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-rw-r--r--lib/MC/MCContext.cpp23
-rw-r--r--lib/MC/MCDwarf.cpp174
-rw-r--r--lib/MC/MCParser/AsmParser.cpp17
-rw-r--r--lib/MC/MCParser/ELFAsmParser.cpp32
4 files changed, 189 insertions, 57 deletions
diff --git a/lib/MC/MCContext.cpp b/lib/MC/MCContext.cpp
index cc98be6ea6..bd2c4e960a 100644
--- a/lib/MC/MCContext.cpp
+++ b/lib/MC/MCContext.cpp
@@ -340,6 +340,29 @@ bool MCContext::isValidDwarfFileNumber(unsigned FileNumber, unsigned CUID) {
return !MCDwarfFiles[FileNumber].Name.empty();
}
+/// finalizeDwarfSections - Emit end symbols for each non-empty code section.
+/// Also remove empty sections from SectionStartEndSyms, to avoid generating
+/// useless debug info for them.
+void MCContext::finalizeDwarfSections(MCStreamer &MCOS) {
+ MCContext &context = MCOS.getContext();
+
+ auto sec = SectionStartEndSyms.begin();
+ while (sec != SectionStartEndSyms.end()) {
+ assert(sec->second.first && "Start symbol must be set by now");
+ MCOS.SwitchSection(sec->first);
+ if (MCOS.mayHaveInstructions()) {
+ MCSymbol *SectionEndSym = context.CreateTempSymbol();
+ MCOS.EmitLabel(SectionEndSym);
+ sec->second.second = SectionEndSym;
+ ++sec;
+ } else {
+ MapVector<const MCSection *, std::pair<MCSymbol *, MCSymbol *> >::iterator
+ to_erase = sec;
+ sec = SectionStartEndSyms.erase(to_erase);
+ }
+ }
+}
+
void MCContext::FatalError(SMLoc Loc, const Twine &Msg) const {
// If we have a source manager and a location, use it. Otherwise just
// use the generic report_fatal_error().
diff --git a/lib/MC/MCDwarf.cpp b/lib/MC/MCDwarf.cpp
index 1016466839..995bee1213 100644
--- a/lib/MC/MCDwarf.cpp
+++ b/lib/MC/MCDwarf.cpp
@@ -19,6 +19,7 @@
#include "llvm/MC/MCObjectFileInfo.h"
#include "llvm/MC/MCObjectStreamer.h"
#include "llvm/MC/MCRegisterInfo.h"
+#include "llvm/MC/MCSection.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
@@ -518,8 +519,12 @@ static void EmitGenDwarfAbbrev(MCStreamer *MCOS) {
MCOS->EmitULEB128IntValue(dwarf::DW_TAG_compile_unit);
MCOS->EmitIntValue(dwarf::DW_CHILDREN_yes, 1);
EmitAbbrev(MCOS, dwarf::DW_AT_stmt_list, dwarf::DW_FORM_data4);
- EmitAbbrev(MCOS, dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr);
- EmitAbbrev(MCOS, dwarf::DW_AT_high_pc, dwarf::DW_FORM_addr);
+ if (MCOS->getContext().getGenDwarfSectionSyms().size() > 1) {
+ EmitAbbrev(MCOS, dwarf::DW_AT_ranges, dwarf::DW_FORM_data4);
+ } else {
+ EmitAbbrev(MCOS, dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr);
+ EmitAbbrev(MCOS, dwarf::DW_AT_high_pc, dwarf::DW_FORM_addr);
+ }
EmitAbbrev(MCOS, dwarf::DW_AT_name, dwarf::DW_FORM_string);
if (!context.getCompilationDir().empty())
EmitAbbrev(MCOS, dwarf::DW_AT_comp_dir, dwarf::DW_FORM_string);
@@ -552,20 +557,14 @@ static void EmitGenDwarfAbbrev(MCStreamer *MCOS) {
}
// When generating dwarf for assembly source files this emits the data for
-// .debug_aranges section. Which contains a header and a table of pairs of
-// PointerSize'ed values for the address and size of section(s) with line table
-// entries (just the default .text in our case) and a terminating pair of zeros.
+// .debug_aranges section. This section contains a header and a table of pairs
+// of PointerSize'ed values for the address and size of section(s) with line
+// table entries.
static void EmitGenDwarfAranges(MCStreamer *MCOS,
const MCSymbol *InfoSectionSymbol) {
MCContext &context = MCOS->getContext();
- // Create a symbol at the end of the section that we are creating the dwarf
- // debugging info to use later in here as part of the expression to calculate
- // the size of the section for the table.
- MCOS->SwitchSection(context.getGenDwarfSection());
- MCSymbol *SectionEndSym = context.CreateTempSymbol();
- MCOS->EmitLabel(SectionEndSym);
- context.setGenDwarfSectionEndSym(SectionEndSym);
+ auto &Sections = context.getGenDwarfSectionSyms();
MCOS->SwitchSection(context.getObjectFileInfo()->getDwarfARangesSection());
@@ -583,8 +582,8 @@ static void EmitGenDwarfAranges(MCStreamer *MCOS,
Length += Pad;
// Add the size of the pair of PointerSize'ed values for the address and size
- // of the one default .text section we have in the table.
- Length += 2 * AddrSize;
+ // of each section we have in the table.
+ Length += 2 * AddrSize * Sections.size();
// And the pair of terminating zeros.
Length += 2 * AddrSize;
@@ -608,14 +607,21 @@ static void EmitGenDwarfAranges(MCStreamer *MCOS,
for(int i = 0; i < Pad; i++)
MCOS->EmitIntValue(0, 1);
- // Now emit the table of pairs of PointerSize'ed values for the section(s)
- // address and size, in our case just the one default .text section.
- const MCExpr *Addr = MCSymbolRefExpr::Create(
- context.getGenDwarfSectionStartSym(), MCSymbolRefExpr::VK_None, context);
- const MCExpr *Size = MakeStartMinusEndExpr(*MCOS,
- *context.getGenDwarfSectionStartSym(), *SectionEndSym, 0);
- MCOS->EmitValue(Addr, AddrSize);
- MCOS->EmitAbsValue(Size, AddrSize);
+ // Now emit the table of pairs of PointerSize'ed values for the section
+ // addresses and sizes.
+ for (const auto &sec : Sections) {
+ MCSymbol* StartSymbol = sec.second.first;
+ MCSymbol* EndSymbol = sec.second.second;
+ assert(StartSymbol && "StartSymbol must not be NULL");
+ assert(EndSymbol && "EndSymbol must not be NULL");
+
+ const MCExpr *Addr = MCSymbolRefExpr::Create(
+ StartSymbol, MCSymbolRefExpr::VK_None, context);
+ const MCExpr *Size = MakeStartMinusEndExpr(*MCOS,
+ *StartSymbol, *EndSymbol, 0);
+ MCOS->EmitValue(Addr, AddrSize);
+ MCOS->EmitAbsValue(Size, AddrSize);
+ }
// And finally the pair of terminating zeros.
MCOS->EmitIntValue(0, AddrSize);
@@ -627,7 +633,8 @@ static void EmitGenDwarfAranges(MCStreamer *MCOS,
// DIE and a list of label DIEs.
static void EmitGenDwarfInfo(MCStreamer *MCOS,
const MCSymbol *AbbrevSectionSymbol,
- const MCSymbol *LineSectionSymbol) {
+ const MCSymbol *LineSectionSymbol,
+ const MCSymbol *RangesSectionSymbol) {
MCContext &context = MCOS->getContext();
MCOS->SwitchSection(context.getObjectFileInfo()->getDwarfInfoSection());
@@ -674,15 +681,37 @@ static void EmitGenDwarfInfo(MCStreamer *MCOS,
MCOS->EmitIntValue(0, 4);
}
- // AT_low_pc, the first address of the default .text section.
- const MCExpr *Start = MCSymbolRefExpr::Create(
- context.getGenDwarfSectionStartSym(), MCSymbolRefExpr::VK_None, context);
- MCOS->EmitValue(Start, AddrSize);
+ if (RangesSectionSymbol) {
+ // There are multiple sections containing code, so we must use the
+ // .debug_ranges sections.
- // AT_high_pc, the last address of the default .text section.
- const MCExpr *End = MCSymbolRefExpr::Create(
- context.getGenDwarfSectionEndSym(), MCSymbolRefExpr::VK_None, context);
- MCOS->EmitValue(End, AddrSize);
+ // AT_ranges, the 4 byte offset from the start of the .debug_ranges section
+ // to the address range list for this compilation unit.
+ MCOS->EmitSymbolValue(RangesSectionSymbol, 4);
+ } else {
+ // If we only have one non-empty code section, we can use the simpler
+ // AT_low_pc and AT_high_pc attributes.
+
+ // Find the first (and only) non-empty text section
+ auto &Sections = context.getGenDwarfSectionSyms();
+ const auto TextSection = Sections.begin();
+ assert(TextSection != Sections.end() && "No text section found");
+
+ MCSymbol* StartSymbol = TextSection->second.first;
+ MCSymbol* EndSymbol = TextSection->second.second;
+ assert(StartSymbol && "StartSymbol must not be NULL");
+ assert(EndSymbol && "EndSymbol must not be NULL");
+
+ // AT_low_pc, the first address of the default .text section.
+ const MCExpr *Start = MCSymbolRefExpr::Create(
+ StartSymbol, MCSymbolRefExpr::VK_None, context);
+ MCOS->EmitValue(Start, AddrSize);
+
+ // AT_high_pc, the last address of the default .text section.
+ const MCExpr *End = MCSymbolRefExpr::Create(
+ EndSymbol, MCSymbolRefExpr::VK_None, context);
+ MCOS->EmitValue(End, AddrSize);
+ }
// AT_name, the name of the source file. Reconstruct from the first directory
// and file table entries.
@@ -766,13 +795,51 @@ static void EmitGenDwarfInfo(MCStreamer *MCOS,
MCOS->EmitLabel(InfoEnd);
}
+// When generating dwarf for assembly source files this emits the data for
+// .debug_ranges section. We only emit one range list, which spans all of the
+// executable sections of this file.
+static void EmitGenDwarfRanges(MCStreamer *MCOS) {
+ MCContext &context = MCOS->getContext();
+ auto &Sections = context.getGenDwarfSectionSyms();
+
+ const MCAsmInfo *AsmInfo = context.getAsmInfo();
+ int AddrSize = AsmInfo->getPointerSize();
+
+ MCOS->SwitchSection(context.getObjectFileInfo()->getDwarfRangesSection());
+
+ for (const auto sec : Sections) {
+
+ MCSymbol* StartSymbol = sec.second.first;
+ MCSymbol* EndSymbol = sec.second.second;
+ assert(StartSymbol && "StartSymbol must not be NULL");
+ assert(EndSymbol && "EndSymbol must not be NULL");
+
+ // Emit a base address selection entry for the start of this section
+ const MCExpr *SectionStartAddr = MCSymbolRefExpr::Create(
+ StartSymbol, MCSymbolRefExpr::VK_None, context);
+ MCOS->EmitFill(AddrSize, 0xFF);
+ MCOS->EmitValue(SectionStartAddr, AddrSize);
+
+ // Emit a range list entry spanning this section
+ const MCExpr *SectionSize = MakeStartMinusEndExpr(*MCOS,
+ *StartSymbol, *EndSymbol, 0);
+ MCOS->EmitIntValue(0, AddrSize);
+ MCOS->EmitAbsValue(SectionSize, AddrSize);
+ }
+
+ // Emit end of list entry
+ MCOS->EmitIntValue(0, AddrSize);
+ MCOS->EmitIntValue(0, AddrSize);
+}
+
//
// When generating dwarf for assembly source files this emits the Dwarf
// sections.
//
void MCGenDwarfInfo::Emit(MCStreamer *MCOS) {
- // Create the dwarf sections in this order (.debug_line already created).
MCContext &context = MCOS->getContext();
+
+ // Create the dwarf sections in this order (.debug_line already created).
const MCAsmInfo *AsmInfo = context.getAsmInfo();
bool CreateDwarfSectionSymbols =
AsmInfo->doesDwarfUseRelocationsAcrossSections();
@@ -781,6 +848,22 @@ void MCGenDwarfInfo::Emit(MCStreamer *MCOS) {
LineSectionSymbol = MCOS->getDwarfLineTableSymbol(0);
MCSymbol *AbbrevSectionSymbol = nullptr;
MCSymbol *InfoSectionSymbol = nullptr;
+ MCSymbol *RangesSectionSymbol = NULL;
+
+ // Create end symbols for each section, and remove empty sections
+ MCOS->getContext().finalizeDwarfSections(*MCOS);
+
+ // If there are no sections to generate debug info for, we don't need
+ // to do anything
+ if (MCOS->getContext().getGenDwarfSectionSyms().empty())
+ return;
+
+ // We only need to use the .debug_ranges section if we have multiple
+ // code sections.
+ const bool UseRangesSection =
+ MCOS->getContext().getGenDwarfSectionSyms().size() > 1;
+ CreateDwarfSectionSymbols |= UseRangesSection;
+
MCOS->SwitchSection(context.getObjectFileInfo()->getDwarfInfoSection());
if (CreateDwarfSectionSymbols) {
InfoSectionSymbol = context.CreateTempSymbol();
@@ -791,20 +874,30 @@ void MCGenDwarfInfo::Emit(MCStreamer *MCOS) {
AbbrevSectionSymbol = context.CreateTempSymbol();
MCOS->EmitLabel(AbbrevSectionSymbol);
}
- MCOS->SwitchSection(context.getObjectFileInfo()->getDwarfARangesSection());
+ if (UseRangesSection) {
+ MCOS->SwitchSection(context.getObjectFileInfo()->getDwarfRangesSection());
+ if (CreateDwarfSectionSymbols) {
+ RangesSectionSymbol = context.CreateTempSymbol();
+ MCOS->EmitLabel(RangesSectionSymbol);
+ }
+ }
- // If there are no line table entries then do not emit any section contents.
- if (!context.hasMCLineSections())
- return;
+ assert((RangesSectionSymbol != NULL) || !UseRangesSection);
+
+ MCOS->SwitchSection(context.getObjectFileInfo()->getDwarfARangesSection());
// Output the data for .debug_aranges section.
EmitGenDwarfAranges(MCOS, InfoSectionSymbol);
+ if (UseRangesSection)
+ EmitGenDwarfRanges(MCOS);
+
// Output the data for .debug_abbrev section.
EmitGenDwarfAbbrev(MCOS);
// Output the data for .debug_info section.
- EmitGenDwarfInfo(MCOS, AbbrevSectionSymbol, LineSectionSymbol);
+ EmitGenDwarfInfo(MCOS, AbbrevSectionSymbol, LineSectionSymbol,
+ RangesSectionSymbol);
}
//
@@ -815,12 +908,13 @@ void MCGenDwarfInfo::Emit(MCStreamer *MCOS) {
//
void MCGenDwarfLabelEntry::Make(MCSymbol *Symbol, MCStreamer *MCOS,
SourceMgr &SrcMgr, SMLoc &Loc) {
- // We won't create dwarf labels for temporary symbols or symbols not in
- // the default text.
+ // We won't create dwarf labels for temporary symbols.
if (Symbol->isTemporary())
return;
MCContext &context = MCOS->getContext();
- if (context.getGenDwarfSection() != MCOS->getCurrentSection().first)
+ // We won't create dwarf labels for symbols in sections that we are not
+ // generating debug info for.
+ if (!context.getGenDwarfSectionSyms().count(MCOS->getCurrentSection().first))
return;
// The dwarf label's name does not have the symbol name's leading
diff --git a/lib/MC/MCParser/AsmParser.cpp b/lib/MC/MCParser/AsmParser.cpp
index 1ba02d181d..50375d37d8 100644
--- a/lib/MC/MCParser/AsmParser.cpp
+++ b/lib/MC/MCParser/AsmParser.cpp
@@ -633,10 +633,12 @@ bool AsmParser::Run(bool NoInitialTextSection, bool NoFinalize) {
// If we are generating dwarf for assembly source files save the initial text
// section and generate a .file directive.
if (getContext().getGenDwarfForAssembly()) {
- getContext().setGenDwarfSection(getStreamer().getCurrentSection().first);
MCSymbol *SectionStartSym = getContext().CreateTempSymbol();
getStreamer().EmitLabel(SectionStartSym);
- getContext().setGenDwarfSectionStartSym(SectionStartSym);
+ auto InsertResult = getContext().addGenDwarfSection(
+ getStreamer().getCurrentSection().first);
+ assert(InsertResult.second && ".text section should not have debug info yet");
+ InsertResult.first->second.first = SectionStartSym;
getContext().setGenDwarfFileNumber(getStreamer().EmitDwarfFileDirective(
0, StringRef(), getContext().getMainFileName()));
}
@@ -1592,12 +1594,11 @@ bool AsmParser::parseStatement(ParseStatementInfo &Info) {
printMessage(IDLoc, SourceMgr::DK_Note, OS.str());
}
- // If we are generating dwarf for assembly source files and the current
- // section is the initial text section then generate a .loc directive for
- // the instruction.
+ // If we are generating dwarf for the current section then generate a .loc
+ // directive for the instruction.
if (!HadError && getContext().getGenDwarfForAssembly() &&
- getContext().getGenDwarfSection() ==
- getStreamer().getCurrentSection().first) {
+ getContext().getGenDwarfSectionSyms().count(
+ getStreamer().getCurrentSection().first)) {
unsigned Line = SrcMgr.FindLineNumber(IDLoc, CurBuffer);
@@ -2029,7 +2030,7 @@ bool AsmParser::parseMacroArguments(const MCAsmMacro *M,
break;
if (FAI >= NParameters) {
- assert(M && "expected macro to be defined");
+ assert(M && "expected macro to be defined");
Error(IDLoc,
"parameter named '" + FA.Name + "' does not exist for macro '" +
M->Name + "'");
diff --git a/lib/MC/MCParser/ELFAsmParser.cpp b/lib/MC/MCParser/ELFAsmParser.cpp
index 78bb6c7aad..98b2b3bd60 100644
--- a/lib/MC/MCParser/ELFAsmParser.cpp
+++ b/lib/MC/MCParser/ELFAsmParser.cpp
@@ -150,7 +150,7 @@ public:
private:
bool ParseSectionName(StringRef &SectionName);
- bool ParseSectionArguments(bool IsPush);
+ bool ParseSectionArguments(bool IsPush, SMLoc loc);
unsigned parseSunStyleSectionFlags();
};
@@ -382,7 +382,7 @@ unsigned ELFAsmParser::parseSunStyleSectionFlags() {
bool ELFAsmParser::ParseDirectivePushSection(StringRef s, SMLoc loc) {
getStreamer().PushSection();
- if (ParseSectionArguments(/*IsPush=*/true)) {
+ if (ParseSectionArguments(/*IsPush=*/true, loc)) {
getStreamer().PopSection();
return true;
}
@@ -397,11 +397,11 @@ bool ELFAsmParser::ParseDirectivePopSection(StringRef, SMLoc) {
}
// FIXME: This is a work in progress.
-bool ELFAsmParser::ParseDirectiveSection(StringRef, SMLoc) {
- return ParseSectionArguments(/*IsPush=*/false);
+bool ELFAsmParser::ParseDirectiveSection(StringRef, SMLoc loc) {
+ return ParseSectionArguments(/*IsPush=*/false, loc);
}
-bool ELFAsmParser::ParseSectionArguments(bool IsPush) {
+bool ELFAsmParser::ParseSectionArguments(bool IsPush, SMLoc loc) {
StringRef SectionName;
if (ParseSectionName(SectionName))
@@ -545,10 +545,24 @@ EndStmt:
}
SectionKind Kind = computeSectionKind(Flags, Size);
- getStreamer().SwitchSection(getContext().getELFSection(SectionName, Type,
- Flags, Kind, Size,
- GroupName),
- Subsection);
+ const MCSection *ELFSection = getContext().getELFSection(
+ SectionName, Type, Flags, Kind, Size, GroupName);
+ getStreamer().SwitchSection(ELFSection, Subsection);
+
+ if (getContext().getGenDwarfForAssembly()) {
+ auto &Sections = getContext().getGenDwarfSectionSyms();
+ auto InsertResult = Sections.insert(
+ std::make_pair(ELFSection, std::make_pair(nullptr, nullptr)));
+ if (InsertResult.second) {
+ if (getContext().getDwarfVersion() <= 2)
+ Error(loc, "DWARF2 only supports one section per compilation unit");
+
+ MCSymbol *SectionStartSymbol = getContext().CreateTempSymbol();
+ getStreamer().EmitLabel(SectionStartSymbol);
+ InsertResult.first->second.first = SectionStartSymbol;
+ }
+ }
+
return false;
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-10 17:54:50 +0000