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[AArch64] Support TLS variables in debug info #146572

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[AArch64] Support TLS variables in debug info #146572

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6 changes: 6 additions & 0 deletions lld/ELF/Arch/AArch64.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -156,6 +156,8 @@ RelExpr AArch64::getRelExpr(RelType type, const Symbol &s,
return R_ABS;
case R_AARCH64_AUTH_ABS64:
return RE_AARCH64_AUTH;
case R_AARCH64_TLS_DTPREL64:
return R_DTPREL;
case R_AARCH64_TLSDESC_ADR_PAGE21:
return RE_AARCH64_TLSDESC_PAGE;
case R_AARCH64_AUTH_TLSDESC_ADR_PAGE21:
Expand Down Expand Up @@ -542,6 +544,10 @@ void AArch64::relocate(uint8_t *loc, const Relocation &rel,
if (isInt<32>(val))
write32(ctx, loc, val);
break;
case R_AARCH64_TLS_DTPREL64:
checkInt(ctx, loc, val, 64, rel);
write64(ctx, loc, val);
break;
case R_AARCH64_ADD_ABS_LO12_NC:
case R_AARCH64_AUTH_GOT_ADD_LO12_NC:
write32Imm12(loc, val);
Expand Down
1 change: 1 addition & 0 deletions lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp
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Expand Up @@ -2843,6 +2843,7 @@ unsigned ObjectFileELF::ApplyRelocations(
case llvm::ELF::EM_AARCH64:
switch (reloc_type(rel)) {
case R_AARCH64_ABS64:
case R_AARCH64_TLS_DTPREL64:
ApplyELF64ABS64Relocation(symtab, rel, debug_data, rel_section);
break;
case R_AARCH64_ABS32:
Expand Down
7 changes: 6 additions & 1 deletion llvm/lib/Target/AArch64/AArch64TargetObjectFile.cpp
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Expand Up @@ -30,7 +30,7 @@ void AArch64_ELFTargetObjectFile::Initialize(MCContext &Ctx,

// AARCH64 ELF ABI does not define static relocation type for TLS offset
// within a module. Do not generate AT_location for TLS variables.
Comment on lines 31 to 32
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SupportDebugThreadLocalLocation = false;
SupportDebugThreadLocalLocation = true;

// Make sure the implicitly created empty .text section has the
// SHF_AARCH64_PURECODE flag set if the "+execute-only" target feature is
Expand Down Expand Up @@ -186,3 +186,8 @@ MCSection *AArch64_ELFTargetObjectFile::SelectSectionForGlobal(

return TargetLoweringObjectFileELF::SelectSectionForGlobal(GO, Kind, TM);
}

const MCExpr *AArch64_ELFTargetObjectFile::getDebugThreadLocalSymbol(
const MCSymbol *Sym) const {
return MCSymbolRefExpr::create(Sym, AArch64::S_DTPREL, getContext());
}
3 changes: 3 additions & 0 deletions llvm/lib/Target/AArch64/AArch64TargetObjectFile.h
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Expand Up @@ -40,6 +40,9 @@ class AArch64_ELFTargetObjectFile : public TargetLoweringObjectFileELF {

MCSection *SelectSectionForGlobal(const GlobalObject *GO, SectionKind Kind,
const TargetMachine &TM) const override;

/// Describe a TLS variable address within debug info.
const MCExpr *getDebugThreadLocalSymbol(const MCSymbol *Sym) const override;
};

/// AArch64_MachoTargetObjectFile - This TLOF implementation is used for Darwin.
Expand Down
3 changes: 3 additions & 0 deletions llvm/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp
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Expand Up @@ -4421,6 +4421,7 @@ bool AArch64AsmParser::parseSymbolicImmVal(const MCExpr *&ImmVal) {
.Case("prel_g1_nc", AArch64::S_PREL_G1_NC)
.Case("prel_g0", AArch64::S_PREL_G0)
.Case("prel_g0_nc", AArch64::S_PREL_G0_NC)
.Case("dtprel", AArch64::S_DTPREL)
.Case("dtprel_g2", AArch64::S_DTPREL_G2)
.Case("dtprel_g1", AArch64::S_DTPREL_G1)
.Case("dtprel_g1_nc", AArch64::S_DTPREL_G1_NC)
Expand Down Expand Up @@ -8191,6 +8192,8 @@ bool AArch64AsmParser::parseDataExpr(const MCExpr *&Res) {
Spec = AArch64::S_GOTPCREL;
else if (Identifier == "plt")
Spec = AArch64::S_PLT;
else if (Identifier == "dtprel")
Spec = AArch64::S_DTPREL;
}
if (Spec == AArch64::S_None)
return Error(Loc, "invalid relocation specifier");
Expand Down
5 changes: 5 additions & 0 deletions llvm/lib/Target/AArch64/MCTargetDesc/AArch64ELFObjectWriter.cpp
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Expand Up @@ -234,6 +234,9 @@ unsigned AArch64ELFObjectWriter::getRelocType(const MCFixup &Fixup,
}
if (RefKind == AArch64::S_AUTH || RefKind == AArch64::S_AUTHADDR)
return ELF::R_AARCH64_AUTH_ABS64;
if (RefKind == AArch64::S_DTPREL) {
return ELF::R_AARCH64_TLS_DTPREL64;
}
return ELF::R_AARCH64_ABS64;
}
case AArch64::fixup_aarch64_add_imm12:
Expand Down Expand Up @@ -448,6 +451,8 @@ unsigned AArch64ELFObjectWriter::getRelocType(const MCFixup &Fixup,
return R_CLS(MOVW_PREL_G0);
if (RefKind == AArch64::S_PREL_G0_NC)
return R_CLS(MOVW_PREL_G0_NC);
if (RefKind == AArch64::S_DTPREL)
return ELF::R_AARCH64_TLS_DTPREL64;
if (RefKind == AArch64::S_DTPREL_G2)
return ELF::R_AARCH64_TLSLD_MOVW_DTPREL_G2;
if (RefKind == AArch64::S_DTPREL_G1)
Expand Down
2 changes: 2 additions & 0 deletions llvm/lib/Target/AArch64/MCTargetDesc/AArch64MCAsmInfo.cpp
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Expand Up @@ -41,6 +41,7 @@ const MCAsmInfo::AtSpecifier ELFAtSpecifiers[] = {
{AArch64::S_GOT, "GOT"},
{AArch64::S_GOTPCREL, "GOTPCREL"},
{AArch64::S_PLT, "PLT"},
{AArch64::S_DTPREL, "DTPREL"},
};

const MCAsmInfo::AtSpecifier MachOAtSpecifiers[] = {
Expand Down Expand Up @@ -76,6 +77,7 @@ StringRef AArch64::getSpecifierName(const MCSpecifierExpr &Expr) {
case AArch64::S_PREL_G1_NC: return ":prel_g1_nc:";
case AArch64::S_PREL_G0: return ":prel_g0:";
case AArch64::S_PREL_G0_NC: return ":prel_g0_nc:";
case AArch64::S_DTPREL: return ":dtprel:";
case AArch64::S_DTPREL_G2: return ":dtprel_g2:";
case AArch64::S_DTPREL_G1: return ":dtprel_g1:";
case AArch64::S_DTPREL_G1_NC: return ":dtprel_g1_nc:";
Expand Down
37 changes: 37 additions & 0 deletions llvm/test/CodeGen/AArch64/tls-dtprel64.ll
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@@ -0,0 +1,37 @@
; RUN: llc -O0 -mtriple=aarch64-linux-gnu -filetype=obj < %s \
; RUN: | llvm-objdump -r - | FileCheck %s
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indent the second line a bit so it's clear it's a continuation:

; RUN: <more spaces> | llvm...


; CHECK: R_AARCH64_TLS_DTPREL64
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What does the full output look like? Because this check looks a bit non-specific. I know it's basically "do we produce this at all" but is there anything else we can check to make sure it is in fact for "var" not something else?


@var = thread_local global i32 0, align 4, !dbg !0

; Function Attrs: noinline nounwind optnone
define i32 @foo() #0 !dbg !11 {
entry:
%0 = load i32, ptr @var, align 4, !dbg !14
ret i32 %0, !dbg !15
}

attributes #0 = { noinline nounwind optnone }

!llvm.dbg.cu = !{!2}
!llvm.module.flags = !{!7, !8, !9}
!llvm.ident = !{!10}

!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
!1 = distinct !DIGlobalVariable(name: "var", scope: !2, file: !3, line: 1, type: !6, isLocal: false, isDefinition: true)
!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 7.0.0", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5)
!3 = !DIFile(filename: "tls-at-location.c", directory: "/home/lliu0/llvm/tls-at-location/DebugInfo/AArch64")
!4 = !{}
!5 = !{!0}
!6 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
!7 = !{i32 2, !"Dwarf Version", i32 4}
!8 = !{i32 2, !"Debug Info Version", i32 3}
!9 = !{i32 1, !"wchar_size", i32 4}
!10 = !{!"clang version 7.0.0"}
!11 = distinct !DISubprogram(name: "foo", scope: !3, file: !3, line: 3, type: !12, isLocal: false, isDefinition: true, scopeLine: 3, isOptimized: false, unit: !2)
!12 = !DISubroutineType(types: !13)
!13 = !{!6}
!14 = !DILocation(line: 4, column: 10, scope: !11)
!15 = !DILocation(line: 4, column: 3, scope: !11)

12 changes: 9 additions & 3 deletions llvm/test/DebugInfo/AArch64/tls-at-location.ll
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@@ -1,8 +1,14 @@
; RUN: llc -filetype=obj -mtriple=aarch64--linux-gnu -o - %s | llvm-dwarfdump -v - | FileCheck %s
;
; RUN: llc -O0 -mtriple=aarch64-non-linux-gnu -filetype=obj < %s \
; RUN: | llvm-dwarfdump - | FileCheck %s

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indent the continuation

; CHECK: .debug_info contents:
; CHECK: DW_TAG_variable
; CHECK-NOT: DW_AT_location
; CHECK: DW_AT_name ("var")
; CHECK-NEXT: DW_AT_type (0x00000040 "int")
; CHECK-NEXT: DW_AT_external (true)
; CHECK-NEXT: DW_AT_decl_file ("{{.*}}tls-at-location.c")
; CHECK-NEXT: DW_AT_decl_line (1)
; CHECK-NEXT: DW_AT_location (DW_OP_const8u 0x0, DW_OP_GNU_push_tls_address)

@var = thread_local global i32 0, align 4, !dbg !0

Expand Down
38 changes: 38 additions & 0 deletions llvm/test/MC/AArch64/tls-dtprel64.s
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@@ -0,0 +1,38 @@
# RUN: llvm-mc -filetype=obj -triple=aarch64-none-linux-gnu %s | llvm-readobj -r - | FileCheck %s

# CHECK: Relocations [
# CHECK: Section {{.*}} .rela.debug_info {
# CHECK: 0x{{[0-9A-F]+}} R_AARCH64_TLS_DTPREL64 var {{.*}}
# CHECK: }

.section .tdata,"awT",@progbits
.globl var
var:
.word 0

.section .debug_abbrev,"",@progbits
.byte 1 // Abbreviation Code
.byte 17 // DW_TAG_compile_unit
.byte 1 // DW_CHILDREN_yes
.byte 0 // EOM(1)
.byte 0 // EOM(2)

.byte 2 // Abbreviation Code
.byte 52 // DW_TAG_variable
.byte 0 // DW_CHILDREN_no
.byte 2; // DW_AT_location
.byte 24 // DW_FORM_exprloc
.byte 0 // EOM(1)
.byte 0 // EOM(2)

.section .debug_info,"",@progbits
.Lcu_begin0:
.word .Lcu_end - .Lcu_body // Length of Unit
.Lcu_body:
.hword 4 // DWARF version number
.word .debug_abbrev // Offset Into Abbrev. Section
.byte 8 // Address Size (in bytes)
.byte 1 // Abbrev [1] DW_TAG_compile_unit
.byte 2 // Abbrev [2] DW_TAG_variable
.xword var@DTPREL
.Lcu_end:
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