Bug Summary

File:build/llvm-toolchain-snapshot-15~++20220419111428+a65f2730d291/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
Warning:line 276, column 5
Called C++ object pointer is null

Annotated Source Code

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clang -cc1 -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name AsmPrinter.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 -setup-static-analyzer -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -mframe-pointer=none -fmath-errno -ffp-contract=on -fno-rounding-math -mconstructor-aliases -funwind-tables=2 -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -ffunction-sections -fdata-sections -fcoverage-compilation-dir=/build/llvm-toolchain-snapshot-15~++20220419111428+a65f2730d291/build-llvm -resource-dir /usr/lib/llvm-15/lib/clang/15.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I lib/CodeGen/AsmPrinter -I /build/llvm-toolchain-snapshot-15~++20220419111428+a65f2730d291/llvm/lib/CodeGen/AsmPrinter -I include -I /build/llvm-toolchain-snapshot-15~++20220419111428+a65f2730d291/llvm/include -D _FORTIFY_SOURCE=2 -D NDEBUG -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/x86_64-linux-gnu/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/backward -internal-isystem /usr/lib/llvm-15/lib/clang/15.0.0/include -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -fmacro-prefix-map=/build/llvm-toolchain-snapshot-15~++20220419111428+a65f2730d291/build-llvm=build-llvm -fmacro-prefix-map=/build/llvm-toolchain-snapshot-15~++20220419111428+a65f2730d291/= -fcoverage-prefix-map=/build/llvm-toolchain-snapshot-15~++20220419111428+a65f2730d291/build-llvm=build-llvm -fcoverage-prefix-map=/build/llvm-toolchain-snapshot-15~++20220419111428+a65f2730d291/= -O3 -Wno-unused-command-line-argument -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-class-memaccess -Wno-redundant-move -Wno-pessimizing-move -Wno-noexcept-type -Wno-comment -std=c++14 -fdeprecated-macro -fdebug-compilation-dir=/build/llvm-toolchain-snapshot-15~++20220419111428+a65f2730d291/build-llvm -fdebug-prefix-map=/build/llvm-toolchain-snapshot-15~++20220419111428+a65f2730d291/build-llvm=build-llvm -fdebug-prefix-map=/build/llvm-toolchain-snapshot-15~++20220419111428+a65f2730d291/= -ferror-limit 19 -fvisibility-inlines-hidden -stack-protector 2 -fgnuc-version=4.2.1 -fcolor-diagnostics -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/scan-build-2022-04-19-125528-33783-1 -x c++ /build/llvm-toolchain-snapshot-15~++20220419111428+a65f2730d291/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
1//===- AsmPrinter.cpp - Common AsmPrinter code ----------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file implements the AsmPrinter class.
10//
11//===----------------------------------------------------------------------===//
12
13#include "llvm/CodeGen/AsmPrinter.h"
14#include "CodeViewDebug.h"
15#include "DwarfDebug.h"
16#include "DwarfException.h"
17#include "PseudoProbePrinter.h"
18#include "WasmException.h"
19#include "WinCFGuard.h"
20#include "WinException.h"
21#include "llvm/ADT/APFloat.h"
22#include "llvm/ADT/APInt.h"
23#include "llvm/ADT/DenseMap.h"
24#include "llvm/ADT/STLExtras.h"
25#include "llvm/ADT/SmallPtrSet.h"
26#include "llvm/ADT/SmallString.h"
27#include "llvm/ADT/SmallVector.h"
28#include "llvm/ADT/Statistic.h"
29#include "llvm/ADT/StringRef.h"
30#include "llvm/ADT/Triple.h"
31#include "llvm/ADT/Twine.h"
32#include "llvm/Analysis/ConstantFolding.h"
33#include "llvm/Analysis/EHPersonalities.h"
34#include "llvm/Analysis/MemoryLocation.h"
35#include "llvm/Analysis/OptimizationRemarkEmitter.h"
36#include "llvm/BinaryFormat/COFF.h"
37#include "llvm/BinaryFormat/Dwarf.h"
38#include "llvm/BinaryFormat/ELF.h"
39#include "llvm/CodeGen/GCMetadata.h"
40#include "llvm/CodeGen/GCMetadataPrinter.h"
41#include "llvm/CodeGen/MachineBasicBlock.h"
42#include "llvm/CodeGen/MachineConstantPool.h"
43#include "llvm/CodeGen/MachineDominators.h"
44#include "llvm/CodeGen/MachineFrameInfo.h"
45#include "llvm/CodeGen/MachineFunction.h"
46#include "llvm/CodeGen/MachineFunctionPass.h"
47#include "llvm/CodeGen/MachineInstr.h"
48#include "llvm/CodeGen/MachineInstrBundle.h"
49#include "llvm/CodeGen/MachineJumpTableInfo.h"
50#include "llvm/CodeGen/MachineLoopInfo.h"
51#include "llvm/CodeGen/MachineModuleInfo.h"
52#include "llvm/CodeGen/MachineModuleInfoImpls.h"
53#include "llvm/CodeGen/MachineOperand.h"
54#include "llvm/CodeGen/MachineOptimizationRemarkEmitter.h"
55#include "llvm/CodeGen/StackMaps.h"
56#include "llvm/CodeGen/TargetFrameLowering.h"
57#include "llvm/CodeGen/TargetInstrInfo.h"
58#include "llvm/CodeGen/TargetLowering.h"
59#include "llvm/CodeGen/TargetOpcodes.h"
60#include "llvm/CodeGen/TargetRegisterInfo.h"
61#include "llvm/Config/config.h"
62#include "llvm/IR/BasicBlock.h"
63#include "llvm/IR/Comdat.h"
64#include "llvm/IR/Constant.h"
65#include "llvm/IR/Constants.h"
66#include "llvm/IR/DataLayout.h"
67#include "llvm/IR/DebugInfoMetadata.h"
68#include "llvm/IR/DerivedTypes.h"
69#include "llvm/IR/Function.h"
70#include "llvm/IR/GCStrategy.h"
71#include "llvm/IR/GlobalAlias.h"
72#include "llvm/IR/GlobalIFunc.h"
73#include "llvm/IR/GlobalObject.h"
74#include "llvm/IR/GlobalValue.h"
75#include "llvm/IR/GlobalVariable.h"
76#include "llvm/IR/Instruction.h"
77#include "llvm/IR/Mangler.h"
78#include "llvm/IR/Metadata.h"
79#include "llvm/IR/Module.h"
80#include "llvm/IR/Operator.h"
81#include "llvm/IR/PseudoProbe.h"
82#include "llvm/IR/Type.h"
83#include "llvm/IR/Value.h"
84#include "llvm/MC/MCAsmInfo.h"
85#include "llvm/MC/MCContext.h"
86#include "llvm/MC/MCDirectives.h"
87#include "llvm/MC/MCExpr.h"
88#include "llvm/MC/MCInst.h"
89#include "llvm/MC/MCSection.h"
90#include "llvm/MC/MCSectionCOFF.h"
91#include "llvm/MC/MCSectionELF.h"
92#include "llvm/MC/MCSectionMachO.h"
93#include "llvm/MC/MCStreamer.h"
94#include "llvm/MC/MCSubtargetInfo.h"
95#include "llvm/MC/MCSymbol.h"
96#include "llvm/MC/MCSymbolELF.h"
97#include "llvm/MC/MCTargetOptions.h"
98#include "llvm/MC/MCValue.h"
99#include "llvm/MC/SectionKind.h"
100#include "llvm/Pass.h"
101#include "llvm/Remarks/RemarkStreamer.h"
102#include "llvm/Support/Casting.h"
103#include "llvm/Support/CommandLine.h"
104#include "llvm/Support/Compiler.h"
105#include "llvm/Support/ErrorHandling.h"
106#include "llvm/Support/FileSystem.h"
107#include "llvm/Support/Format.h"
108#include "llvm/Support/MathExtras.h"
109#include "llvm/Support/Path.h"
110#include "llvm/Support/Timer.h"
111#include "llvm/Support/raw_ostream.h"
112#include "llvm/Target/TargetLoweringObjectFile.h"
113#include "llvm/Target/TargetMachine.h"
114#include "llvm/Target/TargetOptions.h"
115#include <algorithm>
116#include <cassert>
117#include <cinttypes>
118#include <cstdint>
119#include <iterator>
120#include <memory>
121#include <string>
122#include <utility>
123#include <vector>
124
125using namespace llvm;
126
127#define DEBUG_TYPE"asm-printer" "asm-printer"
128
129// FIXME: this option currently only applies to DWARF, and not CodeView, tables
130static cl::opt<bool>
131 DisableDebugInfoPrinting("disable-debug-info-print", cl::Hidden,
132 cl::desc("Disable debug info printing"));
133
134const char DWARFGroupName[] = "dwarf";
135const char DWARFGroupDescription[] = "DWARF Emission";
136const char DbgTimerName[] = "emit";
137const char DbgTimerDescription[] = "Debug Info Emission";
138const char EHTimerName[] = "write_exception";
139const char EHTimerDescription[] = "DWARF Exception Writer";
140const char CFGuardName[] = "Control Flow Guard";
141const char CFGuardDescription[] = "Control Flow Guard";
142const char CodeViewLineTablesGroupName[] = "linetables";
143const char CodeViewLineTablesGroupDescription[] = "CodeView Line Tables";
144const char PPTimerName[] = "emit";
145const char PPTimerDescription[] = "Pseudo Probe Emission";
146const char PPGroupName[] = "pseudo probe";
147const char PPGroupDescription[] = "Pseudo Probe Emission";
148
149STATISTIC(EmittedInsts, "Number of machine instrs printed")static llvm::Statistic EmittedInsts = {"asm-printer", "EmittedInsts"
, "Number of machine instrs printed"}
;
150
151char AsmPrinter::ID = 0;
152
153using gcp_map_type = DenseMap<GCStrategy *, std::unique_ptr<GCMetadataPrinter>>;
154
155static gcp_map_type &getGCMap(void *&P) {
156 if (!P)
157 P = new gcp_map_type();
158 return *(gcp_map_type*)P;
159}
160
161/// getGVAlignment - Return the alignment to use for the specified global
162/// value. This rounds up to the preferred alignment if possible and legal.
163Align AsmPrinter::getGVAlignment(const GlobalObject *GV, const DataLayout &DL,
164 Align InAlign) {
165 Align Alignment;
166 if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV))
167 Alignment = DL.getPreferredAlign(GVar);
168
169 // If InAlign is specified, round it to it.
170 if (InAlign > Alignment)
171 Alignment = InAlign;
172
173 // If the GV has a specified alignment, take it into account.
174 const MaybeAlign GVAlign(GV->getAlign());
175 if (!GVAlign)
176 return Alignment;
177
178 assert(GVAlign && "GVAlign must be set")(static_cast <bool> (GVAlign && "GVAlign must be set"
) ? void (0) : __assert_fail ("GVAlign && \"GVAlign must be set\""
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 178, __extension__
__PRETTY_FUNCTION__))
;
179
180 // If the GVAlign is larger than NumBits, or if we are required to obey
181 // NumBits because the GV has an assigned section, obey it.
182 if (*GVAlign > Alignment || GV->hasSection())
183 Alignment = *GVAlign;
184 return Alignment;
185}
186
187AsmPrinter::AsmPrinter(TargetMachine &tm, std::unique_ptr<MCStreamer> Streamer)
188 : MachineFunctionPass(ID), TM(tm), MAI(tm.getMCAsmInfo()),
189 OutContext(Streamer->getContext()), OutStreamer(std::move(Streamer)) {
190 VerboseAsm = OutStreamer->isVerboseAsm();
191}
192
193AsmPrinter::~AsmPrinter() {
194 assert(!DD && Handlers.size() == NumUserHandlers &&(static_cast <bool> (!DD && Handlers.size() == NumUserHandlers
&& "Debug/EH info didn't get finalized") ? void (0) :
__assert_fail ("!DD && Handlers.size() == NumUserHandlers && \"Debug/EH info didn't get finalized\""
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 195, __extension__
__PRETTY_FUNCTION__))
195 "Debug/EH info didn't get finalized")(static_cast <bool> (!DD && Handlers.size() == NumUserHandlers
&& "Debug/EH info didn't get finalized") ? void (0) :
__assert_fail ("!DD && Handlers.size() == NumUserHandlers && \"Debug/EH info didn't get finalized\""
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 195, __extension__
__PRETTY_FUNCTION__))
;
196
197 if (GCMetadataPrinters) {
198 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
199
200 delete &GCMap;
201 GCMetadataPrinters = nullptr;
202 }
203}
204
205bool AsmPrinter::isPositionIndependent() const {
206 return TM.isPositionIndependent();
207}
208
209/// getFunctionNumber - Return a unique ID for the current function.
210unsigned AsmPrinter::getFunctionNumber() const {
211 return MF->getFunctionNumber();
212}
213
214const TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const {
215 return *TM.getObjFileLowering();
216}
217
218const DataLayout &AsmPrinter::getDataLayout() const {
219 return MMI->getModule()->getDataLayout();
220}
221
222// Do not use the cached DataLayout because some client use it without a Module
223// (dsymutil, llvm-dwarfdump).
224unsigned AsmPrinter::getPointerSize() const {
225 return TM.getPointerSize(0); // FIXME: Default address space
226}
227
228const MCSubtargetInfo &AsmPrinter::getSubtargetInfo() const {
229 assert(MF && "getSubtargetInfo requires a valid MachineFunction!")(static_cast <bool> (MF && "getSubtargetInfo requires a valid MachineFunction!"
) ? void (0) : __assert_fail ("MF && \"getSubtargetInfo requires a valid MachineFunction!\""
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 229, __extension__
__PRETTY_FUNCTION__))
;
230 return MF->getSubtarget<MCSubtargetInfo>();
231}
232
233void AsmPrinter::EmitToStreamer(MCStreamer &S, const MCInst &Inst) {
234 S.emitInstruction(Inst, getSubtargetInfo());
235}
236
237void AsmPrinter::emitInitialRawDwarfLocDirective(const MachineFunction &MF) {
238 if (DD) {
239 assert(OutStreamer->hasRawTextSupport() &&(static_cast <bool> (OutStreamer->hasRawTextSupport(
) && "Expected assembly output mode.") ? void (0) : __assert_fail
("OutStreamer->hasRawTextSupport() && \"Expected assembly output mode.\""
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 240, __extension__
__PRETTY_FUNCTION__))
240 "Expected assembly output mode.")(static_cast <bool> (OutStreamer->hasRawTextSupport(
) && "Expected assembly output mode.") ? void (0) : __assert_fail
("OutStreamer->hasRawTextSupport() && \"Expected assembly output mode.\""
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 240, __extension__
__PRETTY_FUNCTION__))
;
241 // This is NVPTX specific and it's unclear why.
242 // PR51079: If we have code without debug information we need to give up.
243 DISubprogram *MFSP = MF.getFunction().getSubprogram();
244 if (!MFSP)
245 return;
246 (void)DD->emitInitialLocDirective(MF, /*CUID=*/0);
247 }
248}
249
250/// getCurrentSection() - Return the current section we are emitting to.
251const MCSection *AsmPrinter::getCurrentSection() const {
252 return OutStreamer->getCurrentSectionOnly();
253}
254
255void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const {
256 AU.setPreservesAll();
257 MachineFunctionPass::getAnalysisUsage(AU);
258 AU.addRequired<MachineOptimizationRemarkEmitterPass>();
259 AU.addRequired<GCModuleInfo>();
260}
261
262bool AsmPrinter::doInitialization(Module &M) {
263 auto *MMIWP = getAnalysisIfAvailable<MachineModuleInfoWrapperPass>();
264 MMI = MMIWP
0.1
'MMIWP' is null
? &MMIWP->getMMI() : nullptr
;
1
'?' condition is false
2
Null pointer value stored to field 'MMI'
265
266 // Initialize TargetLoweringObjectFile.
267 const_cast<TargetLoweringObjectFile&>(getObjFileLowering())
268 .Initialize(OutContext, TM);
269
270 const_cast<TargetLoweringObjectFile &>(getObjFileLowering())
271 .getModuleMetadata(M);
272
273 OutStreamer->initSections(false, *TM.getMCSubtargetInfo());
274
275 if (DisableDebugInfoPrinting)
3
Assuming the condition is true
4
Taking true branch
276 MMI->setDebugInfoAvailability(false);
5
Called C++ object pointer is null
277
278 // Emit the version-min deployment target directive if needed.
279 //
280 // FIXME: If we end up with a collection of these sorts of Darwin-specific
281 // or ELF-specific things, it may make sense to have a platform helper class
282 // that will work with the target helper class. For now keep it here, as the
283 // alternative is duplicated code in each of the target asm printers that
284 // use the directive, where it would need the same conditionalization
285 // anyway.
286 const Triple &Target = TM.getTargetTriple();
287 Triple TVT(M.getDarwinTargetVariantTriple());
288 OutStreamer->emitVersionForTarget(
289 Target, M.getSDKVersion(),
290 M.getDarwinTargetVariantTriple().empty() ? nullptr : &TVT,
291 M.getDarwinTargetVariantSDKVersion());
292
293 // Allow the target to emit any magic that it wants at the start of the file.
294 emitStartOfAsmFile(M);
295
296 // Very minimal debug info. It is ignored if we emit actual debug info. If we
297 // don't, this at least helps the user find where a global came from.
298 if (MAI->hasSingleParameterDotFile()) {
299 // .file "foo.c"
300
301 SmallString<128> FileName;
302 if (MAI->hasBasenameOnlyForFileDirective())
303 FileName = llvm::sys::path::filename(M.getSourceFileName());
304 else
305 FileName = M.getSourceFileName();
306 if (MAI->hasFourStringsDotFile()) {
307#ifdef PACKAGE_VENDOR"Debian"
308 const char VerStr[] =
309 PACKAGE_VENDOR"Debian" " " PACKAGE_NAME"LLVM" " version " PACKAGE_VERSION"15.0.0";
310#else
311 const char VerStr[] = PACKAGE_NAME"LLVM" " version " PACKAGE_VERSION"15.0.0";
312#endif
313 // TODO: Add timestamp and description.
314 OutStreamer->emitFileDirective(FileName, VerStr, "", "");
315 } else {
316 OutStreamer->emitFileDirective(FileName);
317 }
318 }
319
320 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
321 assert(MI && "AsmPrinter didn't require GCModuleInfo?")(static_cast <bool> (MI && "AsmPrinter didn't require GCModuleInfo?"
) ? void (0) : __assert_fail ("MI && \"AsmPrinter didn't require GCModuleInfo?\""
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 321, __extension__
__PRETTY_FUNCTION__))
;
322 for (auto &I : *MI)
323 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I))
324 MP->beginAssembly(M, *MI, *this);
325
326 // Emit module-level inline asm if it exists.
327 if (!M.getModuleInlineAsm().empty()) {
328 OutStreamer->AddComment("Start of file scope inline assembly");
329 OutStreamer->AddBlankLine();
330 emitInlineAsm(M.getModuleInlineAsm() + "\n", *TM.getMCSubtargetInfo(),
331 TM.Options.MCOptions);
332 OutStreamer->AddComment("End of file scope inline assembly");
333 OutStreamer->AddBlankLine();
334 }
335
336 if (MAI->doesSupportDebugInformation()) {
337 bool EmitCodeView = M.getCodeViewFlag();
338 if (EmitCodeView && TM.getTargetTriple().isOSWindows()) {
339 Handlers.emplace_back(std::make_unique<CodeViewDebug>(this),
340 DbgTimerName, DbgTimerDescription,
341 CodeViewLineTablesGroupName,
342 CodeViewLineTablesGroupDescription);
343 }
344 if (!EmitCodeView || M.getDwarfVersion()) {
345 if (!DisableDebugInfoPrinting) {
346 DD = new DwarfDebug(this);
347 Handlers.emplace_back(std::unique_ptr<DwarfDebug>(DD), DbgTimerName,
348 DbgTimerDescription, DWARFGroupName,
349 DWARFGroupDescription);
350 }
351 }
352 }
353
354 if (M.getNamedMetadata(PseudoProbeDescMetadataName)) {
355 PP = new PseudoProbeHandler(this);
356 Handlers.emplace_back(std::unique_ptr<PseudoProbeHandler>(PP), PPTimerName,
357 PPTimerDescription, PPGroupName, PPGroupDescription);
358 }
359
360 switch (MAI->getExceptionHandlingType()) {
361 case ExceptionHandling::None:
362 // We may want to emit CFI for debug.
363 LLVM_FALLTHROUGH[[gnu::fallthrough]];
364 case ExceptionHandling::SjLj:
365 case ExceptionHandling::DwarfCFI:
366 case ExceptionHandling::ARM:
367 for (auto &F : M.getFunctionList()) {
368 if (getFunctionCFISectionType(F) != CFISection::None)
369 ModuleCFISection = getFunctionCFISectionType(F);
370 // If any function needsUnwindTableEntry(), it needs .eh_frame and hence
371 // the module needs .eh_frame. If we have found that case, we are done.
372 if (ModuleCFISection == CFISection::EH)
373 break;
374 }
375 assert(MAI->getExceptionHandlingType() == ExceptionHandling::DwarfCFI ||(static_cast <bool> (MAI->getExceptionHandlingType()
== ExceptionHandling::DwarfCFI || ModuleCFISection != CFISection
::EH) ? void (0) : __assert_fail ("MAI->getExceptionHandlingType() == ExceptionHandling::DwarfCFI || ModuleCFISection != CFISection::EH"
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 376, __extension__
__PRETTY_FUNCTION__))
376 ModuleCFISection != CFISection::EH)(static_cast <bool> (MAI->getExceptionHandlingType()
== ExceptionHandling::DwarfCFI || ModuleCFISection != CFISection
::EH) ? void (0) : __assert_fail ("MAI->getExceptionHandlingType() == ExceptionHandling::DwarfCFI || ModuleCFISection != CFISection::EH"
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 376, __extension__
__PRETTY_FUNCTION__))
;
377 break;
378 default:
379 break;
380 }
381
382 EHStreamer *ES = nullptr;
383 switch (MAI->getExceptionHandlingType()) {
384 case ExceptionHandling::None:
385 if (!needsCFIForDebug())
386 break;
387 LLVM_FALLTHROUGH[[gnu::fallthrough]];
388 case ExceptionHandling::SjLj:
389 case ExceptionHandling::DwarfCFI:
390 ES = new DwarfCFIException(this);
391 break;
392 case ExceptionHandling::ARM:
393 ES = new ARMException(this);
394 break;
395 case ExceptionHandling::WinEH:
396 switch (MAI->getWinEHEncodingType()) {
397 default: llvm_unreachable("unsupported unwinding information encoding")::llvm::llvm_unreachable_internal("unsupported unwinding information encoding"
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 397)
;
398 case WinEH::EncodingType::Invalid:
399 break;
400 case WinEH::EncodingType::X86:
401 case WinEH::EncodingType::Itanium:
402 ES = new WinException(this);
403 break;
404 }
405 break;
406 case ExceptionHandling::Wasm:
407 ES = new WasmException(this);
408 break;
409 case ExceptionHandling::AIX:
410 ES = new AIXException(this);
411 break;
412 }
413 if (ES)
414 Handlers.emplace_back(std::unique_ptr<EHStreamer>(ES), EHTimerName,
415 EHTimerDescription, DWARFGroupName,
416 DWARFGroupDescription);
417
418 // Emit tables for any value of cfguard flag (i.e. cfguard=1 or cfguard=2).
419 if (mdconst::extract_or_null<ConstantInt>(M.getModuleFlag("cfguard")))
420 Handlers.emplace_back(std::make_unique<WinCFGuard>(this), CFGuardName,
421 CFGuardDescription, DWARFGroupName,
422 DWARFGroupDescription);
423
424 for (const HandlerInfo &HI : Handlers) {
425 NamedRegionTimer T(HI.TimerName, HI.TimerDescription, HI.TimerGroupName,
426 HI.TimerGroupDescription, TimePassesIsEnabled);
427 HI.Handler->beginModule(&M);
428 }
429
430 return false;
431}
432
433static bool canBeHidden(const GlobalValue *GV, const MCAsmInfo &MAI) {
434 if (!MAI.hasWeakDefCanBeHiddenDirective())
435 return false;
436
437 return GV->canBeOmittedFromSymbolTable();
438}
439
440void AsmPrinter::emitLinkage(const GlobalValue *GV, MCSymbol *GVSym) const {
441 GlobalValue::LinkageTypes Linkage = GV->getLinkage();
442 switch (Linkage) {
443 case GlobalValue::CommonLinkage:
444 case GlobalValue::LinkOnceAnyLinkage:
445 case GlobalValue::LinkOnceODRLinkage:
446 case GlobalValue::WeakAnyLinkage:
447 case GlobalValue::WeakODRLinkage:
448 if (MAI->hasWeakDefDirective()) {
449 // .globl _foo
450 OutStreamer->emitSymbolAttribute(GVSym, MCSA_Global);
451
452 if (!canBeHidden(GV, *MAI))
453 // .weak_definition _foo
454 OutStreamer->emitSymbolAttribute(GVSym, MCSA_WeakDefinition);
455 else
456 OutStreamer->emitSymbolAttribute(GVSym, MCSA_WeakDefAutoPrivate);
457 } else if (MAI->avoidWeakIfComdat() && GV->hasComdat()) {
458 // .globl _foo
459 OutStreamer->emitSymbolAttribute(GVSym, MCSA_Global);
460 //NOTE: linkonce is handled by the section the symbol was assigned to.
461 } else {
462 // .weak _foo
463 OutStreamer->emitSymbolAttribute(GVSym, MCSA_Weak);
464 }
465 return;
466 case GlobalValue::ExternalLinkage:
467 OutStreamer->emitSymbolAttribute(GVSym, MCSA_Global);
468 return;
469 case GlobalValue::PrivateLinkage:
470 case GlobalValue::InternalLinkage:
471 return;
472 case GlobalValue::ExternalWeakLinkage:
473 case GlobalValue::AvailableExternallyLinkage:
474 case GlobalValue::AppendingLinkage:
475 llvm_unreachable("Should never emit this")::llvm::llvm_unreachable_internal("Should never emit this", "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 475)
;
476 }
477 llvm_unreachable("Unknown linkage type!")::llvm::llvm_unreachable_internal("Unknown linkage type!", "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 477)
;
478}
479
480void AsmPrinter::getNameWithPrefix(SmallVectorImpl<char> &Name,
481 const GlobalValue *GV) const {
482 TM.getNameWithPrefix(Name, GV, getObjFileLowering().getMangler());
483}
484
485MCSymbol *AsmPrinter::getSymbol(const GlobalValue *GV) const {
486 return TM.getSymbol(GV);
487}
488
489MCSymbol *AsmPrinter::getSymbolPreferLocal(const GlobalValue &GV) const {
490 // On ELF, use .Lfoo$local if GV is a non-interposable GlobalObject with an
491 // exact definion (intersection of GlobalValue::hasExactDefinition() and
492 // !isInterposable()). These linkages include: external, appending, internal,
493 // private. It may be profitable to use a local alias for external. The
494 // assembler would otherwise be conservative and assume a global default
495 // visibility symbol can be interposable, even if the code generator already
496 // assumed it.
497 if (TM.getTargetTriple().isOSBinFormatELF() && GV.canBenefitFromLocalAlias()) {
498 const Module &M = *GV.getParent();
499 if (TM.getRelocationModel() != Reloc::Static &&
500 M.getPIELevel() == PIELevel::Default && GV.isDSOLocal())
501 return getSymbolWithGlobalValueBase(&GV, "$local");
502 }
503 return TM.getSymbol(&GV);
504}
505
506/// EmitGlobalVariable - Emit the specified global variable to the .s file.
507void AsmPrinter::emitGlobalVariable(const GlobalVariable *GV) {
508 bool IsEmuTLSVar = TM.useEmulatedTLS() && GV->isThreadLocal();
509 assert(!(IsEmuTLSVar && GV->hasCommonLinkage()) &&(static_cast <bool> (!(IsEmuTLSVar && GV->hasCommonLinkage
()) && "No emulated TLS variables in the common section"
) ? void (0) : __assert_fail ("!(IsEmuTLSVar && GV->hasCommonLinkage()) && \"No emulated TLS variables in the common section\""
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 510, __extension__
__PRETTY_FUNCTION__))
510 "No emulated TLS variables in the common section")(static_cast <bool> (!(IsEmuTLSVar && GV->hasCommonLinkage
()) && "No emulated TLS variables in the common section"
) ? void (0) : __assert_fail ("!(IsEmuTLSVar && GV->hasCommonLinkage()) && \"No emulated TLS variables in the common section\""
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 510, __extension__
__PRETTY_FUNCTION__))
;
511
512 // Never emit TLS variable xyz in emulated TLS model.
513 // The initialization value is in __emutls_t.xyz instead of xyz.
514 if (IsEmuTLSVar)
515 return;
516
517 if (GV->hasInitializer()) {
518 // Check to see if this is a special global used by LLVM, if so, emit it.
519 if (emitSpecialLLVMGlobal(GV))
520 return;
521
522 // Skip the emission of global equivalents. The symbol can be emitted later
523 // on by emitGlobalGOTEquivs in case it turns out to be needed.
524 if (GlobalGOTEquivs.count(getSymbol(GV)))
525 return;
526
527 if (isVerbose()) {
528 // When printing the control variable __emutls_v.*,
529 // we don't need to print the original TLS variable name.
530 GV->printAsOperand(OutStreamer->GetCommentOS(),
531 /*PrintType=*/false, GV->getParent());
532 OutStreamer->GetCommentOS() << '\n';
533 }
534 }
535
536 MCSymbol *GVSym = getSymbol(GV);
537 MCSymbol *EmittedSym = GVSym;
538
539 // getOrCreateEmuTLSControlSym only creates the symbol with name and default
540 // attributes.
541 // GV's or GVSym's attributes will be used for the EmittedSym.
542 emitVisibility(EmittedSym, GV->getVisibility(), !GV->isDeclaration());
543
544 if (!GV->hasInitializer()) // External globals require no extra code.
545 return;
546
547 GVSym->redefineIfPossible();
548 if (GVSym->isDefined() || GVSym->isVariable())
549 OutContext.reportError(SMLoc(), "symbol '" + Twine(GVSym->getName()) +
550 "' is already defined");
551
552 if (MAI->hasDotTypeDotSizeDirective())
553 OutStreamer->emitSymbolAttribute(EmittedSym, MCSA_ELF_TypeObject);
554
555 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
556
557 const DataLayout &DL = GV->getParent()->getDataLayout();
558 uint64_t Size = DL.getTypeAllocSize(GV->getValueType());
559
560 // If the alignment is specified, we *must* obey it. Overaligning a global
561 // with a specified alignment is a prompt way to break globals emitted to
562 // sections and expected to be contiguous (e.g. ObjC metadata).
563 const Align Alignment = getGVAlignment(GV, DL);
564
565 for (const HandlerInfo &HI : Handlers) {
566 NamedRegionTimer T(HI.TimerName, HI.TimerDescription,
567 HI.TimerGroupName, HI.TimerGroupDescription,
568 TimePassesIsEnabled);
569 HI.Handler->setSymbolSize(GVSym, Size);
570 }
571
572 // Handle common symbols
573 if (GVKind.isCommon()) {
574 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
575 // .comm _foo, 42, 4
576 const bool SupportsAlignment =
577 getObjFileLowering().getCommDirectiveSupportsAlignment();
578 OutStreamer->emitCommonSymbol(GVSym, Size,
579 SupportsAlignment ? Alignment.value() : 0);
580 return;
581 }
582
583 // Determine to which section this global should be emitted.
584 MCSection *TheSection = getObjFileLowering().SectionForGlobal(GV, GVKind, TM);
585
586 // If we have a bss global going to a section that supports the
587 // zerofill directive, do so here.
588 if (GVKind.isBSS() && MAI->hasMachoZeroFillDirective() &&
589 TheSection->isVirtualSection()) {
590 if (Size == 0)
591 Size = 1; // zerofill of 0 bytes is undefined.
592 emitLinkage(GV, GVSym);
593 // .zerofill __DATA, __bss, _foo, 400, 5
594 OutStreamer->emitZerofill(TheSection, GVSym, Size, Alignment.value());
595 return;
596 }
597
598 // If this is a BSS local symbol and we are emitting in the BSS
599 // section use .lcomm/.comm directive.
600 if (GVKind.isBSSLocal() &&
601 getObjFileLowering().getBSSSection() == TheSection) {
602 if (Size == 0)
603 Size = 1; // .comm Foo, 0 is undefined, avoid it.
604
605 // Use .lcomm only if it supports user-specified alignment.
606 // Otherwise, while it would still be correct to use .lcomm in some
607 // cases (e.g. when Align == 1), the external assembler might enfore
608 // some -unknown- default alignment behavior, which could cause
609 // spurious differences between external and integrated assembler.
610 // Prefer to simply fall back to .local / .comm in this case.
611 if (MAI->getLCOMMDirectiveAlignmentType() != LCOMM::NoAlignment) {
612 // .lcomm _foo, 42
613 OutStreamer->emitLocalCommonSymbol(GVSym, Size, Alignment.value());
614 return;
615 }
616
617 // .local _foo
618 OutStreamer->emitSymbolAttribute(GVSym, MCSA_Local);
619 // .comm _foo, 42, 4
620 const bool SupportsAlignment =
621 getObjFileLowering().getCommDirectiveSupportsAlignment();
622 OutStreamer->emitCommonSymbol(GVSym, Size,
623 SupportsAlignment ? Alignment.value() : 0);
624 return;
625 }
626
627 // Handle thread local data for mach-o which requires us to output an
628 // additional structure of data and mangle the original symbol so that we
629 // can reference it later.
630 //
631 // TODO: This should become an "emit thread local global" method on TLOF.
632 // All of this macho specific stuff should be sunk down into TLOFMachO and
633 // stuff like "TLSExtraDataSection" should no longer be part of the parent
634 // TLOF class. This will also make it more obvious that stuff like
635 // MCStreamer::EmitTBSSSymbol is macho specific and only called from macho
636 // specific code.
637 if (GVKind.isThreadLocal() && MAI->hasMachoTBSSDirective()) {
638 // Emit the .tbss symbol
639 MCSymbol *MangSym =
640 OutContext.getOrCreateSymbol(GVSym->getName() + Twine("$tlv$init"));
641
642 if (GVKind.isThreadBSS()) {
643 TheSection = getObjFileLowering().getTLSBSSSection();
644 OutStreamer->emitTBSSSymbol(TheSection, MangSym, Size, Alignment.value());
645 } else if (GVKind.isThreadData()) {
646 OutStreamer->SwitchSection(TheSection);
647
648 emitAlignment(Alignment, GV);
649 OutStreamer->emitLabel(MangSym);
650
651 emitGlobalConstant(GV->getParent()->getDataLayout(),
652 GV->getInitializer());
653 }
654
655 OutStreamer->AddBlankLine();
656
657 // Emit the variable struct for the runtime.
658 MCSection *TLVSect = getObjFileLowering().getTLSExtraDataSection();
659
660 OutStreamer->SwitchSection(TLVSect);
661 // Emit the linkage here.
662 emitLinkage(GV, GVSym);
663 OutStreamer->emitLabel(GVSym);
664
665 // Three pointers in size:
666 // - __tlv_bootstrap - used to make sure support exists
667 // - spare pointer, used when mapped by the runtime
668 // - pointer to mangled symbol above with initializer
669 unsigned PtrSize = DL.getPointerTypeSize(GV->getType());
670 OutStreamer->emitSymbolValue(GetExternalSymbolSymbol("_tlv_bootstrap"),
671 PtrSize);
672 OutStreamer->emitIntValue(0, PtrSize);
673 OutStreamer->emitSymbolValue(MangSym, PtrSize);
674
675 OutStreamer->AddBlankLine();
676 return;
677 }
678
679 MCSymbol *EmittedInitSym = GVSym;
680
681 OutStreamer->SwitchSection(TheSection);
682
683 emitLinkage(GV, EmittedInitSym);
684 emitAlignment(Alignment, GV);
685
686 OutStreamer->emitLabel(EmittedInitSym);
687 MCSymbol *LocalAlias = getSymbolPreferLocal(*GV);
688 if (LocalAlias != EmittedInitSym)
689 OutStreamer->emitLabel(LocalAlias);
690
691 emitGlobalConstant(GV->getParent()->getDataLayout(), GV->getInitializer());
692
693 if (MAI->hasDotTypeDotSizeDirective())
694 // .size foo, 42
695 OutStreamer->emitELFSize(EmittedInitSym,
696 MCConstantExpr::create(Size, OutContext));
697
698 OutStreamer->AddBlankLine();
699}
700
701/// Emit the directive and value for debug thread local expression
702///
703/// \p Value - The value to emit.
704/// \p Size - The size of the integer (in bytes) to emit.
705void AsmPrinter::emitDebugValue(const MCExpr *Value, unsigned Size) const {
706 OutStreamer->emitValue(Value, Size);
707}
708
709void AsmPrinter::emitFunctionHeaderComment() {}
710
711/// EmitFunctionHeader - This method emits the header for the current
712/// function.
713void AsmPrinter::emitFunctionHeader() {
714 const Function &F = MF->getFunction();
715
716 if (isVerbose())
717 OutStreamer->GetCommentOS()
718 << "-- Begin function "
719 << GlobalValue::dropLLVMManglingEscape(F.getName()) << '\n';
720
721 // Print out constants referenced by the function
722 emitConstantPool();
723
724 // Print the 'header' of function.
725 // If basic block sections are desired, explicitly request a unique section
726 // for this function's entry block.
727 if (MF->front().isBeginSection())
728 MF->setSection(getObjFileLowering().getUniqueSectionForFunction(F, TM));
729 else
730 MF->setSection(getObjFileLowering().SectionForGlobal(&F, TM));
731 OutStreamer->SwitchSection(MF->getSection());
732
733 if (!MAI->hasVisibilityOnlyWithLinkage())
734 emitVisibility(CurrentFnSym, F.getVisibility());
735
736 if (MAI->needsFunctionDescriptors())
737 emitLinkage(&F, CurrentFnDescSym);
738
739 emitLinkage(&F, CurrentFnSym);
740 if (MAI->hasFunctionAlignment())
741 emitAlignment(MF->getAlignment(), &F);
742
743 if (MAI->hasDotTypeDotSizeDirective())
744 OutStreamer->emitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
745
746 if (F.hasFnAttribute(Attribute::Cold))
747 OutStreamer->emitSymbolAttribute(CurrentFnSym, MCSA_Cold);
748
749 if (isVerbose()) {
750 F.printAsOperand(OutStreamer->GetCommentOS(),
751 /*PrintType=*/false, F.getParent());
752 emitFunctionHeaderComment();
753 OutStreamer->GetCommentOS() << '\n';
754 }
755
756 // Emit the prefix data.
757 if (F.hasPrefixData()) {
758 if (MAI->hasSubsectionsViaSymbols()) {
759 // Preserving prefix data on platforms which use subsections-via-symbols
760 // is a bit tricky. Here we introduce a symbol for the prefix data
761 // and use the .alt_entry attribute to mark the function's real entry point
762 // as an alternative entry point to the prefix-data symbol.
763 MCSymbol *PrefixSym = OutContext.createLinkerPrivateTempSymbol();
764 OutStreamer->emitLabel(PrefixSym);
765
766 emitGlobalConstant(F.getParent()->getDataLayout(), F.getPrefixData());
767
768 // Emit an .alt_entry directive for the actual function symbol.
769 OutStreamer->emitSymbolAttribute(CurrentFnSym, MCSA_AltEntry);
770 } else {
771 emitGlobalConstant(F.getParent()->getDataLayout(), F.getPrefixData());
772 }
773 }
774
775 // Emit M NOPs for -fpatchable-function-entry=N,M where M>0. We arbitrarily
776 // place prefix data before NOPs.
777 unsigned PatchableFunctionPrefix = 0;
778 unsigned PatchableFunctionEntry = 0;
779 (void)F.getFnAttribute("patchable-function-prefix")
780 .getValueAsString()
781 .getAsInteger(10, PatchableFunctionPrefix);
782 (void)F.getFnAttribute("patchable-function-entry")
783 .getValueAsString()
784 .getAsInteger(10, PatchableFunctionEntry);
785 if (PatchableFunctionPrefix) {
786 CurrentPatchableFunctionEntrySym =
787 OutContext.createLinkerPrivateTempSymbol();
788 OutStreamer->emitLabel(CurrentPatchableFunctionEntrySym);
789 emitNops(PatchableFunctionPrefix);
790 } else if (PatchableFunctionEntry) {
791 // May be reassigned when emitting the body, to reference the label after
792 // the initial BTI (AArch64) or endbr32/endbr64 (x86).
793 CurrentPatchableFunctionEntrySym = CurrentFnBegin;
794 }
795
796 // Emit the function descriptor. This is a virtual function to allow targets
797 // to emit their specific function descriptor. Right now it is only used by
798 // the AIX target. The PowerPC 64-bit V1 ELF target also uses function
799 // descriptors and should be converted to use this hook as well.
800 if (MAI->needsFunctionDescriptors())
801 emitFunctionDescriptor();
802
803 // Emit the CurrentFnSym. This is a virtual function to allow targets to do
804 // their wild and crazy things as required.
805 emitFunctionEntryLabel();
806
807 // If the function had address-taken blocks that got deleted, then we have
808 // references to the dangling symbols. Emit them at the start of the function
809 // so that we don't get references to undefined symbols.
810 std::vector<MCSymbol*> DeadBlockSyms;
811 MMI->takeDeletedSymbolsForFunction(&F, DeadBlockSyms);
812 for (MCSymbol *DeadBlockSym : DeadBlockSyms) {
813 OutStreamer->AddComment("Address taken block that was later removed");
814 OutStreamer->emitLabel(DeadBlockSym);
815 }
816
817 if (CurrentFnBegin) {
818 if (MAI->useAssignmentForEHBegin()) {
819 MCSymbol *CurPos = OutContext.createTempSymbol();
820 OutStreamer->emitLabel(CurPos);
821 OutStreamer->emitAssignment(CurrentFnBegin,
822 MCSymbolRefExpr::create(CurPos, OutContext));
823 } else {
824 OutStreamer->emitLabel(CurrentFnBegin);
825 }
826 }
827
828 // Emit pre-function debug and/or EH information.
829 for (const HandlerInfo &HI : Handlers) {
830 NamedRegionTimer T(HI.TimerName, HI.TimerDescription, HI.TimerGroupName,
831 HI.TimerGroupDescription, TimePassesIsEnabled);
832 HI.Handler->beginFunction(MF);
833 }
834
835 // Emit the prologue data.
836 if (F.hasPrologueData())
837 emitGlobalConstant(F.getParent()->getDataLayout(), F.getPrologueData());
838}
839
840/// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
841/// function. This can be overridden by targets as required to do custom stuff.
842void AsmPrinter::emitFunctionEntryLabel() {
843 CurrentFnSym->redefineIfPossible();
844
845 // The function label could have already been emitted if two symbols end up
846 // conflicting due to asm renaming. Detect this and emit an error.
847 if (CurrentFnSym->isVariable())
848 report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
849 "' is a protected alias");
850
851 OutStreamer->emitLabel(CurrentFnSym);
852
853 if (TM.getTargetTriple().isOSBinFormatELF()) {
854 MCSymbol *Sym = getSymbolPreferLocal(MF->getFunction());
855 if (Sym != CurrentFnSym)
856 OutStreamer->emitLabel(Sym);
857 }
858}
859
860/// emitComments - Pretty-print comments for instructions.
861static void emitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
862 const MachineFunction *MF = MI.getMF();
863 const TargetInstrInfo *TII = MF->getSubtarget().getInstrInfo();
864
865 // Check for spills and reloads
866
867 // We assume a single instruction only has a spill or reload, not
868 // both.
869 Optional<unsigned> Size;
870 if ((Size = MI.getRestoreSize(TII))) {
871 CommentOS << *Size << "-byte Reload\n";
872 } else if ((Size = MI.getFoldedRestoreSize(TII))) {
873 if (*Size) {
874 if (*Size == unsigned(MemoryLocation::UnknownSize))
875 CommentOS << "Unknown-size Folded Reload\n";
876 else
877 CommentOS << *Size << "-byte Folded Reload\n";
878 }
879 } else if ((Size = MI.getSpillSize(TII))) {
880 CommentOS << *Size << "-byte Spill\n";
881 } else if ((Size = MI.getFoldedSpillSize(TII))) {
882 if (*Size) {
883 if (*Size == unsigned(MemoryLocation::UnknownSize))
884 CommentOS << "Unknown-size Folded Spill\n";
885 else
886 CommentOS << *Size << "-byte Folded Spill\n";
887 }
888 }
889
890 // Check for spill-induced copies
891 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
892 CommentOS << " Reload Reuse\n";
893}
894
895/// emitImplicitDef - This method emits the specified machine instruction
896/// that is an implicit def.
897void AsmPrinter::emitImplicitDef(const MachineInstr *MI) const {
898 Register RegNo = MI->getOperand(0).getReg();
899
900 SmallString<128> Str;
901 raw_svector_ostream OS(Str);
902 OS << "implicit-def: "
903 << printReg(RegNo, MF->getSubtarget().getRegisterInfo());
904
905 OutStreamer->AddComment(OS.str());
906 OutStreamer->AddBlankLine();
907}
908
909static void emitKill(const MachineInstr *MI, AsmPrinter &AP) {
910 std::string Str;
911 raw_string_ostream OS(Str);
912 OS << "kill:";
913 for (const MachineOperand &Op : MI->operands()) {
914 assert(Op.isReg() && "KILL instruction must have only register operands")(static_cast <bool> (Op.isReg() && "KILL instruction must have only register operands"
) ? void (0) : __assert_fail ("Op.isReg() && \"KILL instruction must have only register operands\""
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 914, __extension__
__PRETTY_FUNCTION__))
;
915 OS << ' ' << (Op.isDef() ? "def " : "killed ")
916 << printReg(Op.getReg(), AP.MF->getSubtarget().getRegisterInfo());
917 }
918 AP.OutStreamer->AddComment(OS.str());
919 AP.OutStreamer->AddBlankLine();
920}
921
922/// emitDebugValueComment - This method handles the target-independent form
923/// of DBG_VALUE, returning true if it was able to do so. A false return
924/// means the target will need to handle MI in EmitInstruction.
925static bool emitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) {
926 // This code handles only the 4-operand target-independent form.
927 if (MI->isNonListDebugValue() && MI->getNumOperands() != 4)
928 return false;
929
930 SmallString<128> Str;
931 raw_svector_ostream OS(Str);
932 OS << "DEBUG_VALUE: ";
933
934 const DILocalVariable *V = MI->getDebugVariable();
935 if (auto *SP = dyn_cast<DISubprogram>(V->getScope())) {
936 StringRef Name = SP->getName();
937 if (!Name.empty())
938 OS << Name << ":";
939 }
940 OS << V->getName();
941 OS << " <- ";
942
943 const DIExpression *Expr = MI->getDebugExpression();
944 if (Expr->getNumElements()) {
945 OS << '[';
946 ListSeparator LS;
947 for (auto Op : Expr->expr_ops()) {
948 OS << LS << dwarf::OperationEncodingString(Op.getOp());
949 for (unsigned I = 0; I < Op.getNumArgs(); ++I)
950 OS << ' ' << Op.getArg(I);
951 }
952 OS << "] ";
953 }
954
955 // Register or immediate value. Register 0 means undef.
956 for (const MachineOperand &Op : MI->debug_operands()) {
957 if (&Op != MI->debug_operands().begin())
958 OS << ", ";
959 switch (Op.getType()) {
960 case MachineOperand::MO_FPImmediate: {
961 APFloat APF = APFloat(Op.getFPImm()->getValueAPF());
962 Type *ImmTy = Op.getFPImm()->getType();
963 if (ImmTy->isBFloatTy() || ImmTy->isHalfTy() || ImmTy->isFloatTy() ||
964 ImmTy->isDoubleTy()) {
965 OS << APF.convertToDouble();
966 } else {
967 // There is no good way to print long double. Convert a copy to
968 // double. Ah well, it's only a comment.
969 bool ignored;
970 APF.convert(APFloat::IEEEdouble(), APFloat::rmNearestTiesToEven,
971 &ignored);
972 OS << "(long double) " << APF.convertToDouble();
973 }
974 break;
975 }
976 case MachineOperand::MO_Immediate: {
977 OS << Op.getImm();
978 break;
979 }
980 case MachineOperand::MO_CImmediate: {
981 Op.getCImm()->getValue().print(OS, false /*isSigned*/);
982 break;
983 }
984 case MachineOperand::MO_TargetIndex: {
985 OS << "!target-index(" << Op.getIndex() << "," << Op.getOffset() << ")";
986 // NOTE: Want this comment at start of line, don't emit with AddComment.
987 AP.OutStreamer->emitRawComment(OS.str());
988 break;
989 }
990 case MachineOperand::MO_Register:
991 case MachineOperand::MO_FrameIndex: {
992 Register Reg;
993 Optional<StackOffset> Offset;
994 if (Op.isReg()) {
995 Reg = Op.getReg();
996 } else {
997 const TargetFrameLowering *TFI =
998 AP.MF->getSubtarget().getFrameLowering();
999 Offset = TFI->getFrameIndexReference(*AP.MF, Op.getIndex(), Reg);
1000 }
1001 if (!Reg) {
1002 // Suppress offset, it is not meaningful here.
1003 OS << "undef";
1004 break;
1005 }
1006 // The second operand is only an offset if it's an immediate.
1007 if (MI->isIndirectDebugValue())
1008 Offset = StackOffset::getFixed(MI->getDebugOffset().getImm());
1009 if (Offset)
1010 OS << '[';
1011 OS << printReg(Reg, AP.MF->getSubtarget().getRegisterInfo());
1012 if (Offset)
1013 OS << '+' << Offset->getFixed() << ']';
1014 break;
1015 }
1016 default:
1017 llvm_unreachable("Unknown operand type")::llvm::llvm_unreachable_internal("Unknown operand type", "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 1017)
;
1018 }
1019 }
1020
1021 // NOTE: Want this comment at start of line, don't emit with AddComment.
1022 AP.OutStreamer->emitRawComment(OS.str());
1023 return true;
1024}
1025
1026/// This method handles the target-independent form of DBG_LABEL, returning
1027/// true if it was able to do so. A false return means the target will need
1028/// to handle MI in EmitInstruction.
1029static bool emitDebugLabelComment(const MachineInstr *MI, AsmPrinter &AP) {
1030 if (MI->getNumOperands() != 1)
1031 return false;
1032
1033 SmallString<128> Str;
1034 raw_svector_ostream OS(Str);
1035 OS << "DEBUG_LABEL: ";
1036
1037 const DILabel *V = MI->getDebugLabel();
1038 if (auto *SP = dyn_cast<DISubprogram>(
1039 V->getScope()->getNonLexicalBlockFileScope())) {
1040 StringRef Name = SP->getName();
1041 if (!Name.empty())
1042 OS << Name << ":";
1043 }
1044 OS << V->getName();
1045
1046 // NOTE: Want this comment at start of line, don't emit with AddComment.
1047 AP.OutStreamer->emitRawComment(OS.str());
1048 return true;
1049}
1050
1051AsmPrinter::CFISection
1052AsmPrinter::getFunctionCFISectionType(const Function &F) const {
1053 // Ignore functions that won't get emitted.
1054 if (F.isDeclarationForLinker())
1055 return CFISection::None;
1056
1057 if (MAI->getExceptionHandlingType() == ExceptionHandling::DwarfCFI &&
1058 F.needsUnwindTableEntry())
1059 return CFISection::EH;
1060
1061 if (MMI->hasDebugInfo() || TM.Options.ForceDwarfFrameSection)
1062 return CFISection::Debug;
1063
1064 return CFISection::None;
1065}
1066
1067AsmPrinter::CFISection
1068AsmPrinter::getFunctionCFISectionType(const MachineFunction &MF) const {
1069 return getFunctionCFISectionType(MF.getFunction());
1070}
1071
1072bool AsmPrinter::needsSEHMoves() {
1073 return MAI->usesWindowsCFI() && MF->getFunction().needsUnwindTableEntry();
1074}
1075
1076bool AsmPrinter::needsCFIForDebug() const {
1077 return MAI->getExceptionHandlingType() == ExceptionHandling::None &&
1078 MAI->doesUseCFIForDebug() && ModuleCFISection == CFISection::Debug;
1079}
1080
1081void AsmPrinter::emitCFIInstruction(const MachineInstr &MI) {
1082 ExceptionHandling ExceptionHandlingType = MAI->getExceptionHandlingType();
1083 if (!needsCFIForDebug() &&
1084 ExceptionHandlingType != ExceptionHandling::DwarfCFI &&
1085 ExceptionHandlingType != ExceptionHandling::ARM)
1086 return;
1087
1088 if (getFunctionCFISectionType(*MF) == CFISection::None)
1089 return;
1090
1091 // If there is no "real" instruction following this CFI instruction, skip
1092 // emitting it; it would be beyond the end of the function's FDE range.
1093 auto *MBB = MI.getParent();
1094 auto I = std::next(MI.getIterator());
1095 while (I != MBB->end() && I->isTransient())
1096 ++I;
1097 if (I == MBB->instr_end() &&
1098 MBB->getReverseIterator() == MBB->getParent()->rbegin())
1099 return;
1100
1101 const std::vector<MCCFIInstruction> &Instrs = MF->getFrameInstructions();
1102 unsigned CFIIndex = MI.getOperand(0).getCFIIndex();
1103 const MCCFIInstruction &CFI = Instrs[CFIIndex];
1104 emitCFIInstruction(CFI);
1105}
1106
1107void AsmPrinter::emitFrameAlloc(const MachineInstr &MI) {
1108 // The operands are the MCSymbol and the frame offset of the allocation.
1109 MCSymbol *FrameAllocSym = MI.getOperand(0).getMCSymbol();
1110 int FrameOffset = MI.getOperand(1).getImm();
1111
1112 // Emit a symbol assignment.
1113 OutStreamer->emitAssignment(FrameAllocSym,
1114 MCConstantExpr::create(FrameOffset, OutContext));
1115}
1116
1117/// Returns the BB metadata to be emitted in the .llvm_bb_addr_map section for a
1118/// given basic block. This can be used to capture more precise profile
1119/// information. We use the last 4 bits (LSBs) to encode the following
1120/// information:
1121/// * (1): set if return block (ret or tail call).
1122/// * (2): set if ends with a tail call.
1123/// * (3): set if exception handling (EH) landing pad.
1124/// * (4): set if the block can fall through to its next.
1125/// The remaining bits are zero.
1126static unsigned getBBAddrMapMetadata(const MachineBasicBlock &MBB) {
1127 const TargetInstrInfo *TII = MBB.getParent()->getSubtarget().getInstrInfo();
1128 return ((unsigned)MBB.isReturnBlock()) |
1129 ((!MBB.empty() && TII->isTailCall(MBB.back())) << 1) |
1130 (MBB.isEHPad() << 2) |
1131 (const_cast<MachineBasicBlock &>(MBB).canFallThrough() << 3);
1132}
1133
1134void AsmPrinter::emitBBAddrMapSection(const MachineFunction &MF) {
1135 MCSection *BBAddrMapSection =
1136 getObjFileLowering().getBBAddrMapSection(*MF.getSection());
1137 assert(BBAddrMapSection && ".llvm_bb_addr_map section is not initialized.")(static_cast <bool> (BBAddrMapSection && ".llvm_bb_addr_map section is not initialized."
) ? void (0) : __assert_fail ("BBAddrMapSection && \".llvm_bb_addr_map section is not initialized.\""
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 1137, __extension__
__PRETTY_FUNCTION__))
;
1138
1139 const MCSymbol *FunctionSymbol = getFunctionBegin();
1140
1141 OutStreamer->PushSection();
1142 OutStreamer->SwitchSection(BBAddrMapSection);
1143 OutStreamer->emitSymbolValue(FunctionSymbol, getPointerSize());
1144 // Emit the total number of basic blocks in this function.
1145 OutStreamer->emitULEB128IntValue(MF.size());
1146 // Emit BB Information for each basic block in the funciton.
1147 for (const MachineBasicBlock &MBB : MF) {
1148 const MCSymbol *MBBSymbol =
1149 MBB.isEntryBlock() ? FunctionSymbol : MBB.getSymbol();
1150 // Emit the basic block offset.
1151 emitLabelDifferenceAsULEB128(MBBSymbol, FunctionSymbol);
1152 // Emit the basic block size. When BBs have alignments, their size cannot
1153 // always be computed from their offsets.
1154 emitLabelDifferenceAsULEB128(MBB.getEndSymbol(), MBBSymbol);
1155 OutStreamer->emitULEB128IntValue(getBBAddrMapMetadata(MBB));
1156 }
1157 OutStreamer->PopSection();
1158}
1159
1160void AsmPrinter::emitPseudoProbe(const MachineInstr &MI) {
1161 if (PP) {
1162 auto GUID = MI.getOperand(0).getImm();
1163 auto Index = MI.getOperand(1).getImm();
1164 auto Type = MI.getOperand(2).getImm();
1165 auto Attr = MI.getOperand(3).getImm();
1166 DILocation *DebugLoc = MI.getDebugLoc();
1167 PP->emitPseudoProbe(GUID, Index, Type, Attr, DebugLoc);
1168 }
1169}
1170
1171void AsmPrinter::emitStackSizeSection(const MachineFunction &MF) {
1172 if (!MF.getTarget().Options.EmitStackSizeSection)
1173 return;
1174
1175 MCSection *StackSizeSection =
1176 getObjFileLowering().getStackSizesSection(*getCurrentSection());
1177 if (!StackSizeSection)
1178 return;
1179
1180 const MachineFrameInfo &FrameInfo = MF.getFrameInfo();
1181 // Don't emit functions with dynamic stack allocations.
1182 if (FrameInfo.hasVarSizedObjects())
1183 return;
1184
1185 OutStreamer->PushSection();
1186 OutStreamer->SwitchSection(StackSizeSection);
1187
1188 const MCSymbol *FunctionSymbol = getFunctionBegin();
1189 uint64_t StackSize = FrameInfo.getStackSize();
1190 OutStreamer->emitSymbolValue(FunctionSymbol, TM.getProgramPointerSize());
1191 OutStreamer->emitULEB128IntValue(StackSize);
1192
1193 OutStreamer->PopSection();
1194}
1195
1196void AsmPrinter::emitStackUsage(const MachineFunction &MF) {
1197 const std::string &OutputFilename = MF.getTarget().Options.StackUsageOutput;
1198
1199 // OutputFilename empty implies -fstack-usage is not passed.
1200 if (OutputFilename.empty())
1201 return;
1202
1203 const MachineFrameInfo &FrameInfo = MF.getFrameInfo();
1204 uint64_t StackSize = FrameInfo.getStackSize();
1205
1206 if (StackUsageStream == nullptr) {
1207 std::error_code EC;
1208 StackUsageStream =
1209 std::make_unique<raw_fd_ostream>(OutputFilename, EC, sys::fs::OF_Text);
1210 if (EC) {
1211 errs() << "Could not open file: " << EC.message();
1212 return;
1213 }
1214 }
1215
1216 *StackUsageStream << MF.getFunction().getParent()->getName();
1217 if (const DISubprogram *DSP = MF.getFunction().getSubprogram())
1218 *StackUsageStream << ':' << DSP->getLine();
1219
1220 *StackUsageStream << ':' << MF.getName() << '\t' << StackSize << '\t';
1221 if (FrameInfo.hasVarSizedObjects())
1222 *StackUsageStream << "dynamic\n";
1223 else
1224 *StackUsageStream << "static\n";
1225}
1226
1227static bool needFuncLabelsForEHOrDebugInfo(const MachineFunction &MF) {
1228 MachineModuleInfo &MMI = MF.getMMI();
1229 if (!MF.getLandingPads().empty() || MF.hasEHFunclets() || MMI.hasDebugInfo())
1230 return true;
1231
1232 // We might emit an EH table that uses function begin and end labels even if
1233 // we don't have any landingpads.
1234 if (!MF.getFunction().hasPersonalityFn())
1235 return false;
1236 return !isNoOpWithoutInvoke(
1237 classifyEHPersonality(MF.getFunction().getPersonalityFn()));
1238}
1239
1240/// EmitFunctionBody - This method emits the body and trailer for a
1241/// function.
1242void AsmPrinter::emitFunctionBody() {
1243 emitFunctionHeader();
1244
1245 // Emit target-specific gunk before the function body.
1246 emitFunctionBodyStart();
1247
1248 if (isVerbose()) {
1249 // Get MachineDominatorTree or compute it on the fly if it's unavailable
1250 MDT = getAnalysisIfAvailable<MachineDominatorTree>();
1251 if (!MDT) {
1252 OwnedMDT = std::make_unique<MachineDominatorTree>();
1253 OwnedMDT->getBase().recalculate(*MF);
1254 MDT = OwnedMDT.get();
1255 }
1256
1257 // Get MachineLoopInfo or compute it on the fly if it's unavailable
1258 MLI = getAnalysisIfAvailable<MachineLoopInfo>();
1259 if (!MLI) {
1260 OwnedMLI = std::make_unique<MachineLoopInfo>();
1261 OwnedMLI->getBase().analyze(MDT->getBase());
1262 MLI = OwnedMLI.get();
1263 }
1264 }
1265
1266 // Print out code for the function.
1267 bool HasAnyRealCode = false;
1268 int NumInstsInFunction = 0;
1269
1270 bool CanDoExtraAnalysis = ORE->allowExtraAnalysis(DEBUG_TYPE"asm-printer");
1271 for (auto &MBB : *MF) {
1272 // Print a label for the basic block.
1273 emitBasicBlockStart(MBB);
1274 DenseMap<StringRef, unsigned> MnemonicCounts;
1275 for (auto &MI : MBB) {
1276 // Print the assembly for the instruction.
1277 if (!MI.isPosition() && !MI.isImplicitDef() && !MI.isKill() &&
1278 !MI.isDebugInstr()) {
1279 HasAnyRealCode = true;
1280 ++NumInstsInFunction;
1281 }
1282
1283 // If there is a pre-instruction symbol, emit a label for it here.
1284 if (MCSymbol *S = MI.getPreInstrSymbol())
1285 OutStreamer->emitLabel(S);
1286
1287 for (const HandlerInfo &HI : Handlers) {
1288 NamedRegionTimer T(HI.TimerName, HI.TimerDescription, HI.TimerGroupName,
1289 HI.TimerGroupDescription, TimePassesIsEnabled);
1290 HI.Handler->beginInstruction(&MI);
1291 }
1292
1293 if (isVerbose())
1294 emitComments(MI, OutStreamer->GetCommentOS());
1295
1296 switch (MI.getOpcode()) {
1297 case TargetOpcode::CFI_INSTRUCTION:
1298 emitCFIInstruction(MI);
1299 break;
1300 case TargetOpcode::LOCAL_ESCAPE:
1301 emitFrameAlloc(MI);
1302 break;
1303 case TargetOpcode::ANNOTATION_LABEL:
1304 case TargetOpcode::EH_LABEL:
1305 case TargetOpcode::GC_LABEL:
1306 OutStreamer->emitLabel(MI.getOperand(0).getMCSymbol());
1307 break;
1308 case TargetOpcode::INLINEASM:
1309 case TargetOpcode::INLINEASM_BR:
1310 emitInlineAsm(&MI);
1311 break;
1312 case TargetOpcode::DBG_VALUE:
1313 case TargetOpcode::DBG_VALUE_LIST:
1314 if (isVerbose()) {
1315 if (!emitDebugValueComment(&MI, *this))
1316 emitInstruction(&MI);
1317 }
1318 break;
1319 case TargetOpcode::DBG_INSTR_REF:
1320 // This instruction reference will have been resolved to a machine
1321 // location, and a nearby DBG_VALUE created. We can safely ignore
1322 // the instruction reference.
1323 break;
1324 case TargetOpcode::DBG_PHI:
1325 // This instruction is only used to label a program point, it's purely
1326 // meta information.
1327 break;
1328 case TargetOpcode::DBG_LABEL:
1329 if (isVerbose()) {
1330 if (!emitDebugLabelComment(&MI, *this))
1331 emitInstruction(&MI);
1332 }
1333 break;
1334 case TargetOpcode::IMPLICIT_DEF:
1335 if (isVerbose()) emitImplicitDef(&MI);
1336 break;
1337 case TargetOpcode::KILL:
1338 if (isVerbose()) emitKill(&MI, *this);
1339 break;
1340 case TargetOpcode::PSEUDO_PROBE:
1341 emitPseudoProbe(MI);
1342 break;
1343 case TargetOpcode::ARITH_FENCE:
1344 if (isVerbose())
1345 OutStreamer->emitRawComment("ARITH_FENCE");
1346 break;
1347 default:
1348 emitInstruction(&MI);
1349 if (CanDoExtraAnalysis) {
1350 MCInst MCI;
1351 MCI.setOpcode(MI.getOpcode());
1352 auto Name = OutStreamer->getMnemonic(MCI);
1353 auto I = MnemonicCounts.insert({Name, 0u});
1354 I.first->second++;
1355 }
1356 break;
1357 }
1358
1359 // If there is a post-instruction symbol, emit a label for it here.
1360 if (MCSymbol *S = MI.getPostInstrSymbol())
1361 OutStreamer->emitLabel(S);
1362
1363 for (const HandlerInfo &HI : Handlers) {
1364 NamedRegionTimer T(HI.TimerName, HI.TimerDescription, HI.TimerGroupName,
1365 HI.TimerGroupDescription, TimePassesIsEnabled);
1366 HI.Handler->endInstruction();
1367 }
1368 }
1369
1370 // We must emit temporary symbol for the end of this basic block, if either
1371 // we have BBLabels enabled or if this basic blocks marks the end of a
1372 // section.
1373 if (MF->hasBBLabels() ||
1374 (MAI->hasDotTypeDotSizeDirective() && MBB.isEndSection()))
1375 OutStreamer->emitLabel(MBB.getEndSymbol());
1376
1377 if (MBB.isEndSection()) {
1378 // The size directive for the section containing the entry block is
1379 // handled separately by the function section.
1380 if (!MBB.sameSection(&MF->front())) {
1381 if (MAI->hasDotTypeDotSizeDirective()) {
1382 // Emit the size directive for the basic block section.
1383 const MCExpr *SizeExp = MCBinaryExpr::createSub(
1384 MCSymbolRefExpr::create(MBB.getEndSymbol(), OutContext),
1385 MCSymbolRefExpr::create(CurrentSectionBeginSym, OutContext),
1386 OutContext);
1387 OutStreamer->emitELFSize(CurrentSectionBeginSym, SizeExp);
1388 }
1389 MBBSectionRanges[MBB.getSectionIDNum()] =
1390 MBBSectionRange{CurrentSectionBeginSym, MBB.getEndSymbol()};
1391 }
1392 }
1393 emitBasicBlockEnd(MBB);
1394
1395 if (CanDoExtraAnalysis) {
1396 // Skip empty blocks.
1397 if (MBB.empty())
1398 continue;
1399
1400 MachineOptimizationRemarkAnalysis R(DEBUG_TYPE"asm-printer", "InstructionMix",
1401 MBB.begin()->getDebugLoc(), &MBB);
1402
1403 // Generate instruction mix remark. First, sort counts in descending order
1404 // by count and name.
1405 SmallVector<std::pair<StringRef, unsigned>, 128> MnemonicVec;
1406 for (auto &KV : MnemonicCounts)
1407 MnemonicVec.emplace_back(KV.first, KV.second);
1408
1409 sort(MnemonicVec, [](const std::pair<StringRef, unsigned> &A,
1410 const std::pair<StringRef, unsigned> &B) {
1411 if (A.second > B.second)
1412 return true;
1413 if (A.second == B.second)
1414 return StringRef(A.first) < StringRef(B.first);
1415 return false;
1416 });
1417 R << "BasicBlock: " << ore::NV("BasicBlock", MBB.getName()) << "\n";
1418 for (auto &KV : MnemonicVec) {
1419 auto Name = (Twine("INST_") + getToken(KV.first.trim()).first).str();
1420 R << KV.first << ": " << ore::NV(Name, KV.second) << "\n";
1421 }
1422 ORE->emit(R);
1423 }
1424 }
1425
1426 EmittedInsts += NumInstsInFunction;
1427 MachineOptimizationRemarkAnalysis R(DEBUG_TYPE"asm-printer", "InstructionCount",
1428 MF->getFunction().getSubprogram(),
1429 &MF->front());
1430 R << ore::NV("NumInstructions", NumInstsInFunction)
1431 << " instructions in function";
1432 ORE->emit(R);
1433
1434 // If the function is empty and the object file uses .subsections_via_symbols,
1435 // then we need to emit *something* to the function body to prevent the
1436 // labels from collapsing together. Just emit a noop.
1437 // Similarly, don't emit empty functions on Windows either. It can lead to
1438 // duplicate entries (two functions with the same RVA) in the Guard CF Table
1439 // after linking, causing the kernel not to load the binary:
1440 // https://developercommunity.visualstudio.com/content/problem/45366/vc-linker-creates-invalid-dll-with-clang-cl.html
1441 // FIXME: Hide this behind some API in e.g. MCAsmInfo or MCTargetStreamer.
1442 const Triple &TT = TM.getTargetTriple();
1443 if (!HasAnyRealCode && (MAI->hasSubsectionsViaSymbols() ||
1444 (TT.isOSWindows() && TT.isOSBinFormatCOFF()))) {
1445 MCInst Noop = MF->getSubtarget().getInstrInfo()->getNop();
1446
1447 // Targets can opt-out of emitting the noop here by leaving the opcode
1448 // unspecified.
1449 if (Noop.getOpcode()) {
1450 OutStreamer->AddComment("avoids zero-length function");
1451 emitNops(1);
1452 }
1453 }
1454
1455 // Switch to the original section in case basic block sections was used.
1456 OutStreamer->SwitchSection(MF->getSection());
1457
1458 const Function &F = MF->getFunction();
1459 for (const auto &BB : F) {
1460 if (!BB.hasAddressTaken())
1461 continue;
1462 MCSymbol *Sym = GetBlockAddressSymbol(&BB);
1463 if (Sym->isDefined())
1464 continue;
1465 OutStreamer->AddComment("Address of block that was removed by CodeGen");
1466 OutStreamer->emitLabel(Sym);
1467 }
1468
1469 // Emit target-specific gunk after the function body.
1470 emitFunctionBodyEnd();
1471
1472 if (needFuncLabelsForEHOrDebugInfo(*MF) ||
1473 MAI->hasDotTypeDotSizeDirective()) {
1474 // Create a symbol for the end of function.
1475 CurrentFnEnd = createTempSymbol("func_end");
1476 OutStreamer->emitLabel(CurrentFnEnd);
1477 }
1478
1479 // If the target wants a .size directive for the size of the function, emit
1480 // it.
1481 if (MAI->hasDotTypeDotSizeDirective()) {
1482 // We can get the size as difference between the function label and the
1483 // temp label.
1484 const MCExpr *SizeExp = MCBinaryExpr::createSub(
1485 MCSymbolRefExpr::create(CurrentFnEnd, OutContext),
1486 MCSymbolRefExpr::create(CurrentFnSymForSize, OutContext), OutContext);
1487 OutStreamer->emitELFSize(CurrentFnSym, SizeExp);
1488 }
1489
1490 for (const HandlerInfo &HI : Handlers) {
1491 NamedRegionTimer T(HI.TimerName, HI.TimerDescription, HI.TimerGroupName,
1492 HI.TimerGroupDescription, TimePassesIsEnabled);
1493 HI.Handler->markFunctionEnd();
1494 }
1495
1496 MBBSectionRanges[MF->front().getSectionIDNum()] =
1497 MBBSectionRange{CurrentFnBegin, CurrentFnEnd};
1498
1499 // Print out jump tables referenced by the function.
1500 emitJumpTableInfo();
1501
1502 // Emit post-function debug and/or EH information.
1503 for (const HandlerInfo &HI : Handlers) {
1504 NamedRegionTimer T(HI.TimerName, HI.TimerDescription, HI.TimerGroupName,
1505 HI.TimerGroupDescription, TimePassesIsEnabled);
1506 HI.Handler->endFunction(MF);
1507 }
1508
1509 // Emit section containing BB address offsets and their metadata, when
1510 // BB labels are requested for this function. Skip empty functions.
1511 if (MF->hasBBLabels() && HasAnyRealCode)
1512 emitBBAddrMapSection(*MF);
1513
1514 // Emit section containing stack size metadata.
1515 emitStackSizeSection(*MF);
1516
1517 // Emit .su file containing function stack size information.
1518 emitStackUsage(*MF);
1519
1520 emitPatchableFunctionEntries();
1521
1522 if (isVerbose())
1523 OutStreamer->GetCommentOS() << "-- End function\n";
1524
1525 OutStreamer->AddBlankLine();
1526}
1527
1528/// Compute the number of Global Variables that uses a Constant.
1529static unsigned getNumGlobalVariableUses(const Constant *C) {
1530 if (!C)
1531 return 0;
1532
1533 if (isa<GlobalVariable>(C))
1534 return 1;
1535
1536 unsigned NumUses = 0;
1537 for (auto *CU : C->users())
1538 NumUses += getNumGlobalVariableUses(dyn_cast<Constant>(CU));
1539
1540 return NumUses;
1541}
1542
1543/// Only consider global GOT equivalents if at least one user is a
1544/// cstexpr inside an initializer of another global variables. Also, don't
1545/// handle cstexpr inside instructions. During global variable emission,
1546/// candidates are skipped and are emitted later in case at least one cstexpr
1547/// isn't replaced by a PC relative GOT entry access.
1548static bool isGOTEquivalentCandidate(const GlobalVariable *GV,
1549 unsigned &NumGOTEquivUsers) {
1550 // Global GOT equivalents are unnamed private globals with a constant
1551 // pointer initializer to another global symbol. They must point to a
1552 // GlobalVariable or Function, i.e., as GlobalValue.
1553 if (!GV->hasGlobalUnnamedAddr() || !GV->hasInitializer() ||
1554 !GV->isConstant() || !GV->isDiscardableIfUnused() ||
1555 !isa<GlobalValue>(GV->getOperand(0)))
1556 return false;
1557
1558 // To be a got equivalent, at least one of its users need to be a constant
1559 // expression used by another global variable.
1560 for (auto *U : GV->users())
1561 NumGOTEquivUsers += getNumGlobalVariableUses(dyn_cast<Constant>(U));
1562
1563 return NumGOTEquivUsers > 0;
1564}
1565
1566/// Unnamed constant global variables solely contaning a pointer to
1567/// another globals variable is equivalent to a GOT table entry; it contains the
1568/// the address of another symbol. Optimize it and replace accesses to these
1569/// "GOT equivalents" by using the GOT entry for the final global instead.
1570/// Compute GOT equivalent candidates among all global variables to avoid
1571/// emitting them if possible later on, after it use is replaced by a GOT entry
1572/// access.
1573void AsmPrinter::computeGlobalGOTEquivs(Module &M) {
1574 if (!getObjFileLowering().supportIndirectSymViaGOTPCRel())
1575 return;
1576
1577 for (const auto &G : M.globals()) {
1578 unsigned NumGOTEquivUsers = 0;
1579 if (!isGOTEquivalentCandidate(&G, NumGOTEquivUsers))
1580 continue;
1581
1582 const MCSymbol *GOTEquivSym = getSymbol(&G);
1583 GlobalGOTEquivs[GOTEquivSym] = std::make_pair(&G, NumGOTEquivUsers);
1584 }
1585}
1586
1587/// Constant expressions using GOT equivalent globals may not be eligible
1588/// for PC relative GOT entry conversion, in such cases we need to emit such
1589/// globals we previously omitted in EmitGlobalVariable.
1590void AsmPrinter::emitGlobalGOTEquivs() {
1591 if (!getObjFileLowering().supportIndirectSymViaGOTPCRel())
1592 return;
1593
1594 SmallVector<const GlobalVariable *, 8> FailedCandidates;
1595 for (auto &I : GlobalGOTEquivs) {
1596 const GlobalVariable *GV = I.second.first;
1597 unsigned Cnt = I.second.second;
1598 if (Cnt)
1599 FailedCandidates.push_back(GV);
1600 }
1601 GlobalGOTEquivs.clear();
1602
1603 for (auto *GV : FailedCandidates)
1604 emitGlobalVariable(GV);
1605}
1606
1607void AsmPrinter::emitGlobalAlias(Module &M, const GlobalAlias &GA) {
1608 MCSymbol *Name = getSymbol(&GA);
1609 bool IsFunction = GA.getValueType()->isFunctionTy();
1610 // Treat bitcasts of functions as functions also. This is important at least
1611 // on WebAssembly where object and function addresses can't alias each other.
1612 if (!IsFunction)
1613 IsFunction = isa<Function>(GA.getAliasee()->stripPointerCasts());
1614
1615 // AIX's assembly directive `.set` is not usable for aliasing purpose,
1616 // so AIX has to use the extra-label-at-definition strategy. At this
1617 // point, all the extra label is emitted, we just have to emit linkage for
1618 // those labels.
1619 if (TM.getTargetTriple().isOSBinFormatXCOFF()) {
1620 assert(MAI->hasVisibilityOnlyWithLinkage() &&(static_cast <bool> (MAI->hasVisibilityOnlyWithLinkage
() && "Visibility should be handled with emitLinkage() on AIX."
) ? void (0) : __assert_fail ("MAI->hasVisibilityOnlyWithLinkage() && \"Visibility should be handled with emitLinkage() on AIX.\""
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 1621, __extension__
__PRETTY_FUNCTION__))
1621 "Visibility should be handled with emitLinkage() on AIX.")(static_cast <bool> (MAI->hasVisibilityOnlyWithLinkage
() && "Visibility should be handled with emitLinkage() on AIX."
) ? void (0) : __assert_fail ("MAI->hasVisibilityOnlyWithLinkage() && \"Visibility should be handled with emitLinkage() on AIX.\""
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 1621, __extension__
__PRETTY_FUNCTION__))
;
1622 emitLinkage(&GA, Name);
1623 // If it's a function, also emit linkage for aliases of function entry
1624 // point.
1625 if (IsFunction)
1626 emitLinkage(&GA,
1627 getObjFileLowering().getFunctionEntryPointSymbol(&GA, TM));
1628 return;
1629 }
1630
1631 if (GA.hasExternalLinkage() || !MAI->getWeakRefDirective())
1632 OutStreamer->emitSymbolAttribute(Name, MCSA_Global);
1633 else if (GA.hasWeakLinkage() || GA.hasLinkOnceLinkage())
1634 OutStreamer->emitSymbolAttribute(Name, MCSA_WeakReference);
1635 else
1636 assert(GA.hasLocalLinkage() && "Invalid alias linkage")(static_cast <bool> (GA.hasLocalLinkage() && "Invalid alias linkage"
) ? void (0) : __assert_fail ("GA.hasLocalLinkage() && \"Invalid alias linkage\""
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 1636, __extension__
__PRETTY_FUNCTION__))
;
1637
1638 // Set the symbol type to function if the alias has a function type.
1639 // This affects codegen when the aliasee is not a function.
1640 if (IsFunction) {
1641 OutStreamer->emitSymbolAttribute(Name, MCSA_ELF_TypeFunction);
1642 if (TM.getTargetTriple().isOSBinFormatCOFF()) {
1643 OutStreamer->BeginCOFFSymbolDef(Name);
1644 OutStreamer->EmitCOFFSymbolStorageClass(
1645 GA.hasLocalLinkage() ? COFF::IMAGE_SYM_CLASS_STATIC
1646 : COFF::IMAGE_SYM_CLASS_EXTERNAL);
1647 OutStreamer->EmitCOFFSymbolType(COFF::IMAGE_SYM_DTYPE_FUNCTION
1648 << COFF::SCT_COMPLEX_TYPE_SHIFT);
1649 OutStreamer->EndCOFFSymbolDef();
1650 }
1651 }
1652
1653 emitVisibility(Name, GA.getVisibility());
1654
1655 const MCExpr *Expr = lowerConstant(GA.getAliasee());
1656
1657 if (MAI->hasAltEntry() && isa<MCBinaryExpr>(Expr))
1658 OutStreamer->emitSymbolAttribute(Name, MCSA_AltEntry);
1659
1660 // Emit the directives as assignments aka .set:
1661 OutStreamer->emitAssignment(Name, Expr);
1662 MCSymbol *LocalAlias = getSymbolPreferLocal(GA);
1663 if (LocalAlias != Name)
1664 OutStreamer->emitAssignment(LocalAlias, Expr);
1665
1666 // If the aliasee does not correspond to a symbol in the output, i.e. the
1667 // alias is not of an object or the aliased object is private, then set the
1668 // size of the alias symbol from the type of the alias. We don't do this in
1669 // other situations as the alias and aliasee having differing types but same
1670 // size may be intentional.
1671 const GlobalObject *BaseObject = GA.getAliaseeObject();
1672 if (MAI->hasDotTypeDotSizeDirective() && GA.getValueType()->isSized() &&
1673 (!BaseObject || BaseObject->hasPrivateLinkage())) {
1674 const DataLayout &DL = M.getDataLayout();
1675 uint64_t Size = DL.getTypeAllocSize(GA.getValueType());
1676 OutStreamer->emitELFSize(Name, MCConstantExpr::create(Size, OutContext));
1677 }
1678}
1679
1680void AsmPrinter::emitGlobalIFunc(Module &M, const GlobalIFunc &GI) {
1681 assert(!TM.getTargetTriple().isOSBinFormatXCOFF() &&(static_cast <bool> (!TM.getTargetTriple().isOSBinFormatXCOFF
() && "IFunc is not supported on AIX.") ? void (0) : __assert_fail
("!TM.getTargetTriple().isOSBinFormatXCOFF() && \"IFunc is not supported on AIX.\""
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 1682, __extension__
__PRETTY_FUNCTION__))
1682 "IFunc is not supported on AIX.")(static_cast <bool> (!TM.getTargetTriple().isOSBinFormatXCOFF
() && "IFunc is not supported on AIX.") ? void (0) : __assert_fail
("!TM.getTargetTriple().isOSBinFormatXCOFF() && \"IFunc is not supported on AIX.\""
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 1682, __extension__
__PRETTY_FUNCTION__))
;
1683
1684 MCSymbol *Name = getSymbol(&GI);
1685
1686 if (GI.hasExternalLinkage() || !MAI->getWeakRefDirective())
1687 OutStreamer->emitSymbolAttribute(Name, MCSA_Global);
1688 else if (GI.hasWeakLinkage() || GI.hasLinkOnceLinkage())
1689 OutStreamer->emitSymbolAttribute(Name, MCSA_WeakReference);
1690 else
1691 assert(GI.hasLocalLinkage() && "Invalid ifunc linkage")(static_cast <bool> (GI.hasLocalLinkage() && "Invalid ifunc linkage"
) ? void (0) : __assert_fail ("GI.hasLocalLinkage() && \"Invalid ifunc linkage\""
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 1691, __extension__
__PRETTY_FUNCTION__))
;
1692
1693 OutStreamer->emitSymbolAttribute(Name, MCSA_ELF_TypeIndFunction);
1694 emitVisibility(Name, GI.getVisibility());
1695
1696 // Emit the directives as assignments aka .set:
1697 const MCExpr *Expr = lowerConstant(GI.getResolver());
1698 OutStreamer->emitAssignment(Name, Expr);
1699 MCSymbol *LocalAlias = getSymbolPreferLocal(GI);
1700 if (LocalAlias != Name)
1701 OutStreamer->emitAssignment(LocalAlias, Expr);
1702}
1703
1704void AsmPrinter::emitRemarksSection(remarks::RemarkStreamer &RS) {
1705 if (!RS.needsSection())
1706 return;
1707
1708 remarks::RemarkSerializer &RemarkSerializer = RS.getSerializer();
1709
1710 Optional<SmallString<128>> Filename;
1711 if (Optional<StringRef> FilenameRef = RS.getFilename()) {
1712 Filename = *FilenameRef;
1713 sys::fs::make_absolute(*Filename);
1714 assert(!Filename->empty() && "The filename can't be empty.")(static_cast <bool> (!Filename->empty() && "The filename can't be empty."
) ? void (0) : __assert_fail ("!Filename->empty() && \"The filename can't be empty.\""
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 1714, __extension__
__PRETTY_FUNCTION__))
;
1715 }
1716
1717 std::string Buf;
1718 raw_string_ostream OS(Buf);
1719 std::unique_ptr<remarks::MetaSerializer> MetaSerializer =
1720 Filename ? RemarkSerializer.metaSerializer(OS, Filename->str())
1721 : RemarkSerializer.metaSerializer(OS);
1722 MetaSerializer->emit();
1723
1724 // Switch to the remarks section.
1725 MCSection *RemarksSection =
1726 OutContext.getObjectFileInfo()->getRemarksSection();
1727 OutStreamer->SwitchSection(RemarksSection);
1728
1729 OutStreamer->emitBinaryData(OS.str());
1730}
1731
1732bool AsmPrinter::doFinalization(Module &M) {
1733 // Set the MachineFunction to nullptr so that we can catch attempted
1734 // accesses to MF specific features at the module level and so that
1735 // we can conditionalize accesses based on whether or not it is nullptr.
1736 MF = nullptr;
1737
1738 // Gather all GOT equivalent globals in the module. We really need two
1739 // passes over the globals: one to compute and another to avoid its emission
1740 // in EmitGlobalVariable, otherwise we would not be able to handle cases
1741 // where the got equivalent shows up before its use.
1742 computeGlobalGOTEquivs(M);
1743
1744 // Emit global variables.
1745 for (const auto &G : M.globals())
1746 emitGlobalVariable(&G);
1747
1748 // Emit remaining GOT equivalent globals.
1749 emitGlobalGOTEquivs();
1750
1751 const TargetLoweringObjectFile &TLOF = getObjFileLowering();
1752
1753 // Emit linkage(XCOFF) and visibility info for declarations
1754 for (const Function &F : M) {
1755 if (!F.isDeclarationForLinker())
1756 continue;
1757
1758 MCSymbol *Name = getSymbol(&F);
1759 // Function getSymbol gives us the function descriptor symbol for XCOFF.
1760
1761 if (!TM.getTargetTriple().isOSBinFormatXCOFF()) {
1762 GlobalValue::VisibilityTypes V = F.getVisibility();
1763 if (V == GlobalValue::DefaultVisibility)
1764 continue;
1765
1766 emitVisibility(Name, V, false);
1767 continue;
1768 }
1769
1770 if (F.isIntrinsic())
1771 continue;
1772
1773 // Handle the XCOFF case.
1774 // Variable `Name` is the function descriptor symbol (see above). Get the
1775 // function entry point symbol.
1776 MCSymbol *FnEntryPointSym = TLOF.getFunctionEntryPointSymbol(&F, TM);
1777 // Emit linkage for the function entry point.
1778 emitLinkage(&F, FnEntryPointSym);
1779
1780 // Emit linkage for the function descriptor.
1781 emitLinkage(&F, Name);
1782 }
1783
1784 // Emit the remarks section contents.
1785 // FIXME: Figure out when is the safest time to emit this section. It should
1786 // not come after debug info.
1787 if (remarks::RemarkStreamer *RS = M.getContext().getMainRemarkStreamer())
1788 emitRemarksSection(*RS);
1789
1790 TLOF.emitModuleMetadata(*OutStreamer, M);
1791
1792 if (TM.getTargetTriple().isOSBinFormatELF()) {
1793 MachineModuleInfoELF &MMIELF = MMI->getObjFileInfo<MachineModuleInfoELF>();
1794
1795 // Output stubs for external and common global variables.
1796 MachineModuleInfoELF::SymbolListTy Stubs = MMIELF.GetGVStubList();
1797 if (!Stubs.empty()) {
1798 OutStreamer->SwitchSection(TLOF.getDataSection());
1799 const DataLayout &DL = M.getDataLayout();
1800
1801 emitAlignment(Align(DL.getPointerSize()));
1802 for (const auto &Stub : Stubs) {
1803 OutStreamer->emitLabel(Stub.first);
1804 OutStreamer->emitSymbolValue(Stub.second.getPointer(),
1805 DL.getPointerSize());
1806 }
1807 }
1808 }
1809
1810 if (TM.getTargetTriple().isOSBinFormatCOFF()) {
1811 MachineModuleInfoCOFF &MMICOFF =
1812 MMI->getObjFileInfo<MachineModuleInfoCOFF>();
1813
1814 // Output stubs for external and common global variables.
1815 MachineModuleInfoCOFF::SymbolListTy Stubs = MMICOFF.GetGVStubList();
1816 if (!Stubs.empty()) {
1817 const DataLayout &DL = M.getDataLayout();
1818
1819 for (const auto &Stub : Stubs) {
1820 SmallString<256> SectionName = StringRef(".rdata$");
1821 SectionName += Stub.first->getName();
1822 OutStreamer->SwitchSection(OutContext.getCOFFSection(
1823 SectionName,
1824 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ |
1825 COFF::IMAGE_SCN_LNK_COMDAT,
1826 SectionKind::getReadOnly(), Stub.first->getName(),
1827 COFF::IMAGE_COMDAT_SELECT_ANY));
1828 emitAlignment(Align(DL.getPointerSize()));
1829 OutStreamer->emitSymbolAttribute(Stub.first, MCSA_Global);
1830 OutStreamer->emitLabel(Stub.first);
1831 OutStreamer->emitSymbolValue(Stub.second.getPointer(),
1832 DL.getPointerSize());
1833 }
1834 }
1835 }
1836
1837 // This needs to happen before emitting debug information since that can end
1838 // arbitrary sections.
1839 if (auto *TS = OutStreamer->getTargetStreamer())
1840 TS->emitConstantPools();
1841
1842 // Finalize debug and EH information.
1843 for (const HandlerInfo &HI : Handlers) {
1844 NamedRegionTimer T(HI.TimerName, HI.TimerDescription, HI.TimerGroupName,
1845 HI.TimerGroupDescription, TimePassesIsEnabled);
1846 HI.Handler->endModule();
1847 }
1848
1849 // This deletes all the ephemeral handlers that AsmPrinter added, while
1850 // keeping all the user-added handlers alive until the AsmPrinter is
1851 // destroyed.
1852 Handlers.erase(Handlers.begin() + NumUserHandlers, Handlers.end());
1853 DD = nullptr;
1854
1855 // If the target wants to know about weak references, print them all.
1856 if (MAI->getWeakRefDirective()) {
1857 // FIXME: This is not lazy, it would be nice to only print weak references
1858 // to stuff that is actually used. Note that doing so would require targets
1859 // to notice uses in operands (due to constant exprs etc). This should
1860 // happen with the MC stuff eventually.
1861
1862 // Print out module-level global objects here.
1863 for (const auto &GO : M.global_objects()) {
1864 if (!GO.hasExternalWeakLinkage())
1865 continue;
1866 OutStreamer->emitSymbolAttribute(getSymbol(&GO), MCSA_WeakReference);
1867 }
1868 if (shouldEmitWeakSwiftAsyncExtendedFramePointerFlags()) {
1869 auto SymbolName = "swift_async_extendedFramePointerFlags";
1870 auto Global = M.getGlobalVariable(SymbolName);
1871 if (!Global) {
1872 auto Int8PtrTy = Type::getInt8PtrTy(M.getContext());
1873 Global = new GlobalVariable(M, Int8PtrTy, false,
1874 GlobalValue::ExternalWeakLinkage, nullptr,
1875 SymbolName);
1876 OutStreamer->emitSymbolAttribute(getSymbol(Global), MCSA_WeakReference);
1877 }
1878 }
1879 }
1880
1881 // Print aliases in topological order, that is, for each alias a = b,
1882 // b must be printed before a.
1883 // This is because on some targets (e.g. PowerPC) linker expects aliases in
1884 // such an order to generate correct TOC information.
1885 SmallVector<const GlobalAlias *, 16> AliasStack;
1886 SmallPtrSet<const GlobalAlias *, 16> AliasVisited;
1887 for (const auto &Alias : M.aliases()) {
1888 for (const GlobalAlias *Cur = &Alias; Cur;
1889 Cur = dyn_cast<GlobalAlias>(Cur->getAliasee())) {
1890 if (!AliasVisited.insert(Cur).second)
1891 break;
1892 AliasStack.push_back(Cur);
1893 }
1894 for (const GlobalAlias *AncestorAlias : llvm::reverse(AliasStack))
1895 emitGlobalAlias(M, *AncestorAlias);
1896 AliasStack.clear();
1897 }
1898 for (const auto &IFunc : M.ifuncs())
1899 emitGlobalIFunc(M, IFunc);
1900
1901 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
1902 assert(MI && "AsmPrinter didn't require GCModuleInfo?")(static_cast <bool> (MI && "AsmPrinter didn't require GCModuleInfo?"
) ? void (0) : __assert_fail ("MI && \"AsmPrinter didn't require GCModuleInfo?\""
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 1902, __extension__
__PRETTY_FUNCTION__))
;
1903 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
1904 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(**--I))
1905 MP->finishAssembly(M, *MI, *this);
1906
1907 // Emit llvm.ident metadata in an '.ident' directive.
1908 emitModuleIdents(M);
1909
1910 // Emit bytes for llvm.commandline metadata.
1911 emitModuleCommandLines(M);
1912
1913 // Emit __morestack address if needed for indirect calls.
1914 if (MMI->usesMorestackAddr()) {
1915 Align Alignment(1);
1916 MCSection *ReadOnlySection = getObjFileLowering().getSectionForConstant(
1917 getDataLayout(), SectionKind::getReadOnly(),
1918 /*C=*/nullptr, Alignment);
1919 OutStreamer->SwitchSection(ReadOnlySection);
1920
1921 MCSymbol *AddrSymbol =
1922 OutContext.getOrCreateSymbol(StringRef("__morestack_addr"));
1923 OutStreamer->emitLabel(AddrSymbol);
1924
1925 unsigned PtrSize = MAI->getCodePointerSize();
1926 OutStreamer->emitSymbolValue(GetExternalSymbolSymbol("__morestack"),
1927 PtrSize);
1928 }
1929
1930 // Emit .note.GNU-split-stack and .note.GNU-no-split-stack sections if
1931 // split-stack is used.
1932 if (TM.getTargetTriple().isOSBinFormatELF() && MMI->hasSplitStack()) {
1933 OutStreamer->SwitchSection(
1934 OutContext.getELFSection(".note.GNU-split-stack", ELF::SHT_PROGBITS, 0));
1935 if (MMI->hasNosplitStack())
1936 OutStreamer->SwitchSection(
1937 OutContext.getELFSection(".note.GNU-no-split-stack", ELF::SHT_PROGBITS, 0));
1938 }
1939
1940 // If we don't have any trampolines, then we don't require stack memory
1941 // to be executable. Some targets have a directive to declare this.
1942 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
1943 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
1944 if (MCSection *S = MAI->getNonexecutableStackSection(OutContext))
1945 OutStreamer->SwitchSection(S);
1946
1947 if (TM.Options.EmitAddrsig) {
1948 // Emit address-significance attributes for all globals.
1949 OutStreamer->emitAddrsig();
1950 for (const GlobalValue &GV : M.global_values()) {
1951 if (!GV.use_empty() && !GV.isTransitiveUsedByMetadataOnly() &&
1952 !GV.isThreadLocal() && !GV.hasDLLImportStorageClass() &&
1953 !GV.getName().startswith("llvm.") && !GV.hasAtLeastLocalUnnamedAddr())
1954 OutStreamer->emitAddrsigSym(getSymbol(&GV));
1955 }
1956 }
1957
1958 // Emit symbol partition specifications (ELF only).
1959 if (TM.getTargetTriple().isOSBinFormatELF()) {
1960 unsigned UniqueID = 0;
1961 for (const GlobalValue &GV : M.global_values()) {
1962 if (!GV.hasPartition() || GV.isDeclarationForLinker() ||
1963 GV.getVisibility() != GlobalValue::DefaultVisibility)
1964 continue;
1965
1966 OutStreamer->SwitchSection(
1967 OutContext.getELFSection(".llvm_sympart", ELF::SHT_LLVM_SYMPART, 0, 0,
1968 "", false, ++UniqueID, nullptr));
1969 OutStreamer->emitBytes(GV.getPartition());
1970 OutStreamer->emitZeros(1);
1971 OutStreamer->emitValue(
1972 MCSymbolRefExpr::create(getSymbol(&GV), OutContext),
1973 MAI->getCodePointerSize());
1974 }
1975 }
1976
1977 // Allow the target to emit any magic that it wants at the end of the file,
1978 // after everything else has gone out.
1979 emitEndOfAsmFile(M);
1980
1981 MMI = nullptr;
1982
1983 OutStreamer->Finish();
1984 OutStreamer->reset();
1985 OwnedMLI.reset();
1986 OwnedMDT.reset();
1987
1988 return false;
1989}
1990
1991MCSymbol *AsmPrinter::getMBBExceptionSym(const MachineBasicBlock &MBB) {
1992 auto Res = MBBSectionExceptionSyms.try_emplace(MBB.getSectionIDNum());
1993 if (Res.second)
1994 Res.first->second = createTempSymbol("exception");
1995 return Res.first->second;
1996}
1997
1998void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
1999 this->MF = &MF;
2000 const Function &F = MF.getFunction();
2001
2002 // Get the function symbol.
2003 if (!MAI->needsFunctionDescriptors()) {
2004 CurrentFnSym = getSymbol(&MF.getFunction());
2005 } else {
2006 assert(TM.getTargetTriple().isOSAIX() &&(static_cast <bool> (TM.getTargetTriple().isOSAIX() &&
"Only AIX uses the function descriptor hooks.") ? void (0) :
__assert_fail ("TM.getTargetTriple().isOSAIX() && \"Only AIX uses the function descriptor hooks.\""
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 2007, __extension__
__PRETTY_FUNCTION__))
2007 "Only AIX uses the function descriptor hooks.")(static_cast <bool> (TM.getTargetTriple().isOSAIX() &&
"Only AIX uses the function descriptor hooks.") ? void (0) :
__assert_fail ("TM.getTargetTriple().isOSAIX() && \"Only AIX uses the function descriptor hooks.\""
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 2007, __extension__
__PRETTY_FUNCTION__))
;
2008 // AIX is unique here in that the name of the symbol emitted for the
2009 // function body does not have the same name as the source function's
2010 // C-linkage name.
2011 assert(CurrentFnDescSym && "The function descriptor symbol needs to be"(static_cast <bool> (CurrentFnDescSym && "The function descriptor symbol needs to be"
" initalized first.") ? void (0) : __assert_fail ("CurrentFnDescSym && \"The function descriptor symbol needs to be\" \" initalized first.\""
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 2012, __extension__
__PRETTY_FUNCTION__))
2012 " initalized first.")(static_cast <bool> (CurrentFnDescSym && "The function descriptor symbol needs to be"
" initalized first.") ? void (0) : __assert_fail ("CurrentFnDescSym && \"The function descriptor symbol needs to be\" \" initalized first.\""
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 2012, __extension__
__PRETTY_FUNCTION__))
;
2013
2014 // Get the function entry point symbol.
2015 CurrentFnSym = getObjFileLowering().getFunctionEntryPointSymbol(&F, TM);
2016 }
2017
2018 CurrentFnSymForSize = CurrentFnSym;
2019 CurrentFnBegin = nullptr;
2020 CurrentSectionBeginSym = nullptr;
2021 MBBSectionRanges.clear();
2022 MBBSectionExceptionSyms.clear();
2023 bool NeedsLocalForSize = MAI->needsLocalForSize();
2024 if (F.hasFnAttribute("patchable-function-entry") ||
2025 F.hasFnAttribute("function-instrument") ||
2026 F.hasFnAttribute("xray-instruction-threshold") ||
2027 needFuncLabelsForEHOrDebugInfo(MF) || NeedsLocalForSize ||
2028 MF.getTarget().Options.EmitStackSizeSection || MF.hasBBLabels()) {
2029 CurrentFnBegin = createTempSymbol("func_begin");
2030 if (NeedsLocalForSize)
2031 CurrentFnSymForSize = CurrentFnBegin;
2032 }
2033
2034 ORE = &getAnalysis<MachineOptimizationRemarkEmitterPass>().getORE();
2035}
2036
2037namespace {
2038
2039// Keep track the alignment, constpool entries per Section.
2040 struct SectionCPs {
2041 MCSection *S;
2042 Align Alignment;
2043 SmallVector<unsigned, 4> CPEs;
2044
2045 SectionCPs(MCSection *s, Align a) : S(s), Alignment(a) {}
2046 };
2047
2048} // end anonymous namespace
2049
2050/// EmitConstantPool - Print to the current output stream assembly
2051/// representations of the constants in the constant pool MCP. This is
2052/// used to print out constants which have been "spilled to memory" by
2053/// the code generator.
2054void AsmPrinter::emitConstantPool() {
2055 const MachineConstantPool *MCP = MF->getConstantPool();
2056 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
2057 if (CP.empty()) return;
2058
2059 // Calculate sections for constant pool entries. We collect entries to go into
2060 // the same section together to reduce amount of section switch statements.
2061 SmallVector<SectionCPs, 4> CPSections;
2062 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
2063 const MachineConstantPoolEntry &CPE = CP[i];
2064 Align Alignment = CPE.getAlign();
2065
2066 SectionKind Kind = CPE.getSectionKind(&getDataLayout());
2067
2068 const Constant *C = nullptr;
2069 if (!CPE.isMachineConstantPoolEntry())
2070 C = CPE.Val.ConstVal;
2071
2072 MCSection *S = getObjFileLowering().getSectionForConstant(
2073 getDataLayout(), Kind, C, Alignment);
2074
2075 // The number of sections are small, just do a linear search from the
2076 // last section to the first.
2077 bool Found = false;
2078 unsigned SecIdx = CPSections.size();
2079 while (SecIdx != 0) {
2080 if (CPSections[--SecIdx].S == S) {
2081 Found = true;
2082 break;
2083 }
2084 }
2085 if (!Found) {
2086 SecIdx = CPSections.size();
2087 CPSections.push_back(SectionCPs(S, Alignment));
2088 }
2089
2090 if (Alignment > CPSections[SecIdx].Alignment)
2091 CPSections[SecIdx].Alignment = Alignment;
2092 CPSections[SecIdx].CPEs.push_back(i);
2093 }
2094
2095 // Now print stuff into the calculated sections.
2096 const MCSection *CurSection = nullptr;
2097 unsigned Offset = 0;
2098 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
2099 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
2100 unsigned CPI = CPSections[i].CPEs[j];
2101 MCSymbol *Sym = GetCPISymbol(CPI);
2102 if (!Sym->isUndefined())
2103 continue;
2104
2105 if (CurSection != CPSections[i].S) {
2106 OutStreamer->SwitchSection(CPSections[i].S);
2107 emitAlignment(Align(CPSections[i].Alignment));
2108 CurSection = CPSections[i].S;
2109 Offset = 0;
2110 }
2111
2112 MachineConstantPoolEntry CPE = CP[CPI];
2113
2114 // Emit inter-object padding for alignment.
2115 unsigned NewOffset = alignTo(Offset, CPE.getAlign());
2116 OutStreamer->emitZeros(NewOffset - Offset);
2117
2118 Offset = NewOffset + CPE.getSizeInBytes(getDataLayout());
2119
2120 OutStreamer->emitLabel(Sym);
2121 if (CPE.isMachineConstantPoolEntry())
2122 emitMachineConstantPoolValue(CPE.Val.MachineCPVal);
2123 else
2124 emitGlobalConstant(getDataLayout(), CPE.Val.ConstVal);
2125 }
2126 }
2127}
2128
2129// Print assembly representations of the jump tables used by the current
2130// function.
2131void AsmPrinter::emitJumpTableInfo() {
2132 const DataLayout &DL = MF->getDataLayout();
2133 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
2134 if (!MJTI) return;
2135 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
2136 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
2137 if (JT.empty()) return;
2138
2139 // Pick the directive to use to print the jump table entries, and switch to
2140 // the appropriate section.
2141 const Function &F = MF->getFunction();
2142 const TargetLoweringObjectFile &TLOF = getObjFileLowering();
2143 bool JTInDiffSection = !TLOF.shouldPutJumpTableInFunctionSection(
2144 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32,
2145 F);
2146 if (JTInDiffSection) {
2147 // Drop it in the readonly section.
2148 MCSection *ReadOnlySection = TLOF.getSectionForJumpTable(F, TM);
2149 OutStreamer->SwitchSection(ReadOnlySection);
2150 }
2151
2152 emitAlignment(Align(MJTI->getEntryAlignment(DL)));
2153
2154 // Jump tables in code sections are marked with a data_region directive
2155 // where that's supported.
2156 if (!JTInDiffSection)
2157 OutStreamer->emitDataRegion(MCDR_DataRegionJT32);
2158
2159 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
2160 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
2161
2162 // If this jump table was deleted, ignore it.
2163 if (JTBBs.empty()) continue;
2164
2165 // For the EK_LabelDifference32 entry, if using .set avoids a relocation,
2166 /// emit a .set directive for each unique entry.
2167 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
2168 MAI->doesSetDirectiveSuppressReloc()) {
2169 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
2170 const TargetLowering *TLI = MF->getSubtarget().getTargetLowering();
2171 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
2172 for (const MachineBasicBlock *MBB : JTBBs) {
2173 if (!EmittedSets.insert(MBB).second)
2174 continue;
2175
2176 // .set LJTSet, LBB32-base
2177 const MCExpr *LHS =
2178 MCSymbolRefExpr::create(MBB->getSymbol(), OutContext);
2179 OutStreamer->emitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
2180 MCBinaryExpr::createSub(LHS, Base,
2181 OutContext));
2182 }
2183 }
2184
2185 // On some targets (e.g. Darwin) we want to emit two consecutive labels
2186 // before each jump table. The first label is never referenced, but tells
2187 // the assembler and linker the extents of the jump table object. The
2188 // second label is actually referenced by the code.
2189 if (JTInDiffSection && DL.hasLinkerPrivateGlobalPrefix())
2190 // FIXME: This doesn't have to have any specific name, just any randomly
2191 // named and numbered local label started with 'l' would work. Simplify
2192 // GetJTISymbol.
2193 OutStreamer->emitLabel(GetJTISymbol(JTI, true));
2194
2195 MCSymbol* JTISymbol = GetJTISymbol(JTI);
2196 OutStreamer->emitLabel(JTISymbol);
2197
2198 for (const MachineBasicBlock *MBB : JTBBs)
2199 emitJumpTableEntry(MJTI, MBB, JTI);
2200 }
2201 if (!JTInDiffSection)
2202 OutStreamer->emitDataRegion(MCDR_DataRegionEnd);
2203}
2204
2205/// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
2206/// current stream.
2207void AsmPrinter::emitJumpTableEntry(const MachineJumpTableInfo *MJTI,
2208 const MachineBasicBlock *MBB,
2209 unsigned UID) const {
2210 assert(MBB && MBB->getNumber() >= 0 && "Invalid basic block")(static_cast <bool> (MBB && MBB->getNumber()
>= 0 && "Invalid basic block") ? void (0) : __assert_fail
("MBB && MBB->getNumber() >= 0 && \"Invalid basic block\""
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 2210, __extension__
__PRETTY_FUNCTION__))
;
2211 const MCExpr *Value = nullptr;
2212 switch (MJTI->getEntryKind()) {
2213 case MachineJumpTableInfo::EK_Inline:
2214 llvm_unreachable("Cannot emit EK_Inline jump table entry")::llvm::llvm_unreachable_internal("Cannot emit EK_Inline jump table entry"
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 2214)
;
2215 case MachineJumpTableInfo::EK_Custom32:
2216 Value = MF->getSubtarget().getTargetLowering()->LowerCustomJumpTableEntry(
2217 MJTI, MBB, UID, OutContext);
2218 break;
2219 case MachineJumpTableInfo::EK_BlockAddress:
2220 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
2221 // .word LBB123
2222 Value = MCSymbolRefExpr::create(MBB->getSymbol(), OutContext);
2223 break;
2224 case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
2225 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
2226 // with a relocation as gp-relative, e.g.:
2227 // .gprel32 LBB123
2228 MCSymbol *MBBSym = MBB->getSymbol();
2229 OutStreamer->emitGPRel32Value(MCSymbolRefExpr::create(MBBSym, OutContext));
2230 return;
2231 }
2232
2233 case MachineJumpTableInfo::EK_GPRel64BlockAddress: {
2234 // EK_GPRel64BlockAddress - Each entry is an address of block, encoded
2235 // with a relocation as gp-relative, e.g.:
2236 // .gpdword LBB123
2237 MCSymbol *MBBSym = MBB->getSymbol();
2238 OutStreamer->emitGPRel64Value(MCSymbolRefExpr::create(MBBSym, OutContext));
2239 return;
2240 }
2241
2242 case MachineJumpTableInfo::EK_LabelDifference32: {
2243 // Each entry is the address of the block minus the address of the jump
2244 // table. This is used for PIC jump tables where gprel32 is not supported.
2245 // e.g.:
2246 // .word LBB123 - LJTI1_2
2247 // If the .set directive avoids relocations, this is emitted as:
2248 // .set L4_5_set_123, LBB123 - LJTI1_2
2249 // .word L4_5_set_123
2250 if (MAI->doesSetDirectiveSuppressReloc()) {
2251 Value = MCSymbolRefExpr::create(GetJTSetSymbol(UID, MBB->getNumber()),
2252 OutContext);
2253 break;
2254 }
2255 Value = MCSymbolRefExpr::create(MBB->getSymbol(), OutContext);
2256 const TargetLowering *TLI = MF->getSubtarget().getTargetLowering();
2257 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF, UID, OutContext);
2258 Value = MCBinaryExpr::createSub(Value, Base, OutContext);
2259 break;
2260 }
2261 }
2262
2263 assert(Value && "Unknown entry kind!")(static_cast <bool> (Value && "Unknown entry kind!"
) ? void (0) : __assert_fail ("Value && \"Unknown entry kind!\""
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 2263, __extension__
__PRETTY_FUNCTION__))
;
2264
2265 unsigned EntrySize = MJTI->getEntrySize(getDataLayout());
2266 OutStreamer->emitValue(Value, EntrySize);
2267}
2268
2269/// EmitSpecialLLVMGlobal - Check to see if the specified global is a
2270/// special global used by LLVM. If so, emit it and return true, otherwise
2271/// do nothing and return false.
2272bool AsmPrinter::emitSpecialLLVMGlobal(const GlobalVariable *GV) {
2273 if (GV->getName() == "llvm.used") {
2274 if (MAI->hasNoDeadStrip()) // No need to emit this at all.
2275 emitLLVMUsedList(cast<ConstantArray>(GV->getInitializer()));
2276 return true;
2277 }
2278
2279 // Ignore debug and non-emitted data. This handles llvm.compiler.used.
2280 if (GV->getSection() == "llvm.metadata" ||
2281 GV->hasAvailableExternallyLinkage())
2282 return true;
2283
2284 if (!GV->hasAppendingLinkage()) return false;
2285
2286 assert(GV->hasInitializer() && "Not a special LLVM global!")(static_cast <bool> (GV->hasInitializer() &&
"Not a special LLVM global!") ? void (0) : __assert_fail ("GV->hasInitializer() && \"Not a special LLVM global!\""
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 2286, __extension__
__PRETTY_FUNCTION__))
;
2287
2288 if (GV->getName() == "llvm.global_ctors") {
2289 emitXXStructorList(GV->getParent()->getDataLayout(), GV->getInitializer(),
2290 /* isCtor */ true);
2291
2292 return true;
2293 }
2294
2295 if (GV->getName() == "llvm.global_dtors") {
2296 emitXXStructorList(GV->getParent()->getDataLayout(), GV->getInitializer(),
2297 /* isCtor */ false);
2298
2299 return true;
2300 }
2301
2302 report_fatal_error("unknown special variable");
2303}
2304
2305/// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
2306/// global in the specified llvm.used list.
2307void AsmPrinter::emitLLVMUsedList(const ConstantArray *InitList) {
2308 // Should be an array of 'i8*'.
2309 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
2310 const GlobalValue *GV =
2311 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
2312 if (GV)
2313 OutStreamer->emitSymbolAttribute(getSymbol(GV), MCSA_NoDeadStrip);
2314 }
2315}
2316
2317void AsmPrinter::preprocessXXStructorList(const DataLayout &DL,
2318 const Constant *List,
2319 SmallVector<Structor, 8> &Structors) {
2320 // Should be an array of '{ i32, void ()*, i8* }' structs. The first value is
2321 // the init priority.
2322 if (!isa<ConstantArray>(List))
2323 return;
2324
2325 // Gather the structors in a form that's convenient for sorting by priority.
2326 for (Value *O : cast<ConstantArray>(List)->operands()) {
2327 auto *CS = cast<ConstantStruct>(O);
2328 if (CS->getOperand(1)->isNullValue())
2329 break; // Found a null terminator, skip the rest.
2330 ConstantInt *Priority = dyn_cast<ConstantInt>(CS->getOperand(0));
2331 if (!Priority)
2332 continue; // Malformed.
2333 Structors.push_back(Structor());
2334 Structor &S = Structors.back();
2335 S.Priority = Priority->getLimitedValue(65535);
2336 S.Func = CS->getOperand(1);
2337 if (!CS->getOperand(2)->isNullValue()) {
2338 if (TM.getTargetTriple().isOSAIX())
2339 llvm::report_fatal_error(
2340 "associated data of XXStructor list is not yet supported on AIX");
2341 S.ComdatKey =
2342 dyn_cast<GlobalValue>(CS->getOperand(2)->stripPointerCasts());
2343 }
2344 }
2345
2346 // Emit the function pointers in the target-specific order
2347 llvm::stable_sort(Structors, [](const Structor &L, const Structor &R) {
2348 return L.Priority < R.Priority;
2349 });
2350}
2351
2352/// EmitXXStructorList - Emit the ctor or dtor list taking into account the init
2353/// priority.
2354void AsmPrinter::emitXXStructorList(const DataLayout &DL, const Constant *List,
2355 bool IsCtor) {
2356 SmallVector<Structor, 8> Structors;
2357 preprocessXXStructorList(DL, List, Structors);
2358 if (Structors.empty())
2359 return;
2360
2361 // Emit the structors in reverse order if we are using the .ctor/.dtor
2362 // initialization scheme.
2363 if (!TM.Options.UseInitArray)
2364 std::reverse(Structors.begin(), Structors.end());
2365
2366 const Align Align = DL.getPointerPrefAlignment();
2367 for (Structor &S : Structors) {
2368 const TargetLoweringObjectFile &Obj = getObjFileLowering();
2369 const MCSymbol *KeySym = nullptr;
2370 if (GlobalValue *GV = S.ComdatKey) {
2371 if (GV->isDeclarationForLinker())
2372 // If the associated variable is not defined in this module
2373 // (it might be available_externally, or have been an
2374 // available_externally definition that was dropped by the
2375 // EliminateAvailableExternally pass), some other TU
2376 // will provide its dynamic initializer.
2377 continue;
2378
2379 KeySym = getSymbol(GV);
2380 }
2381
2382 MCSection *OutputSection =
2383 (IsCtor ? Obj.getStaticCtorSection(S.Priority, KeySym)
2384 : Obj.getStaticDtorSection(S.Priority, KeySym));
2385 OutStreamer->SwitchSection(OutputSection);
2386 if (OutStreamer->getCurrentSection() != OutStreamer->getPreviousSection())
2387 emitAlignment(Align);
2388 emitXXStructor(DL, S.Func);
2389 }
2390}
2391
2392void AsmPrinter::emitModuleIdents(Module &M) {
2393 if (!MAI->hasIdentDirective())
2394 return;
2395
2396 if (const NamedMDNode *NMD = M.getNamedMetadata("llvm.ident")) {
2397 for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {
2398 const MDNode *N = NMD->getOperand(i);
2399 assert(N->getNumOperands() == 1 &&(static_cast <bool> (N->getNumOperands() == 1 &&
"llvm.ident metadata entry can have only one operand") ? void
(0) : __assert_fail ("N->getNumOperands() == 1 && \"llvm.ident metadata entry can have only one operand\""
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 2400, __extension__
__PRETTY_FUNCTION__))
2400 "llvm.ident metadata entry can have only one operand")(static_cast <bool> (N->getNumOperands() == 1 &&
"llvm.ident metadata entry can have only one operand") ? void
(0) : __assert_fail ("N->getNumOperands() == 1 && \"llvm.ident metadata entry can have only one operand\""
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 2400, __extension__
__PRETTY_FUNCTION__))
;
2401 const MDString *S = cast<MDString>(N->getOperand(0));
2402 OutStreamer->emitIdent(S->getString());
2403 }
2404 }
2405}
2406
2407void AsmPrinter::emitModuleCommandLines(Module &M) {
2408 MCSection *CommandLine = getObjFileLowering().getSectionForCommandLines();
2409 if (!CommandLine)
2410 return;
2411
2412 const NamedMDNode *NMD = M.getNamedMetadata("llvm.commandline");
2413 if (!NMD || !NMD->getNumOperands())
2414 return;
2415
2416 OutStreamer->PushSection();
2417 OutStreamer->SwitchSection(CommandLine);
2418 OutStreamer->emitZeros(1);
2419 for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {
2420 const MDNode *N = NMD->getOperand(i);
2421 assert(N->getNumOperands() == 1 &&(static_cast <bool> (N->getNumOperands() == 1 &&
"llvm.commandline metadata entry can have only one operand")
? void (0) : __assert_fail ("N->getNumOperands() == 1 && \"llvm.commandline metadata entry can have only one operand\""
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 2422, __extension__
__PRETTY_FUNCTION__))
2422 "llvm.commandline metadata entry can have only one operand")(static_cast <bool> (N->getNumOperands() == 1 &&
"llvm.commandline metadata entry can have only one operand")
? void (0) : __assert_fail ("N->getNumOperands() == 1 && \"llvm.commandline metadata entry can have only one operand\""
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 2422, __extension__
__PRETTY_FUNCTION__))
;
2423 const MDString *S = cast<MDString>(N->getOperand(0));
2424 OutStreamer->emitBytes(S->getString());
2425 OutStreamer->emitZeros(1);
2426 }
2427 OutStreamer->PopSection();
2428}
2429
2430//===--------------------------------------------------------------------===//
2431// Emission and print routines
2432//
2433
2434/// Emit a byte directive and value.
2435///
2436void AsmPrinter::emitInt8(int Value) const { OutStreamer->emitInt8(Value); }
2437
2438/// Emit a short directive and value.
2439void AsmPrinter::emitInt16(int Value) const { OutStreamer->emitInt16(Value); }
2440
2441/// Emit a long directive and value.
2442void AsmPrinter::emitInt32(int Value) const { OutStreamer->emitInt32(Value); }
2443
2444/// Emit a long long directive and value.
2445void AsmPrinter::emitInt64(uint64_t Value) const {
2446 OutStreamer->emitInt64(Value);
2447}
2448
2449/// Emit something like ".long Hi-Lo" where the size in bytes of the directive
2450/// is specified by Size and Hi/Lo specify the labels. This implicitly uses
2451/// .set if it avoids relocations.
2452void AsmPrinter::emitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
2453 unsigned Size) const {
2454 OutStreamer->emitAbsoluteSymbolDiff(Hi, Lo, Size);
2455}
2456
2457/// EmitLabelPlusOffset - Emit something like ".long Label+Offset"
2458/// where the size in bytes of the directive is specified by Size and Label
2459/// specifies the label. This implicitly uses .set if it is available.
2460void AsmPrinter::emitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset,
2461 unsigned Size,
2462 bool IsSectionRelative) const {
2463 if (MAI->needsDwarfSectionOffsetDirective() && IsSectionRelative) {
2464 OutStreamer->EmitCOFFSecRel32(Label, Offset);
2465 if (Size > 4)
2466 OutStreamer->emitZeros(Size - 4);
2467 return;
2468 }
2469
2470 // Emit Label+Offset (or just Label if Offset is zero)
2471 const MCExpr *Expr = MCSymbolRefExpr::create(Label, OutContext);
2472 if (Offset)
2473 Expr = MCBinaryExpr::createAdd(
2474 Expr, MCConstantExpr::create(Offset, OutContext), OutContext);
2475
2476 OutStreamer->emitValue(Expr, Size);
2477}
2478
2479//===----------------------------------------------------------------------===//
2480
2481// EmitAlignment - Emit an alignment directive to the specified power of
2482// two boundary. If a global value is specified, and if that global has
2483// an explicit alignment requested, it will override the alignment request
2484// if required for correctness.
2485void AsmPrinter::emitAlignment(Align Alignment, const GlobalObject *GV,
2486 unsigned MaxBytesToEmit) const {
2487 if (GV)
2488 Alignment = getGVAlignment(GV, GV->getParent()->getDataLayout(), Alignment);
2489
2490 if (Alignment == Align(1))
2491 return; // 1-byte aligned: no need to emit alignment.
2492
2493 if (getCurrentSection()->getKind().isText()) {
2494 const MCSubtargetInfo *STI = nullptr;
2495 if (this->MF)
2496 STI = &getSubtargetInfo();
2497 else
2498 STI = TM.getMCSubtargetInfo();
2499 OutStreamer->emitCodeAlignment(Alignment.value(), STI, MaxBytesToEmit);
2500 } else
2501 OutStreamer->emitValueToAlignment(Alignment.value(), 0, 1, MaxBytesToEmit);
2502}
2503
2504//===----------------------------------------------------------------------===//
2505// Constant emission.
2506//===----------------------------------------------------------------------===//
2507
2508const MCExpr *AsmPrinter::lowerConstant(const Constant *CV) {
2509 MCContext &Ctx = OutContext;
2510
2511 if (CV->isNullValue() || isa<UndefValue>(CV))
2512 return MCConstantExpr::create(0, Ctx);
2513
2514 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
2515 return MCConstantExpr::create(CI->getZExtValue(), Ctx);
2516
2517 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
2518 return MCSymbolRefExpr::create(getSymbol(GV), Ctx);
2519
2520 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
2521 return MCSymbolRefExpr::create(GetBlockAddressSymbol(BA), Ctx);
2522
2523 if (const auto *Equiv = dyn_cast<DSOLocalEquivalent>(CV))
2524 return getObjFileLowering().lowerDSOLocalEquivalent(Equiv, TM);
2525
2526 if (const NoCFIValue *NC = dyn_cast<NoCFIValue>(CV))
2527 return MCSymbolRefExpr::create(getSymbol(NC->getGlobalValue()), Ctx);
2528
2529 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
2530 if (!CE) {
2531 llvm_unreachable("Unknown constant value to lower!")::llvm::llvm_unreachable_internal("Unknown constant value to lower!"
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 2531)
;
2532 }
2533
2534 switch (CE->getOpcode()) {
2535 case Instruction::AddrSpaceCast: {
2536 const Constant *Op = CE->getOperand(0);
2537 unsigned DstAS = CE->getType()->getPointerAddressSpace();
2538 unsigned SrcAS = Op->getType()->getPointerAddressSpace();
2539 if (TM.isNoopAddrSpaceCast(SrcAS, DstAS))
2540 return lowerConstant(Op);
2541
2542 // Fallthrough to error.
2543 LLVM_FALLTHROUGH[[gnu::fallthrough]];
2544 }
2545 default: {
2546 // If the code isn't optimized, there may be outstanding folding
2547 // opportunities. Attempt to fold the expression using DataLayout as a
2548 // last resort before giving up.
2549 Constant *C = ConstantFoldConstant(CE, getDataLayout());
2550 if (C != CE)
2551 return lowerConstant(C);
2552
2553 // Otherwise report the problem to the user.
2554 std::string S;
2555 raw_string_ostream OS(S);
2556 OS << "Unsupported expression in static initializer: ";
2557 CE->printAsOperand(OS, /*PrintType=*/false,
2558 !MF ? nullptr : MF->getFunction().getParent());
2559 report_fatal_error(Twine(OS.str()));
2560 }
2561 case Instruction::GetElementPtr: {
2562 // Generate a symbolic expression for the byte address
2563 APInt OffsetAI(getDataLayout().getPointerTypeSizeInBits(CE->getType()), 0);
2564 cast<GEPOperator>(CE)->accumulateConstantOffset(getDataLayout(), OffsetAI);
2565
2566 const MCExpr *Base = lowerConstant(CE->getOperand(0));
2567 if (!OffsetAI)
2568 return Base;
2569
2570 int64_t Offset = OffsetAI.getSExtValue();
2571 return MCBinaryExpr::createAdd(Base, MCConstantExpr::create(Offset, Ctx),
2572 Ctx);
2573 }
2574
2575 case Instruction::Trunc:
2576 // We emit the value and depend on the assembler to truncate the generated
2577 // expression properly. This is important for differences between
2578 // blockaddress labels. Since the two labels are in the same function, it
2579 // is reasonable to treat their delta as a 32-bit value.
2580 LLVM_FALLTHROUGH[[gnu::fallthrough]];
2581 case Instruction::BitCast:
2582 return lowerConstant(CE->getOperand(0));
2583
2584 case Instruction::IntToPtr: {
2585 const DataLayout &DL = getDataLayout();
2586
2587 // Handle casts to pointers by changing them into casts to the appropriate
2588 // integer type. This promotes constant folding and simplifies this code.
2589 Constant *Op = CE->getOperand(0);
2590 Op = ConstantExpr::getIntegerCast(Op, DL.getIntPtrType(CV->getType()),
2591 false/*ZExt*/);
2592 return lowerConstant(Op);
2593 }
2594
2595 case Instruction::PtrToInt: {
2596 const DataLayout &DL = getDataLayout();
2597
2598 // Support only foldable casts to/from pointers that can be eliminated by
2599 // changing the pointer to the appropriately sized integer type.
2600 Constant *Op = CE->getOperand(0);
2601 Type *Ty = CE->getType();
2602
2603 const MCExpr *OpExpr = lowerConstant(Op);
2604
2605 // We can emit the pointer value into this slot if the slot is an
2606 // integer slot equal to the size of the pointer.
2607 //
2608 // If the pointer is larger than the resultant integer, then
2609 // as with Trunc just depend on the assembler to truncate it.
2610 if (DL.getTypeAllocSize(Ty).getFixedSize() <=
2611 DL.getTypeAllocSize(Op->getType()).getFixedSize())
2612 return OpExpr;
2613
2614 // Otherwise the pointer is smaller than the resultant integer, mask off
2615 // the high bits so we are sure to get a proper truncation if the input is
2616 // a constant expr.
2617 unsigned InBits = DL.getTypeAllocSizeInBits(Op->getType());
2618 const MCExpr *MaskExpr = MCConstantExpr::create(~0ULL >> (64-InBits), Ctx);
2619 return MCBinaryExpr::createAnd(OpExpr, MaskExpr, Ctx);
2620 }
2621
2622 case Instruction::Sub: {
2623 GlobalValue *LHSGV;
2624 APInt LHSOffset;
2625 DSOLocalEquivalent *DSOEquiv;
2626 if (IsConstantOffsetFromGlobal(CE->getOperand(0), LHSGV, LHSOffset,
2627 getDataLayout(), &DSOEquiv)) {
2628 GlobalValue *RHSGV;
2629 APInt RHSOffset;
2630 if (IsConstantOffsetFromGlobal(CE->getOperand(1), RHSGV, RHSOffset,
2631 getDataLayout())) {
2632 const MCExpr *RelocExpr =
2633 getObjFileLowering().lowerRelativeReference(LHSGV, RHSGV, TM);
2634 if (!RelocExpr) {
2635 const MCExpr *LHSExpr =
2636 MCSymbolRefExpr::create(getSymbol(LHSGV), Ctx);
2637 if (DSOEquiv &&
2638 getObjFileLowering().supportDSOLocalEquivalentLowering())
2639 LHSExpr =
2640 getObjFileLowering().lowerDSOLocalEquivalent(DSOEquiv, TM);
2641 RelocExpr = MCBinaryExpr::createSub(
2642 LHSExpr, MCSymbolRefExpr::create(getSymbol(RHSGV), Ctx), Ctx);
2643 }
2644 int64_t Addend = (LHSOffset - RHSOffset).getSExtValue();
2645 if (Addend != 0)
2646 RelocExpr = MCBinaryExpr::createAdd(
2647 RelocExpr, MCConstantExpr::create(Addend, Ctx), Ctx);
2648 return RelocExpr;
2649 }
2650 }
2651 }
2652 // else fallthrough
2653 LLVM_FALLTHROUGH[[gnu::fallthrough]];
2654
2655 // The MC library also has a right-shift operator, but it isn't consistently
2656 // signed or unsigned between different targets.
2657 case Instruction::Add:
2658 case Instruction::Mul:
2659 case Instruction::SDiv:
2660 case Instruction::SRem:
2661 case Instruction::Shl:
2662 case Instruction::And:
2663 case Instruction::Or:
2664 case Instruction::Xor: {
2665 const MCExpr *LHS = lowerConstant(CE->getOperand(0));
2666 const MCExpr *RHS = lowerConstant(CE->getOperand(1));
2667 switch (CE->getOpcode()) {
2668 default: llvm_unreachable("Unknown binary operator constant cast expr")::llvm::llvm_unreachable_internal("Unknown binary operator constant cast expr"
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 2668)
;
2669 case Instruction::Add: return MCBinaryExpr::createAdd(LHS, RHS, Ctx);
2670 case Instruction::Sub: return MCBinaryExpr::createSub(LHS, RHS, Ctx);
2671 case Instruction::Mul: return MCBinaryExpr::createMul(LHS, RHS, Ctx);
2672 case Instruction::SDiv: return MCBinaryExpr::createDiv(LHS, RHS, Ctx);
2673 case Instruction::SRem: return MCBinaryExpr::createMod(LHS, RHS, Ctx);
2674 case Instruction::Shl: return MCBinaryExpr::createShl(LHS, RHS, Ctx);
2675 case Instruction::And: return MCBinaryExpr::createAnd(LHS, RHS, Ctx);
2676 case Instruction::Or: return MCBinaryExpr::createOr (LHS, RHS, Ctx);
2677 case Instruction::Xor: return MCBinaryExpr::createXor(LHS, RHS, Ctx);
2678 }
2679 }
2680 }
2681}
2682
2683static void emitGlobalConstantImpl(const DataLayout &DL, const Constant *C,
2684 AsmPrinter &AP,
2685 const Constant *BaseCV = nullptr,
2686 uint64_t Offset = 0);
2687
2688static void emitGlobalConstantFP(const ConstantFP *CFP, AsmPrinter &AP);
2689static void emitGlobalConstantFP(APFloat APF, Type *ET, AsmPrinter &AP);
2690
2691/// isRepeatedByteSequence - Determine whether the given value is
2692/// composed of a repeated sequence of identical bytes and return the
2693/// byte value. If it is not a repeated sequence, return -1.
2694static int isRepeatedByteSequence(const ConstantDataSequential *V) {
2695 StringRef Data = V->getRawDataValues();
2696 assert(!Data.empty() && "Empty aggregates should be CAZ node")(static_cast <bool> (!Data.empty() && "Empty aggregates should be CAZ node"
) ? void (0) : __assert_fail ("!Data.empty() && \"Empty aggregates should be CAZ node\""
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 2696, __extension__
__PRETTY_FUNCTION__))
;
2697 char C = Data[0];
2698 for (unsigned i = 1, e = Data.size(); i != e; ++i)
2699 if (Data[i] != C) return -1;
2700 return static_cast<uint8_t>(C); // Ensure 255 is not returned as -1.
2701}
2702
2703/// isRepeatedByteSequence - Determine whether the given value is
2704/// composed of a repeated sequence of identical bytes and return the
2705/// byte value. If it is not a repeated sequence, return -1.
2706static int isRepeatedByteSequence(const Value *V, const DataLayout &DL) {
2707 if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
2708 uint64_t Size = DL.getTypeAllocSizeInBits(V->getType());
2709 assert(Size % 8 == 0)(static_cast <bool> (Size % 8 == 0) ? void (0) : __assert_fail
("Size % 8 == 0", "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 2709, __extension__ __PRETTY_FUNCTION__))
;
2710
2711 // Extend the element to take zero padding into account.
2712 APInt Value = CI->getValue().zextOrSelf(Size);
2713 if (!Value.isSplat(8))
2714 return -1;
2715
2716 return Value.zextOrTrunc(8).getZExtValue();
2717 }
2718 if (const ConstantArray *CA = dyn_cast<ConstantArray>(V)) {
2719 // Make sure all array elements are sequences of the same repeated
2720 // byte.
2721 assert(CA->getNumOperands() != 0 && "Should be a CAZ")(static_cast <bool> (CA->getNumOperands() != 0 &&
"Should be a CAZ") ? void (0) : __assert_fail ("CA->getNumOperands() != 0 && \"Should be a CAZ\""
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 2721, __extension__
__PRETTY_FUNCTION__))
;
2722 Constant *Op0 = CA->getOperand(0);
2723 int Byte = isRepeatedByteSequence(Op0, DL);
2724 if (Byte == -1)
2725 return -1;
2726
2727 // All array elements must be equal.
2728 for (unsigned i = 1, e = CA->getNumOperands(); i != e; ++i)
2729 if (CA->getOperand(i) != Op0)
2730 return -1;
2731 return Byte;
2732 }
2733
2734 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(V))
2735 return isRepeatedByteSequence(CDS);
2736
2737 return -1;
2738}
2739
2740static void emitGlobalConstantDataSequential(const DataLayout &DL,
2741 const ConstantDataSequential *CDS,
2742 AsmPrinter &AP) {
2743 // See if we can aggregate this into a .fill, if so, emit it as such.
2744 int Value = isRepeatedByteSequence(CDS, DL);
2745 if (Value != -1) {
2746 uint64_t Bytes = DL.getTypeAllocSize(CDS->getType());
2747 // Don't emit a 1-byte object as a .fill.
2748 if (Bytes > 1)
2749 return AP.OutStreamer->emitFill(Bytes, Value);
2750 }
2751
2752 // If this can be emitted with .ascii/.asciz, emit it as such.
2753 if (CDS->isString())
2754 return AP.OutStreamer->emitBytes(CDS->getAsString());
2755
2756 // Otherwise, emit the values in successive locations.
2757 unsigned ElementByteSize = CDS->getElementByteSize();
2758 if (isa<IntegerType>(CDS->getElementType())) {
2759 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
2760 if (AP.isVerbose())
2761 AP.OutStreamer->GetCommentOS() << format("0x%" PRIx64"l" "x" "\n",
2762 CDS->getElementAsInteger(i));
2763 AP.OutStreamer->emitIntValue(CDS->getElementAsInteger(i),
2764 ElementByteSize);
2765 }
2766 } else {
2767 Type *ET = CDS->getElementType();
2768 for (unsigned I = 0, E = CDS->getNumElements(); I != E; ++I)
2769 emitGlobalConstantFP(CDS->getElementAsAPFloat(I), ET, AP);
2770 }
2771
2772 unsigned Size = DL.getTypeAllocSize(CDS->getType());
2773 unsigned EmittedSize =
2774 DL.getTypeAllocSize(CDS->getElementType()) * CDS->getNumElements();
2775 assert(EmittedSize <= Size && "Size cannot be less than EmittedSize!")(static_cast <bool> (EmittedSize <= Size && "Size cannot be less than EmittedSize!"
) ? void (0) : __assert_fail ("EmittedSize <= Size && \"Size cannot be less than EmittedSize!\""
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 2775, __extension__
__PRETTY_FUNCTION__))
;
2776 if (unsigned Padding = Size - EmittedSize)
2777 AP.OutStreamer->emitZeros(Padding);
2778}
2779
2780static void emitGlobalConstantArray(const DataLayout &DL,
2781 const ConstantArray *CA, AsmPrinter &AP,
2782 const Constant *BaseCV, uint64_t Offset) {
2783 // See if we can aggregate some values. Make sure it can be
2784 // represented as a series of bytes of the constant value.
2785 int Value = isRepeatedByteSequence(CA, DL);
2786
2787 if (Value != -1) {
2788 uint64_t Bytes = DL.getTypeAllocSize(CA->getType());
2789 AP.OutStreamer->emitFill(Bytes, Value);
2790 }
2791 else {
2792 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i) {
2793 emitGlobalConstantImpl(DL, CA->getOperand(i), AP, BaseCV, Offset);
2794 Offset += DL.getTypeAllocSize(CA->getOperand(i)->getType());
2795 }
2796 }
2797}
2798
2799static void emitGlobalConstantVector(const DataLayout &DL,
2800 const ConstantVector *CV, AsmPrinter &AP) {
2801 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
2802 emitGlobalConstantImpl(DL, CV->getOperand(i), AP);
2803
2804 unsigned Size = DL.getTypeAllocSize(CV->getType());
2805 unsigned EmittedSize = DL.getTypeAllocSize(CV->getType()->getElementType()) *
2806 CV->getType()->getNumElements();
2807 if (unsigned Padding = Size - EmittedSize)
2808 AP.OutStreamer->emitZeros(Padding);
2809}
2810
2811static void emitGlobalConstantStruct(const DataLayout &DL,
2812 const ConstantStruct *CS, AsmPrinter &AP,
2813 const Constant *BaseCV, uint64_t Offset) {
2814 // Print the fields in successive locations. Pad to align if needed!
2815 unsigned Size = DL.getTypeAllocSize(CS->getType());
2816 const StructLayout *Layout = DL.getStructLayout(CS->getType());
2817 uint64_t SizeSoFar = 0;
2818 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
2819 const Constant *Field = CS->getOperand(i);
2820
2821 // Print the actual field value.
2822 emitGlobalConstantImpl(DL, Field, AP, BaseCV, Offset + SizeSoFar);
2823
2824 // Check if padding is needed and insert one or more 0s.
2825 uint64_t FieldSize = DL.getTypeAllocSize(Field->getType());
2826 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
2827 - Layout->getElementOffset(i)) - FieldSize;
2828 SizeSoFar += FieldSize + PadSize;
2829
2830 // Insert padding - this may include padding to increase the size of the
2831 // current field up to the ABI size (if the struct is not packed) as well
2832 // as padding to ensure that the next field starts at the right offset.
2833 AP.OutStreamer->emitZeros(PadSize);
2834 }
2835 assert(SizeSoFar == Layout->getSizeInBytes() &&(static_cast <bool> (SizeSoFar == Layout->getSizeInBytes
() && "Layout of constant struct may be incorrect!") ?
void (0) : __assert_fail ("SizeSoFar == Layout->getSizeInBytes() && \"Layout of constant struct may be incorrect!\""
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 2836, __extension__
__PRETTY_FUNCTION__))
2836 "Layout of constant struct may be incorrect!")(static_cast <bool> (SizeSoFar == Layout->getSizeInBytes
() && "Layout of constant struct may be incorrect!") ?
void (0) : __assert_fail ("SizeSoFar == Layout->getSizeInBytes() && \"Layout of constant struct may be incorrect!\""
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 2836, __extension__
__PRETTY_FUNCTION__))
;
2837}
2838
2839static void emitGlobalConstantFP(APFloat APF, Type *ET, AsmPrinter &AP) {
2840 assert(ET && "Unknown float type")(static_cast <bool> (ET && "Unknown float type"
) ? void (0) : __assert_fail ("ET && \"Unknown float type\""
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 2840, __extension__
__PRETTY_FUNCTION__))
;
2841 APInt API = APF.bitcastToAPInt();
2842
2843 // First print a comment with what we think the original floating-point value
2844 // should have been.
2845 if (AP.isVerbose()) {
2846 SmallString<8> StrVal;
2847 APF.toString(StrVal);
2848 ET->print(AP.OutStreamer->GetCommentOS());
2849 AP.OutStreamer->GetCommentOS() << ' ' << StrVal << '\n';
2850 }
2851
2852 // Now iterate through the APInt chunks, emitting them in endian-correct
2853 // order, possibly with a smaller chunk at beginning/end (e.g. for x87 80-bit
2854 // floats).
2855 unsigned NumBytes = API.getBitWidth() / 8;
2856 unsigned TrailingBytes = NumBytes % sizeof(uint64_t);
2857 const uint64_t *p = API.getRawData();
2858
2859 // PPC's long double has odd notions of endianness compared to how LLVM
2860 // handles it: p[0] goes first for *big* endian on PPC.
2861 if (AP.getDataLayout().isBigEndian() && !ET->isPPC_FP128Ty()) {
2862 int Chunk = API.getNumWords() - 1;
2863
2864 if (TrailingBytes)
2865 AP.OutStreamer->emitIntValueInHexWithPadding(p[Chunk--], TrailingBytes);
2866
2867 for (; Chunk >= 0; --Chunk)
2868 AP.OutStreamer->emitIntValueInHexWithPadding(p[Chunk], sizeof(uint64_t));
2869 } else {
2870 unsigned Chunk;
2871 for (Chunk = 0; Chunk < NumBytes / sizeof(uint64_t); ++Chunk)
2872 AP.OutStreamer->emitIntValueInHexWithPadding(p[Chunk], sizeof(uint64_t));
2873
2874 if (TrailingBytes)
2875 AP.OutStreamer->emitIntValueInHexWithPadding(p[Chunk], TrailingBytes);
2876 }
2877
2878 // Emit the tail padding for the long double.
2879 const DataLayout &DL = AP.getDataLayout();
2880 AP.OutStreamer->emitZeros(DL.getTypeAllocSize(ET) - DL.getTypeStoreSize(ET));
2881}
2882
2883static void emitGlobalConstantFP(const ConstantFP *CFP, AsmPrinter &AP) {
2884 emitGlobalConstantFP(CFP->getValueAPF(), CFP->getType(), AP);
2885}
2886
2887static void emitGlobalConstantLargeInt(const ConstantInt *CI, AsmPrinter &AP) {
2888 const DataLayout &DL = AP.getDataLayout();
2889 unsigned BitWidth = CI->getBitWidth();
2890
2891 // Copy the value as we may massage the layout for constants whose bit width
2892 // is not a multiple of 64-bits.
2893 APInt Realigned(CI->getValue());
2894 uint64_t ExtraBits = 0;
2895 unsigned ExtraBitsSize = BitWidth & 63;
2896
2897 if (ExtraBitsSize) {
2898 // The bit width of the data is not a multiple of 64-bits.
2899 // The extra bits are expected to be at the end of the chunk of the memory.
2900 // Little endian:
2901 // * Nothing to be done, just record the extra bits to emit.
2902 // Big endian:
2903 // * Record the extra bits to emit.
2904 // * Realign the raw data to emit the chunks of 64-bits.
2905 if (DL.isBigEndian()) {
2906 // Basically the structure of the raw data is a chunk of 64-bits cells:
2907 // 0 1 BitWidth / 64
2908 // [chunk1][chunk2] ... [chunkN].
2909 // The most significant chunk is chunkN and it should be emitted first.
2910 // However, due to the alignment issue chunkN contains useless bits.
2911 // Realign the chunks so that they contain only useful information:
2912 // ExtraBits 0 1 (BitWidth / 64) - 1
2913 // chu[nk1 chu][nk2 chu] ... [nkN-1 chunkN]
2914 ExtraBitsSize = alignTo(ExtraBitsSize, 8);
2915 ExtraBits = Realigned.getRawData()[0] &
2916 (((uint64_t)-1) >> (64 - ExtraBitsSize));
2917 Realigned.lshrInPlace(ExtraBitsSize);
2918 } else
2919 ExtraBits = Realigned.getRawData()[BitWidth / 64];
2920 }
2921
2922 // We don't expect assemblers to support integer data directives
2923 // for more than 64 bits, so we emit the data in at most 64-bit
2924 // quantities at a time.
2925 const uint64_t *RawData = Realigned.getRawData();
2926 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
2927 uint64_t Val = DL.isBigEndian() ? RawData[e - i - 1] : RawData[i];
2928 AP.OutStreamer->emitIntValue(Val, 8);
2929 }
2930
2931 if (ExtraBitsSize) {
2932 // Emit the extra bits after the 64-bits chunks.
2933
2934 // Emit a directive that fills the expected size.
2935 uint64_t Size = AP.getDataLayout().getTypeStoreSize(CI->getType());
2936 Size -= (BitWidth / 64) * 8;
2937 assert(Size && Size * 8 >= ExtraBitsSize &&(static_cast <bool> (Size && Size * 8 >= ExtraBitsSize
&& (ExtraBits & (((uint64_t)-1) >> (64 - ExtraBitsSize
))) == ExtraBits && "Directive too small for extra bits."
) ? void (0) : __assert_fail ("Size && Size * 8 >= ExtraBitsSize && (ExtraBits & (((uint64_t)-1) >> (64 - ExtraBitsSize))) == ExtraBits && \"Directive too small for extra bits.\""
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 2939, __extension__
__PRETTY_FUNCTION__))
2938 (ExtraBits & (((uint64_t)-1) >> (64 - ExtraBitsSize)))(static_cast <bool> (Size && Size * 8 >= ExtraBitsSize
&& (ExtraBits & (((uint64_t)-1) >> (64 - ExtraBitsSize
))) == ExtraBits && "Directive too small for extra bits."
) ? void (0) : __assert_fail ("Size && Size * 8 >= ExtraBitsSize && (ExtraBits & (((uint64_t)-1) >> (64 - ExtraBitsSize))) == ExtraBits && \"Directive too small for extra bits.\""
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 2939, __extension__
__PRETTY_FUNCTION__))
2939 == ExtraBits && "Directive too small for extra bits.")(static_cast <bool> (Size && Size * 8 >= ExtraBitsSize
&& (ExtraBits & (((uint64_t)-1) >> (64 - ExtraBitsSize
))) == ExtraBits && "Directive too small for extra bits."
) ? void (0) : __assert_fail ("Size && Size * 8 >= ExtraBitsSize && (ExtraBits & (((uint64_t)-1) >> (64 - ExtraBitsSize))) == ExtraBits && \"Directive too small for extra bits.\""
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 2939, __extension__
__PRETTY_FUNCTION__))
;
2940 AP.OutStreamer->emitIntValue(ExtraBits, Size);
2941 }
2942}
2943
2944/// Transform a not absolute MCExpr containing a reference to a GOT
2945/// equivalent global, by a target specific GOT pc relative access to the
2946/// final symbol.
2947static void handleIndirectSymViaGOTPCRel(AsmPrinter &AP, const MCExpr **ME,
2948 const Constant *BaseCst,
2949 uint64_t Offset) {
2950 // The global @foo below illustrates a global that uses a got equivalent.
2951 //
2952 // @bar = global i32 42
2953 // @gotequiv = private unnamed_addr constant i32* @bar
2954 // @foo = i32 trunc (i64 sub (i64 ptrtoint (i32** @gotequiv to i64),
2955 // i64 ptrtoint (i32* @foo to i64))
2956 // to i32)
2957 //
2958 // The cstexpr in @foo is converted into the MCExpr `ME`, where we actually
2959 // check whether @foo is suitable to use a GOTPCREL. `ME` is usually in the
2960 // form:
2961 //
2962 // foo = cstexpr, where
2963 // cstexpr := <gotequiv> - "." + <cst>
2964 // cstexpr := <gotequiv> - (<foo> - <offset from @foo base>) + <cst>
2965 //
2966 // After canonicalization by evaluateAsRelocatable `ME` turns into:
2967 //
2968 // cstexpr := <gotequiv> - <foo> + gotpcrelcst, where
2969 // gotpcrelcst := <offset from @foo base> + <cst>
2970 MCValue MV;
2971 if (!(*ME)->evaluateAsRelocatable(MV, nullptr, nullptr) || MV.isAbsolute())
2972 return;
2973 const MCSymbolRefExpr *SymA = MV.getSymA();
2974 if (!SymA)
2975 return;
2976
2977 // Check that GOT equivalent symbol is cached.
2978 const MCSymbol *GOTEquivSym = &SymA->getSymbol();
2979 if (!AP.GlobalGOTEquivs.count(GOTEquivSym))
2980 return;
2981
2982 const GlobalValue *BaseGV = dyn_cast_or_null<GlobalValue>(BaseCst);
2983 if (!BaseGV)
2984 return;
2985
2986 // Check for a valid base symbol
2987 const MCSymbol *BaseSym = AP.getSymbol(BaseGV);
2988 const MCSymbolRefExpr *SymB = MV.getSymB();
2989
2990 if (!SymB || BaseSym != &SymB->getSymbol())
2991 return;
2992
2993 // Make sure to match:
2994 //
2995 // gotpcrelcst := <offset from @foo base> + <cst>
2996 //
2997 // If gotpcrelcst is positive it means that we can safely fold the pc rel
2998 // displacement into the GOTPCREL. We can also can have an extra offset <cst>
2999 // if the target knows how to encode it.
3000 int64_t GOTPCRelCst = Offset + MV.getConstant();
3001 if (GOTPCRelCst < 0)
3002 return;
3003 if (!AP.getObjFileLowering().supportGOTPCRelWithOffset() && GOTPCRelCst != 0)
3004 return;
3005
3006 // Emit the GOT PC relative to replace the got equivalent global, i.e.:
3007 //
3008 // bar:
3009 // .long 42
3010 // gotequiv:
3011 // .quad bar
3012 // foo:
3013 // .long gotequiv - "." + <cst>
3014 //
3015 // is replaced by the target specific equivalent to:
3016 //
3017 // bar:
3018 // .long 42
3019 // foo:
3020 // .long bar@GOTPCREL+<gotpcrelcst>
3021 AsmPrinter::GOTEquivUsePair Result = AP.GlobalGOTEquivs[GOTEquivSym];
3022 const GlobalVariable *GV = Result.first;
3023 int NumUses = (int)Result.second;
3024 const GlobalValue *FinalGV = dyn_cast<GlobalValue>(GV->getOperand(0));
3025 const MCSymbol *FinalSym = AP.getSymbol(FinalGV);
3026 *ME = AP.getObjFileLowering().getIndirectSymViaGOTPCRel(
3027 FinalGV, FinalSym, MV, Offset, AP.MMI, *AP.OutStreamer);
3028
3029 // Update GOT equivalent usage information
3030 --NumUses;
3031 if (NumUses >= 0)
3032 AP.GlobalGOTEquivs[GOTEquivSym] = std::make_pair(GV, NumUses);
3033}
3034
3035static void emitGlobalConstantImpl(const DataLayout &DL, const Constant *CV,
3036 AsmPrinter &AP, const Constant *BaseCV,
3037 uint64_t Offset) {
3038 uint64_t Size = DL.getTypeAllocSize(CV->getType());
3039
3040 // Globals with sub-elements such as combinations of arrays and structs
3041 // are handled recursively by emitGlobalConstantImpl. Keep track of the
3042 // constant symbol base and the current position with BaseCV and Offset.
3043 if (!BaseCV && CV->hasOneUse())
3044 BaseCV = dyn_cast<Constant>(CV->user_back());
3045
3046 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV))
3047 return AP.OutStreamer->emitZeros(Size);
3048
3049 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
3050 const uint64_t StoreSize = DL.getTypeStoreSize(CV->getType());
3051
3052 if (StoreSize <= 8) {
3053 if (AP.isVerbose())
3054 AP.OutStreamer->GetCommentOS() << format("0x%" PRIx64"l" "x" "\n",
3055 CI->getZExtValue());
3056 AP.OutStreamer->emitIntValue(CI->getZExtValue(), StoreSize);
3057 } else {
3058 emitGlobalConstantLargeInt(CI, AP);
3059 }
3060
3061 // Emit tail padding if needed
3062 if (Size != StoreSize)
3063 AP.OutStreamer->emitZeros(Size - StoreSize);
3064
3065 return;
3066 }
3067
3068 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
3069 return emitGlobalConstantFP(CFP, AP);
3070
3071 if (isa<ConstantPointerNull>(CV)) {
3072 AP.OutStreamer->emitIntValue(0, Size);
3073 return;
3074 }
3075
3076 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(CV))
3077 return emitGlobalConstantDataSequential(DL, CDS, AP);
3078
3079 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
3080 return emitGlobalConstantArray(DL, CVA, AP, BaseCV, Offset);
3081
3082 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
3083 return emitGlobalConstantStruct(DL, CVS, AP, BaseCV, Offset);
3084
3085 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV)) {
3086 // Look through bitcasts, which might not be able to be MCExpr'ized (e.g. of
3087 // vectors).
3088 if (CE->getOpcode() == Instruction::BitCast)
3089 return emitGlobalConstantImpl(DL, CE->getOperand(0), AP);
3090
3091 if (Size > 8) {
3092 // If the constant expression's size is greater than 64-bits, then we have
3093 // to emit the value in chunks. Try to constant fold the value and emit it
3094 // that way.
3095 Constant *New = ConstantFoldConstant(CE, DL);
3096 if (New != CE)
3097 return emitGlobalConstantImpl(DL, New, AP);
3098 }
3099 }
3100
3101 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
3102 return emitGlobalConstantVector(DL, V, AP);
3103
3104 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it
3105 // thread the streamer with EmitValue.
3106 const MCExpr *ME = AP.lowerConstant(CV);
3107
3108 // Since lowerConstant already folded and got rid of all IR pointer and
3109 // integer casts, detect GOT equivalent accesses by looking into the MCExpr
3110 // directly.
3111 if (AP.getObjFileLowering().supportIndirectSymViaGOTPCRel())
3112 handleIndirectSymViaGOTPCRel(AP, &ME, BaseCV, Offset);
3113
3114 AP.OutStreamer->emitValue(ME, Size);
3115}
3116
3117/// EmitGlobalConstant - Print a general LLVM constant to the .s file.
3118void AsmPrinter::emitGlobalConstant(const DataLayout &DL, const Constant *CV) {
3119 uint64_t Size = DL.getTypeAllocSize(CV->getType());
3120 if (Size)
3121 emitGlobalConstantImpl(DL, CV, *this);
3122 else if (MAI->hasSubsectionsViaSymbols()) {
3123 // If the global has zero size, emit a single byte so that two labels don't
3124 // look like they are at the same location.
3125 OutStreamer->emitIntValue(0, 1);
3126 }
3127}
3128
3129void AsmPrinter::emitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
3130 // Target doesn't support this yet!
3131 llvm_unreachable("Target does not support EmitMachineConstantPoolValue")::llvm::llvm_unreachable_internal("Target does not support EmitMachineConstantPoolValue"
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 3131)
;
3132}
3133
3134void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const {
3135 if (Offset > 0)
3136 OS << '+' << Offset;
3137 else if (Offset < 0)
3138 OS << Offset;
3139}
3140
3141void AsmPrinter::emitNops(unsigned N) {
3142 MCInst Nop = MF->getSubtarget().getInstrInfo()->getNop();
3143 for (; N; --N)
3144 EmitToStreamer(*OutStreamer, Nop);
3145}
3146
3147//===----------------------------------------------------------------------===//
3148// Symbol Lowering Routines.
3149//===----------------------------------------------------------------------===//
3150
3151MCSymbol *AsmPrinter::createTempSymbol(const Twine &Name) const {
3152 return OutContext.createTempSymbol(Name, true);
3153}
3154
3155MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
3156 return MMI->getAddrLabelSymbol(BA->getBasicBlock());
3157}
3158
3159MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const {
3160 return MMI->getAddrLabelSymbol(BB);
3161}
3162
3163/// GetCPISymbol - Return the symbol for the specified constant pool entry.
3164MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
3165 if (getSubtargetInfo().getTargetTriple().isWindowsMSVCEnvironment()) {
3166 const MachineConstantPoolEntry &CPE =
3167 MF->getConstantPool()->getConstants()[CPID];
3168 if (!CPE.isMachineConstantPoolEntry()) {
3169 const DataLayout &DL = MF->getDataLayout();
3170 SectionKind Kind = CPE.getSectionKind(&DL);
3171 const Constant *C = CPE.Val.ConstVal;
3172 Align Alignment = CPE.Alignment;
3173 if (const MCSectionCOFF *S = dyn_cast<MCSectionCOFF>(
3174 getObjFileLowering().getSectionForConstant(DL, Kind, C,
3175 Alignment))) {
3176 if (MCSymbol *Sym = S->getCOMDATSymbol()) {
3177 if (Sym->isUndefined())
3178 OutStreamer->emitSymbolAttribute(Sym, MCSA_Global);
3179 return Sym;
3180 }
3181 }
3182 }
3183 }
3184
3185 const DataLayout &DL = getDataLayout();
3186 return OutContext.getOrCreateSymbol(Twine(DL.getPrivateGlobalPrefix()) +
3187 "CPI" + Twine(getFunctionNumber()) + "_" +
3188 Twine(CPID));
3189}
3190
3191/// GetJTISymbol - Return the symbol for the specified jump table entry.
3192MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
3193 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
3194}
3195
3196/// GetJTSetSymbol - Return the symbol for the specified jump table .set
3197/// FIXME: privatize to AsmPrinter.
3198MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
3199 const DataLayout &DL = getDataLayout();
3200 return OutContext.getOrCreateSymbol(Twine(DL.getPrivateGlobalPrefix()) +
3201 Twine(getFunctionNumber()) + "_" +
3202 Twine(UID) + "_set_" + Twine(MBBID));
3203}
3204
3205MCSymbol *AsmPrinter::getSymbolWithGlobalValueBase(const GlobalValue *GV,
3206 StringRef Suffix) const {
3207 return getObjFileLowering().getSymbolWithGlobalValueBase(GV, Suffix, TM);
3208}
3209
3210/// Return the MCSymbol for the specified ExternalSymbol.
3211MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
3212 SmallString<60> NameStr;
3213 Mangler::getNameWithPrefix(NameStr, Sym, getDataLayout());
3214 return OutContext.getOrCreateSymbol(NameStr);
3215}
3216
3217/// PrintParentLoopComment - Print comments about parent loops of this one.
3218static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
3219 unsigned FunctionNumber) {
3220 if (!Loop) return;
3221 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
3222 OS.indent(Loop->getLoopDepth()*2)
3223 << "Parent Loop BB" << FunctionNumber << "_"
3224 << Loop->getHeader()->getNumber()
3225 << " Depth=" << Loop->getLoopDepth() << '\n';
3226}
3227
3228/// PrintChildLoopComment - Print comments about child loops within
3229/// the loop for this basic block, with nesting.
3230static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
3231 unsigned FunctionNumber) {
3232 // Add child loop information
3233 for (const MachineLoop *CL : *Loop) {
3234 OS.indent(CL->getLoopDepth()*2)
3235 << "Child Loop BB" << FunctionNumber << "_"
3236 << CL->getHeader()->getNumber() << " Depth " << CL->getLoopDepth()
3237 << '\n';
3238 PrintChildLoopComment(OS, CL, FunctionNumber);
3239 }
3240}
3241
3242/// emitBasicBlockLoopComments - Pretty-print comments for basic blocks.
3243static void emitBasicBlockLoopComments(const MachineBasicBlock &MBB,
3244 const MachineLoopInfo *LI,
3245 const AsmPrinter &AP) {
3246 // Add loop depth information
3247 const MachineLoop *Loop = LI->getLoopFor(&MBB);
3248 if (!Loop) return;
3249
3250 MachineBasicBlock *Header = Loop->getHeader();
3251 assert(Header && "No header for loop")(static_cast <bool> (Header && "No header for loop"
) ? void (0) : __assert_fail ("Header && \"No header for loop\""
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 3251, __extension__
__PRETTY_FUNCTION__))
;
3252
3253 // If this block is not a loop header, just print out what is the loop header
3254 // and return.
3255 if (Header != &MBB) {
3256 AP.OutStreamer->AddComment(" in Loop: Header=BB" +
3257 Twine(AP.getFunctionNumber())+"_" +
3258 Twine(Loop->getHeader()->getNumber())+
3259 " Depth="+Twine(Loop->getLoopDepth()));
3260 return;
3261 }
3262
3263 // Otherwise, it is a loop header. Print out information about child and
3264 // parent loops.
3265 raw_ostream &OS = AP.OutStreamer->GetCommentOS();
3266
3267 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
3268
3269 OS << "=>";
3270 OS.indent(Loop->getLoopDepth()*2-2);
3271
3272 OS << "This ";
3273 if (Loop->isInnermost())
3274 OS << "Inner ";
3275 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
3276
3277 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
3278}
3279
3280/// emitBasicBlockStart - This method prints the label for the specified
3281/// MachineBasicBlock, an alignment (if present) and a comment describing
3282/// it if appropriate.
3283void AsmPrinter::emitBasicBlockStart(const MachineBasicBlock &MBB) {
3284 // End the previous funclet and start a new one.
3285 if (MBB.isEHFuncletEntry()) {
3286 for (const HandlerInfo &HI : Handlers) {
3287 HI.Handler->endFunclet();
3288 HI.Handler->beginFunclet(MBB);
3289 }
3290 }
3291
3292 // Emit an alignment directive for this block, if needed.
3293 const Align Alignment = MBB.getAlignment();
3294 if (Alignment != Align(1))
3295 emitAlignment(Alignment, nullptr, MBB.getMaxBytesForAlignment());
3296
3297 // Switch to a new section if this basic block must begin a section. The
3298 // entry block is always placed in the function section and is handled
3299 // separately.
3300 if (MBB.isBeginSection() && !MBB.isEntryBlock()) {
3301 OutStreamer->SwitchSection(
3302 getObjFileLowering().getSectionForMachineBasicBlock(MF->getFunction(),
3303 MBB, TM));
3304 CurrentSectionBeginSym = MBB.getSymbol();
3305 }
3306
3307 // If the block has its address taken, emit any labels that were used to
3308 // reference the block. It is possible that there is more than one label
3309 // here, because multiple LLVM BB's may have been RAUW'd to this block after
3310 // the references were generated.
3311 const BasicBlock *BB = MBB.getBasicBlock();
3312 if (MBB.hasAddressTaken()) {
3313 if (isVerbose())
3314 OutStreamer->AddComment("Block address taken");
3315
3316 // MBBs can have their address taken as part of CodeGen without having
3317 // their corresponding BB's address taken in IR
3318 if (BB && BB->hasAddressTaken())
3319 for (MCSymbol *Sym : MMI->getAddrLabelSymbolToEmit(BB))
3320 OutStreamer->emitLabel(Sym);
3321 }
3322
3323 // Print some verbose block comments.
3324 if (isVerbose()) {
3325 if (BB) {
3326 if (BB->hasName()) {
3327 BB->printAsOperand(OutStreamer->GetCommentOS(),
3328 /*PrintType=*/false, BB->getModule());
3329 OutStreamer->GetCommentOS() << '\n';
3330 }
3331 }
3332
3333 assert(MLI != nullptr && "MachineLoopInfo should has been computed")(static_cast <bool> (MLI != nullptr && "MachineLoopInfo should has been computed"
) ? void (0) : __assert_fail ("MLI != nullptr && \"MachineLoopInfo should has been computed\""
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 3333, __extension__
__PRETTY_FUNCTION__))
;
3334 emitBasicBlockLoopComments(MBB, MLI, *this);
3335 }
3336
3337 // Print the main label for the block.
3338 if (shouldEmitLabelForBasicBlock(MBB)) {
3339 if (isVerbose() && MBB.hasLabelMustBeEmitted())
3340 OutStreamer->AddComment("Label of block must be emitted");
3341 OutStreamer->emitLabel(MBB.getSymbol());
3342 } else {
3343 if (isVerbose()) {
3344 // NOTE: Want this comment at start of line, don't emit with AddComment.
3345 OutStreamer->emitRawComment(" %bb." + Twine(MBB.getNumber()) + ":",
3346 false);
3347 }
3348 }
3349
3350 if (MBB.isEHCatchretTarget() &&
3351 MAI->getExceptionHandlingType() == ExceptionHandling::WinEH) {
3352 OutStreamer->emitLabel(MBB.getEHCatchretSymbol());
3353 }
3354
3355 // With BB sections, each basic block must handle CFI information on its own
3356 // if it begins a section (Entry block is handled separately by
3357 // AsmPrinterHandler::beginFunction).
3358 if (MBB.isBeginSection() && !MBB.isEntryBlock())
3359 for (const HandlerInfo &HI : Handlers)
3360 HI.Handler->beginBasicBlock(MBB);
3361}
3362
3363void AsmPrinter::emitBasicBlockEnd(const MachineBasicBlock &MBB) {
3364 // Check if CFI information needs to be updated for this MBB with basic block
3365 // sections.
3366 if (MBB.isEndSection())
3367 for (const HandlerInfo &HI : Handlers)
3368 HI.Handler->endBasicBlock(MBB);
3369}
3370
3371void AsmPrinter::emitVisibility(MCSymbol *Sym, unsigned Visibility,
3372 bool IsDefinition) const {
3373 MCSymbolAttr Attr = MCSA_Invalid;
3374
3375 switch (Visibility) {
3376 default: break;
3377 case GlobalValue::HiddenVisibility:
3378 if (IsDefinition)
3379 Attr = MAI->getHiddenVisibilityAttr();
3380 else
3381 Attr = MAI->getHiddenDeclarationVisibilityAttr();
3382 break;
3383 case GlobalValue::ProtectedVisibility:
3384 Attr = MAI->getProtectedVisibilityAttr();
3385 break;
3386 }
3387
3388 if (Attr != MCSA_Invalid)
3389 OutStreamer->emitSymbolAttribute(Sym, Attr);
3390}
3391
3392bool AsmPrinter::shouldEmitLabelForBasicBlock(
3393 const MachineBasicBlock &MBB) const {
3394 // With `-fbasic-block-sections=`, a label is needed for every non-entry block
3395 // in the labels mode (option `=labels`) and every section beginning in the
3396 // sections mode (`=all` and `=list=`).
3397 if ((MF->hasBBLabels() || MBB.isBeginSection()) && !MBB.isEntryBlock())
3398 return true;
3399 // A label is needed for any block with at least one predecessor (when that
3400 // predecessor is not the fallthrough predecessor, or if it is an EH funclet
3401 // entry, or if a label is forced).
3402 return !MBB.pred_empty() &&
3403 (!isBlockOnlyReachableByFallthrough(&MBB) || MBB.isEHFuncletEntry() ||
3404 MBB.hasLabelMustBeEmitted());
3405}
3406
3407/// isBlockOnlyReachableByFallthough - Return true if the basic block has
3408/// exactly one predecessor and the control transfer mechanism between
3409/// the predecessor and this block is a fall-through.
3410bool AsmPrinter::
3411isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const {
3412 // If this is a landing pad, it isn't a fall through. If it has no preds,
3413 // then nothing falls through to it.
3414 if (MBB->isEHPad() || MBB->pred_empty())
3415 return false;
3416
3417 // If there isn't exactly one predecessor, it can't be a fall through.
3418 if (MBB->pred_size() > 1)
3419 return false;
3420
3421 // The predecessor has to be immediately before this block.
3422 MachineBasicBlock *Pred = *MBB->pred_begin();
3423 if (!Pred->isLayoutSuccessor(MBB))
3424 return false;
3425
3426 // If the block is completely empty, then it definitely does fall through.
3427 if (Pred->empty())
3428 return true;
3429
3430 // Check the terminators in the previous blocks
3431 for (const auto &MI : Pred->terminators()) {
3432 // If it is not a simple branch, we are in a table somewhere.
3433 if (!MI.isBranch() || MI.isIndirectBranch())
3434 return false;
3435
3436 // If we are the operands of one of the branches, this is not a fall
3437 // through. Note that targets with delay slots will usually bundle
3438 // terminators with the delay slot instruction.
3439 for (ConstMIBundleOperands OP(MI); OP.isValid(); ++OP) {
3440 if (OP->isJTI())
3441 return false;
3442 if (OP->isMBB() && OP->getMBB() == MBB)
3443 return false;
3444 }
3445 }
3446
3447 return true;
3448}
3449
3450GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy &S) {
3451 if (!S.usesMetadata())
3452 return nullptr;
3453
3454 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
3455 gcp_map_type::iterator GCPI = GCMap.find(&S);
3456 if (GCPI != GCMap.end())
3457 return GCPI->second.get();
3458
3459 auto Name = S.getName();
3460
3461 for (const GCMetadataPrinterRegistry::entry &GCMetaPrinter :
3462 GCMetadataPrinterRegistry::entries())
3463 if (Name == GCMetaPrinter.getName()) {
3464 std::unique_ptr<GCMetadataPrinter> GMP = GCMetaPrinter.instantiate();
3465 GMP->S = &S;
3466 auto IterBool = GCMap.insert(std::make_pair(&S, std::move(GMP)));
3467 return IterBool.first->second.get();
3468 }
3469
3470 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name));
3471}
3472
3473void AsmPrinter::emitStackMaps(StackMaps &SM) {
3474 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
3475 assert(MI && "AsmPrinter didn't require GCModuleInfo?")(static_cast <bool> (MI && "AsmPrinter didn't require GCModuleInfo?"
) ? void (0) : __assert_fail ("MI && \"AsmPrinter didn't require GCModuleInfo?\""
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 3475, __extension__
__PRETTY_FUNCTION__))
;
3476 bool NeedsDefault = false;
3477 if (MI->begin() == MI->end())
3478 // No GC strategy, use the default format.
3479 NeedsDefault = true;
3480 else
3481 for (auto &I : *MI) {
3482 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I))
3483 if (MP->emitStackMaps(SM, *this))
3484 continue;
3485 // The strategy doesn't have printer or doesn't emit custom stack maps.
3486 // Use the default format.
3487 NeedsDefault = true;
3488 }
3489
3490 if (NeedsDefault)
3491 SM.serializeToStackMapSection();
3492}
3493
3494/// Pin vtable to this file.
3495AsmPrinterHandler::~AsmPrinterHandler() = default;
3496
3497void AsmPrinterHandler::markFunctionEnd() {}
3498
3499// In the binary's "xray_instr_map" section, an array of these function entries
3500// describes each instrumentation point. When XRay patches your code, the index
3501// into this table will be given to your handler as a patch point identifier.
3502void AsmPrinter::XRayFunctionEntry::emit(int Bytes, MCStreamer *Out) const {
3503 auto Kind8 = static_cast<uint8_t>(Kind);
3504 Out->emitBinaryData(StringRef(reinterpret_cast<const char *>(&Kind8), 1));
3505 Out->emitBinaryData(
3506 StringRef(reinterpret_cast<const char *>(&AlwaysInstrument), 1));
3507 Out->emitBinaryData(StringRef(reinterpret_cast<const char *>(&Version), 1));
3508 auto Padding = (4 * Bytes) - ((2 * Bytes) + 3);
3509 assert(Padding >= 0 && "Instrumentation map entry > 4 * Word Size")(static_cast <bool> (Padding >= 0 && "Instrumentation map entry > 4 * Word Size"
) ? void (0) : __assert_fail ("Padding >= 0 && \"Instrumentation map entry > 4 * Word Size\""
, "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp", 3509, __extension__
__PRETTY_FUNCTION__))
;
3510 Out->emitZeros(Padding);
3511}
3512
3513void AsmPrinter::emitXRayTable() {
3514 if (Sleds.empty())
3515 return;
3516
3517 auto PrevSection = OutStreamer->getCurrentSectionOnly();
3518 const Function &F = MF->getFunction();
3519 MCSection *InstMap = nullptr;
3520 MCSection *FnSledIndex = nullptr;
3521 const Triple &TT = TM.getTargetTriple();
3522 // Use PC-relative addresses on all targets.
3523 if (TT.isOSBinFormatELF()) {
3524 auto LinkedToSym = cast<MCSymbolELF>(CurrentFnSym);
3525 auto Flags = ELF::SHF_ALLOC | ELF::SHF_LINK_ORDER;
3526 StringRef GroupName;
3527 if (F.hasComdat()) {
3528 Flags |= ELF::SHF_GROUP;
3529 GroupName = F.getComdat()->getName();
3530 }
3531 InstMap = OutContext.getELFSection("xray_instr_map", ELF::SHT_PROGBITS,
3532 Flags, 0, GroupName, F.hasComdat(),
3533 MCSection::NonUniqueID, LinkedToSym);
3534
3535 if (!TM.Options.XRayOmitFunctionIndex)
3536 FnSledIndex = OutContext.getELFSection(
3537 "xray_fn_idx", ELF::SHT_PROGBITS, Flags | ELF::SHF_WRITE, 0,
3538 GroupName, F.hasComdat(), MCSection::NonUniqueID, LinkedToSym);
3539 } else if (MF->getSubtarget().getTargetTriple().isOSBinFormatMachO()) {
3540 InstMap = OutContext.getMachOSection("__DATA", "xray_instr_map", 0,
3541 SectionKind::getReadOnlyWithRel());
3542 if (!TM.Options.XRayOmitFunctionIndex)
3543 FnSledIndex = OutContext.getMachOSection(
3544 "__DATA", "xray_fn_idx", 0, SectionKind::getReadOnlyWithRel());
3545 } else {
3546 llvm_unreachable("Unsupported target")::llvm::llvm_unreachable_internal("Unsupported target", "llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 3546)
;
3547 }
3548
3549 auto WordSizeBytes = MAI->getCodePointerSize();
3550
3551 // Now we switch to the instrumentation map section. Because this is done
3552 // per-function, we are able to create an index entry that will represent the
3553 // range of sleds associated with a function.
3554 auto &Ctx = OutContext;
3555 MCSymbol *SledsStart = OutContext.createTempSymbol("xray_sleds_start", true);
3556 OutStreamer->SwitchSection(InstMap);
3557 OutStreamer->emitLabel(SledsStart);
3558 for (const auto &Sled : Sleds) {
3559 MCSymbol *Dot = Ctx.createTempSymbol();
3560 OutStreamer->emitLabel(Dot);
3561 OutStreamer->emitValueImpl(
3562 MCBinaryExpr::createSub(MCSymbolRefExpr::create(Sled.Sled, Ctx),
3563 MCSymbolRefExpr::create(Dot, Ctx), Ctx),
3564 WordSizeBytes);
3565 OutStreamer->emitValueImpl(
3566 MCBinaryExpr::createSub(
3567 MCSymbolRefExpr::create(CurrentFnBegin, Ctx),
3568 MCBinaryExpr::createAdd(MCSymbolRefExpr::create(Dot, Ctx),
3569 MCConstantExpr::create(WordSizeBytes, Ctx),
3570 Ctx),
3571 Ctx),
3572 WordSizeBytes);
3573 Sled.emit(WordSizeBytes, OutStreamer.get());
3574 }
3575 MCSymbol *SledsEnd = OutContext.createTempSymbol("xray_sleds_end", true);
3576 OutStreamer->emitLabel(SledsEnd);
3577
3578 // We then emit a single entry in the index per function. We use the symbols
3579 // that bound the instrumentation map as the range for a specific function.
3580 // Each entry here will be 2 * word size aligned, as we're writing down two
3581 // pointers. This should work for both 32-bit and 64-bit platforms.
3582 if (FnSledIndex) {
3583 OutStreamer->SwitchSection(FnSledIndex);
3584 OutStreamer->emitCodeAlignment(2 * WordSizeBytes, &getSubtargetInfo());
3585 OutStreamer->emitSymbolValue(SledsStart, WordSizeBytes, false);
3586 OutStreamer->emitSymbolValue(SledsEnd, WordSizeBytes, false);
3587 OutStreamer->SwitchSection(PrevSection);
3588 }
3589 Sleds.clear();
3590}
3591
3592void AsmPrinter::recordSled(MCSymbol *Sled, const MachineInstr &MI,
3593 SledKind Kind, uint8_t Version) {
3594 const Function &F = MI.getMF()->getFunction();
3595 auto Attr = F.getFnAttribute("function-instrument");
3596 bool LogArgs = F.hasFnAttribute("xray-log-args");
3597 bool AlwaysInstrument =
3598 Attr.isStringAttribute() && Attr.getValueAsString() == "xray-always";
3599 if (Kind == SledKind::FUNCTION_ENTER && LogArgs)
3600 Kind = SledKind::LOG_ARGS_ENTER;
3601 Sleds.emplace_back(XRayFunctionEntry{Sled, CurrentFnSym, Kind,
3602 AlwaysInstrument, &F, Version});
3603}
3604
3605void AsmPrinter::emitPatchableFunctionEntries() {
3606 const Function &F = MF->getFunction();
3607 unsigned PatchableFunctionPrefix = 0, PatchableFunctionEntry = 0;
3608 (void)F.getFnAttribute("patchable-function-prefix")
3609 .getValueAsString()
3610 .getAsInteger(10, PatchableFunctionPrefix);
3611 (void)F.getFnAttribute("patchable-function-entry")
3612 .getValueAsString()
3613 .getAsInteger(10, PatchableFunctionEntry);
3614 if (!PatchableFunctionPrefix && !PatchableFunctionEntry)
3615 return;
3616 const unsigned PointerSize = getPointerSize();
3617 if (TM.getTargetTriple().isOSBinFormatELF()) {
3618 auto Flags = ELF::SHF_WRITE | ELF::SHF_ALLOC;
3619 const MCSymbolELF *LinkedToSym = nullptr;
3620 StringRef GroupName;
3621
3622 // GNU as < 2.35 did not support section flag 'o'. GNU ld < 2.36 did not
3623 // support mixed SHF_LINK_ORDER and non-SHF_LINK_ORDER sections.
3624 if (MAI->useIntegratedAssembler() || MAI->binutilsIsAtLeast(2, 36)) {
3625 Flags |= ELF::SHF_LINK_ORDER;
3626 if (F.hasComdat()) {
3627 Flags |= ELF::SHF_GROUP;
3628 GroupName = F.getComdat()->getName();
3629 }
3630 LinkedToSym = cast<MCSymbolELF>(CurrentFnSym);
3631 }
3632 OutStreamer->SwitchSection(OutContext.getELFSection(
3633 "__patchable_function_entries", ELF::SHT_PROGBITS, Flags, 0, GroupName,
3634 F.hasComdat(), MCSection::NonUniqueID, LinkedToSym));
3635 emitAlignment(Align(PointerSize));
3636 OutStreamer->emitSymbolValue(CurrentPatchableFunctionEntrySym, PointerSize);
3637 }
3638}
3639
3640uint16_t AsmPrinter::getDwarfVersion() const {
3641 return OutStreamer->getContext().getDwarfVersion();
3642}
3643
3644void AsmPrinter::setDwarfVersion(uint16_t Version) {
3645 OutStreamer->getContext().setDwarfVersion(Version);
3646}
3647
3648bool AsmPrinter::isDwarf64() const {
3649 return OutStreamer->getContext().getDwarfFormat() == dwarf::DWARF64;
3650}
3651
3652unsigned int AsmPrinter::getDwarfOffsetByteSize() const {
3653 return dwarf::getDwarfOffsetByteSize(
3654 OutStreamer->getContext().getDwarfFormat());
3655}
3656
3657dwarf::FormParams AsmPrinter::getDwarfFormParams() const {
3658 return {getDwarfVersion(), uint8_t(getPointerSize()),
3659 OutStreamer->getContext().getDwarfFormat(),
3660 MAI->doesDwarfUseRelocationsAcrossSections()};
3661}
3662
3663unsigned int AsmPrinter::getUnitLengthFieldByteSize() const {
3664 return dwarf::getUnitLengthFieldByteSize(
3665 OutStreamer->getContext().getDwarfFormat());
3666}