[llvm] [DebugInfo] Fix line 0 records incorrectly having is_stmt set (PR #166627)
via llvm-commits
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Wed Nov 5 12:19:54 PST 2025
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-debuginfo
Author: None (RoshanYSingh23)
<details>
<summary>Changes</summary>
Fixes issue #<!-- -->33870
Line 0 debug records should not have the is_stmt flag set in DWARF. This change ensures is_stmt is only set for non-zero line numbers.
Changes made in DwarfDebug.cpp:
- beginInstruction: Only set is_stmt for prologue_end if line != 0
- beginInstruction: Only set is_stmt for key instructions if line != 0
- emitInitialLocDirective: Set is_stmt=0 if scopeLine == 0
Test results: All 576 X86 DebugInfo tests pass.
---
Full diff: https://github.com/llvm/llvm-project/pull/166627.diff
1 Files Affected:
- (modified) llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp (+84-79)
``````````diff
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 567acf75d1b8d..31035e8085c36 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -101,13 +101,12 @@ static cl::opt<AccelTableKind> AccelTables(
clEnumValN(AccelTableKind::Dwarf, "Dwarf", "DWARF")),
cl::init(AccelTableKind::Default));
-static cl::opt<DefaultOnOff>
-DwarfInlinedStrings("dwarf-inlined-strings", cl::Hidden,
- cl::desc("Use inlined strings rather than string section."),
- cl::values(clEnumVal(Default, "Default for platform"),
- clEnumVal(Enable, "Enabled"),
- clEnumVal(Disable, "Disabled")),
- cl::init(Default));
+static cl::opt<DefaultOnOff> DwarfInlinedStrings(
+ "dwarf-inlined-strings", cl::Hidden,
+ cl::desc("Use inlined strings rather than string section."),
+ cl::values(clEnumVal(Default, "Default for platform"),
+ clEnumVal(Enable, "Enabled"), clEnumVal(Disable, "Disabled")),
+ cl::init(Default));
static cl::opt<bool>
NoDwarfRangesSection("no-dwarf-ranges-section", cl::Hidden,
@@ -231,9 +230,7 @@ void DebugLocDwarfExpression::commitTemporaryBuffer() {
TmpBuf->Comments.clear();
}
-const DIType *DbgVariable::getType() const {
- return getVariable()->getType();
-}
+const DIType *DbgVariable::getType() const { return getVariable()->getType(); }
/// Get .debug_loc entry for the instruction range starting at MI.
static DbgValueLoc getDebugLocValue(const MachineInstr *MI) {
@@ -371,8 +368,9 @@ DwarfDebug::DwarfDebug(AsmPrinter *A)
UseAllLinkageNames = DwarfLinkageNames == AllLinkageNames;
unsigned DwarfVersionNumber = Asm->TM.Options.MCOptions.DwarfVersion;
- unsigned DwarfVersion = DwarfVersionNumber ? DwarfVersionNumber
- : MMI->getModule()->getDwarfVersion();
+ unsigned DwarfVersion = DwarfVersionNumber
+ ? DwarfVersionNumber
+ : MMI->getModule()->getDwarfVersion();
// Use dwarf 4 by default if nothing is requested. For NVPTX, use dwarf 2.
DwarfVersion =
TT.isNVPTX() ? 2 : (DwarfVersion ? DwarfVersion : dwarf::DWARF_VERSION);
@@ -433,7 +431,8 @@ DwarfDebug::DwarfDebug(AsmPrinter *A)
UseDebugMacroSection =
DwarfVersion >= 5 || (UseGNUDebugMacro && !useSplitDwarf());
if (DwarfOpConvert == Default)
- EnableOpConvert = !((tuneForGDB() && useSplitDwarf()) || (tuneForLLDB() && !TT.isOSBinFormatMachO()));
+ EnableOpConvert = !((tuneForGDB() && useSplitDwarf()) ||
+ (tuneForLLDB() && !TT.isOSBinFormatMachO()));
else
EnableOpConvert = (DwarfOpConvert == Enable);
@@ -857,14 +856,16 @@ static void collectCallSiteParameters(const MachineInstr *CallMI,
assert(std::next(Suc) == BundleEnd &&
"More than one instruction in call delay slot");
// Try to interpret value loaded by instruction.
- if (!interpretNextInstr(&*Suc, ForwardedRegWorklist, Params, ClobberedRegUnits))
+ if (!interpretNextInstr(&*Suc, ForwardedRegWorklist, Params,
+ ClobberedRegUnits))
return;
}
// Search for a loading value in forwarding registers.
for (; I != MBB->rend(); ++I) {
// Try to interpret values loaded by instruction.
- if (!interpretNextInstr(&*I, ForwardedRegWorklist, Params, ClobberedRegUnits))
+ if (!interpretNextInstr(&*I, ForwardedRegWorklist, Params,
+ ClobberedRegUnits))
return;
}
@@ -1106,8 +1107,7 @@ DwarfDebug::getOrCreateDwarfCompileUnit(const DICompileUnit *DIUnit) {
if (auto *CU = CUMap.lookup(DIUnit))
return *CU;
- if (useSplitDwarf() &&
- !shareAcrossDWOCUs() &&
+ if (useSplitDwarf() && !shareAcrossDWOCUs() &&
(!DIUnit->getSplitDebugInlining() ||
DIUnit->getEmissionKind() == DICompileUnit::FullDebug) &&
!CUMap.empty()) {
@@ -1201,7 +1201,6 @@ void DwarfDebug::beginModule(Module *M) {
(useSplitDwarf() ? SkeletonHolder : InfoHolder)
.setStringOffsetsStartSym(Asm->createTempSymbol("str_offsets_base"));
-
// Create the symbols that designates the start of the DWARF v5 range list
// and locations list tables. They are located past the table headers.
if (getDwarfVersion() >= 5) {
@@ -1415,7 +1414,7 @@ void DwarfDebug::finalizeModuleInfo() {
TLOF.getDwarfMacinfoSection()->getBeginSymbol());
}
}
- }
+ }
// Emit all frontend-produced Skeleton CUs, i.e., Clang modules.
for (auto *CUNode : MMI->getModule()->debug_compile_units())
@@ -1491,7 +1490,7 @@ void DwarfDebug::endModule() {
emitDebugRanges();
if (useSplitDwarf())
- // Emit info into a debug macinfo.dwo section.
+ // Emit info into a debug macinfo.dwo section.
emitDebugMacinfoDWO();
else
// Emit info into a debug macinfo/macro section.
@@ -1533,8 +1532,8 @@ void DwarfDebug::endModule() {
// FIXME: AbstractVariables.clear();
}
-void DwarfDebug::ensureAbstractEntityIsCreatedIfScoped(DwarfCompileUnit &CU,
- const DINode *Node, const MDNode *ScopeNode) {
+void DwarfDebug::ensureAbstractEntityIsCreatedIfScoped(
+ DwarfCompileUnit &CU, const DINode *Node, const MDNode *ScopeNode) {
if (CU.getExistingAbstractEntity(Node))
return;
@@ -1580,7 +1579,8 @@ void DwarfDebug::collectVariableInfoFromMFTable(
continue;
}
- ensureAbstractEntityIsCreatedIfScoped(TheCU, Var.first, Scope->getScopeNode());
+ ensureAbstractEntityIsCreatedIfScoped(TheCU, Var.first,
+ Scope->getScopeNode());
// If we have already seen information for this variable, add to what we
// already know.
@@ -1607,7 +1607,7 @@ void DwarfDebug::collectVariableInfoFromMFTable(
}
auto RegVar = std::make_unique<DbgVariable>(
- cast<DILocalVariable>(Var.first), Var.second);
+ cast<DILocalVariable>(Var.first), Var.second);
if (VI.inStackSlot())
RegVar->emplace<Loc::MMI>(VI.Expr, VI.getStackSlot());
else
@@ -1723,8 +1723,7 @@ static bool validThroughout(LexicalScopes &LScopes,
// [4-) [(@g, fragment 0, 96)]
bool DwarfDebug::buildLocationList(SmallVectorImpl<DebugLocEntry> &DebugLoc,
const DbgValueHistoryMap::Entries &Entries) {
- using OpenRange =
- std::pair<DbgValueHistoryMap::EntryIndex, DbgValueLoc>;
+ using OpenRange = std::pair<DbgValueHistoryMap::EntryIndex, DbgValueLoc>;
SmallVector<OpenRange, 4> OpenRanges;
bool isSafeForSingleLocation = true;
const MachineInstr *StartDebugMI = nullptr;
@@ -1750,8 +1749,7 @@ bool DwarfDebug::buildLocationList(SmallVectorImpl<DebugLocEntry> &DebugLoc,
EndLabel = Asm->MBBSectionRanges[EndMBB.getSectionID()].EndLabel;
if (EI->isClobber())
EndMI = EI->getInstr();
- }
- else if (std::next(EI)->isClobber())
+ } else if (std::next(EI)->isClobber())
EndLabel = getLabelAfterInsn(std::next(EI)->getInstr());
else
EndLabel = getLabelBeforeInsn(std::next(EI)->getInstr());
@@ -1889,17 +1887,15 @@ DbgEntity *DwarfDebug::createConcreteEntity(DwarfCompileUnit &TheCU,
const MCSymbol *Sym) {
ensureAbstractEntityIsCreatedIfScoped(TheCU, Node, Scope.getScopeNode());
if (isa<const DILocalVariable>(Node)) {
- ConcreteEntities.push_back(
- std::make_unique<DbgVariable>(cast<const DILocalVariable>(Node),
- Location));
- InfoHolder.addScopeVariable(&Scope,
- cast<DbgVariable>(ConcreteEntities.back().get()));
+ ConcreteEntities.push_back(std::make_unique<DbgVariable>(
+ cast<const DILocalVariable>(Node), Location));
+ InfoHolder.addScopeVariable(
+ &Scope, cast<DbgVariable>(ConcreteEntities.back().get()));
} else if (isa<const DILabel>(Node)) {
ConcreteEntities.push_back(
- std::make_unique<DbgLabel>(cast<const DILabel>(Node),
- Location, Sym));
+ std::make_unique<DbgLabel>(cast<const DILabel>(Node), Location, Sym));
InfoHolder.addScopeLabel(&Scope,
- cast<DbgLabel>(ConcreteEntities.back().get()));
+ cast<DbgLabel>(ConcreteEntities.back().get()));
}
return ConcreteEntities.back().get();
}
@@ -1935,8 +1931,8 @@ void DwarfDebug::collectEntityInfo(DwarfCompileUnit &TheCU,
continue;
Processed.insert(IV);
- DbgVariable *RegVar = cast<DbgVariable>(createConcreteEntity(TheCU,
- *Scope, LocalVar, IV.second));
+ DbgVariable *RegVar = cast<DbgVariable>(
+ createConcreteEntity(TheCU, *Scope, LocalVar, IV.second));
const MachineInstr *MInsn = HistoryMapEntries.front().getInstr();
assert(MInsn->isDebugValue() && "History must begin with debug value");
@@ -2150,7 +2146,8 @@ void DwarfDebug::beginInstruction(const MachineInstr *MI) {
(!PrevInstBB ||
PrevInstBB->getSectionID() == MI->getParent()->getSectionID());
bool ForceIsStmt = ForceIsStmtInstrs.contains(MI);
- if (PrevInstInSameSection && !ForceIsStmt && DL.isSameSourceLocation(PrevInstLoc)) {
+ if (PrevInstInSameSection && !ForceIsStmt &&
+ DL.isSameSourceLocation(PrevInstLoc)) {
// If we have an ongoing unspecified location, nothing to do here.
if (!DL)
return;
@@ -2199,12 +2196,16 @@ void DwarfDebug::beginInstruction(const MachineInstr *MI) {
if (DL.getLine() == 0 && LastAsmLine == 0)
return;
if (MI == PrologEndLoc) {
- Flags |= DWARF2_FLAG_PROLOGUE_END | DWARF2_FLAG_IS_STMT;
+ Flags |= DWARF2_FLAG_PROLOGUE_END;
+ // Don't set is_stmt for line 0
+ if (DL.getLine() != 0)
+ Flags |= DWARF2_FLAG_IS_STMT;
PrologEndLoc = nullptr;
}
if (ScopeUsesKeyInstructions) {
- if (IsKey)
+ // Don't set is_stmt for line 0
+ if (IsKey && DL.getLine() != 0)
Flags |= DWARF2_FLAG_IS_STMT;
} else {
// If the line changed, we call that a new statement; unless we went to
@@ -2370,7 +2371,8 @@ static void recordSourceLine(AsmPrinter &Asm, unsigned Line, unsigned Col,
const MachineInstr *
DwarfDebug::emitInitialLocDirective(const MachineFunction &MF, unsigned CUID) {
// Don't deal with functions that have no instructions.
- if (llvm::all_of(MF, [](const MachineBasicBlock &MBB) { return MBB.empty(); }))
+ if (llvm::all_of(MF,
+ [](const MachineBasicBlock &MBB) { return MBB.empty(); }))
return nullptr;
std::pair<const MachineInstr *, bool> PrologEnd = findPrologueEndLoc(&MF);
@@ -2400,8 +2402,11 @@ DwarfDebug::emitInitialLocDirective(const MachineFunction &MF, unsigned CUID) {
(void)getOrCreateDwarfCompileUnit(SP->getUnit());
// We'd like to list the prologue as "not statements" but GDB behaves
// poorly if we do that. Revisit this with caution/GDB (7.5+) testing.
- ::recordSourceLine(*Asm, SP->getScopeLine(), 0, SP, DWARF2_FLAG_IS_STMT,
- CUID, getDwarfVersion(), getUnits());
+ // However, we should not set is_stmt for line 0.
+ unsigned ScopeLine = SP->getScopeLine();
+ unsigned Flags = (ScopeLine != 0) ? DWARF2_FLAG_IS_STMT : 0;
+ ::recordSourceLine(*Asm, ScopeLine, 0, SP, Flags, CUID, getDwarfVersion(),
+ getUnits());
return PrologEndLoc;
}
@@ -2677,7 +2682,8 @@ void DwarfDebug::beginFunctionImpl(const MachineFunction *MF) {
CurFn = MF;
auto *SP = MF->getFunction().getSubprogram();
- assert(LScopes.empty() || SP == LScopes.getCurrentFunctionScope()->getScopeNode());
+ assert(LScopes.empty() ||
+ SP == LScopes.getCurrentFunctionScope()->getScopeNode());
if (SP->getUnit()->getEmissionKind() == DICompileUnit::NoDebug)
return;
@@ -2738,7 +2744,8 @@ void DwarfDebug::endFunctionImpl(const MachineFunction *MF) {
const Function &F = MF->getFunction();
const DISubprogram *SP = F.getSubprogram();
- assert(CurFn == MF &&
+ assert(
+ CurFn == MF &&
"endFunction should be called with the same function as beginFunction");
// Set DwarfDwarfCompileUnitID in MCContext to default value.
@@ -3090,15 +3097,16 @@ void DwarfDebug::emitDebugLocEntry(ByteStreamer &Streamer,
Offset++;
for (unsigned I = 0; I < Op.getDescription().Op.size(); ++I) {
if (Op.getDescription().Op[I] == Encoding::BaseTypeRef) {
- unsigned Length =
- Streamer.emitDIERef(*CU->ExprRefedBaseTypes[Op.getRawOperand(I)].Die);
+ unsigned Length = Streamer.emitDIERef(
+ *CU->ExprRefedBaseTypes[Op.getRawOperand(I)].Die);
// Make sure comments stay aligned.
for (unsigned J = 0; J < Length; ++J)
if (Comment != End)
Comment++;
} else {
for (uint64_t J = Offset; J < Op.getOperandEndOffset(I); ++J)
- Streamer.emitInt8(Data.getData()[J], Comment != End ? *(Comment++) : "");
+ Streamer.emitInt8(Data.getData()[J],
+ Comment != End ? *(Comment++) : "");
}
Offset = Op.getOperandEndOffset(I);
}
@@ -3205,8 +3213,7 @@ void DwarfDebug::emitDebugLocValue(const AsmPrinter &AP, const DIBasicType *BT,
void DebugLocEntry::finalize(const AsmPrinter &AP,
DebugLocStream::ListBuilder &List,
- const DIBasicType *BT,
- DwarfCompileUnit &TheCU) {
+ const DIBasicType *BT, DwarfCompileUnit &TheCU) {
assert(!Values.empty() &&
"location list entries without values are redundant");
assert(Begin != End && "unexpected location list entry with empty range");
@@ -3216,9 +3223,8 @@ void DebugLocEntry::finalize(const AsmPrinter &AP,
const DbgValueLoc &Value = Values[0];
if (Value.isFragment()) {
// Emit all fragments that belong to the same variable and range.
- assert(llvm::all_of(Values, [](DbgValueLoc P) {
- return P.isFragment();
- }) && "all values are expected to be fragments");
+ assert(llvm::all_of(Values, [](DbgValueLoc P) { return P.isFragment(); }) &&
+ "all values are expected to be fragments");
assert(llvm::is_sorted(Values) && "fragments are expected to be sorted");
for (const auto &Fragment : Values)
@@ -3239,7 +3245,8 @@ void DwarfDebug::emitDebugLocEntryLocation(const DebugLocStream::Entry &Entry,
Asm->OutStreamer->AddComment("Loc expr size");
if (getDwarfVersion() >= 5)
Asm->emitULEB128(DebugLocs.getBytes(Entry).size());
- else if (DebugLocs.getBytes(Entry).size() <= std::numeric_limits<uint16_t>::max())
+ else if (DebugLocs.getBytes(Entry).size() <=
+ std::numeric_limits<uint16_t>::max())
Asm->emitInt16(DebugLocs.getBytes(Entry).size());
else {
// The entry is too big to fit into 16 bit, drop it as there is nothing we
@@ -3291,13 +3298,12 @@ static MCSymbol *emitLoclistsTableHeader(AsmPrinter *Asm,
}
template <typename Ranges, typename PayloadEmitter>
-static void emitRangeList(
- DwarfDebug &DD, AsmPrinter *Asm, MCSymbol *Sym, const Ranges &R,
- const DwarfCompileUnit &CU, unsigned BaseAddressx, unsigned OffsetPair,
- unsigned StartxLength, unsigned EndOfList,
- StringRef (*StringifyEnum)(unsigned),
- bool ShouldUseBaseAddress,
- PayloadEmitter EmitPayload) {
+static void
+emitRangeList(DwarfDebug &DD, AsmPrinter *Asm, MCSymbol *Sym, const Ranges &R,
+ const DwarfCompileUnit &CU, unsigned BaseAddressx,
+ unsigned OffsetPair, unsigned StartxLength, unsigned EndOfList,
+ StringRef (*StringifyEnum)(unsigned), bool ShouldUseBaseAddress,
+ PayloadEmitter EmitPayload) {
auto Size = Asm->MAI->getCodePointerSize();
bool UseDwarf5 = DD.getDwarfVersion() >= 5;
@@ -3398,7 +3404,8 @@ static void emitRangeList(
}
// Handles emission of both debug_loclist / debug_loclist.dwo
-static void emitLocList(DwarfDebug &DD, AsmPrinter *Asm, const DebugLocStream::List &List) {
+static void emitLocList(DwarfDebug &DD, AsmPrinter *Asm,
+ const DebugLocStream::List &List) {
emitRangeList(DD, Asm, List.Label, DD.getDebugLocs().getEntries(List),
*List.CU, dwarf::DW_LLE_base_addressx,
dwarf::DW_LLE_offset_pair, dwarf::DW_LLE_startx_length,
@@ -3428,17 +3435,15 @@ void DwarfDebug::emitDebugLocImpl(MCSection *Sec) {
// Emit locations into the .debug_loc/.debug_loclists section.
void DwarfDebug::emitDebugLoc() {
- emitDebugLocImpl(
- getDwarfVersion() >= 5
- ? Asm->getObjFileLowering().getDwarfLoclistsSection()
- : Asm->getObjFileLowering().getDwarfLocSection());
+ emitDebugLocImpl(getDwarfVersion() >= 5
+ ? Asm->getObjFileLowering().getDwarfLoclistsSection()
+ : Asm->getObjFileLowering().getDwarfLocSection());
}
// Emit locations into the .debug_loc.dwo/.debug_loclists.dwo section.
void DwarfDebug::emitDebugLocDWO() {
if (getDwarfVersion() >= 5) {
- emitDebugLocImpl(
- Asm->getObjFileLowering().getDwarfLoclistsDWOSection());
+ emitDebugLocImpl(Asm->getObjFileLowering().getDwarfLoclistsDWOSection());
return;
}
@@ -3626,16 +3631,16 @@ void DwarfDebug::emitDebugARanges() {
/// Emit a single range list. We handle both DWARF v5 and earlier.
static void emitRangeList(DwarfDebug &DD, AsmPrinter *Asm,
const RangeSpanList &List) {
- emitRangeList(DD, Asm, List.Label, List.Ranges, *List.CU,
- dwarf::DW_RLE_base_addressx, dwarf::DW_RLE_offset_pair,
- dwarf::DW_RLE_startx_length, dwarf::DW_RLE_end_of_list,
- llvm::dwarf::RangeListEncodingString,
- List.CU->getCUNode()->getRangesBaseAddress() ||
- DD.getDwarfVersion() >= 5,
- [](auto) {});
+ emitRangeList(
+ DD, Asm, List.Label, List.Ranges, *List.CU, dwarf::DW_RLE_base_addressx,
+ dwarf::DW_RLE_offset_pair, dwarf::DW_RLE_startx_length,
+ dwarf::DW_RLE_end_of_list, llvm::dwarf::RangeListEncodingString,
+ List.CU->getCUNode()->getRangesBaseAddress() || DD.getDwarfVersion() >= 5,
+ [](auto) {});
}
-void DwarfDebug::emitDebugRangesImpl(const DwarfFile &Holder, MCSection *Section) {
+void DwarfDebug::emitDebugRangesImpl(const DwarfFile &Holder,
+ MCSection *Section) {
if (Holder.getRangeLists().empty())
return;
@@ -4059,11 +4064,11 @@ void DwarfDebug::addAccelNameImpl(
assert(((&Current == &AccelTypeUnitsDebugNames) ||
((&Current == &AccelDebugNames) &&
(Unit.getUnitDie().getTag() != dwarf::DW_TAG_type_unit))) &&
- "Kind is CU but TU is being processed.");
+ "Kind is CU but TU is being processed.");
assert(((&Current == &AccelDebugNames) ||
((&Current == &AccelTypeUnitsDebugNames) &&
(Unit.getUnitDie().getTag() == dwarf::DW_TAG_type_unit))) &&
- "Kind is TU but CU is being processed.");
+ "Kind is TU but CU is being processed.");
// The type unit can be discarded, so need to add references to final
// acceleration table once we know it's complete and we emit it.
Current.addName(Ref, Die, Unit.getUniqueID(),
``````````
</details>
https://github.com/llvm/llvm-project/pull/166627
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