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-rw-r--r--llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp77
-rw-r--r--llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h16
-rw-r--r--llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp54
-rw-r--r--llvm/lib/CodeGen/AsmPrinter/DwarfUnit.h15
4 files changed, 61 insertions, 101 deletions
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index ed9e90a7dd2..6925cb6bdde 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -178,7 +178,7 @@ static unsigned getDwarfVersionFromModule(const Module *M) {
DwarfDebug::DwarfDebug(AsmPrinter *A, Module *M)
: Asm(A), MMI(Asm->MMI), FirstCU(0), PrevLabel(NULL), GlobalRangeCount(0),
- InfoHolder(A, "info_string", DIEValueAllocator),
+ InfoHolder(A, "info_string", DIEValueAllocator), HasCURanges(false),
UsedNonDefaultText(false),
SkeletonHolder(A, "skel_string", DIEValueAllocator) {
@@ -947,34 +947,26 @@ void DwarfDebug::finalizeModuleInfo() {
dwarf::DW_FORM_data8, ID);
}
- // If we have code split among multiple sections or non-contiguous
- // ranges of code then emit a DW_AT_ranges attribute on the unit that will
- // remain in the .o file, otherwise add a DW_AT_low_pc.
- // FIXME: We should use ranges allow reordering of code ala
- // .subsections_via_symbols in mach-o. This would mean turning on
- // ranges for all subprogram DIEs for mach-o.
+ // If we have code split among multiple sections or we've requested
+ // it then emit a DW_AT_ranges attribute on the unit that will remain
+ // in the .o file, otherwise add a DW_AT_low_pc.
+ // FIXME: Also add a high pc if we can.
+ // FIXME: We should use ranges if we have multiple compile units or
+ // allow reordering of code ala .subsections_via_symbols in mach-o.
DwarfCompileUnit *U = SkCU ? SkCU : static_cast<DwarfCompileUnit *>(TheU);
- unsigned NumRanges = TheU->getRanges().size();
- if (NumRanges) {
- if (NumRanges > 1) {
- addSectionLabel(Asm, U, U->getUnitDie(), dwarf::DW_AT_ranges,
- Asm->GetTempSymbol("cu_ranges", U->getUniqueID()),
- DwarfDebugRangeSectionSym);
-
- // A DW_AT_low_pc attribute may also be specified in combination with
- // DW_AT_ranges to specify the default base address for use in
- // location lists (see Section 2.6.2) and range lists (see Section
- // 2.17.3).
- U->addUInt(U->getUnitDie(), dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr,
- 0);
- } else {
- RangeSpan &Range = TheU->getRanges().back();
- U->addLocalLabelAddress(U->getUnitDie(), dwarf::DW_AT_low_pc,
- Range.getStart());
- U->addLabelDelta(U->getUnitDie(), dwarf::DW_AT_high_pc,
- Range.getEnd(), Range.getStart());
- }
- }
+ if (useCURanges() && TheU->getRanges().size()) {
+ addSectionLabel(Asm, U, U->getUnitDie(), dwarf::DW_AT_ranges,
+ Asm->GetTempSymbol("cu_ranges", U->getUniqueID()),
+ DwarfDebugRangeSectionSym);
+
+ // A DW_AT_low_pc attribute may also be specified in combination with
+ // DW_AT_ranges to specify the default base address for use in location
+ // lists (see Section 2.6.2) and range lists (see Section 2.17.3).
+ U->addUInt(U->getUnitDie(), dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr,
+ 0);
+ } else
+ U->addUInt(U->getUnitDie(), dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr,
+ 0);
}
}
@@ -1029,6 +1021,14 @@ void DwarfDebug::endSections() {
// Insert a final terminator.
SectionMap[Section].push_back(SymbolCU(NULL, Sym));
}
+
+ // For now only turn on CU ranges if we have -ffunction-sections enabled,
+ // we've emitted a function into a unique section, or we're using LTO. If
+ // we're using LTO then we can't know that any particular function in the
+ // module is correlated to a particular CU and so we need to be conservative.
+ // At this point all sections should be finalized except for dwarf sections.
+ HasCURanges = UsedNonDefaultText || (CUMap.size() > 1) ||
+ TargetMachine::getFunctionSections();
}
// Emit all Dwarf sections that should come after the content.
@@ -1423,8 +1423,12 @@ void DwarfDebug::beginFunction(const MachineFunction *MF) {
// Grab the lexical scopes for the function, if we don't have any of those
// then we're not going to be able to do anything.
LScopes.initialize(*MF);
- if (LScopes.empty())
+ if (LScopes.empty()) {
+ // If we don't have a lexical scope for this function then there will
+ // be a hole in the range information. Keep note of this.
+ UsedNonDefaultText = true;
return;
+ }
assert(UserVariables.empty() && DbgValues.empty() && "Maps weren't cleaned");
@@ -1443,6 +1447,12 @@ void DwarfDebug::beginFunction(const MachineFunction *MF) {
else
Asm->OutStreamer.getContext().setDwarfCompileUnitID(TheCU->getUniqueID());
+ // Check the current section against the standard text section. If different
+ // keep track so that we will know when we're emitting functions into multiple
+ // sections.
+ if (Asm->getObjFileLowering().getTextSection() != Asm->getCurrentSection())
+ UsedNonDefaultText = true;
+
// Emit a label for the function so that we have a beginning address.
FunctionBeginSym = Asm->GetTempSymbol("func_begin", Asm->getFunctionNumber());
// Assumes in correct section after the entry point.
@@ -1648,11 +1658,6 @@ void DwarfDebug::endFunction(const MachineFunction *MF) {
assert(CurFn != 0);
if (!MMI->hasDebugInfo() || LScopes.empty()) {
- // If we don't have a lexical scope for this function then there will
- // be a hole in the range information. Keep note of this by setting the
- // previously used section to nullptr.
- PrevSection = nullptr;
- PrevCU = nullptr;
CurFn = 0;
return;
}
@@ -1703,8 +1708,6 @@ void DwarfDebug::endFunction(const MachineFunction *MF) {
// Add the range of this function to the list of ranges for the CU.
RangeSpan Span(FunctionBeginSym, FunctionEndSym);
TheCU->addRange(std::move(Span));
- PrevSection = Asm->getCurrentSection();
- PrevCU = TheCU;
// Clear debug info
for (auto &I : ScopeVariables)
@@ -2594,7 +2597,7 @@ void DwarfDebug::emitDebugRanges() {
}
// Now emit a range for the CU itself.
- if (TheCU->getRanges().size() > 1) {
+ if (useCURanges() && TheCU->getRanges().size()) {
Asm->OutStreamer.EmitLabel(
Asm->GetTempSymbol("cu_ranges", TheCU->getUniqueID()));
for (const RangeSpan &Range : TheCU->getRanges()) {
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
index 52be24c7963..73150442c67 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
@@ -406,13 +406,6 @@ class DwarfDebug : public AsmPrinterHandler {
// If nonnull, stores the current machine instruction we're processing.
const MachineInstr *CurMI;
- // If nonnull, stores the section that the previous function was allocated to
- // emitting.
- const MCSection *PrevSection;
-
- // If nonnull, stores the CU in which the previous subprogram was contained.
- const DwarfCompileUnit *PrevCU;
-
// Section Symbols: these are assembler temporary labels that are emitted at
// the beginning of each supported dwarf section. These are used to form
// section offsets and are created by EmitSectionLabels.
@@ -748,18 +741,15 @@ public:
/// split dwarf proposal support.
bool useSplitDwarf() const { return HasSplitDwarf; }
+ /// \brief Returns whether or not to use AT_ranges for compilation units.
+ bool useCURanges() const { return HasCURanges; }
+
/// Returns the Dwarf Version.
unsigned getDwarfVersion() const { return DwarfVersion; }
/// Returns the section symbol for the .debug_loc section.
MCSymbol *getDebugLocSym() const { return DwarfDebugLocSectionSym; }
- /// Returns the previous section that was emitted into.
- const MCSection *getPrevSection() const { return PrevSection; }
-
- /// Returns the previous CU that was being updated
- const DwarfCompileUnit *getPrevCU() const { return PrevCU; }
-
/// Returns the entries for the .debug_loc section.
const SmallVectorImpl<DebugLocEntry> &getDebugLocEntries() const {
return DotDebugLocEntries;
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
index c1ece004779..bf377f52d41 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
@@ -282,31 +282,22 @@ void DwarfUnit::addSectionOffset(DIE *Die, dwarf::Attribute Attribute,
/// DW_FORM_addr or DW_FORM_GNU_addr_index.
///
void DwarfCompileUnit::addLabelAddress(DIE *Die, dwarf::Attribute Attribute,
- const MCSymbol *Label) {
-
- if (!DD->useSplitDwarf())
- return addLocalLabelAddress(Die, Attribute, Label);
-
- if (Label)
- DD->addArangeLabel(SymbolCU(this, Label));
-
- unsigned idx = DU->getAddrPoolIndex(Label);
- DIEValue *Value = new (DIEValueAllocator) DIEInteger(idx);
- Die->addValue(Attribute, dwarf::DW_FORM_GNU_addr_index, Value);
-}
-
-void DwarfCompileUnit::addLocalLabelAddress(DIE *Die,
- dwarf::Attribute Attribute,
- const MCSymbol *Label) {
+ MCSymbol *Label) {
if (Label)
DD->addArangeLabel(SymbolCU(this, Label));
- if (Label) {
- DIEValue *Value = new (DIEValueAllocator) DIELabel(Label);
- Die->addValue(Attribute, dwarf::DW_FORM_addr, Value);
+ if (!DD->useSplitDwarf()) {
+ if (Label) {
+ DIEValue *Value = new (DIEValueAllocator) DIELabel(Label);
+ Die->addValue(Attribute, dwarf::DW_FORM_addr, Value);
+ } else {
+ DIEValue *Value = new (DIEValueAllocator) DIEInteger(0);
+ Die->addValue(Attribute, dwarf::DW_FORM_addr, Value);
+ }
} else {
- DIEValue *Value = new (DIEValueAllocator) DIEInteger(0);
- Die->addValue(Attribute, dwarf::DW_FORM_addr, Value);
+ unsigned idx = DU->getAddrPoolIndex(Label);
+ DIEValue *Value = new (DIEValueAllocator) DIEInteger(idx);
+ Die->addValue(Attribute, dwarf::DW_FORM_GNU_addr_index, Value);
}
}
@@ -2043,27 +2034,6 @@ void DwarfUnit::emitHeader(const MCSection *ASection,
Asm->EmitInt8(Asm->getDataLayout().getPointerSize());
}
-void DwarfUnit::addRange(RangeSpan Range) {
- // Only add a range for this unit if we're emitting full debug.
- if (getCUNode().getEmissionKind() == DIBuilder::FullDebug) {
- // If we have no current ranges just add the range and return, otherwise,
- // check the current section and CU against the previous section and CU we
- // emitted into and the subprogram was contained within. If these are the
- // same then extend our current range, otherwise add this as a new range.
- if (CURanges.size() == 0 ||
- this != DD->getPrevCU() ||
- Asm->getCurrentSection() != DD->getPrevSection()) {
- CURanges.push_back(Range);
- return;
- }
-
- assert(&(CURanges.back().getEnd()->getSection()) ==
- &(Range.getEnd()->getSection()) &&
- "We can only append to a range in the same section!");
- CURanges.back().setEnd(Range.getEnd());
- }
-}
-
void DwarfCompileUnit::initStmtList(MCSymbol *DwarfLineSectionSym) {
// Define start line table label for each Compile Unit.
MCSymbol *LineTableStartSym =
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.h b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.h
index a9e52e674a4..6f8e55edc91 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.h
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.h
@@ -41,7 +41,6 @@ public:
RangeSpan(MCSymbol *S, MCSymbol *E) : Start(S), End(E) {}
const MCSymbol *getStart() const { return Start; }
const MCSymbol *getEnd() const { return End; }
- void setEnd(const MCSymbol *E) { End = E; }
private:
const MCSymbol *Start, *End;
@@ -252,7 +251,11 @@ public:
bool hasContent() const { return !UnitDie->getChildren().empty(); }
/// addRange - Add an address range to the list of ranges for this unit.
- void addRange(RangeSpan Range);
+ void addRange(RangeSpan Range) {
+ // Only add a range for this unit if we're emitting full debug.
+ if (getCUNode().getEmissionKind() == DIBuilder::FullDebug)
+ CURanges.push_back(Range);
+ }
/// getRanges - Get the list of ranges for this unit.
const SmallVectorImpl<RangeSpan> &getRanges() const { return CURanges; }
@@ -580,13 +583,7 @@ public:
/// addLabelAddress - Add a dwarf label attribute data and value using
/// either DW_FORM_addr or DW_FORM_GNU_addr_index.
- void addLabelAddress(DIE *Die, dwarf::Attribute Attribute,
- const MCSymbol *Label);
-
- /// addLocalLabelAddress - Add a dwarf label attribute data and value using
- /// DW_FORM_addr only.
- void addLocalLabelAddress(DIE *Die, dwarf::Attribute Attribute,
- const MCSymbol *Label);
+ void addLabelAddress(DIE *Die, dwarf::Attribute Attribute, MCSymbol *Label);
DwarfCompileUnit &getCU() override { return *this; }
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