Bug Summary

File:lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
Warning:line 928, column 22
Forming reference to null pointer

Annotated Source Code

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clang -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name DwarfCompileUnit.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-eagerly-assume -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -mrelocation-model pic -pic-level 2 -mthread-model posix -fmath-errno -masm-verbose -mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu x86-64 -dwarf-column-info -debugger-tuning=gdb -momit-leaf-frame-pointer -ffunction-sections -fdata-sections -resource-dir /usr/lib/llvm-7/lib/clang/7.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-7~svn329677/build-llvm/lib/CodeGen/AsmPrinter -I /build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter -I /build/llvm-toolchain-snapshot-7~svn329677/build-llvm/include -I /build/llvm-toolchain-snapshot-7~svn329677/include -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/7.3.0/../../../../include/c++/7.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/7.3.0/../../../../include/x86_64-linux-gnu/c++/7.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/7.3.0/../../../../include/x86_64-linux-gnu/c++/7.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/7.3.0/../../../../include/c++/7.3.0/backward -internal-isystem /usr/include/clang/7.0.0/include/ -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-7/lib/clang/7.0.0/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-7~svn329677/build-llvm/lib/CodeGen/AsmPrinter -ferror-limit 19 -fmessage-length 0 -fvisibility-inlines-hidden -fobjc-runtime=gcc -fdiagnostics-show-option -vectorize-loops -vectorize-slp -analyzer-checker optin.performance.Padding -analyzer-output=html -analyzer-config stable-report-filename=true -o /tmp/scan-build-2018-04-11-031539-24776-1 -x c++ /build/llvm-toolchain-snapshot-7~svn329677/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)
73 return addLocalLabelAddress(Die, Attribute, Label);
74
75 if (Label)
76 DD->addArangeLabel(SymbolCU(this, Label));
77
78 unsigned idx = DD->getAddressPool().getIndex(Label);
79 Die.addValue(DIEValueAllocator, Attribute, dwarf::DW_FORM_GNU_addr_index,
80 DIEInteger(idx));
81}
82
83void DwarfCompileUnit::addLocalLabelAddress(DIE &Die,
84 dwarf::Attribute Attribute,
85 const MCSymbol *Label) {
86 if (Label)
87 DD->addArangeLabel(SymbolCU(this, Label));
88
89 if (Label)
90 Die.addValue(DIEValueAllocator, Attribute, dwarf::DW_FORM_addr,
91 DIELabel(Label));
92 else
93 Die.addValue(DIEValueAllocator, Attribute, dwarf::DW_FORM_addr,
94 DIEInteger(0));
95}
96
97unsigned DwarfCompileUnit::getOrCreateSourceID(const DIFile *File) {
98 // If we print assembly, we can't separate .file entries according to
99 // compile units. Thus all files will belong to the default compile unit.
100
101 // FIXME: add a better feature test than hasRawTextSupport. Even better,
102 // extend .file to support this.
103 unsigned CUID = Asm->OutStreamer->hasRawTextSupport() ? 0 : getUniqueID();
104 if (!File)
105 return Asm->OutStreamer->EmitDwarfFileDirective(0, "", "", nullptr, None, CUID);
106 return Asm->OutStreamer->EmitDwarfFileDirective(
107 0, File->getDirectory(), File->getFilename(), getMD5AsBytes(File),
108 File->getSource(), CUID);
109}
110
111DIE *DwarfCompileUnit::getOrCreateGlobalVariableDIE(
112 const DIGlobalVariable *GV, ArrayRef<GlobalExpr> GlobalExprs) {
113 // Check for pre-existence.
114 if (DIE *Die = getDIE(GV))
115 return Die;
116
117 assert(GV)(static_cast <bool> (GV) ? void (0) : __assert_fail ("GV"
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 117, __extension__ __PRETTY_FUNCTION__))
;
118
119 auto *GVContext = GV->getScope();
120 auto *GTy = DD->resolve(GV->getType());
121
122 // Construct the context before querying for the existence of the DIE in
123 // case such construction creates the DIE.
124 DIE *ContextDIE = getOrCreateContextDIE(GVContext);
125
126 // Add to map.
127 DIE *VariableDIE = &createAndAddDIE(GV->getTag(), *ContextDIE, GV);
128 DIScope *DeclContext;
129 if (auto *SDMDecl = GV->getStaticDataMemberDeclaration()) {
130 DeclContext = resolve(SDMDecl->getScope());
131 assert(SDMDecl->isStaticMember() && "Expected static member decl")(static_cast <bool> (SDMDecl->isStaticMember() &&
"Expected static member decl") ? void (0) : __assert_fail ("SDMDecl->isStaticMember() && \"Expected static member decl\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 131, __extension__ __PRETTY_FUNCTION__))
;
132 assert(GV->isDefinition())(static_cast <bool> (GV->isDefinition()) ? void (0) :
__assert_fail ("GV->isDefinition()", "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 132, __extension__ __PRETTY_FUNCTION__))
;
133 // We need the declaration DIE that is in the static member's class.
134 DIE *VariableSpecDIE = getOrCreateStaticMemberDIE(SDMDecl);
135 addDIEEntry(*VariableDIE, dwarf::DW_AT_specification, *VariableSpecDIE);
136 // If the global variable's type is different from the one in the class
137 // member type, assume that it's more specific and also emit it.
138 if (GTy != DD->resolve(SDMDecl->getBaseType()))
139 addType(*VariableDIE, GTy);
140 } else {
141 DeclContext = GV->getScope();
142 // Add name and type.
143 addString(*VariableDIE, dwarf::DW_AT_name, GV->getDisplayName());
144 addType(*VariableDIE, GTy);
145
146 // Add scoping info.
147 if (!GV->isLocalToUnit())
148 addFlag(*VariableDIE, dwarf::DW_AT_external);
149
150 // Add line number info.
151 addSourceLine(*VariableDIE, GV);
152 }
153
154 if (!GV->isDefinition())
155 addFlag(*VariableDIE, dwarf::DW_AT_declaration);
156 else
157 addGlobalName(GV->getName(), *VariableDIE, DeclContext);
158
159 if (uint32_t AlignInBytes = GV->getAlignInBytes())
160 addUInt(*VariableDIE, dwarf::DW_AT_alignment, dwarf::DW_FORM_udata,
161 AlignInBytes);
162
163 // Add location.
164 bool addToAccelTable = false;
165 DIELoc *Loc = nullptr;
166 std::unique_ptr<DIEDwarfExpression> DwarfExpr;
167 for (const auto &GE : GlobalExprs) {
168 const GlobalVariable *Global = GE.Var;
169 const DIExpression *Expr = GE.Expr;
170
171 // For compatibility with DWARF 3 and earlier,
172 // DW_AT_location(DW_OP_constu, X, DW_OP_stack_value) becomes
173 // DW_AT_const_value(X).
174 if (GlobalExprs.size() == 1 && Expr && Expr->isConstant()) {
175 addToAccelTable = true;
176 addConstantValue(*VariableDIE, /*Unsigned=*/true, Expr->getElement(1));
177 break;
178 }
179
180 // We cannot describe the location of dllimport'd variables: the
181 // computation of their address requires loads from the IAT.
182 if (Global && Global->hasDLLImportStorageClass())
183 continue;
184
185 // Nothing to describe without address or constant.
186 if (!Global && (!Expr || !Expr->isConstant()))
187 continue;
188
189 if (!Loc) {
190 addToAccelTable = true;
191 Loc = new (DIEValueAllocator) DIELoc;
192 DwarfExpr = llvm::make_unique<DIEDwarfExpression>(*Asm, *this, *Loc);
193 }
194
195 if (Expr)
196 DwarfExpr->addFragmentOffset(Expr);
197
198 if (Global) {
199 const MCSymbol *Sym = Asm->getSymbol(Global);
200 if (Global->isThreadLocal()) {
201 if (Asm->TM.useEmulatedTLS()) {
202 // TODO: add debug info for emulated thread local mode.
203 } else {
204 // FIXME: Make this work with -gsplit-dwarf.
205 unsigned PointerSize = Asm->getDataLayout().getPointerSize();
206 assert((PointerSize == 4 || PointerSize == 8) &&(static_cast <bool> ((PointerSize == 4 || PointerSize ==
8) && "Add support for other sizes if necessary") ? void
(0) : __assert_fail ("(PointerSize == 4 || PointerSize == 8) && \"Add support for other sizes if necessary\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 207, __extension__ __PRETTY_FUNCTION__))
207 "Add support for other sizes if necessary")(static_cast <bool> ((PointerSize == 4 || PointerSize ==
8) && "Add support for other sizes if necessary") ? void
(0) : __assert_fail ("(PointerSize == 4 || PointerSize == 8) && \"Add support for other sizes if necessary\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 207, __extension__ __PRETTY_FUNCTION__))
;
208 // Based on GCC's support for TLS:
209 if (!DD->useSplitDwarf()) {
210 // 1) Start with a constNu of the appropriate pointer size
211 addUInt(*Loc, dwarf::DW_FORM_data1,
212 PointerSize == 4 ? dwarf::DW_OP_const4u
213 : dwarf::DW_OP_const8u);
214 // 2) containing the (relocated) offset of the TLS variable
215 // within the module's TLS block.
216 addExpr(*Loc, dwarf::DW_FORM_udata,
217 Asm->getObjFileLowering().getDebugThreadLocalSymbol(Sym));
218 } else {
219 addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_GNU_const_index);
220 addUInt(*Loc, dwarf::DW_FORM_udata,
221 DD->getAddressPool().getIndex(Sym, /* TLS */ true));
222 }
223 // 3) followed by an OP to make the debugger do a TLS lookup.
224 addUInt(*Loc, dwarf::DW_FORM_data1,
225 DD->useGNUTLSOpcode() ? dwarf::DW_OP_GNU_push_tls_address
226 : dwarf::DW_OP_form_tls_address);
227 }
228 } else {
229 DD->addArangeLabel(SymbolCU(this, Sym));
230 addOpAddress(*Loc, Sym);
231 }
232 }
233 if (Expr)
234 DwarfExpr->addExpression(Expr);
235 }
236 if (Loc)
237 addBlock(*VariableDIE, dwarf::DW_AT_location, DwarfExpr->finalize());
238
239 if (DD->useAllLinkageNames())
240 addLinkageName(*VariableDIE, GV->getLinkageName());
241
242 if (addToAccelTable) {
243 DD->addAccelName(GV->getName(), *VariableDIE);
244
245 // If the linkage name is different than the name, go ahead and output
246 // that as well into the name table.
247 if (GV->getLinkageName() != "" && GV->getName() != GV->getLinkageName())
248 DD->addAccelName(GV->getLinkageName(), *VariableDIE);
249 }
250
251 return VariableDIE;
252}
253
254void DwarfCompileUnit::addRange(RangeSpan Range) {
255 bool SameAsPrevCU = this == DD->getPrevCU();
256 DD->setPrevCU(this);
257 // If we have no current ranges just add the range and return, otherwise,
258 // check the current section and CU against the previous section and CU we
259 // emitted into and the subprogram was contained within. If these are the
260 // same then extend our current range, otherwise add this as a new range.
261 if (CURanges.empty() || !SameAsPrevCU ||
262 (&CURanges.back().getEnd()->getSection() !=
263 &Range.getEnd()->getSection())) {
264 CURanges.push_back(Range);
265 return;
266 }
267
268 CURanges.back().setEnd(Range.getEnd());
269}
270
271void DwarfCompileUnit::initStmtList() {
272 // Define start line table label for each Compile Unit.
273 MCSymbol *LineTableStartSym;
274 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
275 if (DD->useSectionsAsReferences()) {
276 LineTableStartSym = TLOF.getDwarfLineSection()->getBeginSymbol();
277 } else {
278 LineTableStartSym =
279 Asm->OutStreamer->getDwarfLineTableSymbol(getUniqueID());
280 }
281
282 // DW_AT_stmt_list is a offset of line number information for this
283 // compile unit in debug_line section. For split dwarf this is
284 // left in the skeleton CU and so not included.
285 // The line table entries are not always emitted in assembly, so it
286 // is not okay to use line_table_start here.
287 StmtListValue =
288 addSectionLabel(getUnitDie(), dwarf::DW_AT_stmt_list, LineTableStartSym,
289 TLOF.getDwarfLineSection()->getBeginSymbol());
290}
291
292void DwarfCompileUnit::applyStmtList(DIE &D) {
293 D.addValue(DIEValueAllocator, *StmtListValue);
294}
295
296void DwarfCompileUnit::attachLowHighPC(DIE &D, const MCSymbol *Begin,
297 const MCSymbol *End) {
298 assert(Begin && "Begin label should not be null!")(static_cast <bool> (Begin && "Begin label should not be null!"
) ? void (0) : __assert_fail ("Begin && \"Begin label should not be null!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 298, __extension__ __PRETTY_FUNCTION__))
;
299 assert(End && "End label should not be null!")(static_cast <bool> (End && "End label should not be null!"
) ? void (0) : __assert_fail ("End && \"End label should not be null!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 299, __extension__ __PRETTY_FUNCTION__))
;
300 assert(Begin->isDefined() && "Invalid starting label")(static_cast <bool> (Begin->isDefined() && "Invalid starting label"
) ? void (0) : __assert_fail ("Begin->isDefined() && \"Invalid starting label\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 300, __extension__ __PRETTY_FUNCTION__))
;
301 assert(End->isDefined() && "Invalid end label")(static_cast <bool> (End->isDefined() && "Invalid end label"
) ? void (0) : __assert_fail ("End->isDefined() && \"Invalid end label\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 301, __extension__ __PRETTY_FUNCTION__))
;
302
303 addLabelAddress(D, dwarf::DW_AT_low_pc, Begin);
304 if (DD->getDwarfVersion() < 4)
305 addLabelAddress(D, dwarf::DW_AT_high_pc, End);
306 else
307 addLabelDelta(D, dwarf::DW_AT_high_pc, End, Begin);
308}
309
310// Find DIE for the given subprogram and attach appropriate DW_AT_low_pc
311// and DW_AT_high_pc attributes. If there are global variables in this
312// scope then create and insert DIEs for these variables.
313DIE &DwarfCompileUnit::updateSubprogramScopeDIE(const DISubprogram *SP) {
314 DIE *SPDie = getOrCreateSubprogramDIE(SP, includeMinimalInlineScopes());
315
316 attachLowHighPC(*SPDie, Asm->getFunctionBegin(), Asm->getFunctionEnd());
317 if (DD->useAppleExtensionAttributes() &&
2
Assuming the condition is false
318 !DD->getCurrentFunction()->getTarget().Options.DisableFramePointerElim(
319 *DD->getCurrentFunction()))
320 addFlag(*SPDie, dwarf::DW_AT_APPLE_omit_frame_ptr);
321
322 // Only include DW_AT_frame_base in full debug info
323 if (!includeMinimalInlineScopes()) {
3
Taking true branch
324 const TargetRegisterInfo *RI = Asm->MF->getSubtarget().getRegisterInfo();
325 MachineLocation Location(RI->getFrameRegister(*Asm->MF));
326 if (RI->isPhysicalRegister(Location.getReg()))
4
Taking true branch
327 addAddress(*SPDie, dwarf::DW_AT_frame_base, Location);
5
Calling 'DwarfCompileUnit::addAddress'
328 }
329
330 // Add name to the name table, we do this here because we're guaranteed
331 // to have concrete versions of our DW_TAG_subprogram nodes.
332 DD->addSubprogramNames(SP, *SPDie);
333
334 return *SPDie;
335}
336
337// Construct a DIE for this scope.
338void DwarfCompileUnit::constructScopeDIE(
339 LexicalScope *Scope, SmallVectorImpl<DIE *> &FinalChildren) {
340 if (!Scope || !Scope->getScopeNode())
341 return;
342
343 auto *DS = Scope->getScopeNode();
344
345 assert((Scope->getInlinedAt() || !isa<DISubprogram>(DS)) &&(static_cast <bool> ((Scope->getInlinedAt() || !isa<
DISubprogram>(DS)) && "Only handle inlined subprograms here, use "
"constructSubprogramScopeDIE for non-inlined " "subprograms"
) ? void (0) : __assert_fail ("(Scope->getInlinedAt() || !isa<DISubprogram>(DS)) && \"Only handle inlined subprograms here, use \" \"constructSubprogramScopeDIE for non-inlined \" \"subprograms\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 348, __extension__ __PRETTY_FUNCTION__))
346 "Only handle inlined subprograms here, use "(static_cast <bool> ((Scope->getInlinedAt() || !isa<
DISubprogram>(DS)) && "Only handle inlined subprograms here, use "
"constructSubprogramScopeDIE for non-inlined " "subprograms"
) ? void (0) : __assert_fail ("(Scope->getInlinedAt() || !isa<DISubprogram>(DS)) && \"Only handle inlined subprograms here, use \" \"constructSubprogramScopeDIE for non-inlined \" \"subprograms\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 348, __extension__ __PRETTY_FUNCTION__))
347 "constructSubprogramScopeDIE for non-inlined "(static_cast <bool> ((Scope->getInlinedAt() || !isa<
DISubprogram>(DS)) && "Only handle inlined subprograms here, use "
"constructSubprogramScopeDIE for non-inlined " "subprograms"
) ? void (0) : __assert_fail ("(Scope->getInlinedAt() || !isa<DISubprogram>(DS)) && \"Only handle inlined subprograms here, use \" \"constructSubprogramScopeDIE for non-inlined \" \"subprograms\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 348, __extension__ __PRETTY_FUNCTION__))
348 "subprograms")(static_cast <bool> ((Scope->getInlinedAt() || !isa<
DISubprogram>(DS)) && "Only handle inlined subprograms here, use "
"constructSubprogramScopeDIE for non-inlined " "subprograms"
) ? void (0) : __assert_fail ("(Scope->getInlinedAt() || !isa<DISubprogram>(DS)) && \"Only handle inlined subprograms here, use \" \"constructSubprogramScopeDIE for non-inlined \" \"subprograms\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 348, __extension__ __PRETTY_FUNCTION__))
;
349
350 SmallVector<DIE *, 8> Children;
351
352 // We try to create the scope DIE first, then the children DIEs. This will
353 // avoid creating un-used children then removing them later when we find out
354 // the scope DIE is null.
355 DIE *ScopeDIE;
356 if (Scope->getParent() && isa<DISubprogram>(DS)) {
357 ScopeDIE = constructInlinedScopeDIE(Scope);
358 if (!ScopeDIE)
359 return;
360 // We create children when the scope DIE is not null.
361 createScopeChildrenDIE(Scope, Children);
362 } else {
363 // Early exit when we know the scope DIE is going to be null.
364 if (DD->isLexicalScopeDIENull(Scope))
365 return;
366
367 bool HasNonScopeChildren = false;
368
369 // We create children here when we know the scope DIE is not going to be
370 // null and the children will be added to the scope DIE.
371 createScopeChildrenDIE(Scope, Children, &HasNonScopeChildren);
372
373 // If there are only other scopes as children, put them directly in the
374 // parent instead, as this scope would serve no purpose.
375 if (!HasNonScopeChildren) {
376 FinalChildren.insert(FinalChildren.end(),
377 std::make_move_iterator(Children.begin()),
378 std::make_move_iterator(Children.end()));
379 return;
380 }
381 ScopeDIE = constructLexicalScopeDIE(Scope);
382 assert(ScopeDIE && "Scope DIE should not be null.")(static_cast <bool> (ScopeDIE && "Scope DIE should not be null."
) ? void (0) : __assert_fail ("ScopeDIE && \"Scope DIE should not be null.\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 382, __extension__ __PRETTY_FUNCTION__))
;
383 }
384
385 // Add children
386 for (auto &I : Children)
387 ScopeDIE->addChild(std::move(I));
388
389 FinalChildren.push_back(std::move(ScopeDIE));
390}
391
392void DwarfCompileUnit::addScopeRangeList(DIE &ScopeDIE,
393 SmallVector<RangeSpan, 2> Range) {
394 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
395
396 // Emit offset in .debug_range as a relocatable label. emitDIE will handle
397 // emitting it appropriately.
398 const MCSymbol *RangeSectionSym =
399 TLOF.getDwarfRangesSection()->getBeginSymbol();
400
401 RangeSpanList List(Asm->createTempSymbol("debug_ranges"), std::move(Range));
402
403 // Under fission, ranges are specified by constant offsets relative to the
404 // CU's DW_AT_GNU_ranges_base.
405 if (isDwoUnit())
406 addSectionDelta(ScopeDIE, dwarf::DW_AT_ranges, List.getSym(),
407 RangeSectionSym);
408 else
409 addSectionLabel(ScopeDIE, dwarf::DW_AT_ranges, List.getSym(),
410 RangeSectionSym);
411
412 // Add the range list to the set of ranges to be emitted.
413 (Skeleton ? Skeleton : this)->CURangeLists.push_back(std::move(List));
414}
415
416void DwarfCompileUnit::attachRangesOrLowHighPC(
417 DIE &Die, SmallVector<RangeSpan, 2> Ranges) {
418 if (Ranges.size() == 1 || !DD->useRangesSection()) {
419 const RangeSpan &Front = Ranges.front();
420 const RangeSpan &Back = Ranges.back();
421 attachLowHighPC(Die, Front.getStart(), Back.getEnd());
422 } else
423 addScopeRangeList(Die, std::move(Ranges));
424}
425
426void DwarfCompileUnit::attachRangesOrLowHighPC(
427 DIE &Die, const SmallVectorImpl<InsnRange> &Ranges) {
428 SmallVector<RangeSpan, 2> List;
429 List.reserve(Ranges.size());
430 for (const InsnRange &R : Ranges)
431 List.push_back(RangeSpan(DD->getLabelBeforeInsn(R.first),
432 DD->getLabelAfterInsn(R.second)));
433 attachRangesOrLowHighPC(Die, std::move(List));
434}
435
436// This scope represents inlined body of a function. Construct DIE to
437// represent this concrete inlined copy of the function.
438DIE *DwarfCompileUnit::constructInlinedScopeDIE(LexicalScope *Scope) {
439 assert(Scope->getScopeNode())(static_cast <bool> (Scope->getScopeNode()) ? void (
0) : __assert_fail ("Scope->getScopeNode()", "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 439, __extension__ __PRETTY_FUNCTION__))
;
440 auto *DS = Scope->getScopeNode();
441 auto *InlinedSP = getDISubprogram(DS);
442 // Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
443 // was inlined from another compile unit.
444 DIE *OriginDIE = getAbstractSPDies()[InlinedSP];
445 assert(OriginDIE && "Unable to find original DIE for an inlined subprogram.")(static_cast <bool> (OriginDIE && "Unable to find original DIE for an inlined subprogram."
) ? void (0) : __assert_fail ("OriginDIE && \"Unable to find original DIE for an inlined subprogram.\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 445, __extension__ __PRETTY_FUNCTION__))
;
446
447 auto ScopeDIE = DIE::get(DIEValueAllocator, dwarf::DW_TAG_inlined_subroutine);
448 addDIEEntry(*ScopeDIE, dwarf::DW_AT_abstract_origin, *OriginDIE);
449
450 attachRangesOrLowHighPC(*ScopeDIE, Scope->getRanges());
451
452 // Add the call site information to the DIE.
453 const DILocation *IA = Scope->getInlinedAt();
454 addUInt(*ScopeDIE, dwarf::DW_AT_call_file, None,
455 getOrCreateSourceID(IA->getFile()));
456 addUInt(*ScopeDIE, dwarf::DW_AT_call_line, None, IA->getLine());
457 if (IA->getDiscriminator() && DD->getDwarfVersion() >= 4)
458 addUInt(*ScopeDIE, dwarf::DW_AT_GNU_discriminator, None,
459 IA->getDiscriminator());
460
461 // Add name to the name table, we do this here because we're guaranteed
462 // to have concrete versions of our DW_TAG_inlined_subprogram nodes.
463 DD->addSubprogramNames(InlinedSP, *ScopeDIE);
464
465 return ScopeDIE;
466}
467
468// Construct new DW_TAG_lexical_block for this scope and attach
469// DW_AT_low_pc/DW_AT_high_pc labels.
470DIE *DwarfCompileUnit::constructLexicalScopeDIE(LexicalScope *Scope) {
471 if (DD->isLexicalScopeDIENull(Scope))
472 return nullptr;
473
474 auto ScopeDIE = DIE::get(DIEValueAllocator, dwarf::DW_TAG_lexical_block);
475 if (Scope->isAbstractScope())
476 return ScopeDIE;
477
478 attachRangesOrLowHighPC(*ScopeDIE, Scope->getRanges());
479
480 return ScopeDIE;
481}
482
483/// constructVariableDIE - Construct a DIE for the given DbgVariable.
484DIE *DwarfCompileUnit::constructVariableDIE(DbgVariable &DV, bool Abstract) {
485 auto D = constructVariableDIEImpl(DV, Abstract);
486 DV.setDIE(*D);
487 return D;
488}
489
490DIE *DwarfCompileUnit::constructVariableDIEImpl(const DbgVariable &DV,
491 bool Abstract) {
492 // Define variable debug information entry.
493 auto VariableDie = DIE::get(DIEValueAllocator, DV.getTag());
494 insertDIE(DV.getVariable(), VariableDie);
495
496 if (Abstract) {
497 applyVariableAttributes(DV, *VariableDie);
498 return VariableDie;
499 }
500
501 // Add variable address.
502
503 unsigned Offset = DV.getDebugLocListIndex();
504 if (Offset != ~0U) {
505 addLocationList(*VariableDie, dwarf::DW_AT_location, Offset);
506 return VariableDie;
507 }
508
509 // Check if variable is described by a DBG_VALUE instruction.
510 if (const MachineInstr *DVInsn = DV.getMInsn()) {
511 assert(DVInsn->getNumOperands() == 4)(static_cast <bool> (DVInsn->getNumOperands() == 4) ?
void (0) : __assert_fail ("DVInsn->getNumOperands() == 4"
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 511, __extension__ __PRETTY_FUNCTION__))
;
512 if (DVInsn->getOperand(0).isReg()) {
513 auto RegOp = DVInsn->getOperand(0);
514 auto Op1 = DVInsn->getOperand(1);
515 // If the second operand is an immediate, this is an indirect value.
516 assert((!Op1.isImm() || (Op1.getImm() == 0)) && "unexpected offset")(static_cast <bool> ((!Op1.isImm() || (Op1.getImm() == 0
)) && "unexpected offset") ? void (0) : __assert_fail
("(!Op1.isImm() || (Op1.getImm() == 0)) && \"unexpected offset\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 516, __extension__ __PRETTY_FUNCTION__))
;
517 MachineLocation Location(RegOp.getReg(), Op1.isImm());
518 addVariableAddress(DV, *VariableDie, Location);
519 } else if (DVInsn->getOperand(0).isImm()) {
520 // This variable is described by a single constant.
521 // Check whether it has a DIExpression.
522 auto *Expr = DV.getSingleExpression();
523 if (Expr && Expr->getNumElements()) {
524 DIELoc *Loc = new (DIEValueAllocator) DIELoc;
525 DIEDwarfExpression DwarfExpr(*Asm, *this, *Loc);
526 // If there is an expression, emit raw unsigned bytes.
527 DwarfExpr.addFragmentOffset(Expr);
528 DwarfExpr.addUnsignedConstant(DVInsn->getOperand(0).getImm());
529 DwarfExpr.addExpression(Expr);
530 addBlock(*VariableDie, dwarf::DW_AT_location, DwarfExpr.finalize());
531 } else
532 addConstantValue(*VariableDie, DVInsn->getOperand(0), DV.getType());
533 } else if (DVInsn->getOperand(0).isFPImm())
534 addConstantFPValue(*VariableDie, DVInsn->getOperand(0));
535 else if (DVInsn->getOperand(0).isCImm())
536 addConstantValue(*VariableDie, DVInsn->getOperand(0).getCImm(),
537 DV.getType());
538
539 return VariableDie;
540 }
541
542 // .. else use frame index.
543 if (!DV.hasFrameIndexExprs())
544 return VariableDie;
545
546 DIELoc *Loc = new (DIEValueAllocator) DIELoc;
547 DIEDwarfExpression DwarfExpr(*Asm, *this, *Loc);
548 for (auto &Fragment : DV.getFrameIndexExprs()) {
549 unsigned FrameReg = 0;
550 const DIExpression *Expr = Fragment.Expr;
551 const TargetFrameLowering *TFI = Asm->MF->getSubtarget().getFrameLowering();
552 int Offset = TFI->getFrameIndexReference(*Asm->MF, Fragment.FI, FrameReg);
553 DwarfExpr.addFragmentOffset(Expr);
554 SmallVector<uint64_t, 8> Ops;
555 Ops.push_back(dwarf::DW_OP_plus_uconst);
556 Ops.push_back(Offset);
557 Ops.append(Expr->elements_begin(), Expr->elements_end());
558 DIExpressionCursor Cursor(Ops);
559 DwarfExpr.setMemoryLocationKind();
560 DwarfExpr.addMachineRegExpression(
561 *Asm->MF->getSubtarget().getRegisterInfo(), Cursor, FrameReg);
562 DwarfExpr.addExpression(std::move(Cursor));
563 }
564 addBlock(*VariableDie, dwarf::DW_AT_location, DwarfExpr.finalize());
565
566 return VariableDie;
567}
568
569DIE *DwarfCompileUnit::constructVariableDIE(DbgVariable &DV,
570 const LexicalScope &Scope,
571 DIE *&ObjectPointer) {
572 auto Var = constructVariableDIE(DV, Scope.isAbstractScope());
573 if (DV.isObjectPointer())
574 ObjectPointer = Var;
575 return Var;
576}
577
578/// Return all DIVariables that appear in count: expressions.
579static SmallVector<const DIVariable *, 2> dependencies(DbgVariable *Var) {
580 SmallVector<const DIVariable *, 2> Result;
581 auto *Array = dyn_cast<DICompositeType>(Var->getType());
582 if (!Array || Array->getTag() != dwarf::DW_TAG_array_type)
583 return Result;
584 for (auto *El : Array->getElements()) {
585 if (auto *Subrange = dyn_cast<DISubrange>(El)) {
586 auto Count = Subrange->getCount();
587 if (auto *Dependency = Count.dyn_cast<DIVariable *>())
588 Result.push_back(Dependency);
589 }
590 }
591 return Result;
592}
593
594/// Sort local variables so that variables appearing inside of helper
595/// expressions come first.
596static SmallVector<DbgVariable *, 8>
597sortLocalVars(SmallVectorImpl<DbgVariable *> &Input) {
598 SmallVector<DbgVariable *, 8> Result;
599 SmallVector<PointerIntPair<DbgVariable *, 1>, 8> WorkList;
600 // Map back from a DIVariable to its containing DbgVariable.
601 SmallDenseMap<const DILocalVariable *, DbgVariable *> DbgVar;
602 // Set of DbgVariables in Result.
603 SmallDenseSet<DbgVariable *, 8> Visited;
604 // For cycle detection.
605 SmallDenseSet<DbgVariable *, 8> Visiting;
606
607 // Initialize the worklist and the DIVariable lookup table.
608 for (auto Var : reverse(Input)) {
609 DbgVar.insert({Var->getVariable(), Var});
610 WorkList.push_back({Var, 0});
611 }
612
613 // Perform a stable topological sort by doing a DFS.
614 while (!WorkList.empty()) {
615 auto Item = WorkList.back();
616 DbgVariable *Var = Item.getPointer();
617 bool visitedAllDependencies = Item.getInt();
618 WorkList.pop_back();
619
620 // Dependency is in a different lexical scope or a global.
621 if (!Var)
622 continue;
623
624 // Already handled.
625 if (Visited.count(Var))
626 continue;
627
628 // Add to Result if all dependencies are visited.
629 if (visitedAllDependencies) {
630 Visited.insert(Var);
631 Result.push_back(Var);
632 continue;
633 }
634
635 // Detect cycles.
636 auto Res = Visiting.insert(Var);
637 if (!Res.second) {
638 assert(false && "dependency cycle in local variables")(static_cast <bool> (false && "dependency cycle in local variables"
) ? void (0) : __assert_fail ("false && \"dependency cycle in local variables\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 638, __extension__ __PRETTY_FUNCTION__))
;
639 return Result;
640 }
641
642 // Push dependencies and this node onto the worklist, so that this node is
643 // visited again after all of its dependencies are handled.
644 WorkList.push_back({Var, 1});
645 for (auto *Dependency : dependencies(Var)) {
646 auto Dep = dyn_cast_or_null<const DILocalVariable>(Dependency);
647 WorkList.push_back({DbgVar[Dep], 0});
648 }
649 }
650 return Result;
651}
652
653DIE *DwarfCompileUnit::createScopeChildrenDIE(LexicalScope *Scope,
654 SmallVectorImpl<DIE *> &Children,
655 bool *HasNonScopeChildren) {
656 assert(Children.empty())(static_cast <bool> (Children.empty()) ? void (0) : __assert_fail
("Children.empty()", "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 656, __extension__ __PRETTY_FUNCTION__))
;
657 DIE *ObjectPointer = nullptr;
658
659 // Emit function arguments (order is significant).
660 auto Vars = DU->getScopeVariables().lookup(Scope);
661 for (auto &DV : Vars.Args)
662 Children.push_back(constructVariableDIE(*DV.second, *Scope, ObjectPointer));
663
664 // Emit local variables.
665 auto Locals = sortLocalVars(Vars.Locals);
666 for (DbgVariable *DV : Locals)
667 Children.push_back(constructVariableDIE(*DV, *Scope, ObjectPointer));
668
669 // Skip imported directives in gmlt-like data.
670 if (!includeMinimalInlineScopes()) {
671 // There is no need to emit empty lexical block DIE.
672 for (const auto *IE : ImportedEntities[Scope->getScopeNode()])
673 Children.push_back(
674 constructImportedEntityDIE(cast<DIImportedEntity>(IE)));
675 }
676
677 if (HasNonScopeChildren)
678 *HasNonScopeChildren = !Children.empty();
679
680 for (LexicalScope *LS : Scope->getChildren())
681 constructScopeDIE(LS, Children);
682
683 return ObjectPointer;
684}
685
686void DwarfCompileUnit::constructSubprogramScopeDIE(const DISubprogram *Sub, LexicalScope *Scope) {
687 DIE &ScopeDIE = updateSubprogramScopeDIE(Sub);
1
Calling 'DwarfCompileUnit::updateSubprogramScopeDIE'
688
689 if (Scope) {
690 assert(!Scope->getInlinedAt())(static_cast <bool> (!Scope->getInlinedAt()) ? void (
0) : __assert_fail ("!Scope->getInlinedAt()", "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 690, __extension__ __PRETTY_FUNCTION__))
;
691 assert(!Scope->isAbstractScope())(static_cast <bool> (!Scope->isAbstractScope()) ? void
(0) : __assert_fail ("!Scope->isAbstractScope()", "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 691, __extension__ __PRETTY_FUNCTION__))
;
692 // Collect lexical scope children first.
693 // ObjectPointer might be a local (non-argument) local variable if it's a
694 // block's synthetic this pointer.
695 if (DIE *ObjectPointer = createAndAddScopeChildren(Scope, ScopeDIE))
696 addDIEEntry(ScopeDIE, dwarf::DW_AT_object_pointer, *ObjectPointer);
697 }
698
699 // If this is a variadic function, add an unspecified parameter.
700 DITypeRefArray FnArgs = Sub->getType()->getTypeArray();
701
702 // If we have a single element of null, it is a function that returns void.
703 // If we have more than one elements and the last one is null, it is a
704 // variadic function.
705 if (FnArgs.size() > 1 && !FnArgs[FnArgs.size() - 1] &&
706 !includeMinimalInlineScopes())
707 ScopeDIE.addChild(
708 DIE::get(DIEValueAllocator, dwarf::DW_TAG_unspecified_parameters));
709}
710
711DIE *DwarfCompileUnit::createAndAddScopeChildren(LexicalScope *Scope,
712 DIE &ScopeDIE) {
713 // We create children when the scope DIE is not null.
714 SmallVector<DIE *, 8> Children;
715 DIE *ObjectPointer = createScopeChildrenDIE(Scope, Children);
716
717 // Add children
718 for (auto &I : Children)
719 ScopeDIE.addChild(std::move(I));
720
721 return ObjectPointer;
722}
723
724void DwarfCompileUnit::constructAbstractSubprogramScopeDIE(
725 LexicalScope *Scope) {
726 DIE *&AbsDef = getAbstractSPDies()[Scope->getScopeNode()];
727 if (AbsDef)
728 return;
729
730 auto *SP = cast<DISubprogram>(Scope->getScopeNode());
731
732 DIE *ContextDIE;
733 DwarfCompileUnit *ContextCU = this;
734
735 if (includeMinimalInlineScopes())
736 ContextDIE = &getUnitDie();
737 // Some of this is duplicated from DwarfUnit::getOrCreateSubprogramDIE, with
738 // the important distinction that the debug node is not associated with the
739 // DIE (since the debug node will be associated with the concrete DIE, if
740 // any). It could be refactored to some common utility function.
741 else if (auto *SPDecl = SP->getDeclaration()) {
742 ContextDIE = &getUnitDie();
743 getOrCreateSubprogramDIE(SPDecl);
744 } else {
745 ContextDIE = getOrCreateContextDIE(resolve(SP->getScope()));
746 // The scope may be shared with a subprogram that has already been
747 // constructed in another CU, in which case we need to construct this
748 // subprogram in the same CU.
749 ContextCU = DD->lookupCU(ContextDIE->getUnitDie());
750 }
751
752 // Passing null as the associated node because the abstract definition
753 // shouldn't be found by lookup.
754 AbsDef = &ContextCU->createAndAddDIE(dwarf::DW_TAG_subprogram, *ContextDIE, nullptr);
755 ContextCU->applySubprogramAttributesToDefinition(SP, *AbsDef);
756
757 if (!ContextCU->includeMinimalInlineScopes())
758 ContextCU->addUInt(*AbsDef, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);
759 if (DIE *ObjectPointer = ContextCU->createAndAddScopeChildren(Scope, *AbsDef))
760 ContextCU->addDIEEntry(*AbsDef, dwarf::DW_AT_object_pointer, *ObjectPointer);
761}
762
763DIE *DwarfCompileUnit::constructImportedEntityDIE(
764 const DIImportedEntity *Module) {
765 DIE *IMDie = DIE::get(DIEValueAllocator, (dwarf::Tag)Module->getTag());
766 insertDIE(Module, IMDie);
767 DIE *EntityDie;
768 auto *Entity = resolve(Module->getEntity());
769 if (auto *NS = dyn_cast<DINamespace>(Entity))
770 EntityDie = getOrCreateNameSpace(NS);
771 else if (auto *M = dyn_cast<DIModule>(Entity))
772 EntityDie = getOrCreateModule(M);
773 else if (auto *SP = dyn_cast<DISubprogram>(Entity))
774 EntityDie = getOrCreateSubprogramDIE(SP);
775 else if (auto *T = dyn_cast<DIType>(Entity))
776 EntityDie = getOrCreateTypeDIE(T);
777 else if (auto *GV = dyn_cast<DIGlobalVariable>(Entity))
778 EntityDie = getOrCreateGlobalVariableDIE(GV, {});
779 else
780 EntityDie = getDIE(Entity);
781 assert(EntityDie)(static_cast <bool> (EntityDie) ? void (0) : __assert_fail
("EntityDie", "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 781, __extension__ __PRETTY_FUNCTION__))
;
782 addSourceLine(*IMDie, Module->getLine(), Module->getFile());
783 addDIEEntry(*IMDie, dwarf::DW_AT_import, *EntityDie);
784 StringRef Name = Module->getName();
785 if (!Name.empty())
786 addString(*IMDie, dwarf::DW_AT_name, Name);
787
788 return IMDie;
789}
790
791void DwarfCompileUnit::finishSubprogramDefinition(const DISubprogram *SP) {
792 DIE *D = getDIE(SP);
793 if (DIE *AbsSPDIE = getAbstractSPDies().lookup(SP)) {
794 if (D)
795 // If this subprogram has an abstract definition, reference that
796 addDIEEntry(*D, dwarf::DW_AT_abstract_origin, *AbsSPDIE);
797 } else {
798 assert(D || includeMinimalInlineScopes())(static_cast <bool> (D || includeMinimalInlineScopes())
? void (0) : __assert_fail ("D || includeMinimalInlineScopes()"
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 798, __extension__ __PRETTY_FUNCTION__))
;
799 if (D)
800 // And attach the attributes
801 applySubprogramAttributesToDefinition(SP, *D);
802 }
803}
804
805void DwarfCompileUnit::finishVariableDefinition(const DbgVariable &Var) {
806 DbgVariable *AbsVar = getExistingAbstractVariable(
807 InlinedVariable(Var.getVariable(), Var.getInlinedAt()));
808 auto *VariableDie = Var.getDIE();
809 if (AbsVar && AbsVar->getDIE()) {
810 addDIEEntry(*VariableDie, dwarf::DW_AT_abstract_origin,
811 *AbsVar->getDIE());
812 } else
813 applyVariableAttributes(Var, *VariableDie);
814}
815
816DbgVariable *DwarfCompileUnit::getExistingAbstractVariable(InlinedVariable IV) {
817 const DILocalVariable *Cleansed;
818 return getExistingAbstractVariable(IV, Cleansed);
819}
820
821// Find abstract variable, if any, associated with Var.
822DbgVariable *DwarfCompileUnit::getExistingAbstractVariable(
823 InlinedVariable IV, const DILocalVariable *&Cleansed) {
824 // More then one inlined variable corresponds to one abstract variable.
825 Cleansed = IV.first;
826 auto &AbstractVariables = getAbstractVariables();
827 auto I = AbstractVariables.find(Cleansed);
828 if (I != AbstractVariables.end())
829 return I->second.get();
830 return nullptr;
831}
832
833void DwarfCompileUnit::createAbstractVariable(const DILocalVariable *Var,
834 LexicalScope *Scope) {
835 assert(Scope && Scope->isAbstractScope())(static_cast <bool> (Scope && Scope->isAbstractScope
()) ? void (0) : __assert_fail ("Scope && Scope->isAbstractScope()"
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 835, __extension__ __PRETTY_FUNCTION__))
;
836 auto AbsDbgVariable = llvm::make_unique<DbgVariable>(Var, /* IA */ nullptr);
837 DU->addScopeVariable(Scope, AbsDbgVariable.get());
838 getAbstractVariables()[Var] = std::move(AbsDbgVariable);
839}
840
841void DwarfCompileUnit::emitHeader(bool UseOffsets) {
842 // Don't bother labeling the .dwo unit, as its offset isn't used.
843 if (!Skeleton && !DD->useSectionsAsReferences()) {
844 LabelBegin = Asm->createTempSymbol("cu_begin");
845 Asm->OutStreamer->EmitLabel(LabelBegin);
846 }
847
848 dwarf::UnitType UT = Skeleton ? dwarf::DW_UT_split_compile
849 : DD->useSplitDwarf() ? dwarf::DW_UT_skeleton
850 : dwarf::DW_UT_compile;
851 DwarfUnit::emitCommonHeader(UseOffsets, UT);
852}
853
854bool DwarfCompileUnit::hasDwarfPubSections() const {
855 // Opting in to GNU Pubnames/types overrides the default to ensure these are
856 // generated for things like Gold's gdb_index generation.
857 if (CUNode->getGnuPubnames())
858 return true;
859
860 return DD->tuneForGDB() && DD->usePubSections() &&
861 !includeMinimalInlineScopes();
862}
863
864/// addGlobalName - Add a new global name to the compile unit.
865void DwarfCompileUnit::addGlobalName(StringRef Name, const DIE &Die,
866 const DIScope *Context) {
867 if (!hasDwarfPubSections())
868 return;
869 std::string FullName = getParentContextString(Context) + Name.str();
870 GlobalNames[FullName] = &Die;
871}
872
873void DwarfCompileUnit::addGlobalNameForTypeUnit(StringRef Name,
874 const DIScope *Context) {
875 if (!hasDwarfPubSections())
876 return;
877 std::string FullName = getParentContextString(Context) + Name.str();
878 // Insert, allowing the entry to remain as-is if it's already present
879 // This way the CU-level type DIE is preferred over the "can't describe this
880 // type as a unit offset because it's not really in the CU at all, it's only
881 // in a type unit"
882 GlobalNames.insert(std::make_pair(std::move(FullName), &getUnitDie()));
883}
884
885/// Add a new global type to the unit.
886void DwarfCompileUnit::addGlobalType(const DIType *Ty, const DIE &Die,
887 const DIScope *Context) {
888 if (!hasDwarfPubSections())
889 return;
890 std::string FullName = getParentContextString(Context) + Ty->getName().str();
891 GlobalTypes[FullName] = &Die;
892}
893
894void DwarfCompileUnit::addGlobalTypeUnitType(const DIType *Ty,
895 const DIScope *Context) {
896 if (!hasDwarfPubSections())
897 return;
898 std::string FullName = getParentContextString(Context) + Ty->getName().str();
899 // Insert, allowing the entry to remain as-is if it's already present
900 // This way the CU-level type DIE is preferred over the "can't describe this
901 // type as a unit offset because it's not really in the CU at all, it's only
902 // in a type unit"
903 GlobalTypes.insert(std::make_pair(std::move(FullName), &getUnitDie()));
904}
905
906/// addVariableAddress - Add DW_AT_location attribute for a
907/// DbgVariable based on provided MachineLocation.
908void DwarfCompileUnit::addVariableAddress(const DbgVariable &DV, DIE &Die,
909 MachineLocation Location) {
910 // addBlockByrefAddress is obsolete and will be removed soon.
911 // The clang frontend always generates block byref variables with a
912 // complex expression that encodes exactly what addBlockByrefAddress
913 // would do.
914 assert((!DV.isBlockByrefVariable() || DV.hasComplexAddress()) &&(static_cast <bool> ((!DV.isBlockByrefVariable() || DV.
hasComplexAddress()) && "block byref variable without a complex expression"
) ? void (0) : __assert_fail ("(!DV.isBlockByrefVariable() || DV.hasComplexAddress()) && \"block byref variable without a complex expression\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 915, __extension__ __PRETTY_FUNCTION__))
915 "block byref variable without a complex expression")(static_cast <bool> ((!DV.isBlockByrefVariable() || DV.
hasComplexAddress()) && "block byref variable without a complex expression"
) ? void (0) : __assert_fail ("(!DV.isBlockByrefVariable() || DV.hasComplexAddress()) && \"block byref variable without a complex expression\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp"
, 915, __extension__ __PRETTY_FUNCTION__))
;
916 if (DV.hasComplexAddress())
917 addComplexAddress(DV, Die, dwarf::DW_AT_location, Location);
918 else if (DV.isBlockByrefVariable())
919 addBlockByrefAddress(DV, Die, dwarf::DW_AT_location, Location);
920 else
921 addAddress(Die, dwarf::DW_AT_location, Location);
922}
923
924/// Add an address attribute to a die based on the location provided.
925void DwarfCompileUnit::addAddress(DIE &Die, dwarf::Attribute Attribute,
926 const MachineLocation &Location) {
927 DIELoc *Loc = new (DIEValueAllocator) DIELoc;
6
'Loc' initialized to a null pointer value
928 DIEDwarfExpression DwarfExpr(*Asm, *this, *Loc);
7
Forming reference to null pointer
929 if (Location.isIndirect())
930 DwarfExpr.setMemoryLocationKind();
931
932 DIExpressionCursor Cursor({});
933 const TargetRegisterInfo &TRI = *Asm->MF->getSubtarget().getRegisterInfo();
934 if (!DwarfExpr.addMachineRegExpression(TRI, Cursor, Location.getReg()))
935 return;
936 DwarfExpr.addExpression(std::move(Cursor));
937
938 // Now attach the location information to the DIE.
939 addBlock(Die, Attribute, DwarfExpr.finalize());
940}
941
942/// Start with the address based on the location provided, and generate the
943/// DWARF information necessary to find the actual variable given the extra
944/// address information encoded in the DbgVariable, starting from the starting
945/// location. Add the DWARF information to the die.
946void DwarfCompileUnit::addComplexAddress(const DbgVariable &DV, DIE &Die,
947 dwarf::Attribute Attribute,
948 const MachineLocation &Location) {
949 DIELoc *Loc = new (DIEValueAllocator) DIELoc;
950 DIEDwarfExpression DwarfExpr(*Asm, *this, *Loc);
951 const DIExpression *DIExpr = DV.getSingleExpression();
952 DwarfExpr.addFragmentOffset(DIExpr);
953 if (Location.isIndirect())
954 DwarfExpr.setMemoryLocationKind();
955
956 DIExpressionCursor Cursor(DIExpr);
957 const TargetRegisterInfo &TRI = *Asm->MF->getSubtarget().getRegisterInfo();
958 if (!DwarfExpr.addMachineRegExpression(TRI, Cursor, Location.getReg()))
959 return;
960 DwarfExpr.addExpression(std::move(Cursor));
961
962 // Now attach the location information to the DIE.
963 addBlock(Die, Attribute, DwarfExpr.finalize());
964}
965
966/// Add a Dwarf loclistptr attribute data and value.
967void DwarfCompileUnit::addLocationList(DIE &Die, dwarf::Attribute Attribute,
968 unsigned Index) {
969 dwarf::Form Form = DD->getDwarfVersion() >= 4 ? dwarf::DW_FORM_sec_offset
970 : dwarf::DW_FORM_data4;
971 Die.addValue(DIEValueAllocator, Attribute, Form, DIELocList(Index));
972}
973
974void DwarfCompileUnit::applyVariableAttributes(const DbgVariable &Var,
975 DIE &VariableDie) {
976 StringRef Name = Var.getName();
977 if (!Name.empty())
978 addString(VariableDie, dwarf::DW_AT_name, Name);
979 const auto *DIVar = Var.getVariable();
980 if (DIVar)
981 if (uint32_t AlignInBytes = DIVar->getAlignInBytes())
982 addUInt(VariableDie, dwarf::DW_AT_alignment, dwarf::DW_FORM_udata,
983 AlignInBytes);
984
985 addSourceLine(VariableDie, DIVar);
986 addType(VariableDie, Var.getType());
987 if (Var.isArtificial())
988 addFlag(VariableDie, dwarf::DW_AT_artificial);
989}
990
991/// Add a Dwarf expression attribute data and value.
992void DwarfCompileUnit::addExpr(DIELoc &Die, dwarf::Form Form,
993 const MCExpr *Expr) {
994 Die.addValue(DIEValueAllocator, (dwarf::Attribute)0, Form, DIEExpr(Expr));
995}
996
997void DwarfCompileUnit::applySubprogramAttributesToDefinition(
998 const DISubprogram *SP, DIE &SPDie) {
999 auto *SPDecl = SP->getDeclaration();
1000 auto *Context = resolve(SPDecl ? SPDecl->getScope() : SP->getScope());
1001 applySubprogramAttributes(SP, SPDie, includeMinimalInlineScopes());
1002 addGlobalName(SP->getName(), SPDie, Context);
1003}
1004
1005bool DwarfCompileUnit::isDwoUnit() const {
1006 return DD->useSplitDwarf() && Skeleton;
1007}
1008
1009bool DwarfCompileUnit::includeMinimalInlineScopes() const {
1010 return getCUNode()->getEmissionKind() == DICompileUnit::LineTablesOnly ||
1011 (DD->useSplitDwarf() && !Skeleton);
1012}