *getDynamicTagAsString(uint64_t Type) const;
120
121 /// Get the symbol for a given relocation.
122 Expected<const Elf_Sym *> getRelocationSymbol(const Elf_Rel *Rel,
123 const Elf_Shdr *SymTab) const;
124
125 static Expected<ELFFile> create(StringRef Object);
126
127 bool isMipsELF64() const {
128 return getHeader()->e_machine == ELF::EM_MIPS &&
129 getHeader()->getFileClass() == ELF::ELFCLASS64;
130 }
131
132 bool isMips64EL() const {
133 return isMipsELF64() &&
134 getHeader()->getDataEncoding() == ELF::ELFDATA2LSB;
135 }
136
137 Expected<Elf_Shdr_Range> sections() const;
138
139 Expected<Elf_Dyn_Range> dynamicEntries() const;
140
141 Expected<const uint8_t *> toMappedAddr(uint64_t VAddr) const;
142
143 Expected<Elf_Sym_Range> symbols(const Elf_Shdr *Sec) const {
144 if (!Sec)
145 return makeArrayRef<Elf_Sym>(nullptr, nullptr);
146 return getSectionContentsAsArray<Elf_Sym>(Sec);
147 }
148
149 Expected<Elf_Rela_Range> relas(const Elf_Shdr *Sec) const {
150 return getSectionContentsAsArray<Elf_Rela>(Sec);
151 }
152
153 Expected<Elf_Rel_Range> rels(const Elf_Shdr *Sec) const {
154 return getSectionContentsAsArray<Elf_Rel>(Sec);
155 }
156
157 Expected<Elf_Relr_Range> relrs(const Elf_Shdr *Sec) const {
158 return getSectionContentsAsArray<Elf_Relr>(Sec);
159 }
160
161 Expected<std::vector<Elf_Rela>> decode_relrs(Elf_Relr_Range relrs) const;
162
163 Expected<std::vector<Elf_Rela>> android_relas(const Elf_Shdr *Sec) const;
164
165 /// Iterate over program header table.
166 Expected<Elf_Phdr_Range> program_headers() const {
167 if (getHeader()->e_phnum && getHeader()->e_phentsize != sizeof(Elf_Phdr))
168 return createError("invalid e_phentsize");
169 if (getHeader()->e_phoff +
170 (getHeader()->e_phnum * getHeader()->e_phentsize) >
171 getBufSize())
172 return createError("program headers longer than binary");
173 auto *Begin =
174 reinterpret_cast<const Elf_Phdr *>(base() + getHeader()->e_phoff);
175 return makeArrayRef(Begin, Begin + getHeader()->e_phnum);
176 }
177
178 /// Get an iterator over notes in a program header.
179 ///
180 /// The program header must be of type \c PT_NOTE.
181 ///
182 /// \param Phdr the program header to iterate over.
183 /// \param Err [out] an error to support fallible iteration, which should
184 /// be checked after iteration ends.
185 Elf_Note_Iterator notes_begin(const Elf_Phdr &Phdr, Error &Err) const {
186 if (Phdr.p_type != ELF::PT_NOTE) {
187 Err = createError("attempt to iterate notes of non-note program header");
188 return Elf_Note_Iterator(Err);
189 }
190 if (Phdr.p_offset + Phdr.p_filesz > getBufSize()) {
191 Err = createError("invalid program header offset/size");
192 return Elf_Note_Iterator(Err);
193 }
194 return Elf_Note_Iterator(base() + Phdr.p_offset, Phdr.p_filesz, Err);
195 }
196
197 /// Get an iterator over notes in a section.
198 ///
199 /// The section must be of type \c SHT_NOTE.
200 ///
201 /// \param Shdr the section to iterate over.
202 /// \param Err [out] an error to support fallible iteration, which should
203 /// be checked after iteration ends.
204 Elf_Note_Iterator notes_begin(const Elf_Shdr &Shdr, Error &Err) const {
205 if (Shdr.sh_type != ELF::SHT_NOTE) {
206 Err = createError("attempt to iterate notes of non-note section");
207 return Elf_Note_Iterator(Err);
208 }
209 if (Shdr.sh_offset + Shdr.sh_size > getBufSize()) {
210 Err = createError("invalid section offset/size");
211 return Elf_Note_Iterator(Err);
212 }
213 return Elf_Note_Iterator(base() + Shdr.sh_offset, Shdr.sh_size, Err);
214 }
215
216 /// Get the end iterator for notes.
217 Elf_Note_Iterator notes_end() const {
218 return Elf_Note_Iterator();
219 }
220
221 /// Get an iterator range over notes of a program header.
222 ///
223 /// The program header must be of type \c PT_NOTE.
224 ///
225 /// \param Phdr the program header to iterate over.
226 /// \param Err [out] an error to support fallible iteration, which should
227 /// be checked after iteration ends.
228 iterator_range<Elf_Note_Iterator> notes(const Elf_Phdr &Phdr,
229 Error &Err) const {
230 return make_range(notes_begin(Phdr, Err), notes_end());
231 }
232
233 /// Get an iterator range over notes of a section.
234 ///
235 /// The section must be of type \c SHT_NOTE.
236 ///
237 /// \param Shdr the section to iterate over.
238 /// \param Err [out] an error to support fallible iteration, which should
239 /// be checked after iteration ends.
240 iterator_range<Elf_Note_Iterator> notes(const Elf_Shdr &Shdr,
241 Error &Err) const {
242 return make_range(notes_begin(Shdr, Err), notes_end());
243 }
244
245 Expected<StringRef> getSectionStringTable(Elf_Shdr_Range Sections) const;
246 Expected<uint32_t> getSectionIndex(const Elf_Sym *Sym, Elf_Sym_Range Syms,
247 ArrayRef<Elf_Word> ShndxTable) const;
248 Expected<const Elf_Shdr *> getSection(const Elf_Sym *Sym,
249 const Elf_Shdr *SymTab,
250 ArrayRef<Elf_Word> ShndxTable) const;
251 Expected<const Elf_Shdr *> getSection(const Elf_Sym *Sym,
252 Elf_Sym_Range Symtab,
253 ArrayRef<Elf_Word> ShndxTable) const;
254 Expected<const Elf_Shdr *> getSection(uint32_t Index) const;
255 Expected<const Elf_Shdr *> getSection(const StringRef SectionName) const;
256
257 Expected<const Elf_Sym *> getSymbol(const Elf_Shdr *Sec,
258 uint32_t Index) const;
259
260 Expected<StringRef> getSectionName(const Elf_Shdr *Section) const;
261 Expected<StringRef> getSectionName(const Elf_Shdr *Section,
262 StringRef DotShstrtab) const;
263 template <typename T>
264 Expected<ArrayRef<T>> getSectionContentsAsArray(const Elf_Shdr *Sec) const;
265 Expected<ArrayRef<uint8_t>> getSectionContents(const Elf_Shdr *Sec) const;
266};
267
268using ELF32LEFile = ELFFile<ELF32LE>;
269using ELF64LEFile = ELFFile<ELF64LE>;
270using ELF32BEFile = ELFFile<ELF32BE>;
271using ELF64BEFile = ELFFile<ELF64BE>;
272
273template <class ELFT>
274inline Expected<const typename ELFT::Shdr *>
275getSection(typename ELFT::ShdrRange Sections, uint32_t Index) {
276 if (Index >= Sections.size())
277 return createError("invalid section index");
278 return &Sections[Index];
279}
280
281template <class ELFT>
282inline Expected<uint32_t>
283getExtendedSymbolTableIndex(const typename ELFT::Sym *Sym,
284 const typename ELFT::Sym *FirstSym,
285 ArrayRef<typename ELFT::Word> ShndxTable) {
286 assert(Sym->st_shndx == ELF::SHN_XINDEX)((Sym->st_shndx == ELF::SHN_XINDEX) ? static_cast<void>
(0) : __assert_fail ("Sym->st_shndx == ELF::SHN_XINDEX", "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Object/ELF.h"
, 286, __PRETTY_FUNCTION__))
;
287 unsigned Index = Sym - FirstSym;
288 if (Index >= ShndxTable.size())
289 return createError("index past the end of the symbol table");
290
291 // The size of the table was checked in getSHNDXTable.
292 return ShndxTable[Index];
293}
294
295template <class ELFT>
296Expected<uint32_t>
297ELFFile<ELFT>::getSectionIndex(const Elf_Sym *Sym, Elf_Sym_Range Syms,
298 ArrayRef<Elf_Word> ShndxTable) const {
299 uint32_t Index = Sym->st_shndx;
300 if (Index == ELF::SHN_XINDEX) {
301 auto ErrorOrIndex = getExtendedSymbolTableIndex<ELFT>(
302 Sym, Syms.begin(), ShndxTable);
303 if (!ErrorOrIndex)
304 return ErrorOrIndex.takeError();
305 return *ErrorOrIndex;
306 }
307 if (Index == ELF::SHN_UNDEF || Index >= ELF::SHN_LORESERVE)
308 return 0;
309 return Index;
310}
311
312template <class ELFT>
313Expected<const typename ELFT::Shdr *>
314ELFFile<ELFT>::getSection(const Elf_Sym *Sym, const Elf_Shdr *SymTab,
315 ArrayRef<Elf_Word> ShndxTable) const {
316 auto SymsOrErr = symbols(SymTab);
317 if (!SymsOrErr)
318 return SymsOrErr.takeError();
319 return getSection(Sym, *SymsOrErr, ShndxTable);
320}
321
322template <class ELFT>
323Expected<const typename ELFT::Shdr *>
324ELFFile<ELFT>::getSection(const Elf_Sym *Sym, Elf_Sym_Range Symbols,
325 ArrayRef<Elf_Word> ShndxTable) const {
326 auto IndexOrErr = getSectionIndex(Sym, Symbols, ShndxTable);
327 if (!IndexOrErr)
328 return IndexOrErr.takeError();
329 uint32_t Index = *IndexOrErr;
330 if (Index == 0)
331 return nullptr;
332 return getSection(Index);
333}
334
335template <class ELFT>
336inline Expected<const typename ELFT::Sym *>
337getSymbol(typename ELFT::SymRange Symbols, uint32_t Index) {
338 if (Index >= Symbols.size())
339 return createError("invalid symbol index");
340 return &Symbols[Index];
341}
342
343template <class ELFT>
344Expected<const typename ELFT::Sym *>
345ELFFile<ELFT>::getSymbol(const Elf_Shdr *Sec, uint32_t Index) const {
346 auto SymtabOrErr = symbols(Sec);
347 if (!SymtabOrErr)
348 return SymtabOrErr.takeError();
349 return object::getSymbol<ELFT>(*SymtabOrErr, Index);
350}
351
352template <class ELFT>
353template <typename T>
354Expected<ArrayRef<T>>
355ELFFile<ELFT>::getSectionContentsAsArray(const Elf_Shdr *Sec) const {
356 if (Sec->sh_entsize != sizeof(T) && sizeof(T) != 1)
357 return createError("invalid sh_entsize");
358
359 uintX_t Offset = Sec->sh_offset;
360 uintX_t Size = Sec->sh_size;
361
362 if (Size % sizeof(T))
363 return createError("size is not a multiple of sh_entsize");
364 if ((std::numeric_limits<uintX_t>::max() - Offset < Size) ||
365 Offset + Size > Buf.size())
366 return createError("invalid section offset");
367
368 if (Offset % alignof(T))
369 return createError("unaligned data");
370
371 const T *Start = reinterpret_cast<const T *>(base() + Offset);
372 return makeArrayRef(Start, Size / sizeof(T));
373}
374
375template <class ELFT>
376Expected<ArrayRef<uint8_t>>
377ELFFile<ELFT>::getSectionContents(const Elf_Shdr *Sec) const {
378 return getSectionContentsAsArray<uint8_t>(Sec);
379}
380
381template <class ELFT>
382StringRef ELFFile<ELFT>::getRelocationTypeName(uint32_t Type) const {
383 return getELFRelocationTypeName(getHeader()->e_machine, Type);
384}
385
386template <class ELFT>
387void ELFFile<ELFT>::getRelocationTypeName(uint32_t Type,
388 SmallVectorImpl<char> &Result) const {
389 if (!isMipsELF64()) {
390 StringRef Name = getRelocationTypeName(Type);
391 Result.append(Name.begin(), Name.end());
392 } else {
393 // The Mips N64 ABI allows up to three operations to be specified per
394 // relocation record. Unfortunately there's no easy way to test for the
395 // presence of N64 ELFs as they have no special flag that identifies them
396 // as being N64. We can safely assume at the moment that all Mips
397 // ELFCLASS64 ELFs are N64. New Mips64 ABIs should provide enough
398 // information to disambiguate between old vs new ABIs.
399 uint8_t Type1 = (Type >> 0) & 0xFF;
400 uint8_t Type2 = (Type >> 8) & 0xFF;
401 uint8_t Type3 = (Type >> 16) & 0xFF;
402
403 // Concat all three relocation type names.
404 StringRef Name = getRelocationTypeName(Type1);
405 Result.append(Name.begin(), Name.end());
406
407 Name = getRelocationTypeName(Type2);
408 Result.append(1, '/');
409 Result.append(Name.begin(), Name.end());
410
411 Name = getRelocationTypeName(Type3);
412 Result.append(1, '/');
413 Result.append(Name.begin(), Name.end());
414 }
415}
416
417template <class ELFT>
418uint32_t ELFFile<ELFT>::getRelrRelocationType() const {
419 return getELFRelrRelocationType(getHeader()->e_machine);
420}
421
422template <class ELFT>
423Expected<const typename ELFT::Sym *>
424ELFFile<ELFT>::getRelocationSymbol(const Elf_Rel *Rel,
425 const Elf_Shdr *SymTab) const {
426 uint32_t Index = Rel->getSymbol(isMips64EL());
427 if (Index == 0)
428 return nullptr;
429 return getEntry<Elf_Sym>(SymTab, Index);
430}
431
432template <class ELFT>
433Expected<StringRef>
434ELFFile<ELFT>::getSectionStringTable(Elf_Shdr_Range Sections) const {
435 uint32_t Index = getHeader()->e_shstrndx;
436 if (Index == ELF::SHN_XINDEX)
437 Index = Sections[0].sh_link;
438
439 if (!Index) // no section string table.
440 return "";
441 if (Index >= Sections.size())
442 return createError("invalid section index");
443 return getStringTable(&Sections[Index]);
444}
445
446template <class ELFT> ELFFile<ELFT>::ELFFile(StringRef Object) : Buf(Object) {}
447
448template <class ELFT>
449Expected<ELFFile<ELFT>> ELFFile<ELFT>::create(StringRef Object) {
450 if (sizeof(Elf_Ehdr) > Object.size())
7
Assuming the condition is true
8
Taking true branch
451 return createError("Invalid buffer");
9
Calling 'createError'
452 return ELFFile(Object);
453}
454
455template <class ELFT>
456Expected<typename ELFT::ShdrRange> ELFFile<ELFT>::sections() const {
457 const uintX_t SectionTableOffset = getHeader()->e_shoff;
458 if (SectionTableOffset == 0)
459 return ArrayRef<Elf_Shdr>();
460
461 if (getHeader()->e_shentsize != sizeof(Elf_Shdr))
462 return createError(
463 "invalid section header entry size (e_shentsize) in ELF header");
464
465 const uint64_t FileSize = Buf.size();
466
467 if (SectionTableOffset + sizeof(Elf_Shdr) > FileSize)
468 return createError("section header table goes past the end of the file");
469
470 // Invalid address alignment of section headers
471 if (SectionTableOffset & (alignof(Elf_Shdr) - 1))
472 return createError("invalid alignment of section headers");
473
474 const Elf_Shdr *First =
475 reinterpret_cast<const Elf_Shdr *>(base() + SectionTableOffset);
476
477 uintX_t NumSections = getHeader()->e_shnum;
478 if (NumSections == 0)
479 NumSections = First->sh_size;
480
481 if (NumSections > UINT64_MAX(18446744073709551615UL) / sizeof(Elf_Shdr))
482 return createError("section table goes past the end of file");
483
484 const uint64_t SectionTableSize = NumSections * sizeof(Elf_Shdr);
485
486 // Section table goes past end of file!
487 if (SectionTableOffset + SectionTableSize > FileSize)
488 return createError("section table goes past the end of file");
489
490 return makeArrayRef(First, NumSections);
491}
492
493template <class ELFT>
494template <typename T>
495Expected<const T *> ELFFile<ELFT>::getEntry(uint32_t Section,
496 uint32_t Entry) const {
497 auto SecOrErr = getSection(Section);
498 if (!SecOrErr)
499 return SecOrErr.takeError();
500 return getEntry<T>(*SecOrErr, Entry);
501}
502
503template <class ELFT>
504template <typename T>
505Expected<const T *> ELFFile<ELFT>::getEntry(const Elf_Shdr *Section,
506 uint32_t Entry) const {
507 if (sizeof(T) != Section->sh_entsize)
508 return createError("invalid sh_entsize");
509 size_t Pos = Section->sh_offset + Entry * sizeof(T);
510 if (Pos + sizeof(T) > Buf.size())
511 return createError("invalid section offset");
512 return reinterpret_cast<const T *>(base() + Pos);
513}
514
515template <class ELFT>
516Expected<const typename ELFT::Shdr *>
517ELFFile<ELFT>::getSection(uint32_t Index) const {
518 auto TableOrErr = sections();
519 if (!TableOrErr)
520 return TableOrErr.takeError();
521 return object::getSection<ELFT>(*TableOrErr, Index);
522}
523
524template <class ELFT>
525Expected<const typename ELFT::Shdr *>
526ELFFile<ELFT>::getSection(const StringRef SectionName) const {
527 auto TableOrErr = sections();
528 if (!TableOrErr)
529 return TableOrErr.takeError();
530 for (auto &Sec : *TableOrErr) {
531 auto SecNameOrErr = getSectionName(&Sec);
532 if (!SecNameOrErr)
533 return SecNameOrErr.takeError();
534 if (*SecNameOrErr == SectionName)
535 return &Sec;
536 }
537 return createError("invalid section name");
538}
539
540template <class ELFT>
541Expected<StringRef>
542ELFFile<ELFT>::getStringTable(const Elf_Shdr *Section) const {
543 if (Section->sh_type != ELF::SHT_STRTAB)
544 return createError("invalid sh_type for string table, expected SHT_STRTAB");
545 auto V = getSectionContentsAsArray<char>(Section);
546 if (!V)
547 return V.takeError();
548 ArrayRef<char> Data = *V;
549 if (Data.empty())
550 return createError("empty string table");
551 if (Data.back() != '\0')
552 return createError("string table non-null terminated");
553 return StringRef(Data.begin(), Data.size());
554}
555
556template <class ELFT>
557Expected<ArrayRef<typename ELFT::Word>>
558ELFFile<ELFT>::getSHNDXTable(const Elf_Shdr &Section) const {
559 auto SectionsOrErr = sections();
560 if (!SectionsOrErr)
561 return SectionsOrErr.takeError();
562 return getSHNDXTable(Section, *SectionsOrErr);
563}
564
565template <class ELFT>
566Expected<ArrayRef<typename ELFT::Word>>
567ELFFile<ELFT>::getSHNDXTable(const Elf_Shdr &Section,
568 Elf_Shdr_Range Sections) const {
569 assert(Section.sh_type == ELF::SHT_SYMTAB_SHNDX)((Section.sh_type == ELF::SHT_SYMTAB_SHNDX) ? static_cast<
void> (0) : __assert_fail ("Section.sh_type == ELF::SHT_SYMTAB_SHNDX"
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Object/ELF.h"
, 569, __PRETTY_FUNCTION__))
;
570 auto VOrErr = getSectionContentsAsArray<Elf_Word>(&Section);
571 if (!VOrErr)
572 return VOrErr.takeError();
573 ArrayRef<Elf_Word> V = *VOrErr;
574 auto SymTableOrErr = object::getSection<ELFT>(Sections, Section.sh_link);
575 if (!SymTableOrErr)
576 return SymTableOrErr.takeError();
577 const Elf_Shdr &SymTable = **SymTableOrErr;
578 if (SymTable.sh_type != ELF::SHT_SYMTAB &&
579 SymTable.sh_type != ELF::SHT_DYNSYM)
580 return createError("invalid sh_type");
581 if (V.size() != (SymTable.sh_size / sizeof(Elf_Sym)))
582 return createError("invalid section contents size");
583 return V;
584}
585
586template <class ELFT>
587Expected<StringRef>
588ELFFile<ELFT>::getStringTableForSymtab(const Elf_Shdr &Sec) const {
589 auto SectionsOrErr = sections();
590 if (!SectionsOrErr)
591 return SectionsOrErr.takeError();
592 return getStringTableForSymtab(Sec, *SectionsOrErr);
593}
594
595template <class ELFT>
596Expected<StringRef>
597ELFFile<ELFT>::getStringTableForSymtab(const Elf_Shdr &Sec,
598 Elf_Shdr_Range Sections) const {
599
600 if (Sec.sh_type != ELF::SHT_SYMTAB && Sec.sh_type != ELF::SHT_DYNSYM)
601 return createError(
602 "invalid sh_type for symbol table, expected SHT_SYMTAB or SHT_DYNSYM");
603 auto SectionOrErr = object::getSection<ELFT>(Sections, Sec.sh_link);
604 if (!SectionOrErr)
605 return SectionOrErr.takeError();
606 return getStringTable(*SectionOrErr);
607}
608
609template <class ELFT>
610Expected<StringRef>
611ELFFile<ELFT>::getSectionName(const Elf_Shdr *Section) const {
612 auto SectionsOrErr = sections();
613 if (!SectionsOrErr)
614 return SectionsOrErr.takeError();
615 auto Table = getSectionStringTable(*SectionsOrErr);
616 if (!Table)
617 return Table.takeError();
618 return getSectionName(Section, *Table);
619}
620
621template <class ELFT>
622Expected<StringRef> ELFFile<ELFT>::getSectionName(const Elf_Shdr *Section,
623 StringRef DotShstrtab) const {
624 uint32_t Offset = Section->sh_name;
625 if (Offset == 0)
626 return StringRef();
627 if (Offset >= DotShstrtab.size())
628 return createError("invalid string offset");
629 return StringRef(DotShstrtab.data() + Offset);
630}
631
632/// This function returns the hash value for a symbol in the .dynsym section
633/// Name of the API remains consistent as specified in the libelf
634/// REF : http://www.sco.com/developers/gabi/latest/ch5.dynamic.html#hash
635inline unsigned hashSysV(StringRef SymbolName) {
636 unsigned h = 0, g;
637 for (char C : SymbolName) {
638 h = (h << 4) + C;
639 g = h & 0xf0000000L;
640 if (g != 0)
641 h ^= g >> 24;
642 h &= ~g;
643 }
644 return h;
645}
646
647} // end namespace object
648} // end namespace llvm
649
650#endif // LLVM_OBJECT_ELF_H

/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h

1//===- llvm/Support/Error.h - Recoverable error handling --------*- C++ -*-===//
2//
3// The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file defines an API used to report recoverable errors.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_SUPPORT_ERROR_H
15#define LLVM_SUPPORT_ERROR_H
16
17#include "llvm-c/Error.h"
18#include "llvm/ADT/STLExtras.h"
19#include "llvm/ADT/SmallVector.h"
20#include "llvm/ADT/StringExtras.h"
21#include "llvm/ADT/Twine.h"
22#include "llvm/Config/abi-breaking.h"
23#include "llvm/Support/AlignOf.h"
24#include "llvm/Support/Compiler.h"
25#include "llvm/Support/Debug.h"
26#include "llvm/Support/ErrorHandling.h"
27#include "llvm/Support/ErrorOr.h"
28#include "llvm/Support/Format.h"
29#include "llvm/Support/raw_ostream.h"
30#include <algorithm>
31#include <cassert>
32#include <cstdint>
33#include <cstdlib>
34#include <functional>
35#include <memory>
36#include <new>
37#include <string>
38#include <system_error>
39#include <type_traits>
40#include <utility>
41#include <vector>
42
43namespace llvm {
44
45class ErrorSuccess;
46
47/// Base class for error info classes. Do not extend this directly: Extend
48/// the ErrorInfo template subclass instead.
49class ErrorInfoBase {
50public:
51 virtual ~ErrorInfoBase() = default;
52
53 /// Print an error message to an output stream.
54 virtual void log(raw_ostream &OS) const = 0;
55
56 /// Return the error message as a string.
57 virtual std::string message() const {
58 std::string Msg;
59 raw_string_ostream OS(Msg);
60 log(OS);
61 return OS.str();
62 }
63
64 /// Convert this error to a std::error_code.
65 ///
66 /// This is a temporary crutch to enable interaction with code still
67 /// using std::error_code. It will be removed in the future.
68 virtual std::error_code convertToErrorCode() const = 0;
69
70 // Returns the class ID for this type.
71 static const void *classID() { return &ID; }
72
73 // Returns the class ID for the dynamic type of this ErrorInfoBase instance.
74 virtual const void *dynamicClassID() const = 0;
75
76 // Check whether this instance is a subclass of the class identified by
77 // ClassID.
78 virtual bool isA(const void *const ClassID) const {
79 return ClassID == classID();
80 }
81
82 // Check whether this instance is a subclass of ErrorInfoT.
83 template <typename ErrorInfoT> bool isA() const {
84 return isA(ErrorInfoT::classID());
85 }
86
87private:
88 virtual void anchor();
89
90 static char ID;
91};
92
93/// Lightweight error class with error context and mandatory checking.
94///
95/// Instances of this class wrap a ErrorInfoBase pointer. Failure states
96/// are represented by setting the pointer to a ErrorInfoBase subclass
97/// instance containing information describing the failure. Success is
98/// represented by a null pointer value.
99///
100/// Instances of Error also contains a 'Checked' flag, which must be set
101/// before the destructor is called, otherwise the destructor will trigger a
102/// runtime error. This enforces at runtime the requirement that all Error
103/// instances be checked or returned to the caller.
104///
105/// There are two ways to set the checked flag, depending on what state the
106/// Error instance is in. For Error instances indicating success, it
107/// is sufficient to invoke the boolean conversion operator. E.g.:
108///
109/// @code{.cpp}
110/// Error foo(<...>);
111///
112/// if (auto E = foo(<...>))
113/// return E; // <- Return E if it is in the error state.
114/// // We have verified that E was in the success state. It can now be safely
115/// // destroyed.
116/// @endcode
117///
118/// A success value *can not* be dropped. For example, just calling 'foo(<...>)'
119/// without testing the return value will raise a runtime error, even if foo
120/// returns success.
121///
122/// For Error instances representing failure, you must use either the
123/// handleErrors or handleAllErrors function with a typed handler. E.g.:
124///
125/// @code{.cpp}
126/// class MyErrorInfo : public ErrorInfo<MyErrorInfo> {
127/// // Custom error info.
128/// };
129///
130/// Error foo(<...>) { return make_error<MyErrorInfo>(...); }
131///
132/// auto E = foo(<...>); // <- foo returns failure with MyErrorInfo.
133/// auto NewE =
134/// handleErrors(E,
135/// [](const MyErrorInfo &M) {
136/// // Deal with the error.
137/// },
138/// [](std::unique_ptr<OtherError> M) -> Error {
139/// if (canHandle(*M)) {
140/// // handle error.
141/// return Error::success();
142/// }
143/// // Couldn't handle this error instance. Pass it up the stack.
144/// return Error(std::move(M));
145/// );
146/// // Note - we must check or return NewE in case any of the handlers
147/// // returned a new error.
148/// @endcode
149///
150/// The handleAllErrors function is identical to handleErrors, except
151/// that it has a void return type, and requires all errors to be handled and
152/// no new errors be returned. It prevents errors (assuming they can all be
153/// handled) from having to be bubbled all the way to the top-level.
154///
155/// *All* Error instances must be checked before destruction, even if
156/// they're moved-assigned or constructed from Success values that have already
157/// been checked. This enforces checking through all levels of the call stack.
158class LLVM_NODISCARD[[clang::warn_unused_result]] Error {
159 // Both ErrorList and FileError need to be able to yank ErrorInfoBase
160 // pointers out of this class to add to the error list.
161 friend class ErrorList;
162 friend class FileError;
163
164 // handleErrors needs to be able to set the Checked flag.
165 template <typename... HandlerTs>
166 friend Error handleErrors(Error E, HandlerTs &&... Handlers);
167
168 // Expected<T> needs to be able to steal the payload when constructed from an
169 // error.
170 template <typename T> friend class Expected;
171
172 // wrap needs to be able to steal the payload.
173 friend LLVMErrorRef wrap(Error);
174
175protected:
176 /// Create a success value. Prefer using 'Error::success()' for readability
177 Error() {
178 setPtr(nullptr);
179 setChecked(false);
180 }
181
182public:
183 /// Create a success value.
184 static ErrorSuccess success();
185
186 // Errors are not copy-constructable.
187 Error(const Error &Other) = delete;
188
189 /// Move-construct an error value. The newly constructed error is considered
190 /// unchecked, even if the source error had been checked. The original error
191 /// becomes a checked Success value, regardless of its original state.
192 Error(Error &&Other) {
193 setChecked(true);
194 *this = std::move(Other);
195 }
196
197 /// Create an error value. Prefer using the 'make_error' function, but
198 /// this constructor can be useful when "re-throwing" errors from handlers.
199 Error(std::unique_ptr<ErrorInfoBase> Payload) {
200 setPtr(Payload.release());
201 setChecked(false);
15
Potential leak of memory pointed to by 'Payload._M_t._M_head_impl'
202 }
203
204 // Errors are not copy-assignable.
205 Error &operator=(const Error &Other) = delete;
206
207 /// Move-assign an error value. The current error must represent success, you
208 /// you cannot overwrite an unhandled error. The current error is then
209 /// considered unchecked. The source error becomes a checked success value,
210 /// regardless of its original state.
211 Error &operator=(Error &&Other) {
212 // Don't allow overwriting of unchecked values.
213 assertIsChecked();
214 setPtr(Other.getPtr());
215
216 // This Error is unchecked, even if the source error was checked.
217 setChecked(false);
218
219 // Null out Other's payload and set its checked bit.
220 Other.setPtr(nullptr);
221 Other.setChecked(true);
222
223 return *this;
224 }
225
226 /// Destroy a Error. Fails with a call to abort() if the error is
227 /// unchecked.
228 ~Error() {
229 assertIsChecked();
230 delete getPtr();
231 }
232
233 /// Bool conversion. Returns true if this Error is in a failure state,
234 /// and false if it is in an accept state. If the error is in a Success state
235 /// it will be considered checked.
236 explicit operator bool() {
237 setChecked(getPtr() == nullptr);
238 return getPtr() != nullptr;
239 }
240
241 /// Check whether one error is a subclass of another.
242 template <typename ErrT> bool isA() const {
243 return getPtr() && getPtr()->isA(ErrT::classID());
244 }
245
246 /// Returns the dynamic class id of this error, or null if this is a success
247 /// value.
248 const void* dynamicClassID() const {
249 if (!getPtr())
250 return nullptr;
251 return getPtr()->dynamicClassID();
252 }
253
254private:
255#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
256 // assertIsChecked() happens very frequently, but under normal circumstances
257 // is supposed to be a no-op. So we want it to be inlined, but having a bunch
258 // of debug prints can cause the function to be too large for inlining. So
259 // it's important that we define this function out of line so that it can't be
260 // inlined.
261 LLVM_ATTRIBUTE_NORETURN__attribute__((noreturn))
262 void fatalUncheckedError() const;
263#endif
264
265 void assertIsChecked() {
266#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
267 if (LLVM_UNLIKELY(!getChecked() || getPtr())__builtin_expect((bool)(!getChecked() || getPtr()), false))
268 fatalUncheckedError();
269#endif
270 }
271
272 ErrorInfoBase *getPtr() const {
273 return reinterpret_cast<ErrorInfoBase*>(
274 reinterpret_cast<uintptr_t>(Payload) &
275 ~static_cast<uintptr_t>(0x1));
276 }
277
278 void setPtr(ErrorInfoBase *EI) {
279#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
280 Payload = reinterpret_cast<ErrorInfoBase*>(
281 (reinterpret_cast<uintptr_t>(EI) &
282 ~static_cast<uintptr_t>(0x1)) |
283 (reinterpret_cast<uintptr_t>(Payload) & 0x1));
284#else
285 Payload = EI;
286#endif
287 }
288
289 bool getChecked() const {
290#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
291 return (reinterpret_cast<uintptr_t>(Payload) & 0x1) == 0;
292#else
293 return true;
294#endif
295 }
296
297 void setChecked(bool V) {
298 Payload = reinterpret_cast<ErrorInfoBase*>(
299 (reinterpret_cast<uintptr_t>(Payload) &
300 ~static_cast<uintptr_t>(0x1)) |
301 (V ? 0 : 1));
302 }
303
304 std::unique_ptr<ErrorInfoBase> takePayload() {
305 std::unique_ptr<ErrorInfoBase> Tmp(getPtr());
306 setPtr(nullptr);
307 setChecked(true);
308 return Tmp;
309 }
310
311 friend raw_ostream &operator<<(raw_ostream &OS, const Error &E) {
312 if (auto P = E.getPtr())
313 P->log(OS);
314 else
315 OS << "success";
316 return OS;
317 }
318
319 ErrorInfoBase *Payload = nullptr;
320};
321
322/// Subclass of Error for the sole purpose of identifying the success path in
323/// the type system. This allows to catch invalid conversion to Expected<T> at
324/// compile time.
325class ErrorSuccess final : public Error {};
326
327inline ErrorSuccess Error::success() { return ErrorSuccess(); }
328
329/// Make a Error instance representing failure using the given error info
330/// type.
331template <typename ErrT, typename... ArgTs> Error make_error(ArgTs &&... Args) {
332 return Error(llvm::make_unique<ErrT>(std::forward<ArgTs>(Args)...));
11
Calling 'make_unique<llvm::StringError, llvm::StringRef &, llvm::object::object_error>'
13
Returned allocated memory
14
Calling constructor for 'Error'
333}
334
335/// Base class for user error types. Users should declare their error types
336/// like:
337///
338/// class MyError : public ErrorInfo<MyError> {
339/// ....
340/// };
341///
342/// This class provides an implementation of the ErrorInfoBase::kind
343/// method, which is used by the Error RTTI system.
344template <typename ThisErrT, typename ParentErrT = ErrorInfoBase>
345class ErrorInfo : public ParentErrT {
346public:
347 using ParentErrT::ParentErrT; // inherit constructors
348
349 static const void *classID() { return &ThisErrT::ID; }
350
351 const void *dynamicClassID() const override { return &ThisErrT::ID; }
352
353 bool isA(const void *const ClassID) const override {
354 return ClassID == classID() || ParentErrT::isA(ClassID);
355 }
356};
357
358/// Special ErrorInfo subclass representing a list of ErrorInfos.
359/// Instances of this class are constructed by joinError.
360class ErrorList final : public ErrorInfo<ErrorList> {
361 // handleErrors needs to be able to iterate the payload list of an
362 // ErrorList.
363 template <typename... HandlerTs>
364 friend Error handleErrors(Error E, HandlerTs &&... Handlers);
365
366 // joinErrors is implemented in terms of join.
367 friend Error joinErrors(Error, Error);
368
369public:
370 void log(raw_ostream &OS) const override {
371 OS << "Multiple errors:\n";
372 for (auto &ErrPayload : Payloads) {
373 ErrPayload->log(OS);
374 OS << "\n";
375 }
376 }
377
378 std::error_code convertToErrorCode() const override;
379
380 // Used by ErrorInfo::classID.
381 static char ID;
382
383private:
384 ErrorList(std::unique_ptr<ErrorInfoBase> Payload1,
385 std::unique_ptr<ErrorInfoBase> Payload2) {
386 assert(!Payload1->isA<ErrorList>() && !Payload2->isA<ErrorList>() &&((!Payload1->isA<ErrorList>() && !Payload2->
isA<ErrorList>() && "ErrorList constructor payloads should be singleton errors"
) ? static_cast<void> (0) : __assert_fail ("!Payload1->isA<ErrorList>() && !Payload2->isA<ErrorList>() && \"ErrorList constructor payloads should be singleton errors\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 387, __PRETTY_FUNCTION__))
387 "ErrorList constructor payloads should be singleton errors")((!Payload1->isA<ErrorList>() && !Payload2->
isA<ErrorList>() && "ErrorList constructor payloads should be singleton errors"
) ? static_cast<void> (0) : __assert_fail ("!Payload1->isA<ErrorList>() && !Payload2->isA<ErrorList>() && \"ErrorList constructor payloads should be singleton errors\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 387, __PRETTY_FUNCTION__))
;
388 Payloads.push_back(std::move(Payload1));
389 Payloads.push_back(std::move(Payload2));
390 }
391
392 static Error join(Error E1, Error E2) {
393 if (!E1)
394 return E2;
395 if (!E2)
396 return E1;
397 if (E1.isA<ErrorList>()) {
398 auto &E1List = static_cast<ErrorList &>(*E1.getPtr());
399 if (E2.isA<ErrorList>()) {
400 auto E2Payload = E2.takePayload();
401 auto &E2List = static_cast<ErrorList &>(*E2Payload);
402 for (auto &Payload : E2List.Payloads)
403 E1List.Payloads.push_back(std::move(Payload));
404 } else
405 E1List.Payloads.push_back(E2.takePayload());
406
407 return E1;
408 }
409 if (E2.isA<ErrorList>()) {
410 auto &E2List = static_cast<ErrorList &>(*E2.getPtr());
411 E2List.Payloads.insert(E2List.Payloads.begin(), E1.takePayload());
412 return E2;
413 }
414 return Error(std::unique_ptr<ErrorList>(
415 new ErrorList(E1.takePayload(), E2.takePayload())));
416 }
417
418 std::vector<std::unique_ptr<ErrorInfoBase>> Payloads;
419};
420
421/// Concatenate errors. The resulting Error is unchecked, and contains the
422/// ErrorInfo(s), if any, contained in E1, followed by the
423/// ErrorInfo(s), if any, contained in E2.
424inline Error joinErrors(Error E1, Error E2) {
425 return ErrorList::join(std::move(E1), std::move(E2));
426}
427
428/// Tagged union holding either a T or a Error.
429///
430/// This class parallels ErrorOr, but replaces error_code with Error. Since
431/// Error cannot be copied, this class replaces getError() with
432/// takeError(). It also adds an bool errorIsA<ErrT>() method for testing the
433/// error class type.
434template <class T> class LLVM_NODISCARD[[clang::warn_unused_result]] Expected {
435 template <class T1> friend class ExpectedAsOutParameter;
436 template <class OtherT> friend class Expected;
437
438 static const bool isRef = std::is_reference<T>::value;
439
440 using wrap = std::reference_wrapper<typename std::remove_reference<T>::type>;
441
442 using error_type = std::unique_ptr<ErrorInfoBase>;
443
444public:
445 using storage_type = typename std::conditional<isRef, wrap, T>::type;
446 using value_type = T;
447
448private:
449 using reference = typename std::remove_reference<T>::type &;
450 using const_reference = const typename std::remove_reference<T>::type &;
451 using pointer = typename std::remove_reference<T>::type *;
452 using const_pointer = const typename std::remove_reference<T>::type *;
453
454public:
455 /// Create an Expected<T> error value from the given Error.
456 Expected(Error Err)
457 : HasError(true)
458#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
459 // Expected is unchecked upon construction in Debug builds.
460 , Unchecked(true)
461#endif
462 {
463 assert(Err && "Cannot create Expected<T> from Error success value.")((Err && "Cannot create Expected<T> from Error success value."
) ? static_cast<void> (0) : __assert_fail ("Err && \"Cannot create Expected<T> from Error success value.\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 463, __PRETTY_FUNCTION__))
;
464 new (getErrorStorage()) error_type(Err.takePayload());
465 }
466
467 /// Forbid to convert from Error::success() implicitly, this avoids having
468 /// Expected<T> foo() { return Error::success(); } which compiles otherwise
469 /// but triggers the assertion above.
470 Expected(ErrorSuccess) = delete;
471
472 /// Create an Expected<T> success value from the given OtherT value, which
473 /// must be convertible to T.
474 template <typename OtherT>
475 Expected(OtherT &&Val,
476 typename std::enable_if<std::is_convertible<OtherT, T>::value>::type
477 * = nullptr)
478 : HasError(false)
479#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
480 // Expected is unchecked upon construction in Debug builds.
481 , Unchecked(true)
482#endif
483 {
484 new (getStorage()) storage_type(std::forward<OtherT>(Val));
485 }
486
487 /// Move construct an Expected<T> value.
488 Expected(Expected &&Other) { moveConstruct(std::move(Other)); }
489
490 /// Move construct an Expected<T> value from an Expected<OtherT>, where OtherT
491 /// must be convertible to T.
492 template <class OtherT>
493 Expected(Expected<OtherT> &&Other,
494 typename std::enable_if<std::is_convertible<OtherT, T>::value>::type
495 * = nullptr) {
496 moveConstruct(std::move(Other));
497 }
498
499 /// Move construct an Expected<T> value from an Expected<OtherT>, where OtherT
500 /// isn't convertible to T.
501 template <class OtherT>
502 explicit Expected(
503 Expected<OtherT> &&Other,
504 typename std::enable_if<!std::is_convertible<OtherT, T>::value>::type * =
505 nullptr) {
506 moveConstruct(std::move(Other));
507 }
508
509 /// Move-assign from another Expected<T>.
510 Expected &operator=(Expected &&Other) {
511 moveAssign(std::move(Other));
512 return *this;
513 }
514
515 /// Destroy an Expected<T>.
516 ~Expected() {
517 assertIsChecked();
518 if (!HasError)
519 getStorage()->~storage_type();
520 else
521 getErrorStorage()->~error_type();
522 }
523
524 /// Return false if there is an error.
525 explicit operator bool() {
526#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
527 Unchecked = HasError;
528#endif
529 return !HasError;
530 }
531
532 /// Returns a reference to the stored T value.
533 reference get() {
534 assertIsChecked();
535 return *getStorage();
536 }
537
538 /// Returns a const reference to the stored T value.
539 const_reference get() const {
540 assertIsChecked();
541 return const_cast<Expected<T> *>(this)->get();
542 }
543
544 /// Check that this Expected<T> is an error of type ErrT.
545 template <typename ErrT> bool errorIsA() const {
546 return HasError && (*getErrorStorage())->template isA<ErrT>();
547 }
548
549 /// Take ownership of the stored error.
550 /// After calling this the Expected<T> is in an indeterminate state that can
551 /// only be safely destructed. No further calls (beside the destructor) should
552 /// be made on the Expected<T> vaule.
553 Error takeError() {
554#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
555 Unchecked = false;
556#endif
557 return HasError ? Error(std::move(*getErrorStorage())) : Error::success();
558 }
559
560 /// Returns a pointer to the stored T value.
561 pointer operator->() {
562 assertIsChecked();
563 return toPointer(getStorage());
564 }
565
566 /// Returns a const pointer to the stored T value.
567 const_pointer operator->() const {
568 assertIsChecked();
569 return toPointer(getStorage());
570 }
571
572 /// Returns a reference to the stored T value.
573 reference operator*() {
574 assertIsChecked();
575 return *getStorage();
576 }
577
578 /// Returns a const reference to the stored T value.
579 const_reference operator*() const {
580 assertIsChecked();
581 return *getStorage();
582 }
583
584private:
585 template <class T1>
586 static bool compareThisIfSameType(const T1 &a, const T1 &b) {
587 return &a == &b;
588 }
589
590 template <class T1, class T2>
591 static bool compareThisIfSameType(const T1 &a, const T2 &b) {
592 return false;
593 }
594
595 template <class OtherT> void moveConstruct(Expected<OtherT> &&Other) {
596 HasError = Other.HasError;
597#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
598 Unchecked = true;
599 Other.Unchecked = false;
600#endif
601
602 if (!HasError)
603 new (getStorage()) storage_type(std::move(*Other.getStorage()));
604 else
605 new (getErrorStorage()) error_type(std::move(*Other.getErrorStorage()));
606 }
607
608 template <class OtherT> void moveAssign(Expected<OtherT> &&Other) {
609 assertIsChecked();
610
611 if (compareThisIfSameType(*this, Other))
612 return;
613
614 this->~Expected();
615 new (this) Expected(std::move(Other));
616 }
617
618 pointer toPointer(pointer Val) { return Val; }
619
620 const_pointer toPointer(const_pointer Val) const { return Val; }
621
622 pointer toPointer(wrap *Val) { return &Val->get(); }
623
624 const_pointer toPointer(const wrap *Val) const { return &Val->get(); }
625
626 storage_type *getStorage() {
627 assert(!HasError && "Cannot get value when an error exists!")((!HasError && "Cannot get value when an error exists!"
) ? static_cast<void> (0) : __assert_fail ("!HasError && \"Cannot get value when an error exists!\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 627, __PRETTY_FUNCTION__))
;
628 return reinterpret_cast<storage_type *>(TStorage.buffer);
629 }
630
631 const storage_type *getStorage() const {
632 assert(!HasError && "Cannot get value when an error exists!")((!HasError && "Cannot get value when an error exists!"
) ? static_cast<void> (0) : __assert_fail ("!HasError && \"Cannot get value when an error exists!\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 632, __PRETTY_FUNCTION__))
;
633 return reinterpret_cast<const storage_type *>(TStorage.buffer);
634 }
635
636 error_type *getErrorStorage() {
637 assert(HasError && "Cannot get error when a value exists!")((HasError && "Cannot get error when a value exists!"
) ? static_cast<void> (0) : __assert_fail ("HasError && \"Cannot get error when a value exists!\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 637, __PRETTY_FUNCTION__))
;
638 return reinterpret_cast<error_type *>(ErrorStorage.buffer);
639 }
640
641 const error_type *getErrorStorage() const {
642 assert(HasError && "Cannot get error when a value exists!")((HasError && "Cannot get error when a value exists!"
) ? static_cast<void> (0) : __assert_fail ("HasError && \"Cannot get error when a value exists!\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 642, __PRETTY_FUNCTION__))
;
643 return reinterpret_cast<const error_type *>(ErrorStorage.buffer);
644 }
645
646 // Used by ExpectedAsOutParameter to reset the checked flag.
647 void setUnchecked() {
648#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
649 Unchecked = true;
650#endif
651 }
652
653#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
654 LLVM_ATTRIBUTE_NORETURN__attribute__((noreturn))
655 LLVM_ATTRIBUTE_NOINLINE__attribute__((noinline))
656 void fatalUncheckedExpected() const {
657 dbgs() << "Expected<T> must be checked before access or destruction.\n";
658 if (HasError) {
659 dbgs() << "Unchecked Expected<T> contained error:\n";
660 (*getErrorStorage())->log(dbgs());
661 } else
662 dbgs() << "Expected<T> value was in success state. (Note: Expected<T> "
663 "values in success mode must still be checked prior to being "
664 "destroyed).\n";
665 abort();
666 }
667#endif
668
669 void assertIsChecked() {
670#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
671 if (LLVM_UNLIKELY(Unchecked)__builtin_expect((bool)(Unchecked), false))
672 fatalUncheckedExpected();
673#endif
674 }
675
676 union {
677 AlignedCharArrayUnion<storage_type> TStorage;
678 AlignedCharArrayUnion<error_type> ErrorStorage;
679 };
680 bool HasError : 1;
681#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
682 bool Unchecked : 1;
683#endif
684};
685
686/// Report a serious error, calling any installed error handler. See
687/// ErrorHandling.h.
688LLVM_ATTRIBUTE_NORETURN__attribute__((noreturn)) void report_fatal_error(Error Err,
689 bool gen_crash_diag = true);
690
691/// Report a fatal error if Err is a failure value.
692///
693/// This function can be used to wrap calls to fallible functions ONLY when it
694/// is known that the Error will always be a success value. E.g.
695///
696/// @code{.cpp}
697/// // foo only attempts the fallible operation if DoFallibleOperation is
698/// // true. If DoFallibleOperation is false then foo always returns
699/// // Error::success().
700/// Error foo(bool DoFallibleOperation);
701///
702/// cantFail(foo(false));
703/// @endcode
704inline void cantFail(Error Err, const char *Msg = nullptr) {
705 if (Err) {
706 if (!Msg)
707 Msg = "Failure value returned from cantFail wrapped call";
708 llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 708)
;
709 }
710}
711
712/// Report a fatal error if ValOrErr is a failure value, otherwise unwraps and
713/// returns the contained value.
714///
715/// This function can be used to wrap calls to fallible functions ONLY when it
716/// is known that the Error will always be a success value. E.g.
717///
718/// @code{.cpp}
719/// // foo only attempts the fallible operation if DoFallibleOperation is
720/// // true. If DoFallibleOperation is false then foo always returns an int.
721/// Expected<int> foo(bool DoFallibleOperation);
722///
723/// int X = cantFail(foo(false));
724/// @endcode
725template <typename T>
726T cantFail(Expected<T> ValOrErr, const char *Msg = nullptr) {
727 if (ValOrErr)
728 return std::move(*ValOrErr);
729 else {
730 if (!Msg)
731 Msg = "Failure value returned from cantFail wrapped call";
732 llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 732)
;
733 }
734}
735
736/// Report a fatal error if ValOrErr is a failure value, otherwise unwraps and
737/// returns the contained reference.
738///
739/// This function can be used to wrap calls to fallible functions ONLY when it
740/// is known that the Error will always be a success value. E.g.
741///
742/// @code{.cpp}
743/// // foo only attempts the fallible operation if DoFallibleOperation is
744/// // true. If DoFallibleOperation is false then foo always returns a Bar&.
745/// Expected<Bar&> foo(bool DoFallibleOperation);
746///
747/// Bar &X = cantFail(foo(false));
748/// @endcode
749template <typename T>
750T& cantFail(Expected<T&> ValOrErr, const char *Msg = nullptr) {
751 if (ValOrErr)
752 return *ValOrErr;
753 else {
754 if (!Msg)
755 Msg = "Failure value returned from cantFail wrapped call";
756 llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 756)
;
757 }
758}
759
760/// Helper for testing applicability of, and applying, handlers for
761/// ErrorInfo types.
762template <typename HandlerT>
763class ErrorHandlerTraits
764 : public ErrorHandlerTraits<decltype(
765 &std::remove_reference<HandlerT>::type::operator())> {};
766
767// Specialization functions of the form 'Error (const ErrT&)'.
768template <typename ErrT> class ErrorHandlerTraits<Error (&)(ErrT &)> {
769public:
770 static bool appliesTo(const ErrorInfoBase &E) {
771 return E.template isA<ErrT>();
772 }
773
774 template <typename HandlerT>
775 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
776 assert(appliesTo(*E) && "Applying incorrect handler")((appliesTo(*E) && "Applying incorrect handler") ? static_cast
<void> (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 776, __PRETTY_FUNCTION__))
;
777 return H(static_cast<ErrT &>(*E));
778 }
779};
780
781// Specialization functions of the form 'void (const ErrT&)'.
782template <typename ErrT> class ErrorHandlerTraits<void (&)(ErrT &)> {
783public:
784 static bool appliesTo(const ErrorInfoBase &E) {
785 return E.template isA<ErrT>();
786 }
787
788 template <typename HandlerT>
789 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
790 assert(appliesTo(*E) && "Applying incorrect handler")((appliesTo(*E) && "Applying incorrect handler") ? static_cast
<void> (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 790, __PRETTY_FUNCTION__))
;
791 H(static_cast<ErrT &>(*E));
792 return Error::success();
793 }
794};
795
796/// Specialization for functions of the form 'Error (std::unique_ptr<ErrT>)'.
797template <typename ErrT>
798class ErrorHandlerTraits<Error (&)(std::unique_ptr<ErrT>)> {
799public:
800 static bool appliesTo(const ErrorInfoBase &E) {
801 return E.template isA<ErrT>();
802 }
803
804 template <typename HandlerT>
805 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
806 assert(appliesTo(*E) && "Applying incorrect handler")((appliesTo(*E) && "Applying incorrect handler") ? static_cast
<void> (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 806, __PRETTY_FUNCTION__))
;
807 std::unique_ptr<ErrT> SubE(static_cast<ErrT *>(E.release()));
808 return H(std::move(SubE));
809 }
810};
811
812/// Specialization for functions of the form 'void (std::unique_ptr<ErrT>)'.
813template <typename ErrT>
814class ErrorHandlerTraits<void (&)(std::unique_ptr<ErrT>)> {
815public:
816 static bool appliesTo(const ErrorInfoBase &E) {
817 return E.template isA<ErrT>();
818 }
819
820 template <typename HandlerT>
821 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
822 assert(appliesTo(*E) && "Applying incorrect handler")((appliesTo(*E) && "Applying incorrect handler") ? static_cast
<void> (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 822, __PRETTY_FUNCTION__))
;
823 std::unique_ptr<ErrT> SubE(static_cast<ErrT *>(E.release()));
824 H(std::move(SubE));
825 return Error::success();
826 }
827};
828
829// Specialization for member functions of the form 'RetT (const ErrT&)'.
830template <typename C, typename RetT, typename ErrT>
831class ErrorHandlerTraits<RetT (C::*)(ErrT &)>
832 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
833
834// Specialization for member functions of the form 'RetT (const ErrT&) const'.
835template <typename C, typename RetT, typename ErrT>
836class ErrorHandlerTraits<RetT (C::*)(ErrT &) const>
837 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
838
839// Specialization for member functions of the form 'RetT (const ErrT&)'.
840template <typename C, typename RetT, typename ErrT>
841class ErrorHandlerTraits<RetT (C::*)(const ErrT &)>
842 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
843
844// Specialization for member functions of the form 'RetT (const ErrT&) const'.
845template <typename C, typename RetT, typename ErrT>
846class ErrorHandlerTraits<RetT (C::*)(const ErrT &) const>
847 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
848
849/// Specialization for member functions of the form
850/// 'RetT (std::unique_ptr<ErrT>)'.
851template <typename C, typename RetT, typename ErrT>
852class ErrorHandlerTraits<RetT (C::*)(std::unique_ptr<ErrT>)>
853 : public ErrorHandlerTraits<RetT (&)(std::unique_ptr<ErrT>)> {};
854
855/// Specialization for member functions of the form
856/// 'RetT (std::unique_ptr<ErrT>) const'.
857template <typename C, typename RetT, typename ErrT>
858class ErrorHandlerTraits<RetT (C::*)(std::unique_ptr<ErrT>) const>
859 : public ErrorHandlerTraits<RetT (&)(std::unique_ptr<ErrT>)> {};
860
861inline Error handleErrorImpl(std::unique_ptr<ErrorInfoBase> Payload) {
862 return Error(std::move(Payload));
863}
864
865template <typename HandlerT, typename... HandlerTs>
866Error handleErrorImpl(std::unique_ptr<ErrorInfoBase> Payload,
867 HandlerT &&Handler, HandlerTs &&... Handlers) {
868 if (ErrorHandlerTraits<HandlerT>::appliesTo(*Payload))
869 return ErrorHandlerTraits<HandlerT>::apply(std::forward<HandlerT>(Handler),
870 std::move(Payload));
871 return handleErrorImpl(std::move(Payload),
872 std::forward<HandlerTs>(Handlers)...);
873}
874
875/// Pass the ErrorInfo(s) contained in E to their respective handlers. Any
876/// unhandled errors (or Errors returned by handlers) are re-concatenated and
877/// returned.
878/// Because this function returns an error, its result must also be checked
879/// or returned. If you intend to handle all errors use handleAllErrors
880/// (which returns void, and will abort() on unhandled errors) instead.
881template <typename... HandlerTs>
882Error handleErrors(Error E, HandlerTs &&... Hs) {
883 if (!E)
884 return Error::success();
885
886 std::unique_ptr<ErrorInfoBase> Payload = E.takePayload();
887
888 if (Payload->isA<ErrorList>()) {
889 ErrorList &List = static_cast<ErrorList &>(*Payload);
890 Error R;
891 for (auto &P : List.Payloads)
892 R = ErrorList::join(
893 std::move(R),
894 handleErrorImpl(std::move(P), std::forward<HandlerTs>(Hs)...));
895 return R;
896 }
897
898 return handleErrorImpl(std::move(Payload), std::forward<HandlerTs>(Hs)...);
899}
900
901/// Behaves the same as handleErrors, except that by contract all errors
902/// *must* be handled by the given handlers (i.e. there must be no remaining
903/// errors after running the handlers, or llvm_unreachable is called).
904template <typename... HandlerTs>
905void handleAllErrors(Error E, HandlerTs &&... Handlers) {
906 cantFail(handleErrors(std::move(E), std::forward<HandlerTs>(Handlers)...));
907}
908
909/// Check that E is a non-error, then drop it.
910/// If E is an error, llvm_unreachable will be called.
911inline void handleAllErrors(Error E) {
912 cantFail(std::move(E));
913}
914
915/// Handle any errors (if present) in an Expected<T>, then try a recovery path.
916///
917/// If the incoming value is a success value it is returned unmodified. If it
918/// is a failure value then it the contained error is passed to handleErrors.
919/// If handleErrors is able to handle the error then the RecoveryPath functor
920/// is called to supply the final result. If handleErrors is not able to
921/// handle all errors then the unhandled errors are returned.
922///
923/// This utility enables the follow pattern:
924///
925/// @code{.cpp}
926/// enum FooStrategy { Aggressive, Conservative };
927/// Expected<Foo> foo(FooStrategy S);
928///
929/// auto ResultOrErr =
930/// handleExpected(
931/// foo(Aggressive),
932/// []() { return foo(Conservative); },
933/// [](AggressiveStrategyError&) {
934/// // Implicitly conusme this - we'll recover by using a conservative
935/// // strategy.
936/// });
937///
938/// @endcode
939template <typename T, typename RecoveryFtor, typename... HandlerTs>
940Expected<T> handleExpected(Expected<T> ValOrErr, RecoveryFtor &&RecoveryPath,
941 HandlerTs &&... Handlers) {
942 if (ValOrErr)
943 return ValOrErr;
944
945 if (auto Err = handleErrors(ValOrErr.takeError(),
946 std::forward<HandlerTs>(Handlers)...))
947 return std::move(Err);
948
949 return RecoveryPath();
950}
951
952/// Log all errors (if any) in E to OS. If there are any errors, ErrorBanner
953/// will be printed before the first one is logged. A newline will be printed
954/// after each error.
955///
956/// This is useful in the base level of your program to allow clean termination
957/// (allowing clean deallocation of resources, etc.), while reporting error
958/// information to the user.
959void logAllUnhandledErrors(Error E, raw_ostream &OS, Twine ErrorBanner);
960
961/// Write all error messages (if any) in E to a string. The newline character
962/// is used to separate error messages.
963inline std::string toString(Error E) {
964 SmallVector<std::string, 2> Errors;
965 handleAllErrors(std::move(E), [&Errors](const ErrorInfoBase &EI) {
966 Errors.push_back(EI.message());
967 });
968 return join(Errors.begin(), Errors.end(), "\n");
969}
970
971/// Consume a Error without doing anything. This method should be used
972/// only where an error can be considered a reasonable and expected return
973/// value.
974///
975/// Uses of this method are potentially indicative of design problems: If it's
976/// legitimate to do nothing while processing an "error", the error-producer
977/// might be more clearly refactored to return an Optional<T>.
978inline void consumeError(Error Err) {
979 handleAllErrors(std::move(Err), [](const ErrorInfoBase &) {});
980}
981
982/// Helper for converting an Error to a bool.
983///
984/// This method returns true if Err is in an error state, or false if it is
985/// in a success state. Puts Err in a checked state in both cases (unlike
986/// Error::operator bool(), which only does this for success states).
987inline bool errorToBool(Error Err) {
988 bool IsError = static_cast<bool>(Err);
989 if (IsError)
990 consumeError(std::move(Err));
991 return IsError;
992}
993
994/// Helper for Errors used as out-parameters.
995///
996/// This helper is for use with the Error-as-out-parameter idiom, where an error
997/// is passed to a function or method by reference, rather than being returned.
998/// In such cases it is helpful to set the checked bit on entry to the function
999/// so that the error can be written to (unchecked Errors abort on assignment)
1000/// and clear the checked bit on exit so that clients cannot accidentally forget
1001/// to check the result. This helper performs these actions automatically using
1002/// RAII:
1003///
1004/// @code{.cpp}
1005/// Result foo(Error &Err) {
1006/// ErrorAsOutParameter ErrAsOutParam(&Err); // 'Checked' flag set
1007/// // <body of foo>
1008/// // <- 'Checked' flag auto-cleared when ErrAsOutParam is destructed.
1009/// }
1010/// @endcode
1011///
1012/// ErrorAsOutParameter takes an Error* rather than Error& so that it can be
1013/// used with optional Errors (Error pointers that are allowed to be null). If
1014/// ErrorAsOutParameter took an Error reference, an instance would have to be
1015/// created inside every condition that verified that Error was non-null. By
1016/// taking an Error pointer we can just create one instance at the top of the
1017/// function.
1018class ErrorAsOutParameter {
1019public:
1020 ErrorAsOutParameter(Error *Err) : Err(Err) {
1021 // Raise the checked bit if Err is success.
1022 if (Err)
1023 (void)!!*Err;
1024 }
1025
1026 ~ErrorAsOutParameter() {
1027 // Clear the checked bit.
1028 if (Err && !*Err)
1029 *Err = Error::success();
1030 }
1031
1032private:
1033 Error *Err;
1034};
1035
1036/// Helper for Expected<T>s used as out-parameters.
1037///
1038/// See ErrorAsOutParameter.
1039template <typename T>
1040class ExpectedAsOutParameter {
1041public:
1042 ExpectedAsOutParameter(Expected<T> *ValOrErr)
1043 : ValOrErr(ValOrErr) {
1044 if (ValOrErr)
1045 (void)!!*ValOrErr;
1046 }
1047
1048 ~ExpectedAsOutParameter() {
1049 if (ValOrErr)
1050 ValOrErr->setUnchecked();
1051 }
1052
1053private:
1054 Expected<T> *ValOrErr;
1055};
1056
1057/// This class wraps a std::error_code in a Error.
1058///
1059/// This is useful if you're writing an interface that returns a Error
1060/// (or Expected) and you want to call code that still returns
1061/// std::error_codes.
1062class ECError : public ErrorInfo<ECError> {
1063 friend Error errorCodeToError(std::error_code);
1064
1065public:
1066 void setErrorCode(std::error_code EC) { this->EC = EC; }
1067 std::error_code convertToErrorCode() const override { return EC; }
1068 void log(raw_ostream &OS) const override { OS << EC.message(); }
1069
1070 // Used by ErrorInfo::classID.
1071 static char ID;
1072
1073protected:
1074 ECError() = default;
1075 ECError(std::error_code EC) : EC(EC) {}
1076
1077 std::error_code EC;
1078};
1079
1080/// The value returned by this function can be returned from convertToErrorCode
1081/// for Error values where no sensible translation to std::error_code exists.
1082/// It should only be used in this situation, and should never be used where a
1083/// sensible conversion to std::error_code is available, as attempts to convert
1084/// to/from this error will result in a fatal error. (i.e. it is a programmatic
1085///error to try to convert such a value).
1086std::error_code inconvertibleErrorCode();
1087
1088/// Helper for converting an std::error_code to a Error.
1089Error errorCodeToError(std::error_code EC);
1090
1091/// Helper for converting an ECError to a std::error_code.
1092///
1093/// This method requires that Err be Error() or an ECError, otherwise it
1094/// will trigger a call to abort().
1095std::error_code errorToErrorCode(Error Err);
1096
1097/// Convert an ErrorOr<T> to an Expected<T>.
1098template <typename T> Expected<T> errorOrToExpected(ErrorOr<T> &&EO) {
1099 if (auto EC = EO.getError())
1100 return errorCodeToError(EC);
1101 return std::move(*EO);
1102}
1103
1104/// Convert an Expected<T> to an ErrorOr<T>.
1105template <typename T> ErrorOr<T> expectedToErrorOr(Expected<T> &&E) {
1106 if (auto Err = E.takeError())
1107 return errorToErrorCode(std::move(Err));
1108 return std::move(*E);
1109}
1110
1111/// This class wraps a string in an Error.
1112///
1113/// StringError is useful in cases where the client is not expected to be able
1114/// to consume the specific error message programmatically (for example, if the
1115/// error message is to be presented to the user).
1116///
1117/// StringError can also be used when additional information is to be printed
1118/// along with a error_code message. Depending on the constructor called, this
1119/// class can either display:
1120/// 1. the error_code message (ECError behavior)
1121/// 2. a string
1122/// 3. the error_code message and a string
1123///
1124/// These behaviors are useful when subtyping is required; for example, when a
1125/// specific library needs an explicit error type. In the example below,
1126/// PDBError is derived from StringError:
1127///
1128/// @code{.cpp}
1129/// Expected<int> foo() {
1130/// return llvm::make_error<PDBError>(pdb_error_code::dia_failed_loading,
1131/// "Additional information");
1132/// }
1133/// @endcode
1134///
1135class StringError : public ErrorInfo<StringError> {
1136public:
1137 static char ID;
1138
1139 // Prints EC + S and converts to EC
1140 StringError(std::error_code EC, const Twine &S = Twine());
1141
1142 // Prints S and converts to EC
1143 StringError(const Twine &S, std::error_code EC);
1144
1145 void log(raw_ostream &OS) const override;
1146 std::error_code convertToErrorCode() const override;
1147
1148 const std::string &getMessage() const { return Msg; }
1149
1150private:
1151 std::string Msg;
1152 std::error_code EC;
1153 const bool PrintMsgOnly = false;
1154};
1155
1156/// Create formatted StringError object.
1157template <typename... Ts>
1158Error createStringError(std::error_code EC, char const *Fmt,
1159 const Ts &... Vals) {
1160 std::string Buffer;
1161 raw_string_ostream Stream(Buffer);
1162 Stream << format(Fmt, Vals...);
1163 return make_error<StringError>(Stream.str(), EC);
1164}
1165
1166Error createStringError(std::error_code EC, char const *Msg);
1167
1168/// This class wraps a filename and another Error.
1169///
1170/// In some cases, an error needs to live along a 'source' name, in order to
1171/// show more detailed information to the user.
1172class FileError final : public ErrorInfo<FileError> {
1173
1174 friend Error createFileError(std::string, Error);
1175
1176public:
1177 void log(raw_ostream &OS) const override {
1178 assert(Err && !FileName.empty() && "Trying to log after takeError().")((Err && !FileName.empty() && "Trying to log after takeError()."
) ? static_cast<void> (0) : __assert_fail ("Err && !FileName.empty() && \"Trying to log after takeError().\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 1178, __PRETTY_FUNCTION__))
;
1179 OS << "'" << FileName << "': ";
1180 Err->log(OS);
1181 }
1182
1183 Error takeError() { return Error(std::move(Err)); }
1184
1185 std::error_code convertToErrorCode() const override;
1186
1187 // Used by ErrorInfo::classID.
1188 static char ID;
1189
1190private:
1191 FileError(std::string F, std::unique_ptr<ErrorInfoBase> E) {
1192 assert(E && "Cannot create FileError from Error success value.")((E && "Cannot create FileError from Error success value."
) ? static_cast<void> (0) : __assert_fail ("E && \"Cannot create FileError from Error success value.\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 1192, __PRETTY_FUNCTION__))
;
1193 assert(!F.empty() &&((!F.empty() && "The file name provided to FileError must not be empty."
) ? static_cast<void> (0) : __assert_fail ("!F.empty() && \"The file name provided to FileError must not be empty.\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 1194, __PRETTY_FUNCTION__))
1194 "The file name provided to FileError must not be empty.")((!F.empty() && "The file name provided to FileError must not be empty."
) ? static_cast<void> (0) : __assert_fail ("!F.empty() && \"The file name provided to FileError must not be empty.\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 1194, __PRETTY_FUNCTION__))
;
1195 FileName = F;
1196 Err = std::move(E);
1197 }
1198
1199 static Error build(std::string F, Error E) {
1200 return Error(std::unique_ptr<FileError>(new FileError(F, E.takePayload())));
1201 }
1202
1203 std::string FileName;
1204 std::unique_ptr<ErrorInfoBase> Err;
1205};
1206
1207/// Concatenate a source file path and/or name with an Error. The resulting
1208/// Error is unchecked.
1209inline Error createFileError(std::string F, Error E) {
1210 return FileError::build(F, std::move(E));
1211}
1212
1213Error createFileError(std::string F, ErrorSuccess) = delete;
1214
1215/// Helper for check-and-exit error handling.
1216///
1217/// For tool use only. NOT FOR USE IN LIBRARY CODE.
1218///
1219class ExitOnError {
1220public:
1221 /// Create an error on exit helper.
1222 ExitOnError(std::string Banner = "", int DefaultErrorExitCode = 1)
1223 : Banner(std::move(Banner)),
1224 GetExitCode([=](const Error &) { return DefaultErrorExitCode; }) {}
1225
1226 /// Set the banner string for any errors caught by operator().
1227 void setBanner(std::string Banner) { this->Banner = std::move(Banner); }
1228
1229 /// Set the exit-code mapper function.
1230 void setExitCodeMapper(std::function<int(const Error &)> GetExitCode) {
1231 this->GetExitCode = std::move(GetExitCode);
1232 }
1233
1234 /// Check Err. If it's in a failure state log the error(s) and exit.
1235 void operator()(Error Err) const { checkError(std::move(Err)); }
1236
1237 /// Check E. If it's in a success state then return the contained value. If
1238 /// it's in a failure state log the error(s) and exit.
1239 template <typename T> T operator()(Expected<T> &&E) const {
1240 checkError(E.takeError());
1241 return std::move(*E);
1242 }
1243
1244 /// Check E. If it's in a success state then return the contained reference. If
1245 /// it's in a failure state log the error(s) and exit.
1246 template <typename T> T& operator()(Expected<T&> &&E) const {
1247 checkError(E.takeError());
1248 return *E;
1249 }
1250
1251private:
1252 void checkError(Error Err) const {
1253 if (Err) {
1254 int ExitCode = GetExitCode(Err);
1255 logAllUnhandledErrors(std::move(Err), errs(), Banner);
1256 exit(ExitCode);
1257 }
1258 }
1259
1260 std::string Banner;
1261 std::function<int(const Error &)> GetExitCode;
1262};
1263
1264/// Conversion from Error to LLVMErrorRef for C error bindings.
1265inline LLVMErrorRef wrap(Error Err) {
1266 return reinterpret_cast<LLVMErrorRef>(Err.takePayload().release());
1267}
1268
1269/// Conversion from LLVMErrorRef to Error for C error bindings.
1270inline Error unwrap(LLVMErrorRef ErrRef) {
1271 return Error(std::unique_ptr<ErrorInfoBase>(
1272 reinterpret_cast<ErrorInfoBase *>(ErrRef)));
1273}
1274
1275} // end namespace llvm
1276
1277#endif // LLVM_SUPPORT_ERROR_H

/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/ADT/STLExtras.h

1//===- llvm/ADT/STLExtras.h - Useful STL related functions ------*- C++ -*-===//
2//
3// The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file contains some templates that are useful if you are working with the
11// STL at all.
12//
13// No library is required when using these functions.
14//
15//===----------------------------------------------------------------------===//
16
17#ifndef LLVM_ADT_STLEXTRAS_H
18#define LLVM_ADT_STLEXTRAS_H
19
20#include "llvm/ADT/Optional.h"
21#include "llvm/ADT/SmallVector.h"
22#include "llvm/ADT/iterator.h"
23#include "llvm/ADT/iterator_range.h"
24#include "llvm/Config/abi-breaking.h"
25#include "llvm/Support/ErrorHandling.h"
26#include <algorithm>
27#include <cassert>
28#include <cstddef>
29#include <cstdint>
30#include <cstdlib>
31#include <functional>
32#include <initializer_list>
33#include <iterator>
34#include <limits>
35#include <memory>
36#include <tuple>
37#include <type_traits>
38#include <utility>
39
40#ifdef EXPENSIVE_CHECKS
41#include <random> // for std::mt19937
42#endif
43
44namespace llvm {
45
46// Only used by compiler if both template types are the same. Useful when
47// using SFINAE to test for the existence of member functions.
48template <typename T, T> struct SameType;
49
50namespace detail {
51
52template <typename RangeT>
53using IterOfRange = decltype(std::begin(std::declval<RangeT &>()));
54
55template <typename RangeT>
56using ValueOfRange = typename std::remove_reference<decltype(
57 *std::begin(std::declval<RangeT &>()))>::type;
58
59} // end namespace detail
60
61//===----------------------------------------------------------------------===//
62// Extra additions to <type_traits>
63//===----------------------------------------------------------------------===//
64
65template <typename T>
66struct negation : std::integral_constant<bool, !bool(T::value)> {};
67
68template <typename...> struct conjunction : std::true_type {};
69template <typename B1> struct conjunction<B1> : B1 {};
70template <typename B1, typename... Bn>
71struct conjunction<B1, Bn...>
72 : std::conditional<bool(B1::value), conjunction<Bn...>, B1>::type {};
73
74//===----------------------------------------------------------------------===//
75// Extra additions to <functional>
76//===----------------------------------------------------------------------===//
77
78template <class Ty> struct identity {
79 using argument_type = Ty;
80
81 Ty &operator()(Ty &self) const {
82 return self;
83 }
84 const Ty &operator()(const Ty &self) const {
85 return self;
86 }
87};
88
89template <class Ty> struct less_ptr {
90 bool operator()(const Ty* left, const Ty* right) const {
91 return *left < *right;
92 }
93};
94
95template <class Ty> struct greater_ptr {
96 bool operator()(const Ty* left, const Ty* right) const {
97 return *right < *left;
98 }
99};
100
101/// An efficient, type-erasing, non-owning reference to a callable. This is
102/// intended for use as the type of a function parameter that is not used
103/// after the function in question returns.
104///
105/// This class does not own the callable, so it is not in general safe to store
106/// a function_ref.
107template<typename Fn> class function_ref;
108
109template<typename Ret, typename ...Params>
110class function_ref<Ret(Params...)> {
111 Ret (*callback)(intptr_t callable, Params ...params) = nullptr;
112 intptr_t callable;
113
114 template<typename Callable>
115 static Ret callback_fn(intptr_t callable, Params ...params) {
116 return (*reinterpret_cast<Callable*>(callable))(
117 std::forward<Params>(params)...);
118 }
119
120public:
121 function_ref() = default;
122 function_ref(std::nullptr_t) {}
123
124 template <typename Callable>
125 function_ref(Callable &&callable,
126 typename std::enable_if<
127 !std::is_same<typename std::remove_reference<Callable>::type,
128 function_ref>::value>::type * = nullptr)
129 : callback(callback_fn<typename std::remove_reference<Callable>::type>),
130 callable(reinterpret_cast<intptr_t>(&callable)) {}
131
132 Ret operator()(Params ...params) const {
133 return callback(callable, std::forward<Params>(params)...);
134 }
135
136 operator bool() const { return callback; }
137};
138
139// deleter - Very very very simple method that is used to invoke operator
140// delete on something. It is used like this:
141//
142// for_each(V.begin(), B.end(), deleter<Interval>);
143template <class T>
144inline void deleter(T *Ptr) {
145 delete Ptr;
146}
147
148//===----------------------------------------------------------------------===//
149// Extra additions to <iterator>
150//===----------------------------------------------------------------------===//
151
152namespace adl_detail {
153
154using std::begin;
155
156template <typename ContainerTy>
157auto adl_begin(ContainerTy &&container)
158 -> decltype(begin(std::forward<ContainerTy>(container))) {
159 return begin(std::forward<ContainerTy>(container));
160}
161
162using std::end;
163
164template <typename ContainerTy>
165auto adl_end(ContainerTy &&container)
166 -> decltype(end(std::forward<ContainerTy>(container))) {
167 return end(std::forward<ContainerTy>(container));
168}
169
170using std::swap;
171
172template <typename T>
173void adl_swap(T &&lhs, T &&rhs) noexcept(noexcept(swap(std::declval<T>(),
174 std::declval<T>()))) {
175 swap(std::forward<T>(lhs), std::forward<T>(rhs));
176}
177
178} // end namespace adl_detail
179
180template <typename ContainerTy>
181auto adl_begin(ContainerTy &&container)
182 -> decltype(adl_detail::adl_begin(std::forward<ContainerTy>(container))) {
183 return adl_detail::adl_begin(std::forward<ContainerTy>(container));
184}
185
186template <typename ContainerTy>
187auto adl_end(ContainerTy &&container)
188 -> decltype(adl_detail::adl_end(std::forward<ContainerTy>(container))) {
189 return adl_detail::adl_end(std::forward<ContainerTy>(container));
190}
191
192template <typename T>
193void adl_swap(T &&lhs, T &&rhs) noexcept(
194 noexcept(adl_detail::adl_swap(std::declval<T>(), std::declval<T>()))) {
195 adl_detail::adl_swap(std::forward<T>(lhs), std::forward<T>(rhs));
196}
197
198// mapped_iterator - This is a simple iterator adapter that causes a function to
199// be applied whenever operator* is invoked on the iterator.
200
201template <typename ItTy, typename FuncTy,
202 typename FuncReturnTy =
203 decltype(std::declval<FuncTy>()(*std::declval<ItTy>()))>
204class mapped_iterator
205 : public iterator_adaptor_base<
206 mapped_iterator<ItTy, FuncTy>, ItTy,
207 typename std::iterator_traits<ItTy>::iterator_category,
208 typename std::remove_reference<FuncReturnTy>::type> {
209public:
210 mapped_iterator(ItTy U, FuncTy F)
211 : mapped_iterator::iterator_adaptor_base(std::move(U)), F(std::move(F)) {}
212
213 ItTy getCurrent() { return this->I; }
214
215 FuncReturnTy operator*() { return F(*this->I); }
216
217private:
218 FuncTy F;
219};
220
221// map_iterator - Provide a convenient way to create mapped_iterators, just like
222// make_pair is useful for creating pairs...
223template <class ItTy, class FuncTy>
224inline mapped_iterator<ItTy, FuncTy> map_iterator(ItTy I, FuncTy F) {
225 return mapped_iterator<ItTy, FuncTy>(std::move(I), std::move(F));
226}
227
228/// Helper to determine if type T has a member called rbegin().
229template <typename Ty> class has_rbegin_impl {
230 using yes = char[1];
231 using no = char[2];
232
233 template <typename Inner>
234 static yes& test(Inner *I, decltype(I->rbegin()) * = nullptr);
235
236 template <typename>
237 static no& test(...);
238
239public:
240 static const bool value = sizeof(test<Ty>(nullptr)) == sizeof(yes);
241};
242
243/// Metafunction to determine if T& or T has a member called rbegin().
244template <typename Ty>
245struct has_rbegin : has_rbegin_impl<typename std::remove_reference<Ty>::type> {
246};
247
248// Returns an iterator_range over the given container which iterates in reverse.
249// Note that the container must have rbegin()/rend() methods for this to work.
250template <typename ContainerTy>
251auto reverse(ContainerTy &&C,
252 typename std::enable_if<has_rbegin<ContainerTy>::value>::type * =
253 nullptr) -> decltype(make_range(C.rbegin(), C.rend())) {
254 return make_range(C.rbegin(), C.rend());
255}
256
257// Returns a std::reverse_iterator wrapped around the given iterator.
258template <typename IteratorTy>
259std::reverse_iterator<IteratorTy> make_reverse_iterator(IteratorTy It) {
260 return std::reverse_iterator<IteratorTy>(It);
261}
262
263// Returns an iterator_range over the given container which iterates in reverse.
264// Note that the container must have begin()/end() methods which return
265// bidirectional iterators for this to work.
266template <typename ContainerTy>
267auto reverse(
268 ContainerTy &&C,
269 typename std::enable_if<!has_rbegin<ContainerTy>::value>::type * = nullptr)
270 -> decltype(make_range(llvm::make_reverse_iterator(std::end(C)),
271 llvm::make_reverse_iterator(std::begin(C)))) {
272 return make_range(llvm::make_reverse_iterator(std::end(C)),
273 llvm::make_reverse_iterator(std::begin(C)));
274}
275
276/// An iterator adaptor that filters the elements of given inner iterators.
277///
278/// The predicate parameter should be a callable object that accepts the wrapped
279/// iterator's reference type and returns a bool. When incrementing or
280/// decrementing the iterator, it will call the predicate on each element and
281/// skip any where it returns false.
282///
283/// \code
284/// int A[] = { 1, 2, 3, 4 };
285/// auto R = make_filter_range(A, [](int N) { return N % 2 == 1; });
286/// // R contains { 1, 3 }.
287/// \endcode
288///
289/// Note: filter_iterator_base implements support for forward iteration.
290/// filter_iterator_impl exists to provide support for bidirectional iteration,
291/// conditional on whether the wrapped iterator supports it.
292template <typename WrappedIteratorT, typename PredicateT, typename IterTag>
293class filter_iterator_base
294 : public iterator_adaptor_base<
295 filter_iterator_base<WrappedIteratorT, PredicateT, IterTag>,
296 WrappedIteratorT,
297 typename std::common_type<
298 IterTag, typename std::iterator_traits<
299 WrappedIteratorT>::iterator_category>::type> {
300 using BaseT = iterator_adaptor_base<
301 filter_iterator_base<WrappedIteratorT, PredicateT, IterTag>,
302 WrappedIteratorT,
303 typename std::common_type<
304 IterTag, typename std::iterator_traits<
305 WrappedIteratorT>::iterator_category>::type>;
306
307protected:
308 WrappedIteratorT End;
309 PredicateT Pred;
310
311 void findNextValid() {
312 while (this->I != End && !Pred(*this->I))
313 BaseT::operator++();
314 }
315
316 // Construct the iterator. The begin iterator needs to know where the end
317 // is, so that it can properly stop when it gets there. The end iterator only
318 // needs the predicate to support bidirectional iteration.
319 filter_iterator_base(WrappedIteratorT Begin, WrappedIteratorT End,
320 PredicateT Pred)
321 : BaseT(Begin), End(End), Pred(Pred) {
322 findNextValid();
323 }
324
325public:
326 using BaseT::operator++;
327
328 filter_iterator_base &operator++() {
329 BaseT::operator++();
330 findNextValid();
331 return *this;
332 }
333};
334
335/// Specialization of filter_iterator_base for forward iteration only.
336template <typename WrappedIteratorT, typename PredicateT,
337 typename IterTag = std::forward_iterator_tag>
338class filter_iterator_impl
339 : public filter_iterator_base<WrappedIteratorT, PredicateT, IterTag> {
340 using BaseT = filter_iterator_base<WrappedIteratorT, PredicateT, IterTag>;
341
342public:
343 filter_iterator_impl(WrappedIteratorT Begin, WrappedIteratorT End,
344 PredicateT Pred)
345 : BaseT(Begin, End, Pred) {}
346};
347
348/// Specialization of filter_iterator_base for bidirectional iteration.
349template <typename WrappedIteratorT, typename PredicateT>
350class filter_iterator_impl<WrappedIteratorT, PredicateT,
351 std::bidirectional_iterator_tag>
352 : public filter_iterator_base<WrappedIteratorT, PredicateT,
353 std::bidirectional_iterator_tag> {
354 using BaseT = filter_iterator_base<WrappedIteratorT, PredicateT,
355 std::bidirectional_iterator_tag>;
356 void findPrevValid() {
357 while (!this->Pred(*this->I))
358 BaseT::operator--();
359 }
360
361public:
362 using BaseT::operator--;
363
364 filter_iterator_impl(WrappedIteratorT Begin, WrappedIteratorT End,
365 PredicateT Pred)
366 : BaseT(Begin, End, Pred) {}
367
368 filter_iterator_impl &operator--() {
369 BaseT::operator--();
370 findPrevValid();
371 return *this;
372 }
373};
374
375namespace detail {
376
377template <bool is_bidirectional> struct fwd_or_bidi_tag_impl {
378 using type = std::forward_iterator_tag;
379};
380
381template <> struct fwd_or_bidi_tag_impl<true> {
382 using type = std::bidirectional_iterator_tag;
383};
384
385/// Helper which sets its type member to forward_iterator_tag if the category
386/// of \p IterT does not derive from bidirectional_iterator_tag, and to
387/// bidirectional_iterator_tag otherwise.
388template <typename IterT> struct fwd_or_bidi_tag {
389 using type = typename fwd_or_bidi_tag_impl<std::is_base_of<
390 std::bidirectional_iterator_tag,
391 typename std::iterator_traits<IterT>::iterator_category>::value>::type;
392};
393
394} // namespace detail
395
396/// Defines filter_iterator to a suitable specialization of
397/// filter_iterator_impl, based on the underlying iterator's category.
398template <typename WrappedIteratorT, typename PredicateT>
399using filter_iterator = filter_iterator_impl<
400 WrappedIteratorT, PredicateT,
401 typename detail::fwd_or_bidi_tag<WrappedIteratorT>::type>;
402
403/// Convenience function that takes a range of elements and a predicate,
404/// and return a new filter_iterator range.
405///
406/// FIXME: Currently if RangeT && is a rvalue reference to a temporary, the
407/// lifetime of that temporary is not kept by the returned range object, and the
408/// temporary is going to be dropped on the floor after the make_iterator_range
409/// full expression that contains this function call.
410template <typename RangeT, typename PredicateT>
411iterator_range<filter_iterator<detail::IterOfRange<RangeT>, PredicateT>>
412make_filter_range(RangeT &&Range, PredicateT Pred) {
413 using FilterIteratorT =
414 filter_iterator<detail::IterOfRange<RangeT>, PredicateT>;
415 return make_range(
416 FilterIteratorT(std::begin(std::forward<RangeT>(Range)),
417 std::end(std::forward<RangeT>(Range)), Pred),
418 FilterIteratorT(std::end(std::forward<RangeT>(Range)),
419 std::end(std::forward<RangeT>(Range)), Pred));
420}
421
422/// A pseudo-iterator adaptor that is designed to implement "early increment"
423/// style loops.
424///
425/// This is *not a normal iterator* and should almost never be used directly. It
426/// is intended primarily to be used with range based for loops and some range
427/// algorithms.
428///
429/// The iterator isn't quite an `OutputIterator` or an `InputIterator` but
430/// somewhere between them. The constraints of these iterators are:
431///
432/// - On construction or after being incremented, it is comparable and
433/// dereferencable. It is *not* incrementable.
434/// - After being dereferenced, it is neither comparable nor dereferencable, it
435/// is only incrementable.
436///
437/// This means you can only dereference the iterator once, and you can only
438/// increment it once between dereferences.
439template <typename WrappedIteratorT>
440class early_inc_iterator_impl
441 : public iterator_adaptor_base<early_inc_iterator_impl<WrappedIteratorT>,
442 WrappedIteratorT, std::input_iterator_tag> {
443 using BaseT =
444 iterator_adaptor_base<early_inc_iterator_impl<WrappedIteratorT>,
445 WrappedIteratorT, std::input_iterator_tag>;
446
447 using PointerT = typename std::iterator_traits<WrappedIteratorT>::pointer;
448
449protected:
450#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
451 bool IsEarlyIncremented = false;
452#endif
453
454public:
455 early_inc_iterator_impl(WrappedIteratorT I) : BaseT(I) {}
456
457 using BaseT::operator*;
458 typename BaseT::reference operator*() {
459#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
460 assert(!IsEarlyIncremented && "Cannot dereference twice!")((!IsEarlyIncremented && "Cannot dereference twice!")
? static_cast<void> (0) : __assert_fail ("!IsEarlyIncremented && \"Cannot dereference twice!\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/ADT/STLExtras.h"
, 460, __PRETTY_FUNCTION__))
;
461 IsEarlyIncremented = true;
462#endif
463 return *(this->I)++;
464 }
465
466 using BaseT::operator++;
467 early_inc_iterator_impl &operator++() {
468#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
469 assert(IsEarlyIncremented && "Cannot increment before dereferencing!")((IsEarlyIncremented && "Cannot increment before dereferencing!"
) ? static_cast<void> (0) : __assert_fail ("IsEarlyIncremented && \"Cannot increment before dereferencing!\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/ADT/STLExtras.h"
, 469, __PRETTY_FUNCTION__))
;
470 IsEarlyIncremented = false;
471#endif
472 return *this;
473 }
474
475 using BaseT::operator==;
476 bool operator==(const early_inc_iterator_impl &RHS) const {
477#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
478 assert(!IsEarlyIncremented && "Cannot compare after dereferencing!")((!IsEarlyIncremented && "Cannot compare after dereferencing!"
) ? static_cast<void> (0) : __assert_fail ("!IsEarlyIncremented && \"Cannot compare after dereferencing!\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/ADT/STLExtras.h"
, 478, __PRETTY_FUNCTION__))
;
479#endif
480 return BaseT::operator==(RHS);
481 }
482};
483
484/// Make a range that does early increment to allow mutation of the underlying
485/// range without disrupting iteration.
486///
487/// The underlying iterator will be incremented immediately after it is
488/// dereferenced, allowing deletion of the current node or insertion of nodes to
489/// not disrupt iteration provided they do not invalidate the *next* iterator --
490/// the current iterator can be invalidated.
491///
492/// This requires a very exact pattern of use that is only really suitable to
493/// range based for loops and other range algorithms that explicitly guarantee
494/// to dereference exactly once each element, and to increment exactly once each
495/// element.
496template <typename RangeT>
497iterator_range<early_inc_iterator_impl<detail::IterOfRange<RangeT>>>
498make_early_inc_range(RangeT &&Range) {
499 using EarlyIncIteratorT =
500 early_inc_iterator_impl<detail::IterOfRange<RangeT>>;
501 return make_range(EarlyIncIteratorT(std::begin(std::forward<RangeT>(Range))),
502 EarlyIncIteratorT(std::end(std::forward<RangeT>(Range))));
503}
504
505// forward declarations required by zip_shortest/zip_first
506template <typename R, typename UnaryPredicate>
507bool all_of(R &&range, UnaryPredicate P);
508
509template <size_t... I> struct index_sequence;
510
511template <class... Ts> struct index_sequence_for;
512
513namespace detail {
514
515using std::declval;
516
517// We have to alias this since inlining the actual type at the usage site
518// in the parameter list of iterator_facade_base<> below ICEs MSVC 2017.
519template<typename... Iters> struct ZipTupleType {
520 using type = std::tuple<decltype(*declval<Iters>())...>;
521};
522
523template <typename ZipType, typename... Iters>
524using zip_traits = iterator_facade_base<
525 ZipType, typename std::common_type<std::bidirectional_iterator_tag,
526 typename std::iterator_traits<
527 Iters>::iterator_category...>::type,
528 // ^ TODO: Implement random access methods.
529 typename ZipTupleType<Iters...>::type,
530 typename std::iterator_traits<typename std::tuple_element<
531 0, std::tuple<Iters...>>::type>::difference_type,
532 // ^ FIXME: This follows boost::make_zip_iterator's assumption that all
533 // inner iterators have the same difference_type. It would fail if, for
534 // instance, the second field's difference_type were non-numeric while the
535 // first is.
536 typename ZipTupleType<Iters...>::type *,
537 typename ZipTupleType<Iters...>::type>;
538
539template <typename ZipType, typename... Iters>
540struct zip_common : public zip_traits<ZipType, Iters...> {
541 using Base = zip_traits<ZipType, Iters...>;
542 using value_type = typename Base::value_type;
543
544 std::tuple<Iters...> iterators;
545
546protected:
547 template <size_t... Ns> value_type deref(index_sequence<Ns...>) const {
548 return value_type(*std::get<Ns>(iterators)...);
549 }
550
551 template <size_t... Ns>
552 decltype(iterators) tup_inc(index_sequence<Ns...>) const {
553 return std::tuple<Iters...>(std::next(std::get<Ns>(iterators))...);
554 }
555
556 template <size_t... Ns>
557 decltype(iterators) tup_dec(index_sequence<Ns...>) const {
558 return std::tuple<Iters...>(std::prev(std::get<Ns>(iterators))...);
559 }
560
561public:
562 zip_common(Iters &&... ts) : iterators(std::forward<Iters>(ts)...) {}
563
564 value_type operator*() { return deref(index_sequence_for<Iters...>{}); }
565
566 const value_type operator*() const {
567 return deref(index_sequence_for<Iters...>{});
568 }
569
570 ZipType &operator++() {
571 iterators = tup_inc(index_sequence_for<Iters...>{});
572 return *reinterpret_cast<ZipType *>(this);
573 }
574
575 ZipType &operator--() {
576 static_assert(Base::IsBidirectional,
577 "All inner iterators must be at least bidirectional.");
578 iterators = tup_dec(index_sequence_for<Iters...>{});
579 return *reinterpret_cast<ZipType *>(this);
580 }
581};
582
583template <typename... Iters>
584struct zip_first : public zip_common<zip_first<Iters...>, Iters...> {
585 using Base = zip_common<zip_first<Iters...>, Iters...>;
586
587 bool operator==(const zip_first<Iters...> &other) const {
588 return std::get<0>(this->iterators) == std::get<0>(other.iterators);
589 }
590
591 zip_first(Iters &&... ts) : Base(std::forward<Iters>(ts)...) {}
592};
593
594template <typename... Iters>
595class zip_shortest : public zip_common<zip_shortest<Iters...>, Iters...> {
596 template <size_t... Ns>
597 bool test(const zip_shortest<Iters...> &other, index_sequence<Ns...>) const {
598 return all_of(std::initializer_list<bool>{std::get<Ns>(this->iterators) !=
599 std::get<Ns>(other.iterators)...},
600 identity<bool>{});
601 }
602
603public:
604 using Base = zip_common<zip_shortest<Iters...>, Iters...>;
605
606 zip_shortest(Iters &&... ts) : Base(std::forward<Iters>(ts)...) {}
607
608 bool operator==(const zip_shortest<Iters...> &other) const {
609 return !test(other, index_sequence_for<Iters...>{});
610 }
611};
612
613template <template <typename...> class ItType, typename... Args> class zippy {
614public:
615 using iterator = ItType<decltype(std::begin(std::declval<Args>()))...>;
616 using iterator_category = typename iterator::iterator_category;
617 using value_type = typename iterator::value_type;
618 using difference_type = typename iterator::difference_type;
619 using pointer = typename iterator::pointer;
620 using reference = typename iterator::reference;
621
622private:
623 std::tuple<Args...> ts;
624
625 template <size_t... Ns> iterator begin_impl(index_sequence<Ns...>) const {
626 return iterator(std::begin(std::get<Ns>(ts))...);
627 }
628 template <size_t... Ns> iterator end_impl(index_sequence<Ns...>) const {
629 return iterator(std::end(std::get<Ns>(ts))...);
630 }
631
632public:
633 zippy(Args &&... ts_) : ts(std::forward<Args>(ts_)...) {}
634
635 iterator begin() const { return begin_impl(index_sequence_for<Args...>{}); }
636 iterator end() const { return end_impl(index_sequence_for<Args...>{}); }
637};
638
639} // end namespace detail
640
641/// zip iterator for two or more iteratable types.
642template <typename T, typename U, typename... Args>
643detail::zippy<detail::zip_shortest, T, U, Args...> zip(T &&t, U &&u,
644 Args &&... args) {
645 return detail::zippy<detail::zip_shortest, T, U, Args...>(
646 std::forward<T>(t), std::forward<U>(u), std::forward<Args>(args)...);
647}
648
649/// zip iterator that, for the sake of efficiency, assumes the first iteratee to
650/// be the shortest.
651template <typename T, typename U, typename... Args>
652detail::zippy<detail::zip_first, T, U, Args...> zip_first(T &&t, U &&u,
653 Args &&... args) {
654 return detail::zippy<detail::zip_first, T, U, Args...>(
655 std::forward<T>(t), std::forward<U>(u), std::forward<Args>(args)...);
656}
657
658/// Iterator wrapper that concatenates sequences together.
659///
660/// This can concatenate different iterators, even with different types, into
661/// a single iterator provided the value types of all the concatenated
662/// iterators expose `reference` and `pointer` types that can be converted to
663/// `ValueT &` and `ValueT *` respectively. It doesn't support more
664/// interesting/customized pointer or reference types.
665///
666/// Currently this only supports forward or higher iterator categories as
667/// inputs and always exposes a forward iterator interface.
668template <typename ValueT, typename... IterTs>
669class concat_iterator
670 : public iterator_facade_base<concat_iterator<ValueT, IterTs...>,
671 std::forward_iterator_tag, ValueT> {
672 using BaseT = typename concat_iterator::iterator_facade_base;
673
674 /// We store both the current and end iterators for each concatenated
675 /// sequence in a tuple of pairs.
676 ///
677 /// Note that something like iterator_range seems nice at first here, but the
678 /// range properties are of little benefit and end up getting in the way
679 /// because we need to do mutation on the current iterators.
680 std::tuple<IterTs...> Begins;
681 std::tuple<IterTs...> Ends;
682
683 /// Attempts to increment a specific iterator.
684 ///
685 /// Returns true if it was able to increment the iterator. Returns false if
686 /// the iterator is already at the end iterator.
687 template <size_t Index> bool incrementHelper() {
688 auto &Begin = std::get<Index>(Begins);
689 auto &End = std::get<Index>(Ends);
690 if (Begin == End)
691 return false;
692
693 ++Begin;
694 return true;
695 }
696
697 /// Increments the first non-end iterator.
698 ///
699 /// It is an error to call this with all iterators at the end.
700 template <size_t... Ns> void increment(index_sequence<Ns...>) {
701 // Build a sequence of functions to increment each iterator if possible.
702 bool (concat_iterator::*IncrementHelperFns[])() = {
703 &concat_iterator::incrementHelper<Ns>...};
704
705 // Loop over them, and stop as soon as we succeed at incrementing one.
706 for (auto &IncrementHelperFn : IncrementHelperFns)
707 if ((this->*IncrementHelperFn)())
708 return;
709
710 llvm_unreachable("Attempted to increment an end concat iterator!")::llvm::llvm_unreachable_internal("Attempted to increment an end concat iterator!"
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/ADT/STLExtras.h"
, 710)
;
711 }
712
713 /// Returns null if the specified iterator is at the end. Otherwise,
714 /// dereferences the iterator and returns the address of the resulting
715 /// reference.
716 template <size_t Index> ValueT *getHelper() const {
717 auto &Begin = std::get<Index>(Begins);
718 auto &End = std::get<Index>(Ends);
719 if (Begin == End)
720 return nullptr;
721
722 return &*Begin;
723 }
724
725 /// Finds the first non-end iterator, dereferences, and returns the resulting
726 /// reference.
727 ///
728 /// It is an error to call this with all iterators at the end.
729 template <size_t... Ns> ValueT &get(index_sequence<Ns...>) const {
730 // Build a sequence of functions to get from iterator if possible.
731 ValueT *(concat_iterator::*GetHelperFns[])() const = {
732 &concat_iterator::getHelper<Ns>...};
733
734 // Loop over them, and return the first result we find.
735 for (auto &GetHelperFn : GetHelperFns)
736 if (ValueT *P = (this->*GetHelperFn)())
737 return *P;
738
739 llvm_unreachable("Attempted to get a pointer from an end concat iterator!")::llvm::llvm_unreachable_internal("Attempted to get a pointer from an end concat iterator!"
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/ADT/STLExtras.h"
, 739)
;
740 }
741
742public:
743 /// Constructs an iterator from a squence of ranges.
744 ///
745 /// We need the full range to know how to switch between each of the
746 /// iterators.
747 template <typename... RangeTs>
748 explicit concat_iterator(RangeTs &&... Ranges)
749 : Begins(std::begin(Ranges)...), Ends(std::end(Ranges)...) {}
750
751 using BaseT::operator++;
752
753 concat_iterator &operator++() {
754 increment(index_sequence_for<IterTs...>());
755 return *this;
756 }
757
758 ValueT &operator*() const { return get(index_sequence_for<IterTs...>()); }
759
760 bool operator==(const concat_iterator &RHS) const {
761 return Begins == RHS.Begins && Ends == RHS.Ends;
762 }
763};
764
765namespace detail {
766
767/// Helper to store a sequence of ranges being concatenated and access them.
768///
769/// This is designed to facilitate providing actual storage when temporaries
770/// are passed into the constructor such that we can use it as part of range
771/// based for loops.
772template <typename ValueT, typename... RangeTs> class concat_range {
773public:
774 using iterator =
775 concat_iterator<ValueT,
776 decltype(std::begin(std::declval<RangeTs &>()))...>;
777
778private:
779 std::tuple<RangeTs...> Ranges;
780
781 template <size_t... Ns> iterator begin_impl(index_sequence<Ns...>) {
782 return iterator(std::get<Ns>(Ranges)...);
783 }
784 template <size_t... Ns> iterator end_impl(index_sequence<Ns...>) {
785 return iterator(make_range(std::end(std::get<Ns>(Ranges)),
786 std::end(std::get<Ns>(Ranges)))...);
787 }
788
789public:
790 concat_range(RangeTs &&... Ranges)
791 : Ranges(std::forward<RangeTs>(Ranges)...) {}
792
793 iterator begin() { return begin_impl(index_sequence_for<RangeTs...>{}); }
794 iterator end() { return end_impl(index_sequence_for<RangeTs...>{}); }
795};
796
797} // end namespace detail
798
799/// Concatenated range across two or more ranges.
800///
801/// The desired value type must be explicitly specified.
802template <typename ValueT, typename... RangeTs>
803detail::concat_range<ValueT, RangeTs...> concat(RangeTs &&... Ranges) {
804 static_assert(sizeof...(RangeTs) > 1,
805 "Need more than one range to concatenate!");
806 return detail::concat_range<ValueT, RangeTs...>(
807 std::forward<RangeTs>(Ranges)...);
808}
809
810//===----------------------------------------------------------------------===//
811// Extra additions to <utility>
812//===----------------------------------------------------------------------===//
813
814/// Function object to check whether the first component of a std::pair
815/// compares less than the first component of another std::pair.
816struct less_first {
817 template <typename T> bool operator()(const T &lhs, const T &rhs) const {
818 return lhs.first < rhs.first;
819 }
820};
821
822/// Function object to check whether the second component of a std::pair
823/// compares less than the second component of another std::pair.
824struct less_second {
825 template <typename T> bool operator()(const T &lhs, const T &rhs) const {
826 return lhs.second < rhs.second;
827 }
828};
829
830/// \brief Function object to apply a binary function to the first component of
831/// a std::pair.
832template<typename FuncTy>
833struct on_first {
834 FuncTy func;
835
836 template <typename T>
837 auto operator()(const T &lhs, const T &rhs) const
838 -> decltype(func(lhs.first, rhs.first)) {
839 return func(lhs.first, rhs.first);
840 }
841};
842
843// A subset of N3658. More stuff can be added as-needed.
844
845/// Represents a compile-time sequence of integers.
846template <class T, T... I> struct integer_sequence {
847 using value_type = T;
848
849 static constexpr size_t size() { return sizeof...(I); }
850};
851
852/// Alias for the common case of a sequence of size_ts.
853template <size_t... I>
854struct index_sequence : integer_sequence<std::size_t, I...> {};
855
856template <std::size_t N, std::size_t... I>
857struct build_index_impl : build_index_impl<N - 1, N - 1, I...> {};
858template <std::size_t... I>
859struct build_index_impl<0, I...> : index_sequence<I...> {};
860
861/// Creates a compile-time integer sequence for a parameter pack.
862template <class... Ts>
863struct index_sequence_for : build_index_impl<sizeof...(Ts)> {};
864
865/// Utility type to build an inheritance chain that makes it easy to rank
866/// overload candidates.
867template <int N> struct rank : rank<N - 1> {};
868template <> struct rank<0> {};
869
870/// traits class for checking whether type T is one of any of the given
871/// types in the variadic list.
872template <typename T, typename... Ts> struct is_one_of {
873 static const bool value = false;
874};
875
876template <typename T, typename U, typename... Ts>
877struct is_one_of<T, U, Ts...> {
878 static const bool value =
879 std::is_same<T, U>::value || is_one_of<T, Ts...>::value;
880};
881
882/// traits class for checking whether type T is a base class for all
883/// the given types in the variadic list.
884template <typename T, typename... Ts> struct are_base_of {
885 static const bool value = true;
886};
887
888template <typename T, typename U, typename... Ts>
889struct are_base_of<T, U, Ts...> {
890 static const bool value =
891 std::is_base_of<T, U>::value && are_base_of<T, Ts...>::value;
892};
893
894//===----------------------------------------------------------------------===//
895// Extra additions for arrays
896//===----------------------------------------------------------------------===//
897
898/// Find the length of an array.
899template <class T, std::size_t N>
900constexpr inline size_t array_lengthof(T (&)[N]) {
901 return N;
902}
903
904/// Adapt std::less<T> for array_pod_sort.
905template<typename T>
906inline int array_pod_sort_comparator(const void *P1, const void *P2) {
907 if (std::less<T>()(*reinterpret_cast<const T*>(P1),
908 *reinterpret_cast<const T*>(P2)))
909 return -1;
910 if (std::less<T>()(*reinterpret_cast<const T*>(P2),
911 *reinterpret_cast<const T*>(P1)))
912 return 1;
913 return 0;
914}
915
916/// get_array_pod_sort_comparator - This is an internal helper function used to
917/// get type deduction of T right.
918template<typename T>
919inline int (*get_array_pod_sort_comparator(const T &))
920 (const void*, const void*) {
921 return array_pod_sort_comparator<T>;
922}
923
924/// array_pod_sort - This sorts an array with the specified start and end
925/// extent. This is just like std::sort, except that it calls qsort instead of
926/// using an inlined template. qsort is slightly slower than std::sort, but
927/// most sorts are not performance critical in LLVM and std::sort has to be
928/// template instantiated for each type, leading to significant measured code
929/// bloat. This function should generally be used instead of std::sort where
930/// possible.
931///
932/// This function assumes that you have simple POD-like types that can be
933/// compared with std::less and can be moved with memcpy. If this isn't true,
934/// you should use std::sort.
935///
936/// NOTE: If qsort_r were portable, we could allow a custom comparator and
937/// default to std::less.
938template<class IteratorTy>
939inline void array_pod_sort(IteratorTy Start, IteratorTy End) {
940 // Don't inefficiently call qsort with one element or trigger undefined
941 // behavior with an empty sequence.
942 auto NElts = End - Start;
943 if (NElts <= 1) return;
944#ifdef EXPENSIVE_CHECKS
945 std::mt19937 Generator(std::random_device{}());
946 std::shuffle(Start, End, Generator);
947#endif
948 qsort(&*Start, NElts, sizeof(*Start), get_array_pod_sort_comparator(*Start));
949}
950
951template <class IteratorTy>
952inline void array_pod_sort(
953 IteratorTy Start, IteratorTy End,
954 int (*Compare)(
955 const typename std::iterator_traits<IteratorTy>::value_type *,
956 const typename std::iterator_traits<IteratorTy>::value_type *)) {
957 // Don't inefficiently call qsort with one element or trigger undefined
958 // behavior with an empty sequence.
959 auto NElts = End - Start;
960 if (NElts <= 1) return;
961#ifdef EXPENSIVE_CHECKS
962 std::mt19937 Generator(std::random_device{}());
963 std::shuffle(Start, End, Generator);
964#endif
965 qsort(&*Start, NElts, sizeof(*Start),
966 reinterpret_cast<int (*)(const void *, const void *)>(Compare));
967}
968
969// Provide wrappers to std::sort which shuffle the elements before sorting
970// to help uncover non-deterministic behavior (PR35135).
971template <typename IteratorTy>
972inline void sort(IteratorTy Start, IteratorTy End) {
973#ifdef EXPENSIVE_CHECKS
974 std::mt19937 Generator(std::random_device{}());
975 std::shuffle(Start, End, Generator);
976#endif
977 std::sort(Start, End);
978}
979
980template <typename Container> inline void sort(Container &&C) {
981 llvm::sort(adl_begin(C), adl_end(C));
982}
983
984template <typename IteratorTy, typename Compare>
985inline void sort(IteratorTy Start, IteratorTy End, Compare Comp) {
986#ifdef EXPENSIVE_CHECKS
987 std::mt19937 Generator(std::random_device{}());
988 std::shuffle(Start, End, Generator);
989#endif
990 std::sort(Start, End, Comp);
991}
992
993template <typename Container, typename Compare>
994inline void sort(Container &&C, Compare Comp) {
995 llvm::sort(adl_begin(C), adl_end(C), Comp);
996}
997
998//===----------------------------------------------------------------------===//
999// Extra additions to <algorithm>
1000//===----------------------------------------------------------------------===//
1001
1002/// For a container of pointers, deletes the pointers and then clears the
1003/// container.
1004template<typename Container>
1005void DeleteContainerPointers(Container &C) {
1006 for (auto V : C)
1007 delete V;
1008 C.clear();
1009}
1010
1011/// In a container of pairs (usually a map) whose second element is a pointer,
1012/// deletes the second elements and then clears the container.
1013template<typename Container>
1014void DeleteContainerSeconds(Container &C) {
1015 for (auto &V : C)
1016 delete V.second;
1017 C.clear();
1018}
1019
1020/// Get the size of a range. This is a wrapper function around std::distance
1021/// which is only enabled when the operation is O(1).
1022template <typename R>
1023auto size(R &&Range, typename std::enable_if<
1024 std::is_same<typename std::iterator_traits<decltype(
1025 Range.begin())>::iterator_category,
1026 std::random_access_iterator_tag>::value,
1027 void>::type * = nullptr)
1028 -> decltype(std::distance(Range.begin(), Range.end())) {
1029 return std::distance(Range.begin(), Range.end());
1030}
1031
1032/// Provide wrappers to std::for_each which take ranges instead of having to
1033/// pass begin/end explicitly.
1034template <typename R, typename UnaryPredicate>
1035UnaryPredicate for_each(R &&Range, UnaryPredicate P) {
1036 return std::for_each(adl_begin(Range), adl_end(Range), P);
1037}
1038
1039/// Provide wrappers to std::all_of which take ranges instead of having to pass
1040/// begin/end explicitly.
1041template <typename R, typename UnaryPredicate>
1042bool all_of(R &&Range, UnaryPredicate P) {
1043 return std::all_of(adl_begin(Range), adl_end(Range), P);
1044}
1045
1046/// Provide wrappers to std::any_of which take ranges instead of having to pass
1047/// begin/end explicitly.
1048template <typename R, typename UnaryPredicate>
1049bool any_of(R &&Range, UnaryPredicate P) {
1050 return std::any_of(adl_begin(Range), adl_end(Range), P);
1051}
1052
1053/// Provide wrappers to std::none_of which take ranges instead of having to pass
1054/// begin/end explicitly.
1055template <typename R, typename UnaryPredicate>
1056bool none_of(R &&Range, UnaryPredicate P) {
1057 return std::none_of(adl_begin(Range), adl_end(Range), P);
1058}
1059
1060/// Provide wrappers to std::find which take ranges instead of having to pass
1061/// begin/end explicitly.
1062template <typename R, typename T>
1063auto find(R &&Range, const T &Val) -> decltype(adl_begin(Range)) {
1064 return std::find(adl_begin(Range), adl_end(Range), Val);
1065}
1066
1067/// Provide wrappers to std::find_if which take ranges instead of having to pass
1068/// begin/end explicitly.
1069template <typename R, typename UnaryPredicate>
1070auto find_if(R &&Range, UnaryPredicate P) -> decltype(adl_begin(Range)) {
1071 return std::find_if(adl_begin(Range), adl_end(Range), P);
1072}
1073
1074template <typename R, typename UnaryPredicate>
1075auto find_if_not(R &&Range, UnaryPredicate P) -> decltype(adl_begin(Range)) {
1076 return std::find_if_not(adl_begin(Range), adl_end(Range), P);
1077}
1078
1079/// Provide wrappers to std::remove_if which take ranges instead of having to
1080/// pass begin/end explicitly.
1081template <typename R, typename UnaryPredicate>
1082auto remove_if(R &&Range, UnaryPredicate P) -> decltype(adl_begin(Range)) {
1083 return std::remove_if(adl_begin(Range), adl_end(Range), P);
1084}
1085
1086/// Provide wrappers to std::copy_if which take ranges instead of having to
1087/// pass begin/end explicitly.
1088template <typename R, typename OutputIt, typename UnaryPredicate>
1089OutputIt copy_if(R &&Range, OutputIt Out, UnaryPredicate P) {
1090 return std::copy_if(adl_begin(Range), adl_end(Range), Out, P);
1091}
1092
1093template <typename R, typename OutputIt>
1094OutputIt copy(R &&Range, OutputIt Out) {
1095 return std::copy(adl_begin(Range), adl_end(Range), Out);
1096}
1097
1098/// Wrapper function around std::find to detect if an element exists
1099/// in a container.
1100template <typename R, typename E>
1101bool is_contained(R &&Range, const E &Element) {
1102 return std::find(adl_begin(Range), adl_end(Range), Element) != adl_end(Range);
1103}
1104
1105/// Wrapper function around std::count to count the number of times an element
1106/// \p Element occurs in the given range \p Range.
1107template <typename R, typename E>
1108auto count(R &&Range, const E &Element) ->
1109 typename std::iterator_traits<decltype(adl_begin(Range))>::difference_type {
1110 return std::count(adl_begin(Range), adl_end(Range), Element);
1111}
1112
1113/// Wrapper function around std::count_if to count the number of times an
1114/// element satisfying a given predicate occurs in a range.
1115template <typename R, typename UnaryPredicate>
1116auto count_if(R &&Range, UnaryPredicate P) ->
1117 typename std::iterator_traits<decltype(adl_begin(Range))>::difference_type {
1118 return std::count_if(adl_begin(Range), adl_end(Range), P);
1119}
1120
1121/// Wrapper function around std::transform to apply a function to a range and
1122/// store the result elsewhere.
1123template <typename R, typename OutputIt, typename UnaryPredicate>
1124OutputIt transform(R &&Range, OutputIt d_first, UnaryPredicate P) {
1125 return std::transform(adl_begin(Range), adl_end(Range), d_first, P);
1126}
1127
1128/// Provide wrappers to std::partition which take ranges instead of having to
1129/// pass begin/end explicitly.
1130template <typename R, typename UnaryPredicate>
1131auto partition(R &&Range, UnaryPredicate P) -> decltype(adl_begin(Range)) {
1132 return std::partition(adl_begin(Range), adl_end(Range), P);
1133}
1134
1135/// Provide wrappers to std::lower_bound which take ranges instead of having to
1136/// pass begin/end explicitly.
1137template <typename R, typename ForwardIt>
1138auto lower_bound(R &&Range, ForwardIt I) -> decltype(adl_begin(Range)) {
1139 return std::lower_bound(adl_begin(Range), adl_end(Range), I);
1140}
1141
1142template <typename R, typename ForwardIt, typename Compare>
1143auto lower_bound(R &&Range, ForwardIt I, Compare C)
1144 -> decltype(adl_begin(Range)) {
1145 return std::lower_bound(adl_begin(Range), adl_end(Range), I, C);
1146}
1147
1148/// Provide wrappers to std::upper_bound which take ranges instead of having to
1149/// pass begin/end explicitly.
1150template <typename R, typename ForwardIt>
1151auto upper_bound(R &&Range, ForwardIt I) -> decltype(adl_begin(Range)) {
1152 return std::upper_bound(adl_begin(Range), adl_end(Range), I);
1153}
1154
1155template <typename R, typename ForwardIt, typename Compare>
1156auto upper_bound(R &&Range, ForwardIt I, Compare C)
1157 -> decltype(adl_begin(Range)) {
1158 return std::upper_bound(adl_begin(Range), adl_end(Range), I, C);
1159}
1160/// Wrapper function around std::equal to detect if all elements
1161/// in a container are same.
1162template <typename R>
1163bool is_splat(R &&Range) {
1164 size_t range_size = size(Range);
1165 return range_size != 0 && (range_size == 1 ||
1166 std::equal(adl_begin(Range) + 1, adl_end(Range), adl_begin(Range)));
1167}
1168
1169/// Given a range of type R, iterate the entire range and return a
1170/// SmallVector with elements of the vector. This is useful, for example,
1171/// when you want to iterate a range and then sort the results.
1172template <unsigned Size, typename R>
1173SmallVector<typename std::remove_const<detail::ValueOfRange<R>>::type, Size>
1174to_vector(R &&Range) {
1175 return {adl_begin(Range), adl_end(Range)};
1176}
1177
1178/// Provide a container algorithm similar to C++ Library Fundamentals v2's
1179/// `erase_if` which is equivalent to:
1180///
1181/// C.erase(remove_if(C, pred), C.end());
1182///
1183/// This version works for any container with an erase method call accepting
1184/// two iterators.
1185template <typename Container, typename UnaryPredicate>
1186void erase_if(Container &C, UnaryPredicate P) {
1187 C.erase(remove_if(C, P), C.end());
1188}
1189
1190//===----------------------------------------------------------------------===//
1191// Extra additions to <memory>
1192//===----------------------------------------------------------------------===//
1193
1194// Implement make_unique according to N3656.
1195
1196/// Constructs a `new T()` with the given args and returns a
1197/// `unique_ptr<T>` which owns the object.
1198///
1199/// Example:
1200///
1201/// auto p = make_unique<int>();
1202/// auto p = make_unique<std::tuple<int, int>>(0, 1);
1203template <class T, class... Args>
1204typename std::enable_if<!std::is_array<T>::value, std::unique_ptr<T>>::type
1205make_unique(Args &&... args) {
1206 return std::unique_ptr<T>(new T(std::forward<Args>(args)...));
12
Memory is allocated
1207}
1208
1209/// Constructs a `new T[n]` with the given args and returns a
1210/// `unique_ptr<T[]>` which owns the object.
1211///
1212/// \param n size of the new array.
1213///
1214/// Example:
1215///
1216/// auto p = make_unique<int[]>(2); // value-initializes the array with 0's.
1217template <class T>
1218typename std::enable_if<std::is_array<T>::value && std::extent<T>::value == 0,
1219 std::unique_ptr<T>>::type
1220make_unique(size_t n) {
1221 return std::unique_ptr<T>(new typename std::remove_extent<T>::type[n]());
1222}
1223
1224/// This function isn't used and is only here to provide better compile errors.
1225template <class T, class... Args>
1226typename std::enable_if<std::extent<T>::value != 0>::type
1227make_unique(Args &&...) = delete;
1228
1229struct FreeDeleter {
1230 void operator()(void* v) {
1231 ::free(v);
1232 }
1233};
1234
1235template<typename First, typename Second>
1236struct pair_hash {
1237 size_t operator()(const std::pair<First, Second> &P) const {
1238 return std::hash<First>()(P.first) * 31 + std::hash<Second>()(P.second);
1239 }
1240};
1241
1242/// A functor like C++14's std::less<void> in its absence.
1243struct less {
1244 template <typename A, typename B> bool operator()(A &&a, B &&b) const {
1245 return std::forward<A>(a) < std::forward<B>(b);
1246 }
1247};
1248
1249/// A functor like C++14's std::equal<void> in its absence.
1250struct equal {
1251 template <typename A, typename B> bool operator()(A &&a, B &&b) const {
1252 return std::forward<A>(a) == std::forward<B>(b);
1253 }
1254};
1255
1256/// Binary functor that adapts to any other binary functor after dereferencing
1257/// operands.
1258template <typename T> struct deref {
1259 T func;
1260
1261 // Could be further improved to cope with non-derivable functors and
1262 // non-binary functors (should be a variadic template member function
1263 // operator()).
1264 template <typename A, typename B>
1265 auto operator()(A &lhs, B &rhs) const -> decltype(func(*lhs, *rhs)) {
1266 assert(lhs)((lhs) ? static_cast<void> (0) : __assert_fail ("lhs", "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/ADT/STLExtras.h"
, 1266, __PRETTY_FUNCTION__))
;
1267 assert(rhs)((rhs) ? static_cast<void> (0) : __assert_fail ("rhs", "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/ADT/STLExtras.h"
, 1267, __PRETTY_FUNCTION__))
;
1268 return func(*lhs, *rhs);
1269 }
1270};
1271
1272namespace detail {
1273
1274template <typename R> class enumerator_iter;
1275
1276template <typename R> struct result_pair {
1277 friend class enumerator_iter<R>;
1278
1279 result_pair() = default;
1280 result_pair(std::size_t Index, IterOfRange<R> Iter)
1281 : Index(Index), Iter(Iter) {}
1282
1283 result_pair<R> &operator=(const result_pair<R> &Other) {
1284 Index = Other.Index;
1285 Iter = Other.Iter;
1286 return *this;
1287 }
1288
1289 std::size_t index() const { return Index; }
1290 const ValueOfRange<R> &value() const { return *Iter; }
1291 ValueOfRange<R> &value() { return *Iter; }
1292
1293private:
1294 std::size_t Index = std::numeric_limits<std::size_t>::max();
1295 IterOfRange<R> Iter;
1296};
1297
1298template <typename R>
1299class enumerator_iter
1300 : public iterator_facade_base<
1301 enumerator_iter<R>, std::forward_iterator_tag, result_pair<R>,
1302 typename std::iterator_traits<IterOfRange<R>>::difference_type,
1303 typename std::iterator_traits<IterOfRange<R>>::pointer,
1304 typename std::iterator_traits<IterOfRange<R>>::reference> {
1305 using result_type = result_pair<R>;
1306
1307public:
1308 explicit enumerator_iter(IterOfRange<R> EndIter)
1309 : Result(std::numeric_limits<size_t>::max(), EndIter) {}
1310
1311 enumerator_iter(std::size_t Index, IterOfRange<R> Iter)
1312 : Result(Index, Iter) {}
1313
1314 result_type &operator*() { return Result; }
1315 const result_type &operator*() const { return Result; }
1316
1317 enumerator_iter<R> &operator++() {
1318 assert(Result.Index != std::numeric_limits<size_t>::max())((Result.Index != std::numeric_limits<size_t>::max()) ?
static_cast<void> (0) : __assert_fail ("Result.Index != std::numeric_limits<size_t>::max()"
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/ADT/STLExtras.h"
, 1318, __PRETTY_FUNCTION__))
;
1319 ++Result.Iter;
1320 ++Result.Index;
1321 return *this;
1322 }
1323
1324 bool operator==(const enumerator_iter<R> &RHS) const {
1325 // Don't compare indices here, only iterators. It's possible for an end
1326 // iterator to have different indices depending on whether it was created
1327 // by calling std::end() versus incrementing a valid iterator.
1328 return Result.Iter == RHS.Result.Iter;
1329 }
1330
1331 enumerator_iter<R> &operator=(const enumerator_iter<R> &Other) {
1332 Result = Other.Result;
1333 return *this;
1334 }
1335
1336private:
1337 result_type Result;
1338};
1339
1340template <typename R> class enumerator {
1341public:
1342 explicit enumerator(R &&Range) : TheRange(std::forward<R>(Range)) {}
1343
1344 enumerator_iter<R> begin() {
1345 return enumerator_iter<R>(0, std::begin(TheRange));
1346 }
1347
1348 enumerator_iter<R> end() {
1349 return enumerator_iter<R>(std::end(TheRange));
1350 }
1351
1352private:
1353 R TheRange;
1354};
1355
1356} // end namespace detail
1357
1358/// Given an input range, returns a new range whose values are are pair (A,B)
1359/// such that A is the 0-based index of the item in the sequence, and B is
1360/// the value from the original sequence. Example:
1361///
1362/// std::vector<char> Items = {'A', 'B', 'C', 'D'};
1363/// for (auto X : enumerate(Items)) {
1364/// printf("Item %d - %c\n", X.index(), X.value());
1365/// }
1366///
1367/// Output:
1368/// Item 0 - A
1369/// Item 1 - B
1370/// Item 2 - C
1371/// Item 3 - D
1372///
1373template <typename R> detail::enumerator<R> enumerate(R &&TheRange) {
1374 return detail::enumerator<R>(std::forward<R>(TheRange));
1375}
1376
1377namespace detail {
1378
1379template <typename F, typename Tuple, std::size_t... I>
1380auto apply_tuple_impl(F &&f, Tuple &&t, index_sequence<I...>)
1381 -> decltype(std::forward<F>(f)(std::get<I>(std::forward<Tuple>(t))...)) {
1382 return std::forward<F>(f)(std::get<I>(std::forward<Tuple>(t))...);
1383}
1384
1385} // end namespace detail
1386
1387/// Given an input tuple (a1, a2, ..., an), pass the arguments of the
1388/// tuple variadically to f as if by calling f(a1, a2, ..., an) and
1389/// return the result.
1390template <typename F, typename Tuple>
1391auto apply_tuple(F &&f, Tuple &&t) -> decltype(detail::apply_tuple_impl(
1392 std::forward<F>(f), std::forward<Tuple>(t),
1393 build_index_impl<
1394 std::tuple_size<typename std::decay<Tuple>::type>::value>{})) {
1395 using Indices = build_index_impl<
1396 std::tuple_size<typename std::decay<Tuple>::type>::value>;
1397
1398 return detail::apply_tuple_impl(std::forward<F>(f), std::forward<Tuple>(t),
1399 Indices{});
1400}
1401
1402} // end namespace llvm
1403
1404#endif // LLVM_ADT_STLEXTRAS_H