[llvm] [MC] Add .loc_label instruction (PR #99710)
via llvm-commits
llvm-commits at lists.llvm.org
Thu Aug 1 12:59:03 PDT 2024
https://github.com/alx32 updated https://github.com/llvm/llvm-project/pull/99710
>From 33d3ac6051dea8334fbc703bf045dd6844d5bbb4 Mon Sep 17 00:00:00 2001
From: Alex B <alexborcan at meta.com>
Date: Fri, 19 Jul 2024 14:24:35 -0700
Subject: [PATCH 1/4] [MC] Add .loc_label instruction
---
llvm/include/llvm/MC/MCDwarf.h | 10 +++-
llvm/include/llvm/MC/MCStreamer.h | 3 ++
llvm/lib/MC/MCAsmStreamer.cpp | 8 ++++
llvm/lib/MC/MCDwarf.cpp | 18 +++++++-
llvm/lib/MC/MCParser/AsmParser.cpp | 20 +++++++-
llvm/lib/MC/MCStreamer.cpp | 19 ++++++++
llvm/test/MC/ELF/debug-loc-label.s | 74 ++++++++++++++++++++++++++++++
7 files changed, 148 insertions(+), 4 deletions(-)
create mode 100644 llvm/test/MC/ELF/debug-loc-label.s
diff --git a/llvm/include/llvm/MC/MCDwarf.h b/llvm/include/llvm/MC/MCDwarf.h
index 7dba67efa22fa..2d54d51b3eb85 100644
--- a/llvm/include/llvm/MC/MCDwarf.h
+++ b/llvm/include/llvm/MC/MCDwarf.h
@@ -194,11 +194,17 @@ class MCDwarfLineEntry : public MCDwarfLoc {
public:
// Constructor to create an MCDwarfLineEntry given a symbol and the dwarf loc.
- MCDwarfLineEntry(MCSymbol *label, const MCDwarfLoc loc)
- : MCDwarfLoc(loc), Label(label) {}
+ MCDwarfLineEntry(MCSymbol *label, const MCDwarfLoc loc,
+ MCSymbol *lineStreamLabel = nullptr)
+ : MCDwarfLoc(loc), Label(label), LineStreamLabel(lineStreamLabel) {}
MCSymbol *getLabel() const { return Label; }
+ // This is the label that is to be emitted into the line stream. If this is
+ // non-null and we need to emit a label, also make sure to restart the current
+ // line sequence.
+ MCSymbol *LineStreamLabel;
+
// This indicates the line entry is synthesized for an end entry.
bool IsEndEntry = false;
diff --git a/llvm/include/llvm/MC/MCStreamer.h b/llvm/include/llvm/MC/MCStreamer.h
index 78aa12062102c..5fe4534d11d8e 100644
--- a/llvm/include/llvm/MC/MCStreamer.h
+++ b/llvm/include/llvm/MC/MCStreamer.h
@@ -912,6 +912,9 @@ class MCStreamer {
unsigned Isa, unsigned Discriminator,
StringRef FileName);
+ /// This implements the '.loc_label Name' directive.
+ virtual void emitDwarfLocLabelDirective(SMLoc Loc, StringRef Name);
+
/// Associate a filename with a specified logical file number, and also
/// specify that file's checksum information. This implements the '.cv_file 4
/// "foo.c"' assembler directive. Returns true on success.
diff --git a/llvm/lib/MC/MCAsmStreamer.cpp b/llvm/lib/MC/MCAsmStreamer.cpp
index 9309d5987dc94..36d7982d9a25d 100644
--- a/llvm/lib/MC/MCAsmStreamer.cpp
+++ b/llvm/lib/MC/MCAsmStreamer.cpp
@@ -301,6 +301,8 @@ class MCAsmStreamer final : public MCStreamer {
unsigned Flags, unsigned Isa,
unsigned Discriminator,
StringRef FileName) override;
+ virtual void emitDwarfLocLabelDirective(SMLoc Loc, StringRef Name) override;
+
MCSymbol *getDwarfLineTableSymbol(unsigned CUID) override;
bool emitCVFileDirective(unsigned FileNo, StringRef Filename,
@@ -1767,6 +1769,12 @@ void MCAsmStreamer::emitDwarfLocDirective(unsigned FileNo, unsigned Line,
Discriminator, FileName);
}
+void MCAsmStreamer::emitDwarfLocLabelDirective(SMLoc Loc, StringRef Name) {
+ MCStreamer::emitDwarfLocLabelDirective(Loc, Name);
+ OS << "\t.loc_label " << Name;
+ EmitEOL();
+}
+
MCSymbol *MCAsmStreamer::getDwarfLineTableSymbol(unsigned CUID) {
// Always use the zeroth line table, since asm syntax only supports one line
// table for now.
diff --git a/llvm/lib/MC/MCDwarf.cpp b/llvm/lib/MC/MCDwarf.cpp
index 1297dc3828b58..889e5ca6cab76 100644
--- a/llvm/lib/MC/MCDwarf.cpp
+++ b/llvm/lib/MC/MCDwarf.cpp
@@ -172,6 +172,7 @@ void MCDwarfLineTable::emitOne(
const MCLineSection::MCDwarfLineEntryCollection &LineEntries) {
unsigned FileNum, LastLine, Column, Flags, Isa, Discriminator;
+ bool IsAtStartSeq;
MCSymbol *LastLabel;
auto init = [&]() {
FileNum = 1;
@@ -181,6 +182,7 @@ void MCDwarfLineTable::emitOne(
Isa = 0;
Discriminator = 0;
LastLabel = nullptr;
+ IsAtStartSeq = true;
};
init();
@@ -189,11 +191,24 @@ void MCDwarfLineTable::emitOne(
for (const MCDwarfLineEntry &LineEntry : LineEntries) {
MCSymbol *Label = LineEntry.getLabel();
const MCAsmInfo *asmInfo = MCOS->getContext().getAsmInfo();
+
+ if (LineEntry.LineStreamLabel) {
+ if (!IsAtStartSeq) {
+ MCOS->emitDwarfLineEndEntry(Section, LastLabel);
+ init();
+ }
+ MCOS->emitLabel(LineEntry.LineStreamLabel);
+
+ IsAtStartSeq = true;
+ continue;
+ }
+
if (LineEntry.IsEndEntry) {
MCOS->emitDwarfAdvanceLineAddr(INT64_MAX, LastLabel, Label,
asmInfo->getCodePointerSize());
init();
EndEntryEmitted = true;
+ IsAtStartSeq = true;
continue;
}
@@ -243,6 +258,7 @@ void MCDwarfLineTable::emitOne(
Discriminator = 0;
LastLine = LineEntry.getLine();
LastLabel = Label;
+ IsAtStartSeq = false;
}
// Generate DWARF line end entry.
@@ -250,7 +266,7 @@ void MCDwarfLineTable::emitOne(
// table using ranges whenever CU or section changes. However, the MC path
// does not track ranges nor terminate the line table. In that case,
// conservatively use the section end symbol to end the line table.
- if (!EndEntryEmitted)
+ if (!EndEntryEmitted && !IsAtStartSeq)
MCOS->emitDwarfLineEndEntry(Section, LastLabel);
}
diff --git a/llvm/lib/MC/MCParser/AsmParser.cpp b/llvm/lib/MC/MCParser/AsmParser.cpp
index 1b9c624136e8b..50617a533ae56 100644
--- a/llvm/lib/MC/MCParser/AsmParser.cpp
+++ b/llvm/lib/MC/MCParser/AsmParser.cpp
@@ -485,6 +485,7 @@ class AsmParser : public MCAsmParser {
DK_FILE,
DK_LINE,
DK_LOC,
+ DK_LOC_LABEL,
DK_STABS,
DK_CV_FILE,
DK_CV_FUNC_ID,
@@ -580,10 +581,11 @@ class AsmParser : public MCAsmParser {
// ".align{,32}", ".p2align{,w,l}"
bool parseDirectiveAlign(bool IsPow2, unsigned ValueSize);
- // ".file", ".line", ".loc", ".stabs"
+ // ".file", ".line", ".loc", ".loc_label", ".stabs"
bool parseDirectiveFile(SMLoc DirectiveLoc);
bool parseDirectiveLine();
bool parseDirectiveLoc();
+ bool parseDirectiveLocLabel(SMLoc DirectiveLoc);
bool parseDirectiveStabs();
// ".cv_file", ".cv_func_id", ".cv_inline_site_id", ".cv_loc", ".cv_linetable",
@@ -2156,6 +2158,8 @@ bool AsmParser::parseStatement(ParseStatementInfo &Info,
return parseDirectiveLine();
case DK_LOC:
return parseDirectiveLoc();
+ case DK_LOC_LABEL:
+ return parseDirectiveLocLabel(IDLoc);
case DK_STABS:
return parseDirectiveStabs();
case DK_CV_FILE:
@@ -3733,6 +3737,19 @@ bool AsmParser::parseDirectiveLoc() {
return false;
}
+/// parseDirectiveLoc
+/// ::= .loc_label label
+bool AsmParser::parseDirectiveLocLabel(SMLoc DirectiveLoc) {
+ StringRef Name;
+ DirectiveLoc = Lexer.getLoc();
+ if (parseIdentifier(Name))
+ return TokError("expected identifier");
+ if (parseEOL())
+ return true;
+ getStreamer().emitDwarfLocLabelDirective(DirectiveLoc, Name);
+ return false;
+}
+
/// parseDirectiveStabs
/// ::= .stabs string, number, number, number
bool AsmParser::parseDirectiveStabs() {
@@ -5541,6 +5558,7 @@ void AsmParser::initializeDirectiveKindMap() {
DirectiveKindMap[".file"] = DK_FILE;
DirectiveKindMap[".line"] = DK_LINE;
DirectiveKindMap[".loc"] = DK_LOC;
+ DirectiveKindMap[".loc_label"] = DK_LOC_LABEL;
DirectiveKindMap[".stabs"] = DK_STABS;
DirectiveKindMap[".cv_file"] = DK_CV_FILE;
DirectiveKindMap[".cv_func_id"] = DK_CV_FUNC_ID;
diff --git a/llvm/lib/MC/MCStreamer.cpp b/llvm/lib/MC/MCStreamer.cpp
index 1594bd3231abe..d5f323129c4dd 100644
--- a/llvm/lib/MC/MCStreamer.cpp
+++ b/llvm/lib/MC/MCStreamer.cpp
@@ -267,6 +267,25 @@ void MCStreamer::emitDwarfLocDirective(unsigned FileNo, unsigned Line,
Discriminator);
}
+void MCStreamer::emitDwarfLocLabelDirective(SMLoc Loc, StringRef Name) {
+ auto &ctx = getContext();
+
+ auto *LineStreamLabel = ctx.getOrCreateSymbol(Name);
+
+ auto *LineSym = ctx.createTempSymbol();
+ const MCDwarfLoc &DwarfLoc = ctx.getCurrentDwarfLoc();
+
+ // Create a 'fake' line entry by having LineStreamLabel be non-null. This
+ // won't actually emit any line information, it will reset the line table
+ // sequence and emit a label at the start of the new line table sequence.
+ MCDwarfLineEntry LineEntry(LineSym, DwarfLoc, LineStreamLabel);
+
+ // Add the line entry to this section's entries.
+ ctx.getMCDwarfLineTable(ctx.getDwarfCompileUnitID())
+ .getMCLineSections()
+ .addLineEntry(LineEntry, getCurrentSectionOnly());
+}
+
MCSymbol *MCStreamer::getDwarfLineTableSymbol(unsigned CUID) {
MCDwarfLineTable &Table = getContext().getMCDwarfLineTable(CUID);
if (!Table.getLabel()) {
diff --git a/llvm/test/MC/ELF/debug-loc-label.s b/llvm/test/MC/ELF/debug-loc-label.s
new file mode 100644
index 0000000000000..dabf470d417cc
--- /dev/null
+++ b/llvm/test/MC/ELF/debug-loc-label.s
@@ -0,0 +1,74 @@
+// Verify that the .loc_label instruction resets the line sequence and generates
+// the requested label at the correct position in the line stream
+
+// RUN: llvm-mc -filetype obj -triple x86_64-linux-elf %s -o %t.o
+// RUN: llvm-objdump -d %t.o | FileCheck %s --check-prefix=CHECK-ASM
+// RUN: llvm-dwarfdump -v --debug-line %t.o | FileCheck %s --check-prefix=CHECK-LINE-TABLE
+
+# CHECK-ASM: <foo>:
+# CHECK-ASM-NEXT: movq %rdx, 0x33
+# CHECK-ASM-NEXT: movq %rax, 0x3b
+# CHECK-ASM-NEXT: movq %rbx, 0x4e
+# CHECK-ASM-NEXT: movq %rcx, 0x60
+# CHECK-ASM-NEXT: retq
+
+# CHECK-LINE-TABLE: Address Line Column File ISA Discriminator OpIndex Flags
+# CHECK-LINE-TABLE-NEXT: ------------------ ------ ------ ------ --- ------------- ------- -------------
+# CHECK-LINE-TABLE-NEXT: 0x00000028: 05 DW_LNS_set_column (1)
+# CHECK-LINE-TABLE-NEXT: 0x0000002a: 00 DW_LNE_set_address (0x0000000000000000)
+# CHECK-LINE-TABLE-NEXT: 0x00000035: 01 DW_LNS_copy
+# CHECK-LINE-TABLE-NEXT: 0x0000000000000000 1 1 1 0 0 0 is_stmt
+# CHECK-LINE-TABLE-NEXT: 0x00000036: 02 DW_LNS_advance_pc (addr += 33, op-index += 0)
+# CHECK-LINE-TABLE-NEXT: 0x00000038: 00 DW_LNE_end_sequence
+# CHECK-LINE-TABLE-NEXT: 0x0000000000000021 1 1 1 0 0 0 is_stmt end_sequence
+# CHECK-LINE-TABLE-NEXT: 0x0000003b: 05 DW_LNS_set_column (2)
+# CHECK-LINE-TABLE-NEXT: 0x0000003d: 00 DW_LNE_set_address (0x0000000000000008)
+# CHECK-LINE-TABLE-NEXT: 0x00000048: 01 DW_LNS_copy
+# CHECK-LINE-TABLE-NEXT: 0x0000000000000008 1 2 1 0 0 0 is_stmt
+# CHECK-LINE-TABLE-NEXT: 0x00000049: 02 DW_LNS_advance_pc (addr += 25, op-index += 0)
+# CHECK-LINE-TABLE-NEXT: 0x0000004b: 00 DW_LNE_end_sequence
+# CHECK-LINE-TABLE-NEXT: 0x0000000000000021 1 2 1 0 0 0 is_stmt end_sequence
+# CHECK-LINE-TABLE-NEXT: 0x0000004e: 05 DW_LNS_set_column (3)
+# CHECK-LINE-TABLE-NEXT: 0x00000050: 00 DW_LNE_set_address (0x0000000000000010)
+# CHECK-LINE-TABLE-NEXT: 0x0000005b: 01 DW_LNS_copy
+# CHECK-LINE-TABLE-NEXT: 0x0000000000000010 1 3 1 0 0 0 is_stmt
+# CHECK-LINE-TABLE-NEXT: 0x0000005c: 08 DW_LNS_const_add_pc (addr += 0x0000000000000011, op-index += 0)
+# CHECK-LINE-TABLE-NEXT: 0x0000005d: 00 DW_LNE_end_sequence
+# CHECK-LINE-TABLE-NEXT: 0x0000000000000021 1 3 1 0 0 0 is_stmt end_sequence
+# CHECK-LINE-TABLE-NEXT: 0x00000060: 05 DW_LNS_set_column (4)
+# CHECK-LINE-TABLE-NEXT: 0x00000062: 00 DW_LNE_set_address (0x0000000000000018)
+# CHECK-LINE-TABLE-NEXT: 0x0000006d: 01 DW_LNS_copy
+# CHECK-LINE-TABLE-NEXT: 0x0000000000000018 1 4 1 0 0 0 is_stmt
+# CHECK-LINE-TABLE-NEXT: 0x0000006e: 05 DW_LNS_set_column (5)
+# CHECK-LINE-TABLE-NEXT: 0x00000070: 01 DW_LNS_copy
+# CHECK-LINE-TABLE-NEXT: 0x0000000000000018 1 5 1 0 0 0 is_stmt
+# CHECK-LINE-TABLE-NEXT: 0x00000071: 02 DW_LNS_advance_pc (addr += 9, op-index += 0)
+# CHECK-LINE-TABLE-NEXT: 0x00000073: 00 DW_LNE_end_sequence
+# CHECK-LINE-TABLE-NEXT: 0x0000000000000021 1 5 1 0 0 0 is_stmt end_sequence
+ .text
+ .file "test.c"
+ .globl foo
+ .align 16, 0x90
+ .type foo, at function
+foo:
+.Lfunc_begin0:
+ .file 1 "test.c"
+ .cfi_startproc
+ .loc 1 1 1
+ mov %rdx, 0x33
+ .loc_label my_label_02
+ .loc 1 1 2
+ movq %rax, my_label_02-.Lline_table_start0
+ .loc 1 1 3
+ .loc_label my_label_03
+ .loc_label my_label_03.1
+ movq %rbx, my_label_03-.Lline_table_start0
+ .loc 1 1 4
+ .loc_label my_label_05
+ .loc 1 1 5
+ movq %rcx, my_label_05-.Lline_table_start0
+ ret
+ .cfi_endproc
+
+ .section .debug_line,"", at progbits
+.Lline_table_start0:
>From 2977fbc9e7b33eb05ece309ef1f8cb753093cc6e Mon Sep 17 00:00:00 2001
From: Alex B <alexborcan at meta.com>
Date: Mon, 29 Jul 2024 11:22:38 -0700
Subject: [PATCH 2/4] Address Feedback Nr.1
---
llvm/include/llvm/MC/MCDwarf.h | 13 +++++++++--
llvm/lib/MC/MCDwarf.cpp | 19 ++++++++++++++-
llvm/lib/MC/MCStreamer.cpp | 19 +++------------
llvm/test/MC/ELF/debug-loc-label.s | 37 ++++++++++++++++++++----------
4 files changed, 57 insertions(+), 31 deletions(-)
diff --git a/llvm/include/llvm/MC/MCDwarf.h b/llvm/include/llvm/MC/MCDwarf.h
index 2d54d51b3eb85..bea79545d1ab9 100644
--- a/llvm/include/llvm/MC/MCDwarf.h
+++ b/llvm/include/llvm/MC/MCDwarf.h
@@ -195,8 +195,10 @@ class MCDwarfLineEntry : public MCDwarfLoc {
public:
// Constructor to create an MCDwarfLineEntry given a symbol and the dwarf loc.
MCDwarfLineEntry(MCSymbol *label, const MCDwarfLoc loc,
- MCSymbol *lineStreamLabel = nullptr)
- : MCDwarfLoc(loc), Label(label), LineStreamLabel(lineStreamLabel) {}
+ MCSymbol *lineStreamLabel = nullptr,
+ SMLoc streamLabelDefLoc = {})
+ : MCDwarfLoc(loc), Label(label), LineStreamLabel(lineStreamLabel),
+ StreamLabelDefLoc(streamLabelDefLoc) {}
MCSymbol *getLabel() const { return Label; }
@@ -205,6 +207,10 @@ class MCDwarfLineEntry : public MCDwarfLoc {
// line sequence.
MCSymbol *LineStreamLabel;
+ // Location where LineStreamLabel was defined. If there is an error emitting
+ // LineStreamLabel, we can use the SMLoc to report an error.
+ SMLoc StreamLabelDefLoc;
+
// This indicates the line entry is synthesized for an end entry.
bool IsEndEntry = false;
@@ -371,6 +377,9 @@ class MCDwarfLineTable {
emitOne(MCStreamer *MCOS, MCSection *Section,
const MCLineSection::MCDwarfLineEntryCollection &LineEntries);
+ void endCurrentSeqAndEmitLineStreamLabel(MCStreamer *MCOS, SMLoc DefLoc,
+ StringRef Name);
+
Expected<unsigned> tryGetFile(StringRef &Directory, StringRef &FileName,
std::optional<MD5::MD5Result> Checksum,
std::optional<StringRef> Source,
diff --git a/llvm/lib/MC/MCDwarf.cpp b/llvm/lib/MC/MCDwarf.cpp
index 889e5ca6cab76..380475af8d1da 100644
--- a/llvm/lib/MC/MCDwarf.cpp
+++ b/llvm/lib/MC/MCDwarf.cpp
@@ -197,7 +197,7 @@ void MCDwarfLineTable::emitOne(
MCOS->emitDwarfLineEndEntry(Section, LastLabel);
init();
}
- MCOS->emitLabel(LineEntry.LineStreamLabel);
+ MCOS->emitLabel(LineEntry.LineStreamLabel, LineEntry.StreamLabelDefLoc);
IsAtStartSeq = true;
continue;
@@ -270,6 +270,23 @@ void MCDwarfLineTable::emitOne(
MCOS->emitDwarfLineEndEntry(Section, LastLabel);
}
+void MCDwarfLineTable::endCurrentSeqAndEmitLineStreamLabel(MCStreamer *MCOS,
+ SMLoc DefLoc,
+ StringRef Name) {
+ auto &ctx = MCOS->getContext();
+ auto *LineStreamLabel = ctx.getOrCreateSymbol(Name);
+ auto *LineSym = ctx.createTempSymbol();
+ const MCDwarfLoc &DwarfLoc = ctx.getCurrentDwarfLoc();
+
+ // Create a 'fake' line entry by having LineStreamLabel be non-null. This
+ // won't actually emit any line information, it will reset the line table
+ // sequence and emit a label at the start of the new line table sequence.
+ MCDwarfLineEntry LineEntry(LineSym, DwarfLoc, LineStreamLabel, DefLoc);
+
+ // Add the line entry to this section's entries.
+ getMCLineSections().addLineEntry(LineEntry, MCOS->getCurrentSectionOnly());
+}
+
//
// This emits the Dwarf file and the line tables.
//
diff --git a/llvm/lib/MC/MCStreamer.cpp b/llvm/lib/MC/MCStreamer.cpp
index d5f323129c4dd..13b162768578c 100644
--- a/llvm/lib/MC/MCStreamer.cpp
+++ b/llvm/lib/MC/MCStreamer.cpp
@@ -268,22 +268,9 @@ void MCStreamer::emitDwarfLocDirective(unsigned FileNo, unsigned Line,
}
void MCStreamer::emitDwarfLocLabelDirective(SMLoc Loc, StringRef Name) {
- auto &ctx = getContext();
-
- auto *LineStreamLabel = ctx.getOrCreateSymbol(Name);
-
- auto *LineSym = ctx.createTempSymbol();
- const MCDwarfLoc &DwarfLoc = ctx.getCurrentDwarfLoc();
-
- // Create a 'fake' line entry by having LineStreamLabel be non-null. This
- // won't actually emit any line information, it will reset the line table
- // sequence and emit a label at the start of the new line table sequence.
- MCDwarfLineEntry LineEntry(LineSym, DwarfLoc, LineStreamLabel);
-
- // Add the line entry to this section's entries.
- ctx.getMCDwarfLineTable(ctx.getDwarfCompileUnitID())
- .getMCLineSections()
- .addLineEntry(LineEntry, getCurrentSectionOnly());
+ getContext()
+ .getMCDwarfLineTable(getContext().getDwarfCompileUnitID())
+ .endCurrentSeqAndEmitLineStreamLabel(this, Loc, Name);
}
MCSymbol *MCStreamer::getDwarfLineTableSymbol(unsigned CUID) {
diff --git a/llvm/test/MC/ELF/debug-loc-label.s b/llvm/test/MC/ELF/debug-loc-label.s
index dabf470d417cc..b8a4e2d9463d2 100644
--- a/llvm/test/MC/ELF/debug-loc-label.s
+++ b/llvm/test/MC/ELF/debug-loc-label.s
@@ -2,15 +2,10 @@
// the requested label at the correct position in the line stream
// RUN: llvm-mc -filetype obj -triple x86_64-linux-elf %s -o %t.o
-// RUN: llvm-objdump -d %t.o | FileCheck %s --check-prefix=CHECK-ASM
// RUN: llvm-dwarfdump -v --debug-line %t.o | FileCheck %s --check-prefix=CHECK-LINE-TABLE
+// RUN: llvm-objdump -s -j .offset_02 -j .offset_03 -j .offset_05 %t.o | FileCheck %s --check-prefix=CHECK-SECTIONS
+
-# CHECK-ASM: <foo>:
-# CHECK-ASM-NEXT: movq %rdx, 0x33
-# CHECK-ASM-NEXT: movq %rax, 0x3b
-# CHECK-ASM-NEXT: movq %rbx, 0x4e
-# CHECK-ASM-NEXT: movq %rcx, 0x60
-# CHECK-ASM-NEXT: retq
# CHECK-LINE-TABLE: Address Line Column File ISA Discriminator OpIndex Flags
# CHECK-LINE-TABLE-NEXT: ------------------ ------ ------ ------ --- ------------- ------- -------------
@@ -45,6 +40,15 @@
# CHECK-LINE-TABLE-NEXT: 0x00000071: 02 DW_LNS_advance_pc (addr += 9, op-index += 0)
# CHECK-LINE-TABLE-NEXT: 0x00000073: 00 DW_LNE_end_sequence
# CHECK-LINE-TABLE-NEXT: 0x0000000000000021 1 5 1 0 0 0 is_stmt end_sequence
+
+# CHECK-SECTIONS: Contents of section .offset_02:
+# CHECK-SECTIONS-NEXT: 0000 3b000000
+
+# CHECK-SECTIONS: Contents of section .offset_03:
+# CHECK-SECTIONS-NEXT: 0000 4e000000
+
+# CHECK-SECTIONS: Contents of section .offset_05:
+# CHECK-SECTIONS-NEXT: 0000 60000000
.text
.file "test.c"
.globl foo
@@ -55,20 +59,29 @@ foo:
.file 1 "test.c"
.cfi_startproc
.loc 1 1 1
- mov %rdx, 0x33
+ mov %rax, 0x01
.loc_label my_label_02
.loc 1 1 2
- movq %rax, my_label_02-.Lline_table_start0
+ mov %rax, 0x02
.loc 1 1 3
.loc_label my_label_03
.loc_label my_label_03.1
- movq %rbx, my_label_03-.Lline_table_start0
+ mov %rax, 0x03
.loc 1 1 4
- .loc_label my_label_05
+ .loc_label my_label_04
.loc 1 1 5
- movq %rcx, my_label_05-.Lline_table_start0
+ mov %rax, 0x04
ret
.cfi_endproc
.section .debug_line,"", at progbits
.Lline_table_start0:
+
+ .section .offset_02,"", at progbits
+ .quad my_label_02-.Lline_table_start0
+
+ .section .offset_03,"", at progbits
+ .quad my_label_03-.Lline_table_start0
+
+ .section .offset_05,"", at progbits
+ .quad my_label_04-.Lline_table_start0
>From e1fbb1fad8a3f8ddf6d876af6bc8f0789f685169 Mon Sep 17 00:00:00 2001
From: Alex B <alexborcan at meta.com>
Date: Mon, 29 Jul 2024 12:57:06 -0700
Subject: [PATCH 3/4] Address Feedback Nr.2
---
llvm/lib/MC/MCDwarf.cpp | 3 ---
1 file changed, 3 deletions(-)
diff --git a/llvm/lib/MC/MCDwarf.cpp b/llvm/lib/MC/MCDwarf.cpp
index 380475af8d1da..19410cbeb4ca7 100644
--- a/llvm/lib/MC/MCDwarf.cpp
+++ b/llvm/lib/MC/MCDwarf.cpp
@@ -198,8 +198,6 @@ void MCDwarfLineTable::emitOne(
init();
}
MCOS->emitLabel(LineEntry.LineStreamLabel, LineEntry.StreamLabelDefLoc);
-
- IsAtStartSeq = true;
continue;
}
@@ -208,7 +206,6 @@ void MCDwarfLineTable::emitOne(
asmInfo->getCodePointerSize());
init();
EndEntryEmitted = true;
- IsAtStartSeq = true;
continue;
}
>From bf20a0c14fd5cdeba4e63028b2e56839f6c7d8be Mon Sep 17 00:00:00 2001
From: Alex B <alexborcan at meta.com>
Date: Thu, 1 Aug 2024 12:58:06 -0700
Subject: [PATCH 4/4] Correctly set end for end_sequence line entry
---
llvm/include/llvm/MC/MCObjectStreamer.h | 3 +-
llvm/include/llvm/MC/MCStreamer.h | 3 +-
llvm/lib/MC/MCAsmStreamer.cpp | 11 +++---
llvm/lib/MC/MCDwarf.cpp | 4 ++-
llvm/lib/MC/MCObjectStreamer.cpp | 8 +++--
llvm/test/MC/ELF/debug-loc-label.s | 47 ++++++++++++-------------
6 files changed, 41 insertions(+), 35 deletions(-)
diff --git a/llvm/include/llvm/MC/MCObjectStreamer.h b/llvm/include/llvm/MC/MCObjectStreamer.h
index 4241ec1e1881b..aaa13be6b2986 100644
--- a/llvm/include/llvm/MC/MCObjectStreamer.h
+++ b/llvm/include/llvm/MC/MCObjectStreamer.h
@@ -146,7 +146,8 @@ class MCObjectStreamer : public MCStreamer {
void emitDwarfAdvanceLineAddr(int64_t LineDelta, const MCSymbol *LastLabel,
const MCSymbol *Label,
unsigned PointerSize) override;
- void emitDwarfLineEndEntry(MCSection *Section, MCSymbol *LastLabel) override;
+ void emitDwarfLineEndEntry(MCSection *Section, MCSymbol *LastLabel,
+ MCSymbol *EndLabel = nullptr) override;
void emitDwarfAdvanceFrameAddr(const MCSymbol *LastLabel,
const MCSymbol *Label, SMLoc Loc);
void emitCVLocDirective(unsigned FunctionId, unsigned FileNo, unsigned Line,
diff --git a/llvm/include/llvm/MC/MCStreamer.h b/llvm/include/llvm/MC/MCStreamer.h
index 5fe4534d11d8e..24302822872de 100644
--- a/llvm/include/llvm/MC/MCStreamer.h
+++ b/llvm/include/llvm/MC/MCStreamer.h
@@ -1122,7 +1122,8 @@ class MCStreamer {
virtual void emitDwarfLineStartLabel(MCSymbol *StartSym);
/// Emit the debug line end entry.
- virtual void emitDwarfLineEndEntry(MCSection *Section, MCSymbol *LastLabel) {}
+ virtual void emitDwarfLineEndEntry(MCSection *Section, MCSymbol *LastLabel,
+ MCSymbol *EndLabel = nullptr) {}
/// If targets does not support representing debug line section by .loc/.file
/// directives in assembly output, we need to populate debug line section with
diff --git a/llvm/lib/MC/MCAsmStreamer.cpp b/llvm/lib/MC/MCAsmStreamer.cpp
index 36d7982d9a25d..351b759c528f4 100644
--- a/llvm/lib/MC/MCAsmStreamer.cpp
+++ b/llvm/lib/MC/MCAsmStreamer.cpp
@@ -431,7 +431,8 @@ class MCAsmStreamer final : public MCStreamer {
void emitDwarfLineStartLabel(MCSymbol *StartSym) override;
- void emitDwarfLineEndEntry(MCSection *Section, MCSymbol *LastLabel) override;
+ void emitDwarfLineEndEntry(MCSection *Section, MCSymbol *LastLabel,
+ MCSymbol *EndLabel = nullptr) override;
void emitDwarfAdvanceLineAddr(int64_t LineDelta, const MCSymbol *LastLabel,
const MCSymbol *Label,
@@ -2587,7 +2588,8 @@ void MCAsmStreamer::emitDwarfLineStartLabel(MCSymbol *StartSym) {
}
void MCAsmStreamer::emitDwarfLineEndEntry(MCSection *Section,
- MCSymbol *LastLabel) {
+ MCSymbol *LastLabel,
+ MCSymbol *EndLabel) {
// If the targets write the raw debug line data for assembly output (We can
// not switch to Section and add the end symbol there for assembly output)
// we currently use the .text end label as any section end. This will not
@@ -2604,9 +2606,10 @@ void MCAsmStreamer::emitDwarfLineEndEntry(MCSection *Section,
MCSection *TextSection = Ctx.getObjectFileInfo()->getTextSection();
assert(TextSection->hasEnded() && ".text section is not end!");
- MCSymbol *SectionEnd = TextSection->getEndSymbol(Ctx);
+ if (!EndLabel)
+ EndLabel = TextSection->getEndSymbol(Ctx);
const MCAsmInfo *AsmInfo = Ctx.getAsmInfo();
- emitDwarfAdvanceLineAddr(INT64_MAX, LastLabel, SectionEnd,
+ emitDwarfAdvanceLineAddr(INT64_MAX, LastLabel, EndLabel,
AsmInfo->getCodePointerSize());
}
diff --git a/llvm/lib/MC/MCDwarf.cpp b/llvm/lib/MC/MCDwarf.cpp
index 19410cbeb4ca7..20b3c00a38372 100644
--- a/llvm/lib/MC/MCDwarf.cpp
+++ b/llvm/lib/MC/MCDwarf.cpp
@@ -194,7 +194,8 @@ void MCDwarfLineTable::emitOne(
if (LineEntry.LineStreamLabel) {
if (!IsAtStartSeq) {
- MCOS->emitDwarfLineEndEntry(Section, LastLabel);
+ MCOS->emitDwarfLineEndEntry(Section, LastLabel,
+ /*EndLabel =*/LastLabel);
init();
}
MCOS->emitLabel(LineEntry.LineStreamLabel, LineEntry.StreamLabelDefLoc);
@@ -273,6 +274,7 @@ void MCDwarfLineTable::endCurrentSeqAndEmitLineStreamLabel(MCStreamer *MCOS,
auto &ctx = MCOS->getContext();
auto *LineStreamLabel = ctx.getOrCreateSymbol(Name);
auto *LineSym = ctx.createTempSymbol();
+ MCOS->emitLabel(LineSym);
const MCDwarfLoc &DwarfLoc = ctx.getCurrentDwarfLoc();
// Create a 'fake' line entry by having LineStreamLabel be non-null. This
diff --git a/llvm/lib/MC/MCObjectStreamer.cpp b/llvm/lib/MC/MCObjectStreamer.cpp
index 9dc3974fd8f0d..5ddb75cc7ce9b 100644
--- a/llvm/lib/MC/MCObjectStreamer.cpp
+++ b/llvm/lib/MC/MCObjectStreamer.cpp
@@ -467,12 +467,14 @@ void MCObjectStreamer::emitDwarfAdvanceLineAddr(int64_t LineDelta,
}
void MCObjectStreamer::emitDwarfLineEndEntry(MCSection *Section,
- MCSymbol *LastLabel) {
+ MCSymbol *LastLabel,
+ MCSymbol *EndLabel) {
// Emit a DW_LNE_end_sequence for the end of the section.
// Use the section end label to compute the address delta and use INT64_MAX
// as the line delta which is the signal that this is actually a
// DW_LNE_end_sequence.
- MCSymbol *SectionEnd = endSection(Section);
+ if (!EndLabel)
+ EndLabel = endSection(Section);
// Switch back the dwarf line section, in case endSection had to switch the
// section.
@@ -480,7 +482,7 @@ void MCObjectStreamer::emitDwarfLineEndEntry(MCSection *Section,
switchSection(Ctx.getObjectFileInfo()->getDwarfLineSection());
const MCAsmInfo *AsmInfo = Ctx.getAsmInfo();
- emitDwarfAdvanceLineAddr(INT64_MAX, LastLabel, SectionEnd,
+ emitDwarfAdvanceLineAddr(INT64_MAX, LastLabel, EndLabel,
AsmInfo->getCodePointerSize());
}
diff --git a/llvm/test/MC/ELF/debug-loc-label.s b/llvm/test/MC/ELF/debug-loc-label.s
index b8a4e2d9463d2..14f73b19939c6 100644
--- a/llvm/test/MC/ELF/debug-loc-label.s
+++ b/llvm/test/MC/ELF/debug-loc-label.s
@@ -13,42 +13,39 @@
# CHECK-LINE-TABLE-NEXT: 0x0000002a: 00 DW_LNE_set_address (0x0000000000000000)
# CHECK-LINE-TABLE-NEXT: 0x00000035: 01 DW_LNS_copy
# CHECK-LINE-TABLE-NEXT: 0x0000000000000000 1 1 1 0 0 0 is_stmt
-# CHECK-LINE-TABLE-NEXT: 0x00000036: 02 DW_LNS_advance_pc (addr += 33, op-index += 0)
-# CHECK-LINE-TABLE-NEXT: 0x00000038: 00 DW_LNE_end_sequence
-# CHECK-LINE-TABLE-NEXT: 0x0000000000000021 1 1 1 0 0 0 is_stmt end_sequence
-# CHECK-LINE-TABLE-NEXT: 0x0000003b: 05 DW_LNS_set_column (2)
-# CHECK-LINE-TABLE-NEXT: 0x0000003d: 00 DW_LNE_set_address (0x0000000000000008)
-# CHECK-LINE-TABLE-NEXT: 0x00000048: 01 DW_LNS_copy
+# CHECK-LINE-TABLE-NEXT: 0x00000036: 00 DW_LNE_end_sequence
+# CHECK-LINE-TABLE-NEXT: 0x0000000000000000 1 1 1 0 0 0 is_stmt end_sequence
+# CHECK-LINE-TABLE-NEXT: 0x00000039: 05 DW_LNS_set_column (2)
+# CHECK-LINE-TABLE-NEXT: 0x0000003b: 00 DW_LNE_set_address (0x0000000000000008)
+# CHECK-LINE-TABLE-NEXT: 0x00000046: 01 DW_LNS_copy
# CHECK-LINE-TABLE-NEXT: 0x0000000000000008 1 2 1 0 0 0 is_stmt
-# CHECK-LINE-TABLE-NEXT: 0x00000049: 02 DW_LNS_advance_pc (addr += 25, op-index += 0)
-# CHECK-LINE-TABLE-NEXT: 0x0000004b: 00 DW_LNE_end_sequence
-# CHECK-LINE-TABLE-NEXT: 0x0000000000000021 1 2 1 0 0 0 is_stmt end_sequence
-# CHECK-LINE-TABLE-NEXT: 0x0000004e: 05 DW_LNS_set_column (3)
-# CHECK-LINE-TABLE-NEXT: 0x00000050: 00 DW_LNE_set_address (0x0000000000000010)
-# CHECK-LINE-TABLE-NEXT: 0x0000005b: 01 DW_LNS_copy
+# CHECK-LINE-TABLE-NEXT: 0x00000047: 00 DW_LNE_end_sequence
+# CHECK-LINE-TABLE-NEXT: 0x0000000000000008 1 2 1 0 0 0 is_stmt end_sequence
+# CHECK-LINE-TABLE-NEXT: 0x0000004a: 05 DW_LNS_set_column (3)
+# CHECK-LINE-TABLE-NEXT: 0x0000004c: 00 DW_LNE_set_address (0x0000000000000010)
+# CHECK-LINE-TABLE-NEXT: 0x00000057: 01 DW_LNS_copy
# CHECK-LINE-TABLE-NEXT: 0x0000000000000010 1 3 1 0 0 0 is_stmt
-# CHECK-LINE-TABLE-NEXT: 0x0000005c: 08 DW_LNS_const_add_pc (addr += 0x0000000000000011, op-index += 0)
-# CHECK-LINE-TABLE-NEXT: 0x0000005d: 00 DW_LNE_end_sequence
-# CHECK-LINE-TABLE-NEXT: 0x0000000000000021 1 3 1 0 0 0 is_stmt end_sequence
-# CHECK-LINE-TABLE-NEXT: 0x00000060: 05 DW_LNS_set_column (4)
-# CHECK-LINE-TABLE-NEXT: 0x00000062: 00 DW_LNE_set_address (0x0000000000000018)
-# CHECK-LINE-TABLE-NEXT: 0x0000006d: 01 DW_LNS_copy
+# CHECK-LINE-TABLE-NEXT: 0x00000058: 00 DW_LNE_end_sequence
+# CHECK-LINE-TABLE-NEXT: 0x0000000000000010 1 3 1 0 0 0 is_stmt end_sequence
+# CHECK-LINE-TABLE-NEXT: 0x0000005b: 05 DW_LNS_set_column (4)
+# CHECK-LINE-TABLE-NEXT: 0x0000005d: 00 DW_LNE_set_address (0x0000000000000018)
+# CHECK-LINE-TABLE-NEXT: 0x00000068: 01 DW_LNS_copy
# CHECK-LINE-TABLE-NEXT: 0x0000000000000018 1 4 1 0 0 0 is_stmt
-# CHECK-LINE-TABLE-NEXT: 0x0000006e: 05 DW_LNS_set_column (5)
-# CHECK-LINE-TABLE-NEXT: 0x00000070: 01 DW_LNS_copy
+# CHECK-LINE-TABLE-NEXT: 0x00000069: 05 DW_LNS_set_column (5)
+# CHECK-LINE-TABLE-NEXT: 0x0000006b: 01 DW_LNS_copy
# CHECK-LINE-TABLE-NEXT: 0x0000000000000018 1 5 1 0 0 0 is_stmt
-# CHECK-LINE-TABLE-NEXT: 0x00000071: 02 DW_LNS_advance_pc (addr += 9, op-index += 0)
-# CHECK-LINE-TABLE-NEXT: 0x00000073: 00 DW_LNE_end_sequence
+# CHECK-LINE-TABLE-NEXT: 0x0000006c: 02 DW_LNS_advance_pc (addr += 9, op-index += 0)
+# CHECK-LINE-TABLE-NEXT: 0x0000006e: 00 DW_LNE_end_sequence
# CHECK-LINE-TABLE-NEXT: 0x0000000000000021 1 5 1 0 0 0 is_stmt end_sequence
# CHECK-SECTIONS: Contents of section .offset_02:
-# CHECK-SECTIONS-NEXT: 0000 3b000000
+# CHECK-SECTIONS-NEXT: 0000 39000000
# CHECK-SECTIONS: Contents of section .offset_03:
-# CHECK-SECTIONS-NEXT: 0000 4e000000
+# CHECK-SECTIONS-NEXT: 0000 4a000000
# CHECK-SECTIONS: Contents of section .offset_05:
-# CHECK-SECTIONS-NEXT: 0000 60000000
+# CHECK-SECTIONS-NEXT: 0000 5b000000
.text
.file "test.c"
.globl foo
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