Bug Summary

File:include/llvm/CodeGen/DIE.h
Warning:line 641, column 5
Forming reference to null pointer

Annotated Source Code

Press '?' to see keyboard shortcuts

clang -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name DwarfCompileUnit.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 -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -mthread-model posix -fmath-errno -masm-verbose -mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu x86-64 -dwarf-column-info -debugger-tuning=gdb -momit-leaf-frame-pointer -ffunction-sections -fdata-sections -resource-dir /usr/lib/llvm-8/lib/clang/8.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-8~svn350071/build-llvm/lib/CodeGen/AsmPrinter -I /build/llvm-toolchain-snapshot-8~svn350071/lib/CodeGen/AsmPrinter -I /build/llvm-toolchain-snapshot-8~svn350071/build-llvm/include -I /build/llvm-toolchain-snapshot-8~svn350071/include -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0/backward -internal-isystem /usr/include/clang/8.0.0/include/ -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-8/lib/clang/8.0.0/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-comment -std=c++11 -fdeprecated-macro -fdebug-compilation-dir /build/llvm-toolchain-snapshot-8~svn350071/build-llvm/lib/CodeGen/AsmPrinter -fdebug-prefix-map=/build/llvm-toolchain-snapshot-8~svn350071=. -ferror-limit 19 -fmessage-length 0 -fvisibility-inlines-hidden -stack-protector 2 -fobjc-runtime=gcc -fdiagnostics-show-option -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -o /tmp/scan-build-2018-12-27-042839-1215-1 -x c++ /build/llvm-toolchain-snapshot-8~svn350071/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp -faddrsig

/build/llvm-toolchain-snapshot-8~svn350071/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp

1//===- llvm/CodeGen/DwarfCompileUnit.cpp - Dwarf Compile Units ------------===//
2//
3// The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file contains support for constructing a dwarf compile unit.
11//
12//===----------------------------------------------------------------------===//
13
14#include "DwarfCompileUnit.h"
15#include "AddressPool.h"
16#include "DwarfDebug.h"
17#include "DwarfExpression.h"
18#include "DwarfUnit.h"
19#include "llvm/ADT/None.h"
20#include "llvm/ADT/STLExtras.h"
21#include "llvm/ADT/SmallVector.h"
22#include "llvm/ADT/StringRef.h"
23#include "llvm/BinaryFormat/Dwarf.h"
24#include "llvm/CodeGen/AsmPrinter.h"
25#include "llvm/CodeGen/DIE.h"
26#include "llvm/CodeGen/LexicalScopes.h"
27#include "llvm/CodeGen/MachineFunction.h"
28#include "llvm/CodeGen/MachineInstr.h"
29#include "llvm/CodeGen/MachineOperand.h"
30#include "llvm/CodeGen/TargetFrameLowering.h"
31#include "llvm/CodeGen/TargetRegisterInfo.h"
32#include "llvm/CodeGen/TargetSubtargetInfo.h"
33#include "llvm/IR/DataLayout.h"
34#include "llvm/IR/DebugInfo.h"
35#include "llvm/IR/DebugInfoMetadata.h"
36#include "llvm/IR/GlobalVariable.h"
37#include "llvm/MC/MCSection.h"
38#include "llvm/MC/MCStreamer.h"
39#include "llvm/MC/MCSymbol.h"
40#include "llvm/MC/MachineLocation.h"
41#include "llvm/Support/Casting.h"
42#include "llvm/Target/TargetLoweringObjectFile.h"
43#include "llvm/Target/TargetMachine.h"
44#include "llvm/Target/TargetOptions.h"
45#include <algorithm>
46#include <cassert>
47#include <cstdint>
48#include <iterator>
49#include <memory>
50#include <string>
51#include <utility>
52
53using namespace llvm;
54
55DwarfCompileUnit::DwarfCompileUnit(unsigned UID, const DICompileUnit *Node,
56 AsmPrinter *A, DwarfDebug *DW,
57 DwarfFile *DWU)
58 : DwarfUnit(dwarf::DW_TAG_compile_unit, Node, A, DW, DWU), UniqueID(UID) {
59 insertDIE(Node, &getUnitDie());
60 MacroLabelBegin = Asm->createTempSymbol("cu_macro_begin");
61}
62
63/// addLabelAddress - Add a dwarf label attribute data and value using
64/// DW_FORM_addr or DW_FORM_GNU_addr_index.
65void DwarfCompileUnit::addLabelAddress(DIE &Die, dwarf::Attribute Attribute,
66 const MCSymbol *Label) {
67 // Don't use the address pool in non-fission or in the skeleton unit itself.
68 // FIXME: Once GDB supports this, it's probably worthwhile using the address
69 // pool from the skeleton - maybe even in non-fission (possibly fewer
70 // relocations by sharing them in the pool, but we have other ideas about how
71 // to reduce the number of relocations as well/instead).
72 if ((!DD->useSplitDwarf() || !Skeleton) && DD->getDwarfVersion() < 5)
8
Assuming the condition is true
9
Assuming the condition is true
10
Taking true branch
73 return addLocalLabelAddress(Die, Attribute, Label);
11
Calling 'DwarfCompileUnit::addLocalLabelAddress'
74
75 if (Label)
76 DD->addArangeLabel(SymbolCU(this, Label));
77
78 unsigned idx = DD->getAddressPool().getIndex(Label);
79 Die.addValue(DIEValueAllocator, Attribute,
80 DD->getDwarfVersion() >= 5 ? dwarf::DW_FORM_addrx
81 : dwarf::DW_FORM_GNU_addr_index,
82 DIEInteger(idx));
83}
84
85void DwarfCompileUnit::addLocalLabelAddress(DIE &Die,
86 dwarf::Attribute Attribute,
87 const MCSymbol *Label) {
88 if (Label)
12
Taking true branch
89 DD->addArangeLabel(SymbolCU(this, Label));
90
91 if (Label)
13
Taking true branch
92 Die.addValue(DIEValueAllocator, Attribute, dwarf::DW_FORM_addr,
14
Calling 'DIEValueList::addValue'
93 DIELabel(Label));
94 else
95 Die.addValue(DIEValueAllocator, Attribute, dwarf::DW_FORM_addr,
96 DIEInteger(0));
97}
98
99unsigned DwarfCompileUnit::getOrCreateSourceID(const DIFile *File) {
100 // If we print assembly, we can't separate .file entries according to
101 // compile units. Thus all files will belong to the default compile unit.
102
103 // FIXME: add a better feature test than hasRawTextSupport. Even better,
104 // extend .file to support this.
105 unsigned CUID = Asm->OutStreamer->hasRawTextSupport() ? 0 : getUniqueID();
106 if (!File)
107 return Asm->OutStreamer->EmitDwarfFileDirective(0, "", "", nullptr, None, CUID);
108 return Asm->OutStreamer->EmitDwarfFileDirective(
109 0, File->getDirectory(), File->getFilename(), getMD5AsBytes(File),
110 File->getSource(), CUID);
111}
112
113DIE *DwarfCompileUnit::getOrCreateGlobalVariableDIE(
114 const DIGlobalVariable *GV, ArrayRef<GlobalExpr> GlobalExprs) {
115 // Check for pre-existence.
116 if (DIE *Die = getDIE(GV))
117 return Die;
118
119 assert(GV)((GV) ? static_cast<void> (0) : __assert_fail ("GV", "/build/llvm-toolchain-snapshot-8~svn350071/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 119, __PRETTY_FUNCTION__))
;
120
121 auto *GVContext = GV->getScope();
122 auto *GTy = DD->resolve(GV->getType());
123
124 // Construct the context before querying for the existence of the DIE in
125 // case such construction creates the DIE.
126 DIE *ContextDIE = getOrCreateContextDIE(GVContext);
127
128 // Add to map.
129 DIE *VariableDIE = &createAndAddDIE(GV->getTag(), *ContextDIE, GV);
130 DIScope *DeclContext;
131 if (auto *SDMDecl = GV->getStaticDataMemberDeclaration()) {
132 DeclContext = resolve(SDMDecl->getScope());
133 assert(SDMDecl->isStaticMember() && "Expected static member decl")((SDMDecl->isStaticMember() && "Expected static member decl"
) ? static_cast<void> (0) : __assert_fail ("SDMDecl->isStaticMember() && \"Expected static member decl\""
, "/build/llvm-toolchain-snapshot-8~svn350071/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 133, __PRETTY_FUNCTION__))
;
134 assert(GV->isDefinition())((GV->isDefinition()) ? static_cast<void> (0) : __assert_fail
("GV->isDefinition()", "/build/llvm-toolchain-snapshot-8~svn350071/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 134, __PRETTY_FUNCTION__))
;
135 // We need the declaration DIE that is in the static member's class.
136 DIE *VariableSpecDIE = getOrCreateStaticMemberDIE(SDMDecl);
137 addDIEEntry(*VariableDIE, dwarf::DW_AT_specification, *VariableSpecDIE);
138 // If the global variable's type is different from the one in the class
139 // member type, assume that it's more specific and also emit it.
140 if (GTy != DD->resolve(SDMDecl->getBaseType()))
141 addType(*VariableDIE, GTy);
142 } else {
143 DeclContext = GV->getScope();
144 // Add name and type.
145 addString(*VariableDIE, dwarf::DW_AT_name, GV->getDisplayName());
146 addType(*VariableDIE, GTy);
147
148 // Add scoping info.
149 if (!GV->isLocalToUnit())
150 addFlag(*VariableDIE, dwarf::DW_AT_external);
151
152 // Add line number info.
153 addSourceLine(*VariableDIE, GV);
154 }
155
156 if (!GV->isDefinition())
157 addFlag(*VariableDIE, dwarf::DW_AT_declaration);
158 else
159 addGlobalName(GV->getName(), *VariableDIE, DeclContext);
160
161 if (uint32_t AlignInBytes = GV->getAlignInBytes())
162 addUInt(*VariableDIE, dwarf::DW_AT_alignment, dwarf::DW_FORM_udata,
163 AlignInBytes);
164
165 if (MDTuple *TP = GV->getTemplateParams())
166 addTemplateParams(*VariableDIE, DINodeArray(TP));
167
168 // Add location.
169 bool addToAccelTable = false;
170 DIELoc *Loc = nullptr;
171 std::unique_ptr<DIEDwarfExpression> DwarfExpr;
172 for (const auto &GE : GlobalExprs) {
173 const GlobalVariable *Global = GE.Var;
174 const DIExpression *Expr = GE.Expr;
175
176 // For compatibility with DWARF 3 and earlier,
177 // DW_AT_location(DW_OP_constu, X, DW_OP_stack_value) becomes
178 // DW_AT_const_value(X).
179 if (GlobalExprs.size() == 1 && Expr && Expr->isConstant()) {
180 addToAccelTable = true;
181 addConstantValue(*VariableDIE, /*Unsigned=*/true, Expr->getElement(1));
182 break;
183 }
184
185 // We cannot describe the location of dllimport'd variables: the
186 // computation of their address requires loads from the IAT.
187 if (Global && Global->hasDLLImportStorageClass())
188 continue;
189
190 // Nothing to describe without address or constant.
191 if (!Global && (!Expr || !Expr->isConstant()))
192 continue;
193
194 if (Global && Global->isThreadLocal() &&
195 !Asm->getObjFileLowering().supportDebugThreadLocalLocation())
196 continue;
197
198 if (!Loc) {
199 addToAccelTable = true;
200 Loc = new (DIEValueAllocator) DIELoc;
201 DwarfExpr = llvm::make_unique<DIEDwarfExpression>(*Asm, *this, *Loc);
202 }
203
204 if (Expr)
205 DwarfExpr->addFragmentOffset(Expr);
206
207 if (Global) {
208 const MCSymbol *Sym = Asm->getSymbol(Global);
209 if (Global->isThreadLocal()) {
210 if (Asm->TM.useEmulatedTLS()) {
211 // TODO: add debug info for emulated thread local mode.
212 } else {
213 // FIXME: Make this work with -gsplit-dwarf.
214 unsigned PointerSize = Asm->getDataLayout().getPointerSize();
215 assert((PointerSize == 4 || PointerSize == 8) &&(((PointerSize == 4 || PointerSize == 8) && "Add support for other sizes if necessary"
) ? static_cast<void> (0) : __assert_fail ("(PointerSize == 4 || PointerSize == 8) && \"Add support for other sizes if necessary\""
, "/build/llvm-toolchain-snapshot-8~svn350071/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 216, __PRETTY_FUNCTION__))
216 "Add support for other sizes if necessary")(((PointerSize == 4 || PointerSize == 8) && "Add support for other sizes if necessary"
) ? static_cast<void> (0) : __assert_fail ("(PointerSize == 4 || PointerSize == 8) && \"Add support for other sizes if necessary\""
, "/build/llvm-toolchain-snapshot-8~svn350071/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 216, __PRETTY_FUNCTION__))
;
217 // Based on GCC's support for TLS:
218 if (!DD->useSplitDwarf()) {
219 // 1) Start with a constNu of the appropriate pointer size
220 addUInt(*Loc, dwarf::DW_FORM_data1,
221 PointerSize == 4 ? dwarf::DW_OP_const4u
222 : dwarf::DW_OP_const8u);
223 // 2) containing the (relocated) offset of the TLS variable
224 // within the module's TLS block.
225 addExpr(*Loc, dwarf::DW_FORM_udata,
226 Asm->getObjFileLowering().getDebugThreadLocalSymbol(Sym));
227 } else {
228 addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_GNU_const_index);
229 addUInt(*Loc, dwarf::DW_FORM_udata,
230 DD->getAddressPool().getIndex(Sym, /* TLS */ true));
231 }
232 // 3) followed by an OP to make the debugger do a TLS lookup.
233 addUInt(*Loc, dwarf::DW_FORM_data1,
234 DD->useGNUTLSOpcode() ? dwarf::DW_OP_GNU_push_tls_address
235 : dwarf::DW_OP_form_tls_address);
236 }
237 } else {
238 DD->addArangeLabel(SymbolCU(this, Sym));
239 addOpAddress(*Loc, Sym);
240 }
241 }
242 // Global variables attached to symbols are memory locations.
243 // It would be better if this were unconditional, but malformed input that
244 // mixes non-fragments and fragments for the same variable is too expensive
245 // to detect in the verifier.
246 if (DwarfExpr->isUnknownLocation())
247 DwarfExpr->setMemoryLocationKind();
248 DwarfExpr->addExpression(Expr);
249 }
250 if (Loc)
251 addBlock(*VariableDIE, dwarf::DW_AT_location, DwarfExpr->finalize());
252
253 if (DD->useAllLinkageNames())
254 addLinkageName(*VariableDIE, GV->getLinkageName());
255
256 if (addToAccelTable) {
257 DD->addAccelName(*CUNode, GV->getName(), *VariableDIE);
258
259 // If the linkage name is different than the name, go ahead and output
260 // that as well into the name table.
261 if (GV->getLinkageName() != "" && GV->getName() != GV->getLinkageName() &&
262 DD->useAllLinkageNames())
263 DD->addAccelName(*CUNode, GV->getLinkageName(), *VariableDIE);
264 }
265
266 return VariableDIE;
267}
268
269void DwarfCompileUnit::addRange(RangeSpan Range) {
270 bool SameAsPrevCU = this == DD->getPrevCU();
271 DD->setPrevCU(this);
272 // If we have no current ranges just add the range and return, otherwise,
273 // check the current section and CU against the previous section and CU we
274 // emitted into and the subprogram was contained within. If these are the
275 // same then extend our current range, otherwise add this as a new range.
276 if (CURanges.empty() || !SameAsPrevCU ||
277 (&CURanges.back().getEnd()->getSection() !=
278 &Range.getEnd()->getSection())) {
279 CURanges.push_back(Range);
280 DD->addSectionLabel(Range.getStart());
281 return;
282 }
283
284 CURanges.back().setEnd(Range.getEnd());
285}
286
287void DwarfCompileUnit::initStmtList() {
288 if (CUNode->isDebugDirectivesOnly())
289 return;
290
291 // Define start line table label for each Compile Unit.
292 MCSymbol *LineTableStartSym;
293 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
294 if (DD->useSectionsAsReferences()) {
295 LineTableStartSym = TLOF.getDwarfLineSection()->getBeginSymbol();
296 } else {
297 LineTableStartSym =
298 Asm->OutStreamer->getDwarfLineTableSymbol(getUniqueID());
299 }
300
301 // DW_AT_stmt_list is a offset of line number information for this
302 // compile unit in debug_line section. For split dwarf this is
303 // left in the skeleton CU and so not included.
304 // The line table entries are not always emitted in assembly, so it
305 // is not okay to use line_table_start here.
306 StmtListValue =
307 addSectionLabel(getUnitDie(), dwarf::DW_AT_stmt_list, LineTableStartSym,
308 TLOF.getDwarfLineSection()->getBeginSymbol());
309}
310
311void DwarfCompileUnit::applyStmtList(DIE &D) {
312 D.addValue(DIEValueAllocator, *StmtListValue);
313}
314
315void DwarfCompileUnit::attachLowHighPC(DIE &D, const MCSymbol *Begin,
316 const MCSymbol *End) {
317 assert(Begin && "Begin label should not be null!")((Begin && "Begin label should not be null!") ? static_cast
<void> (0) : __assert_fail ("Begin && \"Begin label should not be null!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 317, __PRETTY_FUNCTION__))
;
318 assert(End && "End label should not be null!")((End && "End label should not be null!") ? static_cast
<void> (0) : __assert_fail ("End && \"End label should not be null!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 318, __PRETTY_FUNCTION__))
;
319 assert(Begin->isDefined() && "Invalid starting label")((Begin->isDefined() && "Invalid starting label") ?
static_cast<void> (0) : __assert_fail ("Begin->isDefined() && \"Invalid starting label\""
, "/build/llvm-toolchain-snapshot-8~svn350071/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 319, __PRETTY_FUNCTION__))
;
320 assert(End->isDefined() && "Invalid end label")((End->isDefined() && "Invalid end label") ? static_cast
<void> (0) : __assert_fail ("End->isDefined() && \"Invalid end label\""
, "/build/llvm-toolchain-snapshot-8~svn350071/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 320, __PRETTY_FUNCTION__))
;
321
322 addLabelAddress(D, dwarf::DW_AT_low_pc, Begin);
323 if (DD->getDwarfVersion() < 4)
324 addLabelAddress(D, dwarf::DW_AT_high_pc, End);
325 else
326 addLabelDelta(D, dwarf::DW_AT_high_pc, End, Begin);
327}
328
329// Find DIE for the given subprogram and attach appropriate DW_AT_low_pc
330// and DW_AT_high_pc attributes. If there are global variables in this
331// scope then create and insert DIEs for these variables.
332DIE &DwarfCompileUnit::updateSubprogramScopeDIE(const DISubprogram *SP) {
333 DIE *SPDie = getOrCreateSubprogramDIE(SP, includeMinimalInlineScopes());
334
335 attachLowHighPC(*SPDie, Asm->getFunctionBegin(), Asm->getFunctionEnd());
336 if (DD->useAppleExtensionAttributes() &&
337 !DD->getCurrentFunction()->getTarget().Options.DisableFramePointerElim(
338 *DD->getCurrentFunction()))
339 addFlag(*SPDie, dwarf::DW_AT_APPLE_omit_frame_ptr);
340
341 // Only include DW_AT_frame_base in full debug info
342 if (!includeMinimalInlineScopes()) {
343 if (Asm->MF->getTarget().getTargetTriple().isNVPTX()) {
344 DIELoc *Loc = new (DIEValueAllocator) DIELoc;
345 addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_call_frame_cfa);
346 addBlock(*SPDie, dwarf::DW_AT_frame_base, Loc);
347 } else {
348 const TargetRegisterInfo *RI = Asm->MF->getSubtarget().getRegisterInfo();
349 MachineLocation Location(RI->getFrameRegister(*Asm->MF));
350 if (RI->isPhysicalRegister(Location.getReg()))
351 addAddress(*SPDie, dwarf::DW_AT_frame_base, Location);
352 }
353 }
354
355 // Add name to the name table, we do this here because we're guaranteed
356 // to have concrete versions of our DW_TAG_subprogram nodes.
357 DD->addSubprogramNames(*CUNode, SP, *SPDie);
358
359 return *SPDie;
360}
361
362// Construct a DIE for this scope.
363void DwarfCompileUnit::constructScopeDIE(
364 LexicalScope *Scope, SmallVectorImpl<DIE *> &FinalChildren) {
365 if (!Scope || !Scope->getScopeNode())
366 return;
367
368 auto *DS = Scope->getScopeNode();
369
370 assert((Scope->getInlinedAt() || !isa<DISubprogram>(DS)) &&(((Scope->getInlinedAt() || !isa<DISubprogram>(DS)) &&
"Only handle inlined subprograms here, use " "constructSubprogramScopeDIE for non-inlined "
"subprograms") ? static_cast<void> (0) : __assert_fail
("(Scope->getInlinedAt() || !isa<DISubprogram>(DS)) && \"Only handle inlined subprograms here, use \" \"constructSubprogramScopeDIE for non-inlined \" \"subprograms\""
, "/build/llvm-toolchain-snapshot-8~svn350071/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 373, __PRETTY_FUNCTION__))
371 "Only handle inlined subprograms here, use "(((Scope->getInlinedAt() || !isa<DISubprogram>(DS)) &&
"Only handle inlined subprograms here, use " "constructSubprogramScopeDIE for non-inlined "
"subprograms") ? static_cast<void> (0) : __assert_fail
("(Scope->getInlinedAt() || !isa<DISubprogram>(DS)) && \"Only handle inlined subprograms here, use \" \"constructSubprogramScopeDIE for non-inlined \" \"subprograms\""
, "/build/llvm-toolchain-snapshot-8~svn350071/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 373, __PRETTY_FUNCTION__))
372 "constructSubprogramScopeDIE for non-inlined "(((Scope->getInlinedAt() || !isa<DISubprogram>(DS)) &&
"Only handle inlined subprograms here, use " "constructSubprogramScopeDIE for non-inlined "
"subprograms") ? static_cast<void> (0) : __assert_fail
("(Scope->getInlinedAt() || !isa<DISubprogram>(DS)) && \"Only handle inlined subprograms here, use \" \"constructSubprogramScopeDIE for non-inlined \" \"subprograms\""
, "/build/llvm-toolchain-snapshot-8~svn350071/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 373, __PRETTY_FUNCTION__))
373 "subprograms")(((Scope->getInlinedAt() || !isa<DISubprogram>(DS)) &&
"Only handle inlined subprograms here, use " "constructSubprogramScopeDIE for non-inlined "
"subprograms") ? static_cast<void> (0) : __assert_fail
("(Scope->getInlinedAt() || !isa<DISubprogram>(DS)) && \"Only handle inlined subprograms here, use \" \"constructSubprogramScopeDIE for non-inlined \" \"subprograms\""
, "/build/llvm-toolchain-snapshot-8~svn350071/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 373, __PRETTY_FUNCTION__))
;
374
375 SmallVector<DIE *, 8> Children;
376
377 // We try to create the scope DIE first, then the children DIEs. This will
378 // avoid creating un-used children then removing them later when we find out
379 // the scope DIE is null.
380 DIE *ScopeDIE;
381 if (Scope->getParent() && isa<DISubprogram>(DS)) {
382 ScopeDIE = constructInlinedScopeDIE(Scope);
383 if (!ScopeDIE)
384 return;
385 // We create children when the scope DIE is not null.
386 createScopeChildrenDIE(Scope, Children);
387 } else {
388 // Early exit when we know the scope DIE is going to be null.
389 if (DD->isLexicalScopeDIENull(Scope))
390 return;
391
392 bool HasNonScopeChildren = false;
393
394 // We create children here when we know the scope DIE is not going to be
395 // null and the children will be added to the scope DIE.
396 createScopeChildrenDIE(Scope, Children, &HasNonScopeChildren);
397
398 // If there are only other scopes as children, put them directly in the
399 // parent instead, as this scope would serve no purpose.
400 if (!HasNonScopeChildren) {
401 FinalChildren.insert(FinalChildren.end(),
402 std::make_move_iterator(Children.begin()),
403 std::make_move_iterator(Children.end()));
404 return;
405 }
406 ScopeDIE = constructLexicalScopeDIE(Scope);
407 assert(ScopeDIE && "Scope DIE should not be null.")((ScopeDIE && "Scope DIE should not be null.") ? static_cast
<void> (0) : __assert_fail ("ScopeDIE && \"Scope DIE should not be null.\""
, "/build/llvm-toolchain-snapshot-8~svn350071/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 407, __PRETTY_FUNCTION__))
;
408 }
409
410 // Add children
411 for (auto &I : Children)
412 ScopeDIE->addChild(std::move(I));
413
414 FinalChildren.push_back(std::move(ScopeDIE));
415}
416
417void DwarfCompileUnit::addScopeRangeList(DIE &ScopeDIE,
418 SmallVector<RangeSpan, 2> Range) {
419 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
420
421 // Emit the offset into .debug_ranges or .debug_rnglists as a relocatable
422 // label. emitDIE() will handle emitting it appropriately.
423 const MCSymbol *RangeSectionSym =
424 DD->getDwarfVersion() >= 5
425 ? TLOF.getDwarfRnglistsSection()->getBeginSymbol()
426 : TLOF.getDwarfRangesSection()->getBeginSymbol();
427
428 HasRangeLists = true;
429
430 // Add the range list to the set of ranges to be emitted.
431 auto IndexAndList =
432 (DD->getDwarfVersion() < 5 && Skeleton ? Skeleton->DU : DU)
433 ->addRange(*(Skeleton ? Skeleton : this), std::move(Range));
434
435 uint32_t Index = IndexAndList.first;
436 auto &List = *IndexAndList.second;
437
438 // Under fission, ranges are specified by constant offsets relative to the
439 // CU's DW_AT_GNU_ranges_base.
440 // FIXME: For DWARF v5, do not generate the DW_AT_ranges attribute under
441 // fission until we support the forms using the .debug_addr section
442 // (DW_RLE_startx_endx etc.).
443 if (DD->getDwarfVersion() >= 5)
444 addUInt(ScopeDIE, dwarf::DW_AT_ranges, dwarf::DW_FORM_rnglistx, Index);
445 else if (isDwoUnit())
446 addSectionDelta(ScopeDIE, dwarf::DW_AT_ranges, List.getSym(),
447 RangeSectionSym);
448 else
449 addSectionLabel(ScopeDIE, dwarf::DW_AT_ranges, List.getSym(),
450 RangeSectionSym);
451}
452
453void DwarfCompileUnit::attachRangesOrLowHighPC(
454 DIE &Die, SmallVector<RangeSpan, 2> Ranges) {
455 if (Ranges.size() == 1 || !DD->useRangesSection()) {
456 const RangeSpan &Front = Ranges.front();
457 const RangeSpan &Back = Ranges.back();
458 attachLowHighPC(Die, Front.getStart(), Back.getEnd());
459 } else
460 addScopeRangeList(Die, std::move(Ranges));
461}
462
463void DwarfCompileUnit::attachRangesOrLowHighPC(
464 DIE &Die, const SmallVectorImpl<InsnRange> &Ranges) {
465 SmallVector<RangeSpan, 2> List;
466 List.reserve(Ranges.size());
467 for (const InsnRange &R : Ranges)
468 List.push_back(RangeSpan(DD->getLabelBeforeInsn(R.first),
469 DD->getLabelAfterInsn(R.second)));
470 attachRangesOrLowHighPC(Die, std::move(List));
471}
472
473// This scope represents inlined body of a function. Construct DIE to
474// represent this concrete inlined copy of the function.
475DIE *DwarfCompileUnit::constructInlinedScopeDIE(LexicalScope *Scope) {
476 assert(Scope->getScopeNode())((Scope->getScopeNode()) ? static_cast<void> (0) : __assert_fail
("Scope->getScopeNode()", "/build/llvm-toolchain-snapshot-8~svn350071/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 476, __PRETTY_FUNCTION__))
;
477 auto *DS = Scope->getScopeNode();
478 auto *InlinedSP = getDISubprogram(DS);
479 // Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
480 // was inlined from another compile unit.
481 DIE *OriginDIE = getAbstractSPDies()[InlinedSP];
482 assert(OriginDIE && "Unable to find original DIE for an inlined subprogram.")((OriginDIE && "Unable to find original DIE for an inlined subprogram."
) ? static_cast<void> (0) : __assert_fail ("OriginDIE && \"Unable to find original DIE for an inlined subprogram.\""
, "/build/llvm-toolchain-snapshot-8~svn350071/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 482, __PRETTY_FUNCTION__))
;
483
484 auto ScopeDIE = DIE::get(DIEValueAllocator, dwarf::DW_TAG_inlined_subroutine);
485 addDIEEntry(*ScopeDIE, dwarf::DW_AT_abstract_origin, *OriginDIE);
486
487 attachRangesOrLowHighPC(*ScopeDIE, Scope->getRanges());
488
489 // Add the call site information to the DIE.
490 const DILocation *IA = Scope->getInlinedAt();
491 addUInt(*ScopeDIE, dwarf::DW_AT_call_file, None,
492 getOrCreateSourceID(IA->getFile()));
493 addUInt(*ScopeDIE, dwarf::DW_AT_call_line, None, IA->getLine());
494 if (IA->getDiscriminator() && DD->getDwarfVersion() >= 4)
495 addUInt(*ScopeDIE, dwarf::DW_AT_GNU_discriminator, None,
496 IA->getDiscriminator());
497
498 // Add name to the name table, we do this here because we're guaranteed
499 // to have concrete versions of our DW_TAG_inlined_subprogram nodes.
500 DD->addSubprogramNames(*CUNode, InlinedSP, *ScopeDIE);
501
502 return ScopeDIE;
503}
504
505// Construct new DW_TAG_lexical_block for this scope and attach
506// DW_AT_low_pc/DW_AT_high_pc labels.
507DIE *DwarfCompileUnit::constructLexicalScopeDIE(LexicalScope *Scope) {
508 if (DD->isLexicalScopeDIENull(Scope))
509 return nullptr;
510
511 auto ScopeDIE = DIE::get(DIEValueAllocator, dwarf::DW_TAG_lexical_block);
512 if (Scope->isAbstractScope())
513 return ScopeDIE;
514
515 attachRangesOrLowHighPC(*ScopeDIE, Scope->getRanges());
516
517 return ScopeDIE;
518}
519
520/// constructVariableDIE - Construct a DIE for the given DbgVariable.
521DIE *DwarfCompileUnit::constructVariableDIE(DbgVariable &DV, bool Abstract) {
522 auto D = constructVariableDIEImpl(DV, Abstract);
523 DV.setDIE(*D);
524 return D;
525}
526
527DIE *DwarfCompileUnit::constructLabelDIE(DbgLabel &DL,
528 const LexicalScope &Scope) {
529 auto LabelDie = DIE::get(DIEValueAllocator, DL.getTag());
530 insertDIE(DL.getLabel(), LabelDie);
531 DL.setDIE(*LabelDie);
532
533 if (Scope.isAbstractScope())
534 applyLabelAttributes(DL, *LabelDie);
535
536 return LabelDie;
537}
538
539DIE *DwarfCompileUnit::constructVariableDIEImpl(const DbgVariable &DV,
540 bool Abstract) {
541 // Define variable debug information entry.
542 auto VariableDie = DIE::get(DIEValueAllocator, DV.getTag());
543 insertDIE(DV.getVariable(), VariableDie);
544
545 if (Abstract) {
546 applyVariableAttributes(DV, *VariableDie);
547 return VariableDie;
548 }
549
550 // Add variable address.
551
552 unsigned Offset = DV.getDebugLocListIndex();
553 if (Offset != ~0U) {
554 addLocationList(*VariableDie, dwarf::DW_AT_location, Offset);
555 return VariableDie;
556 }
557
558 // Check if variable is described by a DBG_VALUE instruction.
559 if (const MachineInstr *DVInsn = DV.getMInsn()) {
560 assert(DVInsn->getNumOperands() == 4)((DVInsn->getNumOperands() == 4) ? static_cast<void>
(0) : __assert_fail ("DVInsn->getNumOperands() == 4", "/build/llvm-toolchain-snapshot-8~svn350071/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 560, __PRETTY_FUNCTION__))
;
561 if (DVInsn->getOperand(0).isReg()) {
562 auto RegOp = DVInsn->getOperand(0);
563 auto Op1 = DVInsn->getOperand(1);
564 // If the second operand is an immediate, this is an indirect value.
565 assert((!Op1.isImm() || (Op1.getImm() == 0)) && "unexpected offset")(((!Op1.isImm() || (Op1.getImm() == 0)) && "unexpected offset"
) ? static_cast<void> (0) : __assert_fail ("(!Op1.isImm() || (Op1.getImm() == 0)) && \"unexpected offset\""
, "/build/llvm-toolchain-snapshot-8~svn350071/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 565, __PRETTY_FUNCTION__))
;
566 MachineLocation Location(RegOp.getReg(), Op1.isImm());
567 addVariableAddress(DV, *VariableDie, Location);
568 } else if (DVInsn->getOperand(0).isImm()) {
569 // This variable is described by a single constant.
570 // Check whether it has a DIExpression.
571 auto *Expr = DV.getSingleExpression();
572 if (Expr && Expr->getNumElements()) {
573 DIELoc *Loc = new (DIEValueAllocator) DIELoc;
574 DIEDwarfExpression DwarfExpr(*Asm, *this, *Loc);
575 // If there is an expression, emit raw unsigned bytes.
576 DwarfExpr.addFragmentOffset(Expr);
577 DwarfExpr.addUnsignedConstant(DVInsn->getOperand(0).getImm());
578 DwarfExpr.addExpression(Expr);
579 addBlock(*VariableDie, dwarf::DW_AT_location, DwarfExpr.finalize());
580 } else
581 addConstantValue(*VariableDie, DVInsn->getOperand(0), DV.getType());
582 } else if (DVInsn->getOperand(0).isFPImm())
583 addConstantFPValue(*VariableDie, DVInsn->getOperand(0));
584 else if (DVInsn->getOperand(0).isCImm())
585 addConstantValue(*VariableDie, DVInsn->getOperand(0).getCImm(),
586 DV.getType());
587
588 return VariableDie;
589 }
590
591 // .. else use frame index.
592 if (!DV.hasFrameIndexExprs())
593 return VariableDie;
594
595 DIELoc *Loc = new (DIEValueAllocator) DIELoc;
596 DIEDwarfExpression DwarfExpr(*Asm, *this, *Loc);
597 for (auto &Fragment : DV.getFrameIndexExprs()) {
598 unsigned FrameReg = 0;
599 const DIExpression *Expr = Fragment.Expr;
600 const TargetFrameLowering *TFI = Asm->MF->getSubtarget().getFrameLowering();
601 int Offset = TFI->getFrameIndexReference(*Asm->MF, Fragment.FI, FrameReg);
602 DwarfExpr.addFragmentOffset(Expr);
603 SmallVector<uint64_t, 8> Ops;
604 Ops.push_back(dwarf::DW_OP_plus_uconst);
605 Ops.push_back(Offset);
606 Ops.append(Expr->elements_begin(), Expr->elements_end());
607 DIExpressionCursor Cursor(Ops);
608 DwarfExpr.setMemoryLocationKind();
609 if (const MCSymbol *FrameSymbol = Asm->getFunctionFrameSymbol())
610 addOpAddress(*Loc, FrameSymbol);
611 else
612 DwarfExpr.addMachineRegExpression(
613 *Asm->MF->getSubtarget().getRegisterInfo(), Cursor, FrameReg);
614 DwarfExpr.addExpression(std::move(Cursor));
615 }
616 addBlock(*VariableDie, dwarf::DW_AT_location, DwarfExpr.finalize());
617
618 return VariableDie;
619}
620
621DIE *DwarfCompileUnit::constructVariableDIE(DbgVariable &DV,
622 const LexicalScope &Scope,
623 DIE *&ObjectPointer) {
624 auto Var = constructVariableDIE(DV, Scope.isAbstractScope());
625 if (DV.isObjectPointer())
626 ObjectPointer = Var;
627 return Var;
628}
629
630/// Return all DIVariables that appear in count: expressions.
631static SmallVector<const DIVariable *, 2> dependencies(DbgVariable *Var) {
632 SmallVector<const DIVariable *, 2> Result;
633 auto *Array = dyn_cast<DICompositeType>(Var->getType());
634 if (!Array || Array->getTag() != dwarf::DW_TAG_array_type)
635 return Result;
636 for (auto *El : Array->getElements()) {
637 if (auto *Subrange = dyn_cast<DISubrange>(El)) {
638 auto Count = Subrange->getCount();
639 if (auto *Dependency = Count.dyn_cast<DIVariable *>())
640 Result.push_back(Dependency);
641 }
642 }
643 return Result;
644}
645
646/// Sort local variables so that variables appearing inside of helper
647/// expressions come first.
648static SmallVector<DbgVariable *, 8>
649sortLocalVars(SmallVectorImpl<DbgVariable *> &Input) {
650 SmallVector<DbgVariable *, 8> Result;
651 SmallVector<PointerIntPair<DbgVariable *, 1>, 8> WorkList;
652 // Map back from a DIVariable to its containing DbgVariable.
653 SmallDenseMap<const DILocalVariable *, DbgVariable *> DbgVar;
654 // Set of DbgVariables in Result.
655 SmallDenseSet<DbgVariable *, 8> Visited;
656 // For cycle detection.
657 SmallDenseSet<DbgVariable *, 8> Visiting;
658
659 // Initialize the worklist and the DIVariable lookup table.
660 for (auto Var : reverse(Input)) {
661 DbgVar.insert({Var->getVariable(), Var});
662 WorkList.push_back({Var, 0});
663 }
664
665 // Perform a stable topological sort by doing a DFS.
666 while (!WorkList.empty()) {
667 auto Item = WorkList.back();
668 DbgVariable *Var = Item.getPointer();
669 bool visitedAllDependencies = Item.getInt();
670 WorkList.pop_back();
671
672 // Dependency is in a different lexical scope or a global.
673 if (!Var)
674 continue;
675
676 // Already handled.
677 if (Visited.count(Var))
678 continue;
679
680 // Add to Result if all dependencies are visited.
681 if (visitedAllDependencies) {
682 Visited.insert(Var);
683 Result.push_back(Var);
684 continue;
685 }
686
687 // Detect cycles.
688 auto Res = Visiting.insert(Var);
689 if (!Res.second) {
690 assert(false && "dependency cycle in local variables")((false && "dependency cycle in local variables") ? static_cast
<void> (0) : __assert_fail ("false && \"dependency cycle in local variables\""
, "/build/llvm-toolchain-snapshot-8~svn350071/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 690, __PRETTY_FUNCTION__))
;
691 return Result;
692 }
693
694 // Push dependencies and this node onto the worklist, so that this node is
695 // visited again after all of its dependencies are handled.
696 WorkList.push_back({Var, 1});
697 for (auto *Dependency : dependencies(Var)) {
698 auto Dep = dyn_cast_or_null<const DILocalVariable>(Dependency);
699 WorkList.push_back({DbgVar[Dep], 0});
700 }
701 }
702 return Result;
703}
704
705DIE *DwarfCompileUnit::createScopeChildrenDIE(LexicalScope *Scope,
706 SmallVectorImpl<DIE *> &Children,
707 bool *HasNonScopeChildren) {
708 assert(Children.empty())((Children.empty()) ? static_cast<void> (0) : __assert_fail
("Children.empty()", "/build/llvm-toolchain-snapshot-8~svn350071/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 708, __PRETTY_FUNCTION__))
;
709 DIE *ObjectPointer = nullptr;
710
711 // Emit function arguments (order is significant).
712 auto Vars = DU->getScopeVariables().lookup(Scope);
713 for (auto &DV : Vars.Args)
714 Children.push_back(constructVariableDIE(*DV.second, *Scope, ObjectPointer));
715
716 // Emit local variables.
717 auto Locals = sortLocalVars(Vars.Locals);
718 for (DbgVariable *DV : Locals)
719 Children.push_back(constructVariableDIE(*DV, *Scope, ObjectPointer));
720
721 // Skip imported directives in gmlt-like data.
722 if (!includeMinimalInlineScopes()) {
723 // There is no need to emit empty lexical block DIE.
724 for (const auto *IE : ImportedEntities[Scope->getScopeNode()])
725 Children.push_back(
726 constructImportedEntityDIE(cast<DIImportedEntity>(IE)));
727 }
728
729 if (HasNonScopeChildren)
730 *HasNonScopeChildren = !Children.empty();
731
732 for (DbgLabel *DL : DU->getScopeLabels().lookup(Scope))
733 Children.push_back(constructLabelDIE(*DL, *Scope));
734
735 for (LexicalScope *LS : Scope->getChildren())
736 constructScopeDIE(LS, Children);
737
738 return ObjectPointer;
739}
740
741DIE &DwarfCompileUnit::constructSubprogramScopeDIE(const DISubprogram *Sub,
742 LexicalScope *Scope) {
743 DIE &ScopeDIE = updateSubprogramScopeDIE(Sub);
744
745 if (Scope) {
746 assert(!Scope->getInlinedAt())((!Scope->getInlinedAt()) ? static_cast<void> (0) : __assert_fail
("!Scope->getInlinedAt()", "/build/llvm-toolchain-snapshot-8~svn350071/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 746, __PRETTY_FUNCTION__))
;
747 assert(!Scope->isAbstractScope())((!Scope->isAbstractScope()) ? static_cast<void> (0)
: __assert_fail ("!Scope->isAbstractScope()", "/build/llvm-toolchain-snapshot-8~svn350071/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 747, __PRETTY_FUNCTION__))
;
748 // Collect lexical scope children first.
749 // ObjectPointer might be a local (non-argument) local variable if it's a
750 // block's synthetic this pointer.
751 if (DIE *ObjectPointer = createAndAddScopeChildren(Scope, ScopeDIE))
752 addDIEEntry(ScopeDIE, dwarf::DW_AT_object_pointer, *ObjectPointer);
753 }
754
755 // If this is a variadic function, add an unspecified parameter.
756 DITypeRefArray FnArgs = Sub->getType()->getTypeArray();
757
758 // If we have a single element of null, it is a function that returns void.
759 // If we have more than one elements and the last one is null, it is a
760 // variadic function.
761 if (FnArgs.size() > 1 && !FnArgs[FnArgs.size() - 1] &&
762 !includeMinimalInlineScopes())
763 ScopeDIE.addChild(
764 DIE::get(DIEValueAllocator, dwarf::DW_TAG_unspecified_parameters));
765
766 return ScopeDIE;
767}
768
769DIE *DwarfCompileUnit::createAndAddScopeChildren(LexicalScope *Scope,
770 DIE &ScopeDIE) {
771 // We create children when the scope DIE is not null.
772 SmallVector<DIE *, 8> Children;
773 DIE *ObjectPointer = createScopeChildrenDIE(Scope, Children);
774
775 // Add children
776 for (auto &I : Children)
777 ScopeDIE.addChild(std::move(I));
778
779 return ObjectPointer;
780}
781
782void DwarfCompileUnit::constructAbstractSubprogramScopeDIE(
783 LexicalScope *Scope) {
784 DIE *&AbsDef = getAbstractSPDies()[Scope->getScopeNode()];
785 if (AbsDef)
786 return;
787
788 auto *SP = cast<DISubprogram>(Scope->getScopeNode());
789
790 DIE *ContextDIE;
791 DwarfCompileUnit *ContextCU = this;
792
793 if (includeMinimalInlineScopes())
794 ContextDIE = &getUnitDie();
795 // Some of this is duplicated from DwarfUnit::getOrCreateSubprogramDIE, with
796 // the important distinction that the debug node is not associated with the
797 // DIE (since the debug node will be associated with the concrete DIE, if
798 // any). It could be refactored to some common utility function.
799 else if (auto *SPDecl = SP->getDeclaration()) {
800 ContextDIE = &getUnitDie();
801 getOrCreateSubprogramDIE(SPDecl);
802 } else {
803 ContextDIE = getOrCreateContextDIE(resolve(SP->getScope()));
804 // The scope may be shared with a subprogram that has already been
805 // constructed in another CU, in which case we need to construct this
806 // subprogram in the same CU.
807 ContextCU = DD->lookupCU(ContextDIE->getUnitDie());
808 }
809
810 // Passing null as the associated node because the abstract definition
811 // shouldn't be found by lookup.
812 AbsDef = &ContextCU->createAndAddDIE(dwarf::DW_TAG_subprogram, *ContextDIE, nullptr);
813 ContextCU->applySubprogramAttributesToDefinition(SP, *AbsDef);
814
815 if (!ContextCU->includeMinimalInlineScopes())
816 ContextCU->addUInt(*AbsDef, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);
817 if (DIE *ObjectPointer = ContextCU->createAndAddScopeChildren(Scope, *AbsDef))
818 ContextCU->addDIEEntry(*AbsDef, dwarf::DW_AT_object_pointer, *ObjectPointer);
819}
820
821DIE &DwarfCompileUnit::constructCallSiteEntryDIE(DIE &ScopeDIE,
822 const DISubprogram &CalleeSP,
823 bool IsTail,
824 const MCExpr *PCOffset) {
825 // Insert a call site entry DIE within ScopeDIE.
826 DIE &CallSiteDIE =
827 createAndAddDIE(dwarf::DW_TAG_call_site, ScopeDIE, nullptr);
828
829 // For the purposes of showing tail call frames in backtraces, a key piece of
830 // information is DW_AT_call_origin, a pointer to the callee DIE.
831 DIE *CalleeDIE = getOrCreateSubprogramDIE(&CalleeSP);
832 assert(CalleeDIE && "Could not create DIE for call site entry origin")((CalleeDIE && "Could not create DIE for call site entry origin"
) ? static_cast<void> (0) : __assert_fail ("CalleeDIE && \"Could not create DIE for call site entry origin\""
, "/build/llvm-toolchain-snapshot-8~svn350071/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 832, __PRETTY_FUNCTION__))
;
833 addDIEEntry(CallSiteDIE, dwarf::DW_AT_call_origin, *CalleeDIE);
834
835 if (IsTail) {
836 // Attach DW_AT_call_tail_call to tail calls for standards compliance.
837 addFlag(CallSiteDIE, dwarf::DW_AT_call_tail_call);
838 } else {
839 // Attach the return PC to allow the debugger to disambiguate call paths
840 // from one function to another.
841 assert(PCOffset && "Missing return PC information for a call")((PCOffset && "Missing return PC information for a call"
) ? static_cast<void> (0) : __assert_fail ("PCOffset && \"Missing return PC information for a call\""
, "/build/llvm-toolchain-snapshot-8~svn350071/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 841, __PRETTY_FUNCTION__))
;
842 addAddressExpr(CallSiteDIE, dwarf::DW_AT_call_return_pc, PCOffset);
843 }
844 return CallSiteDIE;
845}
846
847DIE *DwarfCompileUnit::constructImportedEntityDIE(
848 const DIImportedEntity *Module) {
849 DIE *IMDie = DIE::get(DIEValueAllocator, (dwarf::Tag)Module->getTag());
850 insertDIE(Module, IMDie);
851 DIE *EntityDie;
852 auto *Entity = resolve(Module->getEntity());
853 if (auto *NS = dyn_cast<DINamespace>(Entity))
854 EntityDie = getOrCreateNameSpace(NS);
855 else if (auto *M = dyn_cast<DIModule>(Entity))
856 EntityDie = getOrCreateModule(M);
857 else if (auto *SP = dyn_cast<DISubprogram>(Entity))
858 EntityDie = getOrCreateSubprogramDIE(SP);
859 else if (auto *T = dyn_cast<DIType>(Entity))
860 EntityDie = getOrCreateTypeDIE(T);
861 else if (auto *GV = dyn_cast<DIGlobalVariable>(Entity))
862 EntityDie = getOrCreateGlobalVariableDIE(GV, {});
863 else
864 EntityDie = getDIE(Entity);
865 assert(EntityDie)((EntityDie) ? static_cast<void> (0) : __assert_fail ("EntityDie"
, "/build/llvm-toolchain-snapshot-8~svn350071/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 865, __PRETTY_FUNCTION__))
;
866 addSourceLine(*IMDie, Module->getLine(), Module->getFile());
867 addDIEEntry(*IMDie, dwarf::DW_AT_import, *EntityDie);
868 StringRef Name = Module->getName();
869 if (!Name.empty())
870 addString(*IMDie, dwarf::DW_AT_name, Name);
871
872 return IMDie;
873}
874
875void DwarfCompileUnit::finishSubprogramDefinition(const DISubprogram *SP) {
876 DIE *D = getDIE(SP);
877 if (DIE *AbsSPDIE = getAbstractSPDies().lookup(SP)) {
878 if (D)
879 // If this subprogram has an abstract definition, reference that
880 addDIEEntry(*D, dwarf::DW_AT_abstract_origin, *AbsSPDIE);
881 } else {
882 assert(D || includeMinimalInlineScopes())((D || includeMinimalInlineScopes()) ? static_cast<void>
(0) : __assert_fail ("D || includeMinimalInlineScopes()", "/build/llvm-toolchain-snapshot-8~svn350071/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 882, __PRETTY_FUNCTION__))
;
883 if (D)
884 // And attach the attributes
885 applySubprogramAttributesToDefinition(SP, *D);
886 }
887}
888
889void DwarfCompileUnit::finishEntityDefinition(const DbgEntity *Entity) {
890 DbgEntity *AbsEntity = getExistingAbstractEntity(Entity->getEntity());
891
892 auto *Die = Entity->getDIE();
893 /// Label may be used to generate DW_AT_low_pc, so put it outside
894 /// if/else block.
895 const DbgLabel *Label = nullptr;
896 if (AbsEntity && AbsEntity->getDIE()) {
1
Assuming 'AbsEntity' is non-null
2
Assuming the condition is true
3
Taking true branch
897 addDIEEntry(*Die, dwarf::DW_AT_abstract_origin, *AbsEntity->getDIE());
898 Label = dyn_cast<const DbgLabel>(Entity);
899 } else {
900 if (const DbgVariable *Var = dyn_cast<const DbgVariable>(Entity))
901 applyVariableAttributes(*Var, *Die);
902 else if ((Label = dyn_cast<const DbgLabel>(Entity)))
903 applyLabelAttributes(*Label, *Die);
904 else
905 llvm_unreachable("DbgEntity must be DbgVariable or DbgLabel.")::llvm::llvm_unreachable_internal("DbgEntity must be DbgVariable or DbgLabel."
, "/build/llvm-toolchain-snapshot-8~svn350071/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 905)
;
906 }
907
908 if (Label)
4
Taking true branch
909 if (const auto *Sym = Label->getSymbol())
5
Assuming 'Sym' is non-null
6
Taking true branch
910 addLabelAddress(*Die, dwarf::DW_AT_low_pc, Sym);
7
Calling 'DwarfCompileUnit::addLabelAddress'
911}
912
913DbgEntity *DwarfCompileUnit::getExistingAbstractEntity(const DINode *Node) {
914 auto &AbstractEntities = getAbstractEntities();
915 auto I = AbstractEntities.find(Node);
916 if (I != AbstractEntities.end())
917 return I->second.get();
918 return nullptr;
919}
920
921void DwarfCompileUnit::createAbstractEntity(const DINode *Node,
922 LexicalScope *Scope) {
923 assert(Scope && Scope->isAbstractScope())((Scope && Scope->isAbstractScope()) ? static_cast
<void> (0) : __assert_fail ("Scope && Scope->isAbstractScope()"
, "/build/llvm-toolchain-snapshot-8~svn350071/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 923, __PRETTY_FUNCTION__))
;
924 auto &Entity = getAbstractEntities()[Node];
925 if (isa<const DILocalVariable>(Node)) {
926 Entity = llvm::make_unique<DbgVariable>(
927 cast<const DILocalVariable>(Node), nullptr /* IA */);;
928 DU->addScopeVariable(Scope, cast<DbgVariable>(Entity.get()));
929 } else if (isa<const DILabel>(Node)) {
930 Entity = llvm::make_unique<DbgLabel>(
931 cast<const DILabel>(Node), nullptr /* IA */);
932 DU->addScopeLabel(Scope, cast<DbgLabel>(Entity.get()));
933 }
934}
935
936void DwarfCompileUnit::emitHeader(bool UseOffsets) {
937 // Don't bother labeling the .dwo unit, as its offset isn't used.
938 if (!Skeleton && !DD->useSectionsAsReferences()) {
939 LabelBegin = Asm->createTempSymbol("cu_begin");
940 Asm->OutStreamer->EmitLabel(LabelBegin);
941 }
942
943 dwarf::UnitType UT = Skeleton ? dwarf::DW_UT_split_compile
944 : DD->useSplitDwarf() ? dwarf::DW_UT_skeleton
945 : dwarf::DW_UT_compile;
946 DwarfUnit::emitCommonHeader(UseOffsets, UT);
947 if (DD->getDwarfVersion() >= 5 && UT != dwarf::DW_UT_compile)
948 Asm->emitInt64(getDWOId());
949}
950
951bool DwarfCompileUnit::hasDwarfPubSections() const {
952 switch (CUNode->getNameTableKind()) {
953 case DICompileUnit::DebugNameTableKind::None:
954 return false;
955 // Opting in to GNU Pubnames/types overrides the default to ensure these are
956 // generated for things like Gold's gdb_index generation.
957 case DICompileUnit::DebugNameTableKind::GNU:
958 return true;
959 case DICompileUnit::DebugNameTableKind::Default:
960 return DD->tuneForGDB() && !includeMinimalInlineScopes() &&
961 !CUNode->isDebugDirectivesOnly();
962 }
963 llvm_unreachable("Unhandled DICompileUnit::DebugNameTableKind enum")::llvm::llvm_unreachable_internal("Unhandled DICompileUnit::DebugNameTableKind enum"
, "/build/llvm-toolchain-snapshot-8~svn350071/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 963)
;
964}
965
966/// addGlobalName - Add a new global name to the compile unit.
967void DwarfCompileUnit::addGlobalName(StringRef Name, const DIE &Die,
968 const DIScope *Context) {
969 if (!hasDwarfPubSections())
970 return;
971 std::string FullName = getParentContextString(Context) + Name.str();
972 GlobalNames[FullName] = &Die;
973}
974
975void DwarfCompileUnit::addGlobalNameForTypeUnit(StringRef Name,
976 const DIScope *Context) {
977 if (!hasDwarfPubSections())
978 return;
979 std::string FullName = getParentContextString(Context) + Name.str();
980 // Insert, allowing the entry to remain as-is if it's already present
981 // This way the CU-level type DIE is preferred over the "can't describe this
982 // type as a unit offset because it's not really in the CU at all, it's only
983 // in a type unit"
984 GlobalNames.insert(std::make_pair(std::move(FullName), &getUnitDie()));
985}
986
987/// Add a new global type to the unit.
988void DwarfCompileUnit::addGlobalType(const DIType *Ty, const DIE &Die,
989 const DIScope *Context) {
990 if (!hasDwarfPubSections())
991 return;
992 std::string FullName = getParentContextString(Context) + Ty->getName().str();
993 GlobalTypes[FullName] = &Die;
994}
995
996void DwarfCompileUnit::addGlobalTypeUnitType(const DIType *Ty,
997 const DIScope *Context) {
998 if (!hasDwarfPubSections())
999 return;
1000 std::string FullName = getParentContextString(Context) + Ty->getName().str();
1001 // Insert, allowing the entry to remain as-is if it's already present
1002 // This way the CU-level type DIE is preferred over the "can't describe this
1003 // type as a unit offset because it's not really in the CU at all, it's only
1004 // in a type unit"
1005 GlobalTypes.insert(std::make_pair(std::move(FullName), &getUnitDie()));
1006}
1007
1008/// addVariableAddress - Add DW_AT_location attribute for a
1009/// DbgVariable based on provided MachineLocation.
1010void DwarfCompileUnit::addVariableAddress(const DbgVariable &DV, DIE &Die,
1011 MachineLocation Location) {
1012 // addBlockByrefAddress is obsolete and will be removed soon.
1013 // The clang frontend always generates block byref variables with a
1014 // complex expression that encodes exactly what addBlockByrefAddress
1015 // would do.
1016 assert((!DV.isBlockByrefVariable() || DV.hasComplexAddress()) &&(((!DV.isBlockByrefVariable() || DV.hasComplexAddress()) &&
"block byref variable without a complex expression") ? static_cast
<void> (0) : __assert_fail ("(!DV.isBlockByrefVariable() || DV.hasComplexAddress()) && \"block byref variable without a complex expression\""
, "/build/llvm-toolchain-snapshot-8~svn350071/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 1017, __PRETTY_FUNCTION__))
1017 "block byref variable without a complex expression")(((!DV.isBlockByrefVariable() || DV.hasComplexAddress()) &&
"block byref variable without a complex expression") ? static_cast
<void> (0) : __assert_fail ("(!DV.isBlockByrefVariable() || DV.hasComplexAddress()) && \"block byref variable without a complex expression\""
, "/build/llvm-toolchain-snapshot-8~svn350071/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 1017, __PRETTY_FUNCTION__))
;
1018 if (DV.hasComplexAddress())
1019 addComplexAddress(DV, Die, dwarf::DW_AT_location, Location);
1020 else
1021 addAddress(Die, dwarf::DW_AT_location, Location);
1022}
1023
1024/// Add an address attribute to a die based on the location provided.
1025void DwarfCompileUnit::addAddress(DIE &Die, dwarf::Attribute Attribute,
1026 const MachineLocation &Location) {
1027 DIELoc *Loc = new (DIEValueAllocator) DIELoc;
1028 DIEDwarfExpression DwarfExpr(*Asm, *this, *Loc);
1029 if (Location.isIndirect())
1030 DwarfExpr.setMemoryLocationKind();
1031
1032 DIExpressionCursor Cursor({});
1033 const TargetRegisterInfo &TRI = *Asm->MF->getSubtarget().getRegisterInfo();
1034 if (!DwarfExpr.addMachineRegExpression(TRI, Cursor, Location.getReg()))
1035 return;
1036 DwarfExpr.addExpression(std::move(Cursor));
1037
1038 // Now attach the location information to the DIE.
1039 addBlock(Die, Attribute, DwarfExpr.finalize());
1040}
1041
1042/// Start with the address based on the location provided, and generate the
1043/// DWARF information necessary to find the actual variable given the extra
1044/// address information encoded in the DbgVariable, starting from the starting
1045/// location. Add the DWARF information to the die.
1046void DwarfCompileUnit::addComplexAddress(const DbgVariable &DV, DIE &Die,
1047 dwarf::Attribute Attribute,
1048 const MachineLocation &Location) {
1049 DIELoc *Loc = new (DIEValueAllocator) DIELoc;
1050 DIEDwarfExpression DwarfExpr(*Asm, *this, *Loc);
1051 const DIExpression *DIExpr = DV.getSingleExpression();
1052 DwarfExpr.addFragmentOffset(DIExpr);
1053 if (Location.isIndirect())
1054 DwarfExpr.setMemoryLocationKind();
1055
1056 DIExpressionCursor Cursor(DIExpr);
1057 const TargetRegisterInfo &TRI = *Asm->MF->getSubtarget().getRegisterInfo();
1058 if (!DwarfExpr.addMachineRegExpression(TRI, Cursor, Location.getReg()))
1059 return;
1060 DwarfExpr.addExpression(std::move(Cursor));
1061
1062 // Now attach the location information to the DIE.
1063 addBlock(Die, Attribute, DwarfExpr.finalize());
1064}
1065
1066/// Add a Dwarf loclistptr attribute data and value.
1067void DwarfCompileUnit::addLocationList(DIE &Die, dwarf::Attribute Attribute,
1068 unsigned Index) {
1069 dwarf::Form Form = DD->getDwarfVersion() >= 4 ? dwarf::DW_FORM_sec_offset
1070 : dwarf::DW_FORM_data4;
1071 Die.addValue(DIEValueAllocator, Attribute, Form, DIELocList(Index));
1072}
1073
1074void DwarfCompileUnit::applyVariableAttributes(const DbgVariable &Var,
1075 DIE &VariableDie) {
1076 StringRef Name = Var.getName();
1077 if (!Name.empty())
1078 addString(VariableDie, dwarf::DW_AT_name, Name);
1079 const auto *DIVar = Var.getVariable();
1080 if (DIVar)
1081 if (uint32_t AlignInBytes = DIVar->getAlignInBytes())
1082 addUInt(VariableDie, dwarf::DW_AT_alignment, dwarf::DW_FORM_udata,
1083 AlignInBytes);
1084
1085 addSourceLine(VariableDie, DIVar);
1086 addType(VariableDie, Var.getType());
1087 if (Var.isArtificial())
1088 addFlag(VariableDie, dwarf::DW_AT_artificial);
1089}
1090
1091void DwarfCompileUnit::applyLabelAttributes(const DbgLabel &Label,
1092 DIE &LabelDie) {
1093 StringRef Name = Label.getName();
1094 if (!Name.empty())
1095 addString(LabelDie, dwarf::DW_AT_name, Name);
1096 const auto *DILabel = Label.getLabel();
1097 addSourceLine(LabelDie, DILabel);
1098}
1099
1100/// Add a Dwarf expression attribute data and value.
1101void DwarfCompileUnit::addExpr(DIELoc &Die, dwarf::Form Form,
1102 const MCExpr *Expr) {
1103 Die.addValue(DIEValueAllocator, (dwarf::Attribute)0, Form, DIEExpr(Expr));
1104}
1105
1106void DwarfCompileUnit::addAddressExpr(DIE &Die, dwarf::Attribute Attribute,
1107 const MCExpr *Expr) {
1108 Die.addValue(DIEValueAllocator, Attribute, dwarf::DW_FORM_addr,
1109 DIEExpr(Expr));
1110}
1111
1112void DwarfCompileUnit::applySubprogramAttributesToDefinition(
1113 const DISubprogram *SP, DIE &SPDie) {
1114 auto *SPDecl = SP->getDeclaration();
1115 auto *Context = resolve(SPDecl ? SPDecl->getScope() : SP->getScope());
1116 applySubprogramAttributes(SP, SPDie, includeMinimalInlineScopes());
1117 addGlobalName(SP->getName(), SPDie, Context);
1118}
1119
1120bool DwarfCompileUnit::isDwoUnit() const {
1121 return DD->useSplitDwarf() && Skeleton;
1122}
1123
1124bool DwarfCompileUnit::includeMinimalInlineScopes() const {
1125 return getCUNode()->getEmissionKind() == DICompileUnit::LineTablesOnly ||
1126 (DD->useSplitDwarf() && !Skeleton);
1127}
1128
1129void DwarfCompileUnit::addAddrTableBase() {
1130 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
1131 MCSymbol *Label = DD->getAddressPool().getLabel();
1132 addSectionLabel(getUnitDie(),
1133 getDwarfVersion() >= 5 ? dwarf::DW_AT_addr_base
1134 : dwarf::DW_AT_GNU_addr_base,
1135 Label, TLOF.getDwarfAddrSection()->getBeginSymbol());
1136}

/build/llvm-toolchain-snapshot-8~svn350071/include/llvm/CodeGen/DIE.h

1//===- lib/CodeGen/DIE.h - DWARF Info Entries -------------------*- C++ -*-===//
2//
3// The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// Data structures for DWARF info entries.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_LIB_CODEGEN_ASMPRINTER_DIE_H
15#define LLVM_LIB_CODEGEN_ASMPRINTER_DIE_H
16
17#include "llvm/ADT/FoldingSet.h"
18#include "llvm/ADT/PointerIntPair.h"
19#include "llvm/ADT/PointerUnion.h"
20#include "llvm/ADT/SmallVector.h"
21#include "llvm/ADT/StringRef.h"
22#include "llvm/ADT/iterator.h"
23#include "llvm/ADT/iterator_range.h"
24#include "llvm/BinaryFormat/Dwarf.h"
25#include "llvm/CodeGen/DwarfStringPoolEntry.h"
26#include "llvm/Support/AlignOf.h"
27#include "llvm/Support/Allocator.h"
28#include <cassert>
29#include <cstddef>
30#include <cstdint>
31#include <iterator>
32#include <new>
33#include <type_traits>
34#include <utility>
35#include <vector>
36
37namespace llvm {
38
39class AsmPrinter;
40class DIE;
41class DIEUnit;
42class MCExpr;
43class MCSection;
44class MCSymbol;
45class raw_ostream;
46
47//===--------------------------------------------------------------------===//
48/// Dwarf abbreviation data, describes one attribute of a Dwarf abbreviation.
49class DIEAbbrevData {
50 /// Dwarf attribute code.
51 dwarf::Attribute Attribute;
52
53 /// Dwarf form code.
54 dwarf::Form Form;
55
56 /// Dwarf attribute value for DW_FORM_implicit_const
57 int64_t Value = 0;
58
59public:
60 DIEAbbrevData(dwarf::Attribute A, dwarf::Form F)
61 : Attribute(A), Form(F) {}
62 DIEAbbrevData(dwarf::Attribute A, int64_t V)
63 : Attribute(A), Form(dwarf::DW_FORM_implicit_const), Value(V) {}
64
65 /// Accessors.
66 /// @{
67 dwarf::Attribute getAttribute() const { return Attribute; }
68 dwarf::Form getForm() const { return Form; }
69 int64_t getValue() const { return Value; }
70 /// @}
71
72 /// Used to gather unique data for the abbreviation folding set.
73 void Profile(FoldingSetNodeID &ID) const;
74};
75
76//===--------------------------------------------------------------------===//
77/// Dwarf abbreviation, describes the organization of a debug information
78/// object.
79class DIEAbbrev : public FoldingSetNode {
80 /// Unique number for node.
81 unsigned Number;
82
83 /// Dwarf tag code.
84 dwarf::Tag Tag;
85
86 /// Whether or not this node has children.
87 ///
88 /// This cheats a bit in all of the uses since the values in the standard
89 /// are 0 and 1 for no children and children respectively.
90 bool Children;
91
92 /// Raw data bytes for abbreviation.
93 SmallVector<DIEAbbrevData, 12> Data;
94
95public:
96 DIEAbbrev(dwarf::Tag T, bool C) : Tag(T), Children(C) {}
97
98 /// Accessors.
99 /// @{
100 dwarf::Tag getTag() const { return Tag; }
101 unsigned getNumber() const { return Number; }
102 bool hasChildren() const { return Children; }
103 const SmallVectorImpl<DIEAbbrevData> &getData() const { return Data; }
104 void setChildrenFlag(bool hasChild) { Children = hasChild; }
105 void setNumber(unsigned N) { Number = N; }
106 /// @}
107
108 /// Adds another set of attribute information to the abbreviation.
109 void AddAttribute(dwarf::Attribute Attribute, dwarf::Form Form) {
110 Data.push_back(DIEAbbrevData(Attribute, Form));
111 }
112
113 /// Adds attribute with DW_FORM_implicit_const value
114 void AddImplicitConstAttribute(dwarf::Attribute Attribute, int64_t Value) {
115 Data.push_back(DIEAbbrevData(Attribute, Value));
116 }
117
118 /// Used to gather unique data for the abbreviation folding set.
119 void Profile(FoldingSetNodeID &ID) const;
120
121 /// Print the abbreviation using the specified asm printer.
122 void Emit(const AsmPrinter *AP) const;
123
124 void print(raw_ostream &O) const;
125 void dump() const;
126};
127
128//===--------------------------------------------------------------------===//
129/// Helps unique DIEAbbrev objects and assigns abbreviation numbers.
130///
131/// This class will unique the DIE abbreviations for a llvm::DIE object and
132/// assign a unique abbreviation number to each unique DIEAbbrev object it
133/// finds. The resulting collection of DIEAbbrev objects can then be emitted
134/// into the .debug_abbrev section.
135class DIEAbbrevSet {
136 /// The bump allocator to use when creating DIEAbbrev objects in the uniqued
137 /// storage container.
138 BumpPtrAllocator &Alloc;
139 /// FoldingSet that uniques the abbreviations.
140 FoldingSet<DIEAbbrev> AbbreviationsSet;
141 /// A list of all the unique abbreviations in use.
142 std::vector<DIEAbbrev *> Abbreviations;
143
144public:
145 DIEAbbrevSet(BumpPtrAllocator &A) : Alloc(A) {}
146 ~DIEAbbrevSet();
147
148 /// Generate the abbreviation declaration for a DIE and return a pointer to
149 /// the generated abbreviation.
150 ///
151 /// \param Die the debug info entry to generate the abbreviation for.
152 /// \returns A reference to the uniqued abbreviation declaration that is
153 /// owned by this class.
154 DIEAbbrev &uniqueAbbreviation(DIE &Die);
155
156 /// Print all abbreviations using the specified asm printer.
157 void Emit(const AsmPrinter *AP, MCSection *Section) const;
158};
159
160//===--------------------------------------------------------------------===//
161/// An integer value DIE.
162///
163class DIEInteger {
164 uint64_t Integer;
165
166public:
167 explicit DIEInteger(uint64_t I) : Integer(I) {}
168
169 /// Choose the best form for integer.
170 static dwarf::Form BestForm(bool IsSigned, uint64_t Int) {
171 if (IsSigned) {
172 const int64_t SignedInt = Int;
173 if ((char)Int == SignedInt)
174 return dwarf::DW_FORM_data1;
175 if ((short)Int == SignedInt)
176 return dwarf::DW_FORM_data2;
177 if ((int)Int == SignedInt)
178 return dwarf::DW_FORM_data4;
179 } else {
180 if ((unsigned char)Int == Int)
181 return dwarf::DW_FORM_data1;
182 if ((unsigned short)Int == Int)
183 return dwarf::DW_FORM_data2;
184 if ((unsigned int)Int == Int)
185 return dwarf::DW_FORM_data4;
186 }
187 return dwarf::DW_FORM_data8;
188 }
189
190 uint64_t getValue() const { return Integer; }
191 void setValue(uint64_t Val) { Integer = Val; }
192
193 void EmitValue(const AsmPrinter *Asm, dwarf::Form Form) const;
194 unsigned SizeOf(const AsmPrinter *AP, dwarf::Form Form) const;
195
196 void print(raw_ostream &O) const;
197};
198
199//===--------------------------------------------------------------------===//
200/// An expression DIE.
201class DIEExpr {
202 const MCExpr *Expr;
203
204public:
205 explicit DIEExpr(const MCExpr *E) : Expr(E) {}
206
207 /// Get MCExpr.
208 const MCExpr *getValue() const { return Expr; }
209
210 void EmitValue(const AsmPrinter *AP, dwarf::Form Form) const;
211 unsigned SizeOf(const AsmPrinter *AP, dwarf::Form Form) const;
212
213 void print(raw_ostream &O) const;
214};
215
216//===--------------------------------------------------------------------===//
217/// A label DIE.
218class DIELabel {
219 const MCSymbol *Label;
220
221public:
222 explicit DIELabel(const MCSymbol *L) : Label(L) {}
223
224 /// Get MCSymbol.
225 const MCSymbol *getValue() const { return Label; }
226
227 void EmitValue(const AsmPrinter *AP, dwarf::Form Form) const;
228 unsigned SizeOf(const AsmPrinter *AP, dwarf::Form Form) const;
229
230 void print(raw_ostream &O) const;
231};
232
233//===--------------------------------------------------------------------===//
234/// A simple label difference DIE.
235///
236class DIEDelta {
237 const MCSymbol *LabelHi;
238 const MCSymbol *LabelLo;
239
240public:
241 DIEDelta(const MCSymbol *Hi, const MCSymbol *Lo) : LabelHi(Hi), LabelLo(Lo) {}
242
243 void EmitValue(const AsmPrinter *AP, dwarf::Form Form) const;
244 unsigned SizeOf(const AsmPrinter *AP, dwarf::Form Form) const;
245
246 void print(raw_ostream &O) const;
247};
248
249//===--------------------------------------------------------------------===//
250/// A container for string pool string values.
251///
252/// This class is used with the DW_FORM_strp and DW_FORM_GNU_str_index forms.
253class DIEString {
254 DwarfStringPoolEntryRef S;
255
256public:
257 DIEString(DwarfStringPoolEntryRef S) : S(S) {}
258
259 /// Grab the string out of the object.
260 StringRef getString() const { return S.getString(); }
261
262 void EmitValue(const AsmPrinter *AP, dwarf::Form Form) const;
263 unsigned SizeOf(const AsmPrinter *AP, dwarf::Form Form) const;
264
265 void print(raw_ostream &O) const;
266};
267
268//===--------------------------------------------------------------------===//
269/// A container for inline string values.
270///
271/// This class is used with the DW_FORM_string form.
272class DIEInlineString {
273 StringRef S;
274
275public:
276 template <typename Allocator>
277 explicit DIEInlineString(StringRef Str, Allocator &A) : S(Str.copy(A)) {}
278
279 ~DIEInlineString() = default;
280
281 /// Grab the string out of the object.
282 StringRef getString() const { return S; }
283
284 void EmitValue(const AsmPrinter *AP, dwarf::Form Form) const;
285 unsigned SizeOf(const AsmPrinter *AP, dwarf::Form Form) const;
286
287 void print(raw_ostream &O) const;
288};
289
290//===--------------------------------------------------------------------===//
291/// A pointer to another debug information entry. An instance of this class can
292/// also be used as a proxy for a debug information entry not yet defined
293/// (ie. types.)
294class DIEEntry {
295 DIE *Entry;
296
297public:
298 DIEEntry() = delete;
299 explicit DIEEntry(DIE &E) : Entry(&E) {}
300
301 DIE &getEntry() const { return *Entry; }
302
303 void EmitValue(const AsmPrinter *AP, dwarf::Form Form) const;
304 unsigned SizeOf(const AsmPrinter *AP, dwarf::Form Form) const;
305
306 void print(raw_ostream &O) const;
307};
308
309//===--------------------------------------------------------------------===//
310/// Represents a pointer to a location list in the debug_loc
311/// section.
312class DIELocList {
313 /// Index into the .debug_loc vector.
314 size_t Index;
315
316public:
317 DIELocList(size_t I) : Index(I) {}
318
319 /// Grab the current index out.
320 size_t getValue() const { return Index; }
321
322 void EmitValue(const AsmPrinter *AP, dwarf::Form Form) const;
323 unsigned SizeOf(const AsmPrinter *AP, dwarf::Form Form) const;
324
325 void print(raw_ostream &O) const;
326};
327
328//===--------------------------------------------------------------------===//
329/// A debug information entry value. Some of these roughly correlate
330/// to DWARF attribute classes.
331class DIEBlock;
332class DIELoc;
333class DIEValue {
334public:
335 enum Type {
336 isNone,
337#define HANDLE_DIEVALUE(T) is##T,
338#include "llvm/CodeGen/DIEValue.def"
339 };
340
341private:
342 /// Type of data stored in the value.
343 Type Ty = isNone;
344 dwarf::Attribute Attribute = (dwarf::Attribute)0;
345 dwarf::Form Form = (dwarf::Form)0;
346
347 /// Storage for the value.
348 ///
349 /// All values that aren't standard layout (or are larger than 8 bytes)
350 /// should be stored by reference instead of by value.
351 using ValTy = AlignedCharArrayUnion<DIEInteger, DIEString, DIEExpr, DIELabel,
352 DIEDelta *, DIEEntry, DIEBlock *,
353 DIELoc *, DIELocList>;
354
355 static_assert(sizeof(ValTy) <= sizeof(uint64_t) ||
356 sizeof(ValTy) <= sizeof(void *),
357 "Expected all large types to be stored via pointer");
358
359 /// Underlying stored value.
360 ValTy Val;
361
362 template <class T> void construct(T V) {
363 static_assert(std::is_standard_layout<T>::value ||
364 std::is_pointer<T>::value,
365 "Expected standard layout or pointer");
366 new (reinterpret_cast<void *>(Val.buffer)) T(V);
367 }
368
369 template <class T> T *get() { return reinterpret_cast<T *>(Val.buffer); }
370 template <class T> const T *get() const {
371 return reinterpret_cast<const T *>(Val.buffer);
372 }
373 template <class T> void destruct() { get<T>()->~T(); }
374
375 /// Destroy the underlying value.
376 ///
377 /// This should get optimized down to a no-op. We could skip it if we could
378 /// add a static assert on \a std::is_trivially_copyable(), but we currently
379 /// support versions of GCC that don't understand that.
380 void destroyVal() {
381 switch (Ty) {
382 case isNone:
383 return;
384#define HANDLE_DIEVALUE_SMALL(T) \
385 case is##T: \
386 destruct<DIE##T>(); \
387 return;
388#define HANDLE_DIEVALUE_LARGE(T) \
389 case is##T: \
390 destruct<const DIE##T *>(); \
391 return;
392#include "llvm/CodeGen/DIEValue.def"
393 }
394 }
395
396 /// Copy the underlying value.
397 ///
398 /// This should get optimized down to a simple copy. We need to actually
399 /// construct the value, rather than calling memcpy, to satisfy strict
400 /// aliasing rules.
401 void copyVal(const DIEValue &X) {
402 switch (Ty) {
403 case isNone:
404 return;
405#define HANDLE_DIEVALUE_SMALL(T) \
406 case is##T: \
407 construct<DIE##T>(*X.get<DIE##T>()); \
408 return;
409#define HANDLE_DIEVALUE_LARGE(T) \
410 case is##T: \
411 construct<const DIE##T *>(*X.get<const DIE##T *>()); \
412 return;
413#include "llvm/CodeGen/DIEValue.def"
414 }
415 }
416
417public:
418 DIEValue() = default;
419
420 DIEValue(const DIEValue &X) : Ty(X.Ty), Attribute(X.Attribute), Form(X.Form) {
421 copyVal(X);
422 }
423
424 DIEValue &operator=(const DIEValue &X) {
425 destroyVal();
426 Ty = X.Ty;
427 Attribute = X.Attribute;
428 Form = X.Form;
429 copyVal(X);
430 return *this;
431 }
432
433 ~DIEValue() { destroyVal(); }
434
435#define HANDLE_DIEVALUE_SMALL(T) \
436 DIEValue(dwarf::Attribute Attribute, dwarf::Form Form, const DIE##T &V) \
437 : Ty(is##T), Attribute(Attribute), Form(Form) { \
438 construct<DIE##T>(V); \
439 }
440#define HANDLE_DIEVALUE_LARGE(T) \
441 DIEValue(dwarf::Attribute Attribute, dwarf::Form Form, const DIE##T *V) \
442 : Ty(is##T), Attribute(Attribute), Form(Form) { \
443 assert(V && "Expected valid value")((V && "Expected valid value") ? static_cast<void>
(0) : __assert_fail ("V && \"Expected valid value\""
, "/build/llvm-toolchain-snapshot-8~svn350071/include/llvm/CodeGen/DIE.h"
, 443, __PRETTY_FUNCTION__))
; \
444 construct<const DIE##T *>(V); \
445 }
446#include "llvm/CodeGen/DIEValue.def"
447
448 /// Accessors.
449 /// @{
450 Type getType() const { return Ty; }
451 dwarf::Attribute getAttribute() const { return Attribute; }
452 dwarf::Form getForm() const { return Form; }
453 explicit operator bool() const { return Ty; }
454 /// @}
455
456#define HANDLE_DIEVALUE_SMALL(T) \
457 const DIE##T &getDIE##T() const { \
458 assert(getType() == is##T && "Expected " #T)((getType() == is##T && "Expected " #T) ? static_cast
<void> (0) : __assert_fail ("getType() == is##T && \"Expected \" #T"
, "/build/llvm-toolchain-snapshot-8~svn350071/include/llvm/CodeGen/DIE.h"
, 458, __PRETTY_FUNCTION__))
; \
459 return *get<DIE##T>(); \
460 }
461#define HANDLE_DIEVALUE_LARGE(T) \
462 const DIE##T &getDIE##T() const { \
463 assert(getType() == is##T && "Expected " #T)((getType() == is##T && "Expected " #T) ? static_cast
<void> (0) : __assert_fail ("getType() == is##T && \"Expected \" #T"
, "/build/llvm-toolchain-snapshot-8~svn350071/include/llvm/CodeGen/DIE.h"
, 463, __PRETTY_FUNCTION__))
; \
464 return **get<const DIE##T *>(); \
465 }
466#include "llvm/CodeGen/DIEValue.def"
467
468 /// Emit value via the Dwarf writer.
469 void EmitValue(const AsmPrinter *AP) const;
470
471 /// Return the size of a value in bytes.
472 unsigned SizeOf(const AsmPrinter *AP) const;
473
474 void print(raw_ostream &O) const;
475 void dump() const;
476};
477
478struct IntrusiveBackListNode {
479 PointerIntPair<IntrusiveBackListNode *, 1> Next;
480
481 IntrusiveBackListNode() : Next(this, true) {}
482
483 IntrusiveBackListNode *getNext() const {
484 return Next.getInt() ? nullptr : Next.getPointer();
485 }
486};
487
488struct IntrusiveBackListBase {
489 using Node = IntrusiveBackListNode;
490
491 Node *Last = nullptr;
492
493 bool empty() const { return !Last; }
494
495 void push_back(Node &N) {
496 assert(N.Next.getPointer() == &N && "Expected unlinked node")((N.Next.getPointer() == &N && "Expected unlinked node"
) ? static_cast<void> (0) : __assert_fail ("N.Next.getPointer() == &N && \"Expected unlinked node\""
, "/build/llvm-toolchain-snapshot-8~svn350071/include/llvm/CodeGen/DIE.h"
, 496, __PRETTY_FUNCTION__))
;
497 assert(N.Next.getInt() == true && "Expected unlinked node")((N.Next.getInt() == true && "Expected unlinked node"
) ? static_cast<void> (0) : __assert_fail ("N.Next.getInt() == true && \"Expected unlinked node\""
, "/build/llvm-toolchain-snapshot-8~svn350071/include/llvm/CodeGen/DIE.h"
, 497, __PRETTY_FUNCTION__))
;
498
499 if (Last) {
500 N.Next = Last->Next;
501 Last->Next.setPointerAndInt(&N, false);
502 }
503 Last = &N;
504 }
505};
506
507template <class T> class IntrusiveBackList : IntrusiveBackListBase {
508public:
509 using IntrusiveBackListBase::empty;
510
511 void push_back(T &N) { IntrusiveBackListBase::push_back(N); }
512 T &back() { return *static_cast<T *>(Last); }
513 const T &back() const { return *static_cast<T *>(Last); }
514
515 class const_iterator;
516 class iterator
517 : public iterator_facade_base<iterator, std::forward_iterator_tag, T> {
518 friend class const_iterator;
519
520 Node *N = nullptr;
521
522 public:
523 iterator() = default;
524 explicit iterator(T *N) : N(N) {}
525
526 iterator &operator++() {
527 N = N->getNext();
528 return *this;
529 }
530
531 explicit operator bool() const { return N; }
532 T &operator*() const { return *static_cast<T *>(N); }
533
534 bool operator==(const iterator &X) const { return N == X.N; }
535 bool operator!=(const iterator &X) const { return N != X.N; }
536 };
537
538 class const_iterator
539 : public iterator_facade_base<const_iterator, std::forward_iterator_tag,
540 const T> {
541 const Node *N = nullptr;
542
543 public:
544 const_iterator() = default;
545 // Placate MSVC by explicitly scoping 'iterator'.
546 const_iterator(typename IntrusiveBackList<T>::iterator X) : N(X.N) {}
547 explicit const_iterator(const T *N) : N(N) {}
548
549 const_iterator &operator++() {
550 N = N->getNext();
551 return *this;
552 }
553
554 explicit operator bool() const { return N; }
555 const T &operator*() const { return *static_cast<const T *>(N); }
556
557 bool operator==(const const_iterator &X) const { return N == X.N; }
558 bool operator!=(const const_iterator &X) const { return N != X.N; }
559 };
560
561 iterator begin() {
562 return Last ? iterator(static_cast<T *>(Last->Next.getPointer())) : end();
563 }
564 const_iterator begin() const {
565 return const_cast<IntrusiveBackList *>(this)->begin();
566 }
567 iterator end() { return iterator(); }
568 const_iterator end() const { return const_iterator(); }
569
570 static iterator toIterator(T &N) { return iterator(&N); }
571 static const_iterator toIterator(const T &N) { return const_iterator(&N); }
572};
573
574/// A list of DIE values.
575///
576/// This is a singly-linked list, but instead of reversing the order of
577/// insertion, we keep a pointer to the back of the list so we can push in
578/// order.
579///
580/// There are two main reasons to choose a linked list over a customized
581/// vector-like data structure.
582///
583/// 1. For teardown efficiency, we want DIEs to be BumpPtrAllocated. Using a
584/// linked list here makes this way easier to accomplish.
585/// 2. Carrying an extra pointer per \a DIEValue isn't expensive. 45% of DIEs
586/// have 2 or fewer values, and 90% have 5 or fewer. A vector would be
587/// over-allocated by 50% on average anyway, the same cost as the
588/// linked-list node.
589class DIEValueList {
590 struct Node : IntrusiveBackListNode {
591 DIEValue V;
592
593 explicit Node(DIEValue V) : V(V) {}
594 };
595
596 using ListTy = IntrusiveBackList<Node>;
597
598 ListTy List;
599
600public:
601 class const_value_iterator;
602 class value_iterator
603 : public iterator_adaptor_base<value_iterator, ListTy::iterator,
604 std::forward_iterator_tag, DIEValue> {
605 friend class const_value_iterator;
606
607 using iterator_adaptor =
608 iterator_adaptor_base<value_iterator, ListTy::iterator,
609 std::forward_iterator_tag, DIEValue>;
610
611 public:
612 value_iterator() = default;
613 explicit value_iterator(ListTy::iterator X) : iterator_adaptor(X) {}
614
615 explicit operator bool() const { return bool(wrapped()); }
616 DIEValue &operator*() const { return wrapped()->V; }
617 };
618
619 class const_value_iterator : public iterator_adaptor_base<
620 const_value_iterator, ListTy::const_iterator,
621 std::forward_iterator_tag, const DIEValue> {
622 using iterator_adaptor =
623 iterator_adaptor_base<const_value_iterator, ListTy::const_iterator,
624 std::forward_iterator_tag, const DIEValue>;
625
626 public:
627 const_value_iterator() = default;
628 const_value_iterator(DIEValueList::value_iterator X)
629 : iterator_adaptor(X.wrapped()) {}
630 explicit const_value_iterator(ListTy::const_iterator X)
631 : iterator_adaptor(X) {}
632
633 explicit operator bool() const { return bool(wrapped()); }
634 const DIEValue &operator*() const { return wrapped()->V; }
635 };
636
637 using value_range = iterator_range<value_iterator>;
638 using const_value_range = iterator_range<const_value_iterator>;
639
640 value_iterator addValue(BumpPtrAllocator &Alloc, const DIEValue &V) {
641 List.push_back(*new (Alloc) Node(V));
16
Forming reference to null pointer
642 return value_iterator(ListTy::toIterator(List.back()));
643 }
644 template <class T>
645 value_iterator addValue(BumpPtrAllocator &Alloc, dwarf::Attribute Attribute,
646 dwarf::Form Form, T &&Value) {
647 return addValue(Alloc, DIEValue(Attribute, Form, std::forward<T>(Value)));
15
Calling 'DIEValueList::addValue'
648 }
649
650 value_range values() {
651 return make_range(value_iterator(List.begin()), value_iterator(List.end()));
652 }
653 const_value_range values() const {
654 return make_range(const_value_iterator(List.begin()),
655 const_value_iterator(List.end()));
656 }
657};
658
659//===--------------------------------------------------------------------===//
660/// A structured debug information entry. Has an abbreviation which
661/// describes its organization.
662class DIE : IntrusiveBackListNode, public DIEValueList {
663 friend class IntrusiveBackList<DIE>;
664 friend class DIEUnit;
665
666 /// Dwarf unit relative offset.
667 unsigned Offset = 0;
668 /// Size of instance + children.
669 unsigned Size = 0;
670 unsigned AbbrevNumber = ~0u;
671 /// Dwarf tag code.
672 dwarf::Tag Tag = (dwarf::Tag)0;
673 /// Set to true to force a DIE to emit an abbreviation that says it has
674 /// children even when it doesn't. This is used for unit testing purposes.
675 bool ForceChildren = false;
676 /// Children DIEs.
677 IntrusiveBackList<DIE> Children;
678
679 /// The owner is either the parent DIE for children of other DIEs, or a
680 /// DIEUnit which contains this DIE as its unit DIE.
681 PointerUnion<DIE *, DIEUnit *> Owner;
682
683 explicit DIE(dwarf::Tag Tag) : Tag(Tag) {}
684
685public:
686 DIE() = delete;
687 DIE(const DIE &RHS) = delete;
688 DIE(DIE &&RHS) = delete;
689 DIE &operator=(const DIE &RHS) = delete;
690 DIE &operator=(const DIE &&RHS) = delete;
691
692 static DIE *get(BumpPtrAllocator &Alloc, dwarf::Tag Tag) {
693 return new (Alloc) DIE(Tag);
694 }
695
696 // Accessors.
697 unsigned getAbbrevNumber() const { return AbbrevNumber; }
698 dwarf::Tag getTag() const { return Tag; }
699 /// Get the compile/type unit relative offset of this DIE.
700 unsigned getOffset() const { return Offset; }
701 unsigned getSize() const { return Size; }
702 bool hasChildren() const { return ForceChildren || !Children.empty(); }
703 void setForceChildren(bool B) { ForceChildren = B; }
704
705 using child_iterator = IntrusiveBackList<DIE>::iterator;
706 using const_child_iterator = IntrusiveBackList<DIE>::const_iterator;
707 using child_range = iterator_range<child_iterator>;
708 using const_child_range = iterator_range<const_child_iterator>;
709
710 child_range children() {
711 return make_range(Children.begin(), Children.end());
712 }
713 const_child_range children() const {
714 return make_range(Children.begin(), Children.end());
715 }
716
717 DIE *getParent() const;
718
719 /// Generate the abbreviation for this DIE.
720 ///
721 /// Calculate the abbreviation for this, which should be uniqued and
722 /// eventually used to call \a setAbbrevNumber().
723 DIEAbbrev generateAbbrev() const;
724
725 /// Set the abbreviation number for this DIE.
726 void setAbbrevNumber(unsigned I) { AbbrevNumber = I; }
727
728 /// Get the absolute offset within the .debug_info or .debug_types section
729 /// for this DIE.
730 unsigned getDebugSectionOffset() const;
731
732 /// Compute the offset of this DIE and all its children.
733 ///
734 /// This function gets called just before we are going to generate the debug
735 /// information and gives each DIE a chance to figure out its CU relative DIE
736 /// offset, unique its abbreviation and fill in the abbreviation code, and
737 /// return the unit offset that points to where the next DIE will be emitted
738 /// within the debug unit section. After this function has been called for all
739 /// DIE objects, the DWARF can be generated since all DIEs will be able to
740 /// properly refer to other DIE objects since all DIEs have calculated their
741 /// offsets.
742 ///
743 /// \param AP AsmPrinter to use when calculating sizes.
744 /// \param AbbrevSet the abbreviation used to unique DIE abbreviations.
745 /// \param CUOffset the compile/type unit relative offset in bytes.
746 /// \returns the offset for the DIE that follows this DIE within the
747 /// current compile/type unit.
748 unsigned computeOffsetsAndAbbrevs(const AsmPrinter *AP,
749 DIEAbbrevSet &AbbrevSet, unsigned CUOffset);
750
751 /// Climb up the parent chain to get the compile unit or type unit DIE that
752 /// this DIE belongs to.
753 ///
754 /// \returns the compile or type unit DIE that owns this DIE, or NULL if
755 /// this DIE hasn't been added to a unit DIE.
756 const DIE *getUnitDie() const;
757
758 /// Climb up the parent chain to get the compile unit or type unit that this
759 /// DIE belongs to.
760 ///
761 /// \returns the DIEUnit that represents the compile or type unit that owns
762 /// this DIE, or NULL if this DIE hasn't been added to a unit DIE.
763 const DIEUnit *getUnit() const;
764
765 void setOffset(unsigned O) { Offset = O; }
766 void setSize(unsigned S) { Size = S; }
767
768 /// Add a child to the DIE.
769 DIE &addChild(DIE *Child) {
770 assert(!Child->getParent() && "Child should be orphaned")((!Child->getParent() && "Child should be orphaned"
) ? static_cast<void> (0) : __assert_fail ("!Child->getParent() && \"Child should be orphaned\""
, "/build/llvm-toolchain-snapshot-8~svn350071/include/llvm/CodeGen/DIE.h"
, 770, __PRETTY_FUNCTION__))
;
771 Child->Owner = this;
772 Children.push_back(*Child);
773 return Children.back();
774 }
775
776 /// Find a value in the DIE with the attribute given.
777 ///
778 /// Returns a default-constructed DIEValue (where \a DIEValue::getType()
779 /// gives \a DIEValue::isNone) if no such attribute exists.
780 DIEValue findAttribute(dwarf::Attribute Attribute) const;
781
782 void print(raw_ostream &O, unsigned IndentCount = 0) const;
783 void dump() const;
784};
785
786//===--------------------------------------------------------------------===//
787/// Represents a compile or type unit.
788class DIEUnit {
789 /// The compile unit or type unit DIE. This variable must be an instance of
790 /// DIE so that we can calculate the DIEUnit from any DIE by traversing the
791 /// parent backchain and getting the Unit DIE, and then casting itself to a
792 /// DIEUnit. This allows us to be able to find the DIEUnit for any DIE without
793 /// having to store a pointer to the DIEUnit in each DIE instance.
794 DIE Die;
795 /// The section this unit will be emitted in. This may or may not be set to
796 /// a valid section depending on the client that is emitting DWARF.
797 MCSection *Section;
798 uint64_t Offset; /// .debug_info or .debug_types absolute section offset.
799 uint32_t Length; /// The length in bytes of all of the DIEs in this unit.
800 const uint16_t Version; /// The Dwarf version number for this unit.
801 const uint8_t AddrSize; /// The size in bytes of an address for this unit.
802protected:
803 ~DIEUnit() = default;
804
805public:
806 DIEUnit(uint16_t Version, uint8_t AddrSize, dwarf::Tag UnitTag);
807 DIEUnit(const DIEUnit &RHS) = delete;
808 DIEUnit(DIEUnit &&RHS) = delete;
809 void operator=(const DIEUnit &RHS) = delete;
810 void operator=(const DIEUnit &&RHS) = delete;
811 /// Set the section that this DIEUnit will be emitted into.
812 ///
813 /// This function is used by some clients to set the section. Not all clients
814 /// that emit DWARF use this section variable.
815 void setSection(MCSection *Section) {
816 assert(!this->Section)((!this->Section) ? static_cast<void> (0) : __assert_fail
("!this->Section", "/build/llvm-toolchain-snapshot-8~svn350071/include/llvm/CodeGen/DIE.h"
, 816, __PRETTY_FUNCTION__))
;
817 this->Section = Section;
818 }
819
820 virtual const MCSymbol *getCrossSectionRelativeBaseAddress() const {
821 return nullptr;
822 }
823
824 /// Return the section that this DIEUnit will be emitted into.
825 ///
826 /// \returns Section pointer which can be NULL.
827 MCSection *getSection() const { return Section; }
828 void setDebugSectionOffset(unsigned O) { Offset = O; }
829 unsigned getDebugSectionOffset() const { return Offset; }
830 void setLength(uint64_t L) { Length = L; }
831 uint64_t getLength() const { return Length; }
832 uint16_t getDwarfVersion() const { return Version; }
833 uint16_t getAddressSize() const { return AddrSize; }
834 DIE &getUnitDie() { return Die; }
835 const DIE &getUnitDie() const { return Die; }
836};
837
838struct BasicDIEUnit final : DIEUnit {
839 BasicDIEUnit(uint16_t Version, uint8_t AddrSize, dwarf::Tag UnitTag)
840 : DIEUnit(Version, AddrSize, UnitTag) {}
841};
842
843//===--------------------------------------------------------------------===//
844/// DIELoc - Represents an expression location.
845//
846class DIELoc : public DIEValueList {
847 mutable unsigned Size = 0; // Size in bytes excluding size header.
848
849public:
850 DIELoc() = default;
851
852 /// ComputeSize - Calculate the size of the location expression.
853 ///
854 unsigned ComputeSize(const AsmPrinter *AP) const;
855
856 /// BestForm - Choose the best form for data.
857 ///
858 dwarf::Form BestForm(unsigned DwarfVersion) const {
859 if (DwarfVersion > 3)
860 return dwarf::DW_FORM_exprloc;
861 // Pre-DWARF4 location expressions were blocks and not exprloc.
862 if ((unsigned char)Size == Size)
863 return dwarf::DW_FORM_block1;
864 if ((unsigned short)Size == Size)
865 return dwarf::DW_FORM_block2;
866 if ((unsigned int)Size == Size)
867 return dwarf::DW_FORM_block4;
868 return dwarf::DW_FORM_block;
869 }
870
871 void EmitValue(const AsmPrinter *Asm, dwarf::Form Form) const;
872 unsigned SizeOf(const AsmPrinter *AP, dwarf::Form Form) const;
873
874 void print(raw_ostream &O) const;
875};
876
877//===--------------------------------------------------------------------===//
878/// DIEBlock - Represents a block of values.
879//
880class DIEBlock : public DIEValueList {
881 mutable unsigned Size = 0; // Size in bytes excluding size header.
882
883public:
884 DIEBlock() = default;
885
886 /// ComputeSize - Calculate the size of the location expression.
887 ///
888 unsigned ComputeSize(const AsmPrinter *AP) const;
889
890 /// BestForm - Choose the best form for data.
891 ///
892 dwarf::Form BestForm() const {
893 if ((unsigned char)Size == Size)
894 return dwarf::DW_FORM_block1;
895 if ((unsigned short)Size == Size)
896 return dwarf::DW_FORM_block2;
897 if ((unsigned int)Size == Size)
898 return dwarf::DW_FORM_block4;
899 return dwarf::DW_FORM_block;
900 }
901
902 void EmitValue(const AsmPrinter *Asm, dwarf::Form Form) const;
903 unsigned SizeOf(const AsmPrinter *AP, dwarf::Form Form) const;
904
905 void print(raw_ostream &O) const;
906};
907
908} // end namespace llvm
909
910#endif // LLVM_LIB_CODEGEN_ASMPRINTER_DIE_H