[llvm] [DebugInfo][DWARF] Emit Per-Function Line Table Offsets and End Sequences (PR #110192)
via llvm-commits
llvm-commits at lists.llvm.org
Tue Nov 12 18:03:37 PST 2024
https://github.com/alx32 updated https://github.com/llvm/llvm-project/pull/110192
>From bd3f96d30f1b2137c658a19ae1094afd6e85836c Mon Sep 17 00:00:00 2001
From: Alex B <alexborcan at meta.com>
Date: Thu, 26 Sep 2024 17:30:48 -0700
Subject: [PATCH 1/4] [DebugInfo][DWARF] Emit Per-Function Line Table Offsets
and End Sequences
---
llvm/include/llvm/BinaryFormat/Dwarf.def | 1 +
llvm/include/llvm/MC/MCDwarf.h | 5 +-
llvm/include/llvm/MC/MCStreamer.h | 27 ++++++
.../CodeGen/AsmPrinter/DwarfCompileUnit.cpp | 8 ++
llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp | 30 ++++++-
llvm/lib/MC/MCDwarf.cpp | 22 ++++-
.../X86/DW_AT_LLVM_stmt_seq_sec_offset.ll | 82 +++++++++++++++++++
7 files changed, 169 insertions(+), 6 deletions(-)
create mode 100644 llvm/test/DebugInfo/X86/DW_AT_LLVM_stmt_seq_sec_offset.ll
diff --git a/llvm/include/llvm/BinaryFormat/Dwarf.def b/llvm/include/llvm/BinaryFormat/Dwarf.def
index ca86474365355d..4aa6defdc3a41f 100644
--- a/llvm/include/llvm/BinaryFormat/Dwarf.def
+++ b/llvm/include/llvm/BinaryFormat/Dwarf.def
@@ -618,6 +618,7 @@ HANDLE_DW_AT(0x3e08, LLVM_ptrauth_isa_pointer, 0, LLVM)
HANDLE_DW_AT(0x3e09, LLVM_ptrauth_authenticates_null_values, 0, LLVM)
HANDLE_DW_AT(0x3e0a, LLVM_ptrauth_authentication_mode, 0, LLVM)
HANDLE_DW_AT(0x3e0b, LLVM_num_extra_inhabitants, 0, LLVM)
+HANDLE_DW_AT(0x3e0c, LLVM_stmt_sequence, 0, LLVM)
// Apple extensions.
diff --git a/llvm/include/llvm/MC/MCDwarf.h b/llvm/include/llvm/MC/MCDwarf.h
index 1392336968e74a..3a39ff33a24782 100644
--- a/llvm/include/llvm/MC/MCDwarf.h
+++ b/llvm/include/llvm/MC/MCDwarf.h
@@ -123,6 +123,9 @@ class MCDwarfLoc {
friend class MCContext;
friend class MCDwarfLineEntry;
+ // DwarfDebug::endFunctionImpl needs to construct MCDwarfLoc(IsEndOfFunction)
+ friend class DwarfDebug;
+
MCDwarfLoc(unsigned fileNum, unsigned line, unsigned column, unsigned flags,
unsigned isa, unsigned discriminator)
: FileNum(fileNum), Line(line), Column(column), Flags(flags), Isa(isa),
@@ -239,7 +242,7 @@ class MCLineSection {
// Add an end entry by cloning the last entry, if exists, for the section
// the given EndLabel belongs to. The label is replaced by the given EndLabel.
- void addEndEntry(MCSymbol *EndLabel);
+ void addEndEntry(MCSymbol *EndLabel, bool generatingFuncLineTableOffsets);
using MCDwarfLineEntryCollection = std::vector<MCDwarfLineEntry>;
using iterator = MCDwarfLineEntryCollection::iterator;
diff --git a/llvm/include/llvm/MC/MCStreamer.h b/llvm/include/llvm/MC/MCStreamer.h
index df2eb9cf136bc9..5aabb0a61ac3d7 100644
--- a/llvm/include/llvm/MC/MCStreamer.h
+++ b/llvm/include/llvm/MC/MCStreamer.h
@@ -251,6 +251,15 @@ class MCStreamer {
/// discussion for future inclusion.
bool AllowAutoPadding = false;
+ // Flag specifying weather functions will have an offset into the line table
+ // where the line data for that function starts
+ bool GenerateFuncLineTableOffsets = false;
+
+ // Symbol that tracks the stream symbol for first line of the current function
+ // being generated. This symbol can be used to reference where the line
+ // entries for the function start in the generated line table.
+ MCSymbol *CurrentFuncFirstLineStreamSym;
+
protected:
MCFragment *CurFrag = nullptr;
@@ -313,6 +322,24 @@ class MCStreamer {
void setAllowAutoPadding(bool v) { AllowAutoPadding = v; }
bool getAllowAutoPadding() const { return AllowAutoPadding; }
+ void setGenerateFuncLineTableOffsets(bool v) {
+ GenerateFuncLineTableOffsets = v;
+ }
+ bool getGenerateFuncLineTableOffsets() const {
+ return GenerateFuncLineTableOffsets;
+ }
+
+ // Use the below functions to track the symbol that points to the current
+ // function's line info in the output stream.
+ void beginFunction() { CurrentFuncFirstLineStreamSym = nullptr; }
+ void emittedLineStreamSym(MCSymbol *StreamSym) {
+ if (!CurrentFuncFirstLineStreamSym)
+ CurrentFuncFirstLineStreamSym = StreamSym;
+ }
+ MCSymbol *getCurrentFuncFirstLineStreamSym() {
+ return CurrentFuncFirstLineStreamSym;
+ }
+
/// When emitting an object file, create and emit a real label. When emitting
/// textual assembly, this should do nothing to avoid polluting our output.
virtual MCSymbol *emitCFILabel();
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
index c4ce0f2ebc6b89..5e6fdc8486b6e5 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
@@ -526,6 +526,14 @@ DIE &DwarfCompileUnit::updateSubprogramScopeDIE(const DISubprogram *SP) {
*DD->getCurrentFunction()))
addFlag(*SPDie, dwarf::DW_AT_APPLE_omit_frame_ptr);
+ if (Asm->OutStreamer->getGenerateFuncLineTableOffsets() &&
+ Asm->OutStreamer->getCurrentFuncFirstLineStreamSym()) {
+ addSectionLabel(
+ *SPDie, dwarf::DW_AT_LLVM_stmt_sequence,
+ Asm->OutStreamer->getCurrentFuncFirstLineStreamSym(),
+ Asm->getObjFileLowering().getDwarfLineSection()->getBeginSymbol());
+ }
+
// Only include DW_AT_frame_base in full debug info
if (!includeMinimalInlineScopes()) {
const TargetFrameLowering *TFI = Asm->MF->getSubtarget().getFrameLowering();
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 88ed3f5dc7b4b4..183c4f0a6ec366 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -170,6 +170,12 @@ static cl::opt<DwarfDebug::MinimizeAddrInV5> MinimizeAddrInV5Option(
"Stuff")),
cl::init(DwarfDebug::MinimizeAddrInV5::Default));
+static cl::opt<bool> EmitFuncLineTableOffsetsOption(
+ "emit-func-debug-line-table-offsets", cl::Hidden,
+ cl::desc("Include line table offset in function's debug info and emit end "
+ "sequence after each function's line data."),
+ cl::init(false));
+
static constexpr unsigned ULEB128PadSize = 4;
void DebugLocDwarfExpression::emitOp(uint8_t Op, const char *Comment) {
@@ -441,6 +447,8 @@ DwarfDebug::DwarfDebug(AsmPrinter *A)
Asm->OutStreamer->getContext().setDwarfVersion(DwarfVersion);
Asm->OutStreamer->getContext().setDwarfFormat(Dwarf64 ? dwarf::DWARF64
: dwarf::DWARF32);
+ Asm->OutStreamer->setGenerateFuncLineTableOffsets(
+ EmitFuncLineTableOffsetsOption);
}
// Define out of line so we don't have to include DwarfUnit.h in DwarfDebug.h.
@@ -2222,6 +2230,10 @@ void DwarfDebug::beginFunctionImpl(const MachineFunction *MF) {
if (SP->getUnit()->getEmissionKind() == DICompileUnit::NoDebug)
return;
+ // Notify the streamer that we are beginning a function - this will reset the
+ // label pointing to the currently generated function's first line entry
+ Asm->OutStreamer->beginFunction();
+
DwarfCompileUnit &CU = getOrCreateDwarfCompileUnit(SP->getUnit());
Asm->OutStreamer->getContext().setDwarfCompileUnitID(
@@ -2250,7 +2262,8 @@ void DwarfDebug::terminateLineTable(const DwarfCompileUnit *CU) {
getDwarfCompileUnitIDForLineTable(*CU));
// Add the last range label for the given CU.
LineTable.getMCLineSections().addEndEntry(
- const_cast<MCSymbol *>(CURanges.back().End));
+ const_cast<MCSymbol *>(CURanges.back().End),
+ EmitFuncLineTableOffsetsOption);
}
void DwarfDebug::skippedNonDebugFunction() {
@@ -2343,6 +2356,21 @@ void DwarfDebug::endFunctionImpl(const MachineFunction *MF) {
// Construct call site entries.
constructCallSiteEntryDIEs(*SP, TheCU, ScopeDIE, *MF);
+ // If we're emitting line table offsets, we also need to emit an end label
+ // after all function's line entries
+ if (EmitFuncLineTableOffsetsOption) {
+ MCSymbol *LineSym = Asm->OutStreamer->getContext().createTempSymbol();
+ Asm->OutStreamer->emitLabel(LineSym);
+ MCDwarfLoc DwarfLoc(
+ 1, 1, 0, DWARF2_LINE_DEFAULT_IS_STMT ? DWARF2_FLAG_IS_STMT : 0, 0, 0);
+ MCDwarfLineEntry LineEntry(LineSym, DwarfLoc);
+ Asm->OutStreamer->getContext()
+ .getMCDwarfLineTable(
+ Asm->OutStreamer->getContext().getDwarfCompileUnitID())
+ .getMCLineSections()
+ .addLineEntry(LineEntry, Asm->OutStreamer->getCurrentSectionOnly());
+ }
+
// Clear debug info
// Ownership of DbgVariables is a bit subtle - ScopeVariables owns all the
// DbgVariables except those that are also in AbstractVariables (since they
diff --git a/llvm/lib/MC/MCDwarf.cpp b/llvm/lib/MC/MCDwarf.cpp
index e058358fb8ad4b..05ac3f860f962f 100644
--- a/llvm/lib/MC/MCDwarf.cpp
+++ b/llvm/lib/MC/MCDwarf.cpp
@@ -104,8 +104,17 @@ void MCDwarfLineEntry::make(MCStreamer *MCOS, MCSection *Section) {
// Get the current .loc info saved in the context.
const MCDwarfLoc &DwarfLoc = MCOS->getContext().getCurrentDwarfLoc();
+ MCSymbol *LineStreamLabel = nullptr;
+ // If functions need offsets into the generated line table, then we need to
+ // create a label referencing where the line was generated in the output
+ // stream
+ if (MCOS->getGenerateFuncLineTableOffsets()) {
+ LineStreamLabel = MCOS->getContext().createTempSymbol();
+ MCOS->emittedLineStreamSym(LineStreamLabel);
+ }
+
// Create a (local) line entry with the symbol and the current .loc info.
- MCDwarfLineEntry LineEntry(LineSym, DwarfLoc);
+ MCDwarfLineEntry LineEntry(LineSym, DwarfLoc, LineStreamLabel);
// clear DwarfLocSeen saying the current .loc info is now used.
MCOS->getContext().clearDwarfLocSeen();
@@ -145,7 +154,8 @@ makeStartPlusIntExpr(MCContext &Ctx, const MCSymbol &Start, int IntVal) {
return Res;
}
-void MCLineSection::addEndEntry(MCSymbol *EndLabel) {
+void MCLineSection::addEndEntry(MCSymbol *EndLabel,
+ bool generatingFuncLineTableOffsets) {
auto *Sec = &EndLabel->getSection();
// The line table may be empty, which we should skip adding an end entry.
// There are two cases:
@@ -158,8 +168,12 @@ void MCLineSection::addEndEntry(MCSymbol *EndLabel) {
if (I != MCLineDivisions.end()) {
auto &Entries = I->second;
auto EndEntry = Entries.back();
- EndEntry.setEndLabel(EndLabel);
- Entries.push_back(EndEntry);
+ // If generatingFuncLineTableOffsets is set, then we already generated an
+ // end label at the end of the last function, so skip generating another one
+ if (!generatingFuncLineTableOffsets) {
+ EndEntry.setEndLabel(EndLabel);
+ Entries.push_back(EndEntry);
+ }
}
}
diff --git a/llvm/test/DebugInfo/X86/DW_AT_LLVM_stmt_seq_sec_offset.ll b/llvm/test/DebugInfo/X86/DW_AT_LLVM_stmt_seq_sec_offset.ll
new file mode 100644
index 00000000000000..ef8b0c817cfb67
--- /dev/null
+++ b/llvm/test/DebugInfo/X86/DW_AT_LLVM_stmt_seq_sec_offset.ll
@@ -0,0 +1,82 @@
+; RUN: llc -mtriple=i686-w64-mingw32 -o %t -filetype=obj %s
+; RUN: llvm-dwarfdump -v -all %t | FileCheck %s -check-prefix=NO_STMT_SEQ
+
+; RUN: llc -mtriple=i686-w64-mingw32 -o %t -filetype=obj %s -emit-func-debug-line-table-offsets
+; RUN: llvm-dwarfdump -v -all %t | FileCheck %s -check-prefix=STMT_SEQ
+
+; NO_STMT_SEQ-NOT: DW_AT_LLVM_stmt_sequence
+
+; STMT_SEQ: [[[ABBREV_CODE:[0-9]+]]] DW_TAG_subprogram
+; STMT_SEQ: DW_AT_LLVM_stmt_sequence DW_FORM_sec_offset
+; STMT_SEQ: DW_TAG_subprogram [[[ABBREV_CODE]]]
+; STMT_SEQ: DW_AT_LLVM_stmt_sequence [DW_FORM_sec_offset] (0x00000028)
+; STMT_SEQ: DW_AT_name {{.*}}func01
+; STMT_SEQ: DW_TAG_subprogram [[[ABBREV_CODE]]]
+; STMT_SEQ: DW_AT_LLVM_stmt_sequence [DW_FORM_sec_offset] (0x00000033)
+; STMT_SEQ: DW_AT_name {{.*}}main
+
+;; Check that the line table starts at 0x00000028 (first function)
+; STMT_SEQ: Address Line Column File ISA Discriminator OpIndex Flags
+; STMT_SEQ-NEXT: ------------------ ------ ------ ------ --- ------------- ------- -------------
+; STMT_SEQ-NEXT: 0x00000028: 00 DW_LNE_set_address (0x00000006)
+
+;; Check that we have an 'end_sequence' just before the next function (0x00000033)
+; STMT_SEQ: 0x0000000000000006 1 0 1 0 0 0 is_stmt end_sequence
+; STMT_SEQ-NEXT: 0x00000033: 00 DW_LNE_set_address (0x00000027)
+
+;; Check that the end of the line table still has an 'end_sequence'
+; STMT_SEQ 0x00000049: 00 DW_LNE_end_sequence
+; STMT_SEQ-NEXT 0x0000000000000027 6 3 1 0 0 0 end_sequence
+
+
+; generated from:
+; clang -g -S -emit-llvm test.c -o test.ll
+; ======= test.c ======
+; int func01() {
+; return 1;
+; }
+; int main() {
+; return 0;
+; }
+; =====================
+
+
+; ModuleID = 'test.c'
+source_filename = "test.c"
+target datalayout = "e-m:o-i64:64-i128:128-n32:64-S128"
+target triple = "arm64-apple-macosx14.0.0"
+
+; Function Attrs: noinline nounwind optnone ssp uwtable(sync)
+define i32 @func01() #0 !dbg !9 {
+ ret i32 1, !dbg !13
+}
+
+; Function Attrs: noinline nounwind optnone ssp uwtable(sync)
+define i32 @main() #0 !dbg !14 {
+ %1 = alloca i32, align 4
+ store i32 0, ptr %1, align 4
+ ret i32 0, !dbg !15
+}
+
+attributes #0 = { noinline nounwind optnone ssp uwtable(sync) "frame-pointer"="non-leaf" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="apple-m1" "target-features"="+aes,+crc,+dotprod,+fp-armv8,+fp16fml,+fullfp16,+lse,+neon,+ras,+rcpc,+rdm,+sha2,+sha3,+v8.1a,+v8.2a,+v8.3a,+v8.4a,+v8.5a,+v8a,+zcm,+zcz" }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!2, !3, !4, !5, !6, !7}
+!llvm.ident = !{!8}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C11, file: !1, producer: "Homebrew clang version 17.0.6", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, splitDebugInlining: false, nameTableKind: Apple, sysroot: "/Library/Developer/CommandLineTools/SDKs/MacOSX14.sdk", sdk: "MacOSX14.sdk")
+!1 = !DIFile(filename: "test.c", directory: "/tmp/clang_test")
+!2 = !{i32 7, !"Dwarf Version", i32 4}
+!3 = !{i32 2, !"Debug Info Version", i32 3}
+!4 = !{i32 1, !"wchar_size", i32 4}
+!5 = !{i32 8, !"PIC Level", i32 2}
+!6 = !{i32 7, !"uwtable", i32 1}
+!7 = !{i32 7, !"frame-pointer", i32 1}
+!8 = !{!"Homebrew clang version 17.0.6"}
+!9 = distinct !DISubprogram(name: "func01", scope: !1, file: !1, line: 1, type: !10, scopeLine: 1, spFlags: DISPFlagDefinition, unit: !0)
+!10 = !DISubroutineType(types: !11)
+!11 = !{!12}
+!12 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!13 = !DILocation(line: 2, column: 3, scope: !9)
+!14 = distinct !DISubprogram(name: "main", scope: !1, file: !1, line: 5, type: !10, scopeLine: 5, spFlags: DISPFlagDefinition, unit: !0)
+!15 = !DILocation(line: 6, column: 3, scope: !14)
>From 662dcecd4626e47d5e5d622bc7d37f028ed26252 Mon Sep 17 00:00:00 2001
From: Alex B <alexborcan at meta.com>
Date: Fri, 25 Oct 2024 10:36:19 -0700
Subject: [PATCH 2/4] Fix compatibility with current MCStreamer Line Label
implementation
---
llvm/include/llvm/MC/MCDwarf.h | 5 +---
llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp | 18 +-------------
llvm/lib/MC/MCDwarf.cpp | 24 +++++++++----------
.../X86/DW_AT_LLVM_stmt_seq_sec_offset.ll | 12 +++++-----
4 files changed, 20 insertions(+), 39 deletions(-)
diff --git a/llvm/include/llvm/MC/MCDwarf.h b/llvm/include/llvm/MC/MCDwarf.h
index 3a39ff33a24782..1392336968e74a 100644
--- a/llvm/include/llvm/MC/MCDwarf.h
+++ b/llvm/include/llvm/MC/MCDwarf.h
@@ -123,9 +123,6 @@ class MCDwarfLoc {
friend class MCContext;
friend class MCDwarfLineEntry;
- // DwarfDebug::endFunctionImpl needs to construct MCDwarfLoc(IsEndOfFunction)
- friend class DwarfDebug;
-
MCDwarfLoc(unsigned fileNum, unsigned line, unsigned column, unsigned flags,
unsigned isa, unsigned discriminator)
: FileNum(fileNum), Line(line), Column(column), Flags(flags), Isa(isa),
@@ -242,7 +239,7 @@ class MCLineSection {
// Add an end entry by cloning the last entry, if exists, for the section
// the given EndLabel belongs to. The label is replaced by the given EndLabel.
- void addEndEntry(MCSymbol *EndLabel, bool generatingFuncLineTableOffsets);
+ void addEndEntry(MCSymbol *EndLabel);
using MCDwarfLineEntryCollection = std::vector<MCDwarfLineEntry>;
using iterator = MCDwarfLineEntryCollection::iterator;
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 183c4f0a6ec366..54237309b7ec99 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -2262,8 +2262,7 @@ void DwarfDebug::terminateLineTable(const DwarfCompileUnit *CU) {
getDwarfCompileUnitIDForLineTable(*CU));
// Add the last range label for the given CU.
LineTable.getMCLineSections().addEndEntry(
- const_cast<MCSymbol *>(CURanges.back().End),
- EmitFuncLineTableOffsetsOption);
+ const_cast<MCSymbol *>(CURanges.back().End));
}
void DwarfDebug::skippedNonDebugFunction() {
@@ -2356,21 +2355,6 @@ void DwarfDebug::endFunctionImpl(const MachineFunction *MF) {
// Construct call site entries.
constructCallSiteEntryDIEs(*SP, TheCU, ScopeDIE, *MF);
- // If we're emitting line table offsets, we also need to emit an end label
- // after all function's line entries
- if (EmitFuncLineTableOffsetsOption) {
- MCSymbol *LineSym = Asm->OutStreamer->getContext().createTempSymbol();
- Asm->OutStreamer->emitLabel(LineSym);
- MCDwarfLoc DwarfLoc(
- 1, 1, 0, DWARF2_LINE_DEFAULT_IS_STMT ? DWARF2_FLAG_IS_STMT : 0, 0, 0);
- MCDwarfLineEntry LineEntry(LineSym, DwarfLoc);
- Asm->OutStreamer->getContext()
- .getMCDwarfLineTable(
- Asm->OutStreamer->getContext().getDwarfCompileUnitID())
- .getMCLineSections()
- .addLineEntry(LineEntry, Asm->OutStreamer->getCurrentSectionOnly());
- }
-
// Clear debug info
// Ownership of DbgVariables is a bit subtle - ScopeVariables owns all the
// DbgVariables except those that are also in AbstractVariables (since they
diff --git a/llvm/lib/MC/MCDwarf.cpp b/llvm/lib/MC/MCDwarf.cpp
index 05ac3f860f962f..0b078f7bb0c523 100644
--- a/llvm/lib/MC/MCDwarf.cpp
+++ b/llvm/lib/MC/MCDwarf.cpp
@@ -104,17 +104,22 @@ void MCDwarfLineEntry::make(MCStreamer *MCOS, MCSection *Section) {
// Get the current .loc info saved in the context.
const MCDwarfLoc &DwarfLoc = MCOS->getContext().getCurrentDwarfLoc();
- MCSymbol *LineStreamLabel = nullptr;
// If functions need offsets into the generated line table, then we need to
// create a label referencing where the line was generated in the output
// stream
- if (MCOS->getGenerateFuncLineTableOffsets()) {
- LineStreamLabel = MCOS->getContext().createTempSymbol();
+ if (MCOS->getGenerateFuncLineTableOffsets() &&
+ !MCOS->getCurrentFuncFirstLineStreamSym()) {
+ MCSymbol *LineStreamLabel = MCOS->getContext().createTempSymbol();
MCOS->emittedLineStreamSym(LineStreamLabel);
+ MCDwarfLineEntry LabelLineEntry(LineSym, DwarfLoc, LineStreamLabel);
+ MCOS->getContext()
+ .getMCDwarfLineTable(MCOS->getContext().getDwarfCompileUnitID())
+ .getMCLineSections()
+ .addLineEntry(LabelLineEntry, Section);
}
// Create a (local) line entry with the symbol and the current .loc info.
- MCDwarfLineEntry LineEntry(LineSym, DwarfLoc, LineStreamLabel);
+ MCDwarfLineEntry LineEntry(LineSym, DwarfLoc);
// clear DwarfLocSeen saying the current .loc info is now used.
MCOS->getContext().clearDwarfLocSeen();
@@ -154,8 +159,7 @@ makeStartPlusIntExpr(MCContext &Ctx, const MCSymbol &Start, int IntVal) {
return Res;
}
-void MCLineSection::addEndEntry(MCSymbol *EndLabel,
- bool generatingFuncLineTableOffsets) {
+void MCLineSection::addEndEntry(MCSymbol *EndLabel) {
auto *Sec = &EndLabel->getSection();
// The line table may be empty, which we should skip adding an end entry.
// There are two cases:
@@ -168,12 +172,8 @@ void MCLineSection::addEndEntry(MCSymbol *EndLabel,
if (I != MCLineDivisions.end()) {
auto &Entries = I->second;
auto EndEntry = Entries.back();
- // If generatingFuncLineTableOffsets is set, then we already generated an
- // end label at the end of the last function, so skip generating another one
- if (!generatingFuncLineTableOffsets) {
- EndEntry.setEndLabel(EndLabel);
- Entries.push_back(EndEntry);
- }
+ EndEntry.setEndLabel(EndLabel);
+ Entries.push_back(EndEntry);
}
}
diff --git a/llvm/test/DebugInfo/X86/DW_AT_LLVM_stmt_seq_sec_offset.ll b/llvm/test/DebugInfo/X86/DW_AT_LLVM_stmt_seq_sec_offset.ll
index ef8b0c817cfb67..d3bed46ab86be0 100644
--- a/llvm/test/DebugInfo/X86/DW_AT_LLVM_stmt_seq_sec_offset.ll
+++ b/llvm/test/DebugInfo/X86/DW_AT_LLVM_stmt_seq_sec_offset.ll
@@ -12,20 +12,20 @@
; STMT_SEQ: DW_AT_LLVM_stmt_sequence [DW_FORM_sec_offset] (0x00000028)
; STMT_SEQ: DW_AT_name {{.*}}func01
; STMT_SEQ: DW_TAG_subprogram [[[ABBREV_CODE]]]
-; STMT_SEQ: DW_AT_LLVM_stmt_sequence [DW_FORM_sec_offset] (0x00000033)
+; STMT_SEQ: DW_AT_LLVM_stmt_sequence [DW_FORM_sec_offset] (0x00000036)
; STMT_SEQ: DW_AT_name {{.*}}main
;; Check that the line table starts at 0x00000028 (first function)
; STMT_SEQ: Address Line Column File ISA Discriminator OpIndex Flags
; STMT_SEQ-NEXT: ------------------ ------ ------ ------ --- ------------- ------- -------------
-; STMT_SEQ-NEXT: 0x00000028: 00 DW_LNE_set_address (0x00000006)
+; STMT_SEQ-NEXT: 0x00000028: 05 DW_LNS_set_column (3)
-;; Check that we have an 'end_sequence' just before the next function (0x00000033)
-; STMT_SEQ: 0x0000000000000006 1 0 1 0 0 0 is_stmt end_sequence
-; STMT_SEQ-NEXT: 0x00000033: 00 DW_LNE_set_address (0x00000027)
+;; Check that we have an 'end_sequence' just before the next function (0x00000036)
+; STMT_SEQ: 0x0000000000000000 2 3 1 0 0 0 is_stmt end_sequence
+; STMT_SEQ-NEXT: 0x00000036: 00 DW_LNE_set_address (0x00000010)
;; Check that the end of the line table still has an 'end_sequence'
-; STMT_SEQ 0x00000049: 00 DW_LNE_end_sequence
+; STMT_SEQ 0x00000047: 00 DW_LNE_end_sequence
; STMT_SEQ-NEXT 0x0000000000000027 6 3 1 0 0 0 end_sequence
>From ab07e40dd701e874ba6bb7bfb5a719e5c68ffa9e Mon Sep 17 00:00:00 2001
From: Alex B <alexborcan at meta.com>
Date: Tue, 5 Nov 2024 14:31:53 -0800
Subject: [PATCH 3/4] More comprehensive test
---
.../X86/DW_AT_LLVM_stmt_seq_sec_offset.ll | 163 +++++++++++-------
1 file changed, 102 insertions(+), 61 deletions(-)
diff --git a/llvm/test/DebugInfo/X86/DW_AT_LLVM_stmt_seq_sec_offset.ll b/llvm/test/DebugInfo/X86/DW_AT_LLVM_stmt_seq_sec_offset.ll
index d3bed46ab86be0..58f6495924b90c 100644
--- a/llvm/test/DebugInfo/X86/DW_AT_LLVM_stmt_seq_sec_offset.ll
+++ b/llvm/test/DebugInfo/X86/DW_AT_LLVM_stmt_seq_sec_offset.ll
@@ -1,82 +1,123 @@
-; RUN: llc -mtriple=i686-w64-mingw32 -o %t -filetype=obj %s
-; RUN: llvm-dwarfdump -v -all %t | FileCheck %s -check-prefix=NO_STMT_SEQ
+; RUN: llc -O3 -mtriple=i686-w64-mingw32 -o %t_no -filetype=obj %s
+; RUN: llvm-dwarfdump -v -all %t_no | FileCheck %s -check-prefix=NO_STMT_SEQ
-; RUN: llc -mtriple=i686-w64-mingw32 -o %t -filetype=obj %s -emit-func-debug-line-table-offsets
-; RUN: llvm-dwarfdump -v -all %t | FileCheck %s -check-prefix=STMT_SEQ
+; RUN: llc -O3 -mtriple=i686-w64-mingw32 -o %t_yes -filetype=obj %s -emit-func-debug-line-table-offsets
+; RUN: llvm-dwarfdump -v -all %t_yes | FileCheck %s -check-prefix=STMT_SEQ
; NO_STMT_SEQ-NOT: DW_AT_LLVM_stmt_sequence
-; STMT_SEQ: [[[ABBREV_CODE:[0-9]+]]] DW_TAG_subprogram
+; STMT_SEQ: [[[ABBREV_CODE1:[0-9]+]]] DW_TAG_subprogram
; STMT_SEQ: DW_AT_LLVM_stmt_sequence DW_FORM_sec_offset
-; STMT_SEQ: DW_TAG_subprogram [[[ABBREV_CODE]]]
-; STMT_SEQ: DW_AT_LLVM_stmt_sequence [DW_FORM_sec_offset] (0x00000028)
+; STMT_SEQ: [[[ABBREV_CODE2:[0-9]+]]] DW_TAG_subprogram
+; STMT_SEQ: DW_AT_LLVM_stmt_sequence DW_FORM_sec_offset
+; STMT_SEQ: DW_TAG_subprogram [[[ABBREV_CODE1]]]
+; STMT_SEQ: DW_AT_LLVM_stmt_sequence [DW_FORM_sec_offset] (0x00000043)
; STMT_SEQ: DW_AT_name {{.*}}func01
-; STMT_SEQ: DW_TAG_subprogram [[[ABBREV_CODE]]]
-; STMT_SEQ: DW_AT_LLVM_stmt_sequence [DW_FORM_sec_offset] (0x00000036)
+; STMT_SEQ: DW_TAG_subprogram [[[ABBREV_CODE2]]]
+; STMT_SEQ: DW_AT_LLVM_stmt_sequence [DW_FORM_sec_offset] (0x00000056)
; STMT_SEQ: DW_AT_name {{.*}}main
-;; Check that the line table starts at 0x00000028 (first function)
-; STMT_SEQ: Address Line Column File ISA Discriminator OpIndex Flags
-; STMT_SEQ-NEXT: ------------------ ------ ------ ------ --- ------------- ------- -------------
-; STMT_SEQ-NEXT: 0x00000028: 05 DW_LNS_set_column (3)
-
-;; Check that we have an 'end_sequence' just before the next function (0x00000036)
-; STMT_SEQ: 0x0000000000000000 2 3 1 0 0 0 is_stmt end_sequence
-; STMT_SEQ-NEXT: 0x00000036: 00 DW_LNE_set_address (0x00000010)
-
-;; Check that the end of the line table still has an 'end_sequence'
-; STMT_SEQ 0x00000047: 00 DW_LNE_end_sequence
-; STMT_SEQ-NEXT 0x0000000000000027 6 3 1 0 0 0 end_sequence
-
+;; Check the entire line sequence to see that it's correct
+; STMT_SEQ: Address Line Column File ISA Discriminator OpIndex Flags
+; STMT_SEQ-NEXT: ------------------ ------ ------ ------ --- ------------- ------- -------------
+; STMT_SEQ-NEXT: 0x00000043: 04 DW_LNS_set_file (0)
+; STMT_SEQ-NEXT: 0x00000045: 05 DW_LNS_set_column (9)
+; STMT_SEQ-NEXT: 0x00000047: 0a DW_LNS_set_prologue_end
+; STMT_SEQ-NEXT: 0x00000048: 00 DW_LNE_set_address (0x00000000)
+; STMT_SEQ-NEXT: 0x0000004f: 16 address += 0, line += 4, op-index += 0
+; STMT_SEQ-NEXT: 0x0000000000000000 5 9 0 0 0 0 is_stmt prologue_end
+; STMT_SEQ-NEXT: 0x00000050: 05 DW_LNS_set_column (3)
+; STMT_SEQ-NEXT: 0x00000052: 67 address += 6, line += 1, op-index += 0
+; STMT_SEQ-NEXT: 0x0000000000000006 6 3 0 0 0 0 is_stmt
+; STMT_SEQ-NEXT: 0x00000053: 00 DW_LNE_end_sequence
+; STMT_SEQ-NEXT: 0x0000000000000006 6 3 0 0 0 0 is_stmt end_sequence
+; STMT_SEQ-NEXT: 0x00000056: 04 DW_LNS_set_file (0)
+; STMT_SEQ-NEXT: 0x00000058: 00 DW_LNE_set_address (0x00000008)
+; STMT_SEQ-NEXT: 0x0000005f: 03 DW_LNS_advance_line (10)
+; STMT_SEQ-NEXT: 0x00000061: 01 DW_LNS_copy
+; STMT_SEQ-NEXT: 0x0000000000000008 10 0 0 0 0 0 is_stmt
+; STMT_SEQ-NEXT: 0x00000062: 05 DW_LNS_set_column (10)
+; STMT_SEQ-NEXT: 0x00000064: 0a DW_LNS_set_prologue_end
+; STMT_SEQ-NEXT: 0x00000065: 83 address += 8, line += 1, op-index += 0
+; STMT_SEQ-NEXT: 0x0000000000000010 11 10 0 0 0 0 is_stmt prologue_end
+; STMT_SEQ-NEXT: 0x00000066: 05 DW_LNS_set_column (3)
+; STMT_SEQ-NEXT: 0x00000068: 9f address += 10, line += 1, op-index += 0
+; STMT_SEQ-NEXT: 0x000000000000001a 12 3 0 0 0 0 is_stmt
+; STMT_SEQ-NEXT: 0x00000069: 02 DW_LNS_advance_pc (addr += 5, op-index += 0)
+; STMT_SEQ-NEXT: 0x0000006b: 00 DW_LNE_end_sequence
+; STMT_SEQ-NEXT: 0x000000000000001f 12 3 0 0 0 0 is_stmt end_sequence
; generated from:
-; clang -g -S -emit-llvm test.c -o test.ll
+; clang -Oz -g -S -emit-llvm test.c -o test.ll
; ======= test.c ======
-; int func01() {
+; volatile int g_var1 = 1;
+; #define ATTR __attribute__((noinline))
+; ATTR int func01() {
+; g_var1++;
+; func01();
; return 1;
; }
-; int main() {
-; return 0;
+; ATTR int main() {
+; g_var1 = 100;
+; func01();
+; g_var1--;
+; return g_var1;
; }
; =====================
; ModuleID = 'test.c'
source_filename = "test.c"
-target datalayout = "e-m:o-i64:64-i128:128-n32:64-S128"
-target triple = "arm64-apple-macosx14.0.0"
-
-; Function Attrs: noinline nounwind optnone ssp uwtable(sync)
-define i32 @func01() #0 !dbg !9 {
- ret i32 1, !dbg !13
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+ at g_var1 = dso_local global i32 1, align 4, !dbg !0
+; Function Attrs: minsize nofree noinline norecurse noreturn nounwind optsize memory(readwrite, argmem: none) uwtable
+define dso_local noundef i32 @func01() local_unnamed_addr #0 !dbg !14 {
+entry:
+ br label %tailrecurse
+tailrecurse: ; preds = %tailrecurse, %entry
+ %0 = load volatile i32, ptr @g_var1, align 4, !dbg !17, !tbaa !18
+ %inc = add nsw i32 %0, 1, !dbg !17
+ store volatile i32 %inc, ptr @g_var1, align 4, !dbg !17, !tbaa !18
+ br label %tailrecurse, !dbg !22
}
-
-; Function Attrs: noinline nounwind optnone ssp uwtable(sync)
-define i32 @main() #0 !dbg !14 {
- %1 = alloca i32, align 4
- store i32 0, ptr %1, align 4
- ret i32 0, !dbg !15
+; Function Attrs: minsize nofree noinline norecurse noreturn nounwind optsize uwtable
+define dso_local noundef i32 @main() local_unnamed_addr #1 !dbg !23 {
+entry:
+ store volatile i32 100, ptr @g_var1, align 4, !dbg !24, !tbaa !18
+ %call = tail call i32 @func01() #2, !dbg !25
+ unreachable, !dbg !26
}
-
-attributes #0 = { noinline nounwind optnone ssp uwtable(sync) "frame-pointer"="non-leaf" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="apple-m1" "target-features"="+aes,+crc,+dotprod,+fp-armv8,+fp16fml,+fullfp16,+lse,+neon,+ras,+rcpc,+rdm,+sha2,+sha3,+v8.1a,+v8.2a,+v8.3a,+v8.4a,+v8.5a,+v8a,+zcm,+zcz" }
-
-!llvm.dbg.cu = !{!0}
-!llvm.module.flags = !{!2, !3, !4, !5, !6, !7}
-!llvm.ident = !{!8}
-
-!0 = distinct !DICompileUnit(language: DW_LANG_C11, file: !1, producer: "Homebrew clang version 17.0.6", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, splitDebugInlining: false, nameTableKind: Apple, sysroot: "/Library/Developer/CommandLineTools/SDKs/MacOSX14.sdk", sdk: "MacOSX14.sdk")
-!1 = !DIFile(filename: "test.c", directory: "/tmp/clang_test")
-!2 = !{i32 7, !"Dwarf Version", i32 4}
-!3 = !{i32 2, !"Debug Info Version", i32 3}
-!4 = !{i32 1, !"wchar_size", i32 4}
-!5 = !{i32 8, !"PIC Level", i32 2}
-!6 = !{i32 7, !"uwtable", i32 1}
-!7 = !{i32 7, !"frame-pointer", i32 1}
-!8 = !{!"Homebrew clang version 17.0.6"}
-!9 = distinct !DISubprogram(name: "func01", scope: !1, file: !1, line: 1, type: !10, scopeLine: 1, spFlags: DISPFlagDefinition, unit: !0)
-!10 = !DISubroutineType(types: !11)
-!11 = !{!12}
-!12 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
-!13 = !DILocation(line: 2, column: 3, scope: !9)
-!14 = distinct !DISubprogram(name: "main", scope: !1, file: !1, line: 5, type: !10, scopeLine: 5, spFlags: DISPFlagDefinition, unit: !0)
-!15 = !DILocation(line: 6, column: 3, scope: !14)
+attributes #0 = { minsize nofree noinline norecurse noreturn nounwind optsize memory(readwrite, argmem: none) uwtable "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cmov,+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
+attributes #1 = { minsize nofree noinline norecurse noreturn nounwind optsize uwtable "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cmov,+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
+attributes #2 = { minsize optsize }
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!7, !8, !9, !10, !11, !12}
+!llvm.ident = !{!13}
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "g_var1", scope: !2, file: !3, line: 1, type: !5, isLocal: false, isDefinition: true)
+!2 = distinct !DICompileUnit(language: DW_LANG_C11, file: !3, producer: "clang version 20.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, globals: !4, splitDebugInlining: false, nameTableKind: None)
+!3 = !DIFile(filename: "test.c", directory: "/tmp/tst", checksumkind: CSK_MD5, checksum: "eee003eb3c4fd0a1ff078d3148679e06")
+!4 = !{!0}
+!5 = !DIDerivedType(tag: DW_TAG_volatile_type, baseType: !6)
+!6 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!7 = !{i32 7, !"Dwarf Version", i32 5}
+!8 = !{i32 2, !"Debug Info Version", i32 3}
+!9 = !{i32 1, !"wchar_size", i32 4}
+!10 = !{i32 8, !"PIC Level", i32 2}
+!11 = !{i32 7, !"PIE Level", i32 2}
+!12 = !{i32 7, !"uwtable", i32 2}
+!13 = !{!"clang version 20.0.0"}
+!14 = distinct !DISubprogram(name: "func01", scope: !3, file: !3, line: 4, type: !15, scopeLine: 4, flags: DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !2)
+!15 = !DISubroutineType(types: !16)
+!16 = !{!6}
+!17 = !DILocation(line: 5, column: 9, scope: !14)
+!18 = !{!19, !19, i64 0}
+!19 = !{!"int", !20, i64 0}
+!20 = !{!"omnipotent char", !21, i64 0}
+!21 = !{!"Simple C/C++ TBAA"}
+!22 = !DILocation(line: 6, column: 3, scope: !14)
+!23 = distinct !DISubprogram(name: "main", scope: !3, file: !3, line: 10, type: !15, scopeLine: 10, flags: DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !2)
+!24 = !DILocation(line: 11, column: 10, scope: !23)
+!25 = !DILocation(line: 12, column: 3, scope: !23)
+!26 = !DILocation(line: 13, column: 9, scope: !23)
>From 9d8003d9174426549d8732f64b5c77cd1e51fbe6 Mon Sep 17 00:00:00 2001
From: Alex B <alexborcan at meta.com>
Date: Tue, 12 Nov 2024 18:03:22 -0800
Subject: [PATCH 4/4] Reimplement with better encapsulation
---
llvm/include/llvm/MC/MCStreamer.h | 27 +------------------
.../CodeGen/AsmPrinter/DwarfCompileUnit.cpp | 24 ++++++++++++-----
.../lib/CodeGen/AsmPrinter/DwarfCompileUnit.h | 14 +++++-----
llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp | 22 ++++++---------
llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h | 3 +++
llvm/lib/MC/MCDwarf.cpp | 14 ----------
llvm/lib/MC/MCStreamer.cpp | 14 ++++++++++
7 files changed, 51 insertions(+), 67 deletions(-)
diff --git a/llvm/include/llvm/MC/MCStreamer.h b/llvm/include/llvm/MC/MCStreamer.h
index 5aabb0a61ac3d7..ee23751527d650 100644
--- a/llvm/include/llvm/MC/MCStreamer.h
+++ b/llvm/include/llvm/MC/MCStreamer.h
@@ -251,15 +251,6 @@ class MCStreamer {
/// discussion for future inclusion.
bool AllowAutoPadding = false;
- // Flag specifying weather functions will have an offset into the line table
- // where the line data for that function starts
- bool GenerateFuncLineTableOffsets = false;
-
- // Symbol that tracks the stream symbol for first line of the current function
- // being generated. This symbol can be used to reference where the line
- // entries for the function start in the generated line table.
- MCSymbol *CurrentFuncFirstLineStreamSym;
-
protected:
MCFragment *CurFrag = nullptr;
@@ -322,23 +313,7 @@ class MCStreamer {
void setAllowAutoPadding(bool v) { AllowAutoPadding = v; }
bool getAllowAutoPadding() const { return AllowAutoPadding; }
- void setGenerateFuncLineTableOffsets(bool v) {
- GenerateFuncLineTableOffsets = v;
- }
- bool getGenerateFuncLineTableOffsets() const {
- return GenerateFuncLineTableOffsets;
- }
-
- // Use the below functions to track the symbol that points to the current
- // function's line info in the output stream.
- void beginFunction() { CurrentFuncFirstLineStreamSym = nullptr; }
- void emittedLineStreamSym(MCSymbol *StreamSym) {
- if (!CurrentFuncFirstLineStreamSym)
- CurrentFuncFirstLineStreamSym = StreamSym;
- }
- MCSymbol *getCurrentFuncFirstLineStreamSym() {
- return CurrentFuncFirstLineStreamSym;
- }
+ MCSymbol *emitLineTableLabel();
/// When emitting an object file, create and emit a real label. When emitting
/// textual assembly, this should do nothing to avoid polluting our output.
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
index 5e6fdc8486b6e5..2f96366b78e97d 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
@@ -49,6 +49,12 @@ cl::opt<cl::boolOrDefault> AddLinkageNamesToDeclCallOrigins(
"referenced by DW_AT_call_origin attributes. Enabled by default "
"for -gsce debugger tuning."));
+static cl::opt<bool> EmitFuncLineTableOffsetsOption(
+ "emit-func-debug-line-table-offsets", cl::Hidden,
+ cl::desc("Include line table offset in function's debug info and emit end "
+ "sequence after each function's line data."),
+ cl::init(false));
+
static bool AddLinkageNamesToDeclCallOriginsForTuning(const DwarfDebug *DD) {
bool EnabledByDefault = DD->tuneForSCE();
if (EnabledByDefault)
@@ -511,7 +517,8 @@ void DwarfCompileUnit::addWasmRelocBaseGlobal(DIELoc *Loc, StringRef GlobalName,
// Find DIE for the given subprogram and attach appropriate DW_AT_low_pc
// and DW_AT_high_pc attributes. If there are global variables in this
// scope then create and insert DIEs for these variables.
-DIE &DwarfCompileUnit::updateSubprogramScopeDIE(const DISubprogram *SP) {
+DIE &DwarfCompileUnit::updateSubprogramScopeDIE(const DISubprogram *SP,
+ MCSymbol *LineTableSym) {
DIE *SPDie = getOrCreateSubprogramDIE(SP, includeMinimalInlineScopes());
SmallVector<RangeSpan, 2> BB_List;
// If basic block sections are on, ranges for each basic block section has
@@ -526,11 +533,9 @@ DIE &DwarfCompileUnit::updateSubprogramScopeDIE(const DISubprogram *SP) {
*DD->getCurrentFunction()))
addFlag(*SPDie, dwarf::DW_AT_APPLE_omit_frame_ptr);
- if (Asm->OutStreamer->getGenerateFuncLineTableOffsets() &&
- Asm->OutStreamer->getCurrentFuncFirstLineStreamSym()) {
+ if (emitFuncLineTableOffsets() && LineTableSym) {
addSectionLabel(
- *SPDie, dwarf::DW_AT_LLVM_stmt_sequence,
- Asm->OutStreamer->getCurrentFuncFirstLineStreamSym(),
+ *SPDie, dwarf::DW_AT_LLVM_stmt_sequence, LineTableSym,
Asm->getObjFileLowering().getDwarfLineSection()->getBeginSymbol());
}
@@ -1104,8 +1109,9 @@ sortLocalVars(SmallVectorImpl<DbgVariable *> &Input) {
}
DIE &DwarfCompileUnit::constructSubprogramScopeDIE(const DISubprogram *Sub,
- LexicalScope *Scope) {
- DIE &ScopeDIE = updateSubprogramScopeDIE(Sub);
+ LexicalScope *Scope,
+ MCSymbol *LineTableSym) {
+ DIE &ScopeDIE = updateSubprogramScopeDIE(Sub, LineTableSym);
if (Scope) {
assert(!Scope->getInlinedAt());
@@ -1699,6 +1705,10 @@ bool DwarfCompileUnit::includeMinimalInlineScopes() const {
(DD->useSplitDwarf() && !Skeleton);
}
+bool DwarfCompileUnit::emitFuncLineTableOffsets() const {
+ return EmitFuncLineTableOffsetsOption;
+}
+
void DwarfCompileUnit::addAddrTableBase() {
const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
MCSymbol *Label = DD->getAddressPool().getLabel();
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.h b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.h
index 76584b3eb8e78d..104039db03c7ca 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.h
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.h
@@ -152,6 +152,8 @@ class DwarfCompileUnit final : public DwarfUnit {
bool includeMinimalInlineScopes() const;
+ bool emitFuncLineTableOffsets() const;
+
void initStmtList();
/// Apply the DW_AT_stmt_list from this compile unit to the specified DIE.
@@ -207,10 +209,10 @@ class DwarfCompileUnit final : public DwarfUnit {
void attachLowHighPC(DIE &D, const MCSymbol *Begin, const MCSymbol *End);
/// Find DIE for the given subprogram and attach appropriate
- /// DW_AT_low_pc and DW_AT_high_pc attributes. If there are global
- /// variables in this scope then create and insert DIEs for these
- /// variables.
- DIE &updateSubprogramScopeDIE(const DISubprogram *SP);
+ /// DW_AT_low_pc, DW_AT_high_pc and DW_AT_LLVM_stmt_sequence attributes.
+ /// If there are global variables in this scope then create and insert DIEs
+ /// for these variables.
+ DIE &updateSubprogramScopeDIE(const DISubprogram *SP, MCSymbol *LineTableSym);
void constructScopeDIE(LexicalScope *Scope, DIE &ParentScopeDIE);
@@ -254,8 +256,8 @@ class DwarfCompileUnit final : public DwarfUnit {
DIE *getOrCreateContextDIE(const DIScope *Ty) override;
/// Construct a DIE for this subprogram scope.
- DIE &constructSubprogramScopeDIE(const DISubprogram *Sub,
- LexicalScope *Scope);
+ DIE &constructSubprogramScopeDIE(const DISubprogram *Sub, LexicalScope *Scope,
+ MCSymbol *LineTableSym);
DIE *createAndAddScopeChildren(LexicalScope *Scope, DIE &ScopeDIE);
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 54237309b7ec99..b347fe09d48ee7 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -170,12 +170,6 @@ static cl::opt<DwarfDebug::MinimizeAddrInV5> MinimizeAddrInV5Option(
"Stuff")),
cl::init(DwarfDebug::MinimizeAddrInV5::Default));
-static cl::opt<bool> EmitFuncLineTableOffsetsOption(
- "emit-func-debug-line-table-offsets", cl::Hidden,
- cl::desc("Include line table offset in function's debug info and emit end "
- "sequence after each function's line data."),
- cl::init(false));
-
static constexpr unsigned ULEB128PadSize = 4;
void DebugLocDwarfExpression::emitOp(uint8_t Op, const char *Comment) {
@@ -447,8 +441,6 @@ DwarfDebug::DwarfDebug(AsmPrinter *A)
Asm->OutStreamer->getContext().setDwarfVersion(DwarfVersion);
Asm->OutStreamer->getContext().setDwarfFormat(Dwarf64 ? dwarf::DWARF64
: dwarf::DWARF32);
- Asm->OutStreamer->setGenerateFuncLineTableOffsets(
- EmitFuncLineTableOffsetsOption);
}
// Define out of line so we don't have to include DwarfUnit.h in DwarfDebug.h.
@@ -2230,11 +2222,10 @@ void DwarfDebug::beginFunctionImpl(const MachineFunction *MF) {
if (SP->getUnit()->getEmissionKind() == DICompileUnit::NoDebug)
return;
- // Notify the streamer that we are beginning a function - this will reset the
- // label pointing to the currently generated function's first line entry
- Asm->OutStreamer->beginFunction();
-
DwarfCompileUnit &CU = getOrCreateDwarfCompileUnit(SP->getUnit());
+ FunctionLineTableLabel = CU.emitFuncLineTableOffsets()
+ ? Asm->OutStreamer->emitLineTableLabel()
+ : nullptr;
Asm->OutStreamer->getContext().setDwarfCompileUnitID(
getDwarfCompileUnitIDForLineTable(CU));
@@ -2346,11 +2337,14 @@ void DwarfDebug::endFunctionImpl(const MachineFunction *MF) {
}
ProcessedSPNodes.insert(SP);
- DIE &ScopeDIE = TheCU.constructSubprogramScopeDIE(SP, FnScope);
+ DIE &ScopeDIE =
+ TheCU.constructSubprogramScopeDIE(SP, FnScope, FunctionLineTableLabel);
if (auto *SkelCU = TheCU.getSkeleton())
if (!LScopes.getAbstractScopesList().empty() &&
TheCU.getCUNode()->getSplitDebugInlining())
- SkelCU->constructSubprogramScopeDIE(SP, FnScope);
+ SkelCU->constructSubprogramScopeDIE(SP, FnScope, FunctionLineTableLabel);
+
+ FunctionLineTableLabel = nullptr;
// Construct call site entries.
constructCallSiteEntryDIEs(*SP, TheCU, ScopeDIE, *MF);
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
index 6ed03124a2626f..61d7049ffb0a11 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
@@ -408,6 +408,9 @@ class DwarfDebug : public DebugHandlerBase {
std::pair<std::unique_ptr<DwarfTypeUnit>, const DICompositeType *>, 1>
TypeUnitsUnderConstruction;
+ /// Symbol pointing to the current function's DWARF line table entries.
+ MCSymbol *FunctionLineTableLabel;
+
/// Used to set a uniqe ID for a Type Unit.
/// This counter represents number of DwarfTypeUnits created, not necessarily
/// number of type units that will be emitted.
diff --git a/llvm/lib/MC/MCDwarf.cpp b/llvm/lib/MC/MCDwarf.cpp
index 0b078f7bb0c523..e058358fb8ad4b 100644
--- a/llvm/lib/MC/MCDwarf.cpp
+++ b/llvm/lib/MC/MCDwarf.cpp
@@ -104,20 +104,6 @@ void MCDwarfLineEntry::make(MCStreamer *MCOS, MCSection *Section) {
// Get the current .loc info saved in the context.
const MCDwarfLoc &DwarfLoc = MCOS->getContext().getCurrentDwarfLoc();
- // If functions need offsets into the generated line table, then we need to
- // create a label referencing where the line was generated in the output
- // stream
- if (MCOS->getGenerateFuncLineTableOffsets() &&
- !MCOS->getCurrentFuncFirstLineStreamSym()) {
- MCSymbol *LineStreamLabel = MCOS->getContext().createTempSymbol();
- MCOS->emittedLineStreamSym(LineStreamLabel);
- MCDwarfLineEntry LabelLineEntry(LineSym, DwarfLoc, LineStreamLabel);
- MCOS->getContext()
- .getMCDwarfLineTable(MCOS->getContext().getDwarfCompileUnitID())
- .getMCLineSections()
- .addLineEntry(LabelLineEntry, Section);
- }
-
// Create a (local) line entry with the symbol and the current .loc info.
MCDwarfLineEntry LineEntry(LineSym, DwarfLoc);
diff --git a/llvm/lib/MC/MCStreamer.cpp b/llvm/lib/MC/MCStreamer.cpp
index 5474db1315f141..9c7d5658a7a34f 100644
--- a/llvm/lib/MC/MCStreamer.cpp
+++ b/llvm/lib/MC/MCStreamer.cpp
@@ -483,6 +483,20 @@ void MCStreamer::emitCFIEndProcImpl(MCDwarfFrameInfo &Frame) {
Frame.End = (MCSymbol *)1;
}
+MCSymbol *MCStreamer::emitLineTableLabel() {
+ // Create a label and insert it into the line table and return this label
+ const MCDwarfLoc &DwarfLoc = getContext().getCurrentDwarfLoc();
+
+ MCSymbol *LineStreamLabel = getContext().createTempSymbol();
+ MCDwarfLineEntry LabelLineEntry(nullptr, DwarfLoc, LineStreamLabel);
+ getContext()
+ .getMCDwarfLineTable(getContext().getDwarfCompileUnitID())
+ .getMCLineSections()
+ .addLineEntry(LabelLineEntry, getCurrentSectionOnly() /*Section*/);
+
+ return LineStreamLabel;
+}
+
MCSymbol *MCStreamer::emitCFILabel() {
// Return a dummy non-null value so that label fields appear filled in when
// generating textual assembly.
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