From 095432eb33975bc0a5a5cfa85ac198c0b2038ba8 Mon Sep 17 00:00:00 2001 From: Orlando Cazalet-Hyams Date: Tue, 16 Dec 2025 10:02:36 +0000 Subject: [PATCH 1/3] [DWARF] Support block-form DW_AT_GNU_call_site_target_clobbered --- llvm/lib/DebugInfo/DWARF/DWARFDie.cpp | 1 + .../MIR/X86/dwarf-dump-call-target-block.mir | 70 +++++++++++++++++++ 2 files changed, 71 insertions(+) create mode 100644 llvm/test/DebugInfo/MIR/X86/dwarf-dump-call-target-block.mir diff --git a/llvm/lib/DebugInfo/DWARF/DWARFDie.cpp b/llvm/lib/DebugInfo/DWARF/DWARFDie.cpp index a10becb252006..cd8a2b305a0f9 100644 --- a/llvm/lib/DebugInfo/DWARF/DWARFDie.cpp +++ b/llvm/lib/DebugInfo/DWARF/DWARFDie.cpp @@ -853,6 +853,7 @@ bool DWARFAttribute::mayHaveLocationExpr(dwarf::Attribute Attr) { // Extensions. case DW_AT_GNU_call_site_value: case DW_AT_GNU_call_site_target: + case DW_AT_GNU_call_site_target_clobbered: return true; default: return false; diff --git a/llvm/test/DebugInfo/MIR/X86/dwarf-dump-call-target-block.mir b/llvm/test/DebugInfo/MIR/X86/dwarf-dump-call-target-block.mir new file mode 100644 index 0000000000000..9fbc5e5dc6857 --- /dev/null +++ b/llvm/test/DebugInfo/MIR/X86/dwarf-dump-call-target-block.mir @@ -0,0 +1,70 @@ +# RUN: llc %s -start-after=livedebugvalues --filetype=obj -o - | llvm-dwarfdump - -v + +## Contrived test: -gdwarf-3 -ggdb and hand-modified IR adding DISubprogram +## flag DIFlagAllCallsDescribed to force call site emission using DW_FORM_block, +## to check block form expressions are handled. + +# CHECK: DW_AT_GNU_call_site_target_clobbered [DW_FORM_block1] (DW_OP_breg5 RDI+0) + +--- | + 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" + + define dso_local void @_Z8call_memPPFvvE(ptr noundef readonly captures(none) %f) local_unnamed_addr !dbg !5 { + entry: + %0 = load ptr, ptr %f, align 8 + call void %0(), !dbg !13 + ret void + } + + !llvm.dbg.cu = !{!0} + !llvm.module.flags = !{!2, !3} + !llvm.ident = !{!4} + + !0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: !1, producer: "clang version 22.0.0git", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, splitDebugInlining: false, nameTableKind: None) + !1 = !DIFile(filename: "test.cpp", directory: "/") + !2 = !{i32 7, !"Dwarf Version", i32 3} + !3 = !{i32 2, !"Debug Info Version", i32 3} + !4 = !{!"clang version 22.0.0git"} + !5 = distinct !DISubprogram(name: "call_mem", linkageName: "_Z8call_memPPFvvE", scope: !1, file: !1, line: 1, type: !6, scopeLine: 1, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !12) + !6 = !DISubroutineType(types: !7) + !7 = !{null, !8} + !8 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !9, size: 64) + !9 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !10, size: 64) + !10 = !DISubroutineType(types: !11) + !11 = !{null} + !12 = !{} + !13 = !DILocation(line: 3, scope: !5) +... +--- +name: _Z8call_memPPFvvE +alignment: 16 +tracksRegLiveness: true +noPhis: true +isSSA: false +noVRegs: true +hasFakeUses: false +debugInstrRef: true +tracksDebugUserValues: true +liveins: + - { reg: '$rdi' } +frameInfo: + stackSize: 8 + offsetAdjustment: -8 + maxAlignment: 1 + adjustsStack: true + hasCalls: true + maxCallFrameSize: 0 + isCalleeSavedInfoValid: true +machineFunctionInfo: + amxProgModel: None +body: | + bb.0.entry: + liveins: $rdi + + frame-setup PUSH64r undef $rax, implicit-def $rsp, implicit $rsp + frame-setup CFI_INSTRUCTION def_cfa_offset 16 + CALL64m killed renamable $rdi, 1, $noreg, 0, $noreg, csr_64, implicit $rsp, implicit $ssp, implicit-def $rsp, implicit-def $ssp, debug-location !13 :: (load (s64) from %ir.f) + $rax = frame-destroy POP64r implicit-def $rsp, implicit $rsp + frame-destroy CFI_INSTRUCTION def_cfa_offset 8 + RET64 +... From 958a035420194ed02c5fc3d886ff5f1480a1a49a Mon Sep 17 00:00:00 2001 From: Orlando Cazalet-Hyams Date: Tue, 16 Dec 2025 14:04:25 +0000 Subject: [PATCH 2/3] FileCheck --- llvm/test/DebugInfo/MIR/X86/dwarf-dump-call-target-block.mir | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/llvm/test/DebugInfo/MIR/X86/dwarf-dump-call-target-block.mir b/llvm/test/DebugInfo/MIR/X86/dwarf-dump-call-target-block.mir index 9fbc5e5dc6857..928177b1e9420 100644 --- a/llvm/test/DebugInfo/MIR/X86/dwarf-dump-call-target-block.mir +++ b/llvm/test/DebugInfo/MIR/X86/dwarf-dump-call-target-block.mir @@ -1,4 +1,6 @@ -# RUN: llc %s -start-after=livedebugvalues --filetype=obj -o - | llvm-dwarfdump - -v +# RUN: llc %s -start-after=livedebugvalues --filetype=obj -o - \ +# RUN: | llvm-dwarfdump - -v \ +# RUN: | FileCheck %s ## Contrived test: -gdwarf-3 -ggdb and hand-modified IR adding DISubprogram ## flag DIFlagAllCallsDescribed to force call site emission using DW_FORM_block, From 4b0f7c2b7cab4cc58d2cef84cc6f0c7b7beb63ca Mon Sep 17 00:00:00 2001 From: Orlando Cazalet-Hyams Date: Tue, 16 Dec 2025 15:09:44 +0000 Subject: [PATCH 3/3] add triple --- llvm/test/DebugInfo/MIR/X86/dwarf-dump-call-target-block.mir | 1 + 1 file changed, 1 insertion(+) diff --git a/llvm/test/DebugInfo/MIR/X86/dwarf-dump-call-target-block.mir b/llvm/test/DebugInfo/MIR/X86/dwarf-dump-call-target-block.mir index 928177b1e9420..ae2f678c21ec7 100644 --- a/llvm/test/DebugInfo/MIR/X86/dwarf-dump-call-target-block.mir +++ b/llvm/test/DebugInfo/MIR/X86/dwarf-dump-call-target-block.mir @@ -9,6 +9,7 @@ # CHECK: DW_AT_GNU_call_site_target_clobbered [DW_FORM_block1] (DW_OP_breg5 RDI+0) --- | + target triple = "x86_64-unknown-linux" 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" define dso_local void @_Z8call_memPPFvvE(ptr noundef readonly captures(none) %f) local_unnamed_addr !dbg !5 {