[XRay][CodeGen] Use the current function symbol as the associated symbol for the instrumentation map
Summary: XRay had been assuming that the previous section is the "text" section of the function when lowering the instrumentation map. Unfortunately this is not a safe assumption, because we may be coming from lowering debug type information for the function being lowered. This fixes an issue with combining -gsplit-dwarf, -generate-type-units, -debug-compile and -fxray-instrument for sole member functions. When the split dwarf section is stripped, we're left with references from the xray_instr_map to the debug section. The change now uses the function's symbol instead of the previous section's start symbol. We found the bug while attempting to strip the split debug sections off an XRay-instrumented object file, which had a peculiar edge-case for single-function classes where the single function is being lowered. Because XRay had assocaited the instrumentation map for a function to the debug types section instead of the function's section, the objcopy call will fail due to the misplaced reference from the xray_instr_map section. Reviewers: pcc, dblaikie, echristo Subscribers: llvm-commits, aprantl Differential Revision: https://reviews.llvm.org/D37791 llvm-svn: 313233
This commit is contained in:
Dean Michael Berris
parent
0fd7c5ccd6
commit
01fd7c8bd4
|
|
@ -2785,7 +2785,7 @@ void AsmPrinter::emitXRayTable() {
|
|||
MCSection *InstMap = nullptr;
|
||||
MCSection *FnSledIndex = nullptr;
|
||||
if (MF->getSubtarget().getTargetTriple().isOSBinFormatELF()) {
|
||||
auto Associated = dyn_cast<MCSymbolELF>(PrevSection->getBeginSymbol());
|
||||
auto Associated = dyn_cast<MCSymbolELF>(CurrentFnSym);
|
||||
assert(Associated != nullptr);
|
||||
auto Flags = ELF::SHF_WRITE | ELF::SHF_ALLOC | ELF::SHF_LINK_ORDER;
|
||||
std::string GroupName;
|
||||
|
|
|
|||
|
|
@ -14,7 +14,7 @@
|
|||
define i32 @foo() nounwind noinline uwtable "function-instrument"="xray-always" {
|
||||
; CHECK: .section .text.foo,"ax",@progbits
|
||||
ret i32 0
|
||||
; CHECK: .section xray_instr_map,"awo",@progbits,.text.foo,unique,1
|
||||
; CHECK: .section xray_instr_map,"awo",@progbits,foo,unique,1
|
||||
}
|
||||
|
||||
; CHECK-OBJ: Section {
|
||||
|
|
@ -24,7 +24,7 @@ $bar = comdat any
|
|||
define i32 @bar() nounwind noinline uwtable "function-instrument"="xray-always" comdat($bar) {
|
||||
; CHECK: .section .text.bar,"axG",@progbits,bar,comdat
|
||||
ret i32 1
|
||||
; CHECK: .section xray_instr_map,"aGwo",@progbits,bar,comdat,.text.bar,unique,2
|
||||
; CHECK: .section xray_instr_map,"aGwo",@progbits,bar,comdat,bar,unique,2
|
||||
}
|
||||
|
||||
; CHECK-OBJ: Section {
|
||||
|
|
|
|||
|
|
@ -22,7 +22,7 @@ define i32 @foo() nounwind noinline uwtable "function-instrument"="xray-always"
|
|||
; CHECK-NEXT: nop
|
||||
; CHECK-NEXT: mtlr 0
|
||||
}
|
||||
; CHECK-LABEL: xray_instr_map,"awo",@progbits,.text,unique,1
|
||||
; CHECK-LABEL: xray_instr_map,"awo",@progbits,foo,unique,1
|
||||
; CHECK: .Lxray_sleds_start0:
|
||||
; CHECK-NEXT: .quad .Ltmp0
|
||||
; CHECK-NEXT: .quad foo
|
||||
|
|
@ -37,7 +37,7 @@ define i32 @foo() nounwind noinline uwtable "function-instrument"="xray-always"
|
|||
; CHECK-NEXT: .byte 0x00
|
||||
; CHECK-NEXT: .space 13
|
||||
; CHECK-NEXT: .Lxray_sleds_end0:
|
||||
; CHECK-LABEL: xray_fn_idx,"awo",@progbits,.text,unique,1
|
||||
; CHECK-LABEL: xray_fn_idx,"awo",@progbits,foo,unique,1
|
||||
; CHECK: .p2align 4
|
||||
; CHECK-NEXT: .quad .Lxray_sleds_start0
|
||||
; CHECK-NEXT: .quad .Lxray_sleds_end0
|
||||
|
|
|
|||
|
|
@ -5,14 +5,14 @@
|
|||
define i32 @foo() nounwind noinline uwtable "function-instrument"="xray-always" {
|
||||
; CHECK: .section .text.foo,"ax",@progbits
|
||||
ret i32 0
|
||||
; CHECK: .section xray_instr_map,"awo",@progbits,.text.foo,unique,1
|
||||
; CHECK: .section xray_instr_map,"awo",@progbits,foo,unique,1
|
||||
}
|
||||
|
||||
$bar = comdat any
|
||||
define i32 @bar() nounwind noinline uwtable "function-instrument"="xray-always" comdat($bar) {
|
||||
; CHECK: .section .text.bar,"axG",@progbits,bar,comdat
|
||||
ret i32 1
|
||||
; CHECK: .section xray_instr_map,"aGwo",@progbits,bar,comdat,.text.bar,unique,2
|
||||
; CHECK: .section xray_instr_map,"aGwo",@progbits,bar,comdat,bar,unique,2
|
||||
}
|
||||
|
||||
; CHECK-OBJ: section xray_instr_map:
|
||||
|
|
|
|||
|
|
@ -0,0 +1,84 @@
|
|||
; RUN: %llc_dwarf -split-dwarf-file=input.dwo -O3 \
|
||||
; RUN: -function-sections -data-sections \
|
||||
; RUN: -relocation-model=pic -filetype=asm \
|
||||
; RUN: -generate-type-units -debug-compile -o - %s | \
|
||||
; RUN: FileCheck %s --check-prefix=CHECK-ASM
|
||||
; RUN: %llc_dwarf -split-dwarf-file=input.dwo -O3 \
|
||||
; RUN: -function-sections -data-sections \
|
||||
; RUN: -relocation-model=pic -filetype=obj \
|
||||
; RUN: -generate-type-units -debug-compile -o - %s | \
|
||||
; RUN: llvm-readelf -sections | \
|
||||
; RUN: FileCheck %s --check-prefix=CHECK-ELF
|
||||
; Created from `clang++ -fxray-instrument -gsplit-dwarf -fdebug-types-section
|
||||
; -ffunction-sections -fdata-sections -emit-llvm -S input.cc`:
|
||||
; input.cc:
|
||||
;
|
||||
; class a {
|
||||
; int b();
|
||||
; };
|
||||
; int a::b() {
|
||||
; for (;;)
|
||||
; ;
|
||||
; }
|
||||
;
|
||||
; In this test we want to make sure that the xray_instr_map section for
|
||||
; `a::b()` is actually associated with the function's symbol instead of the
|
||||
; .debug_types.dwo section.
|
||||
;
|
||||
; CHECK-ASM: xray_fn_idx,"awo",@progbits,_ZN1a1bEv,unique,1
|
||||
;
|
||||
; CHECK-ELF-DAG: [[FSECT:[0-9]+]]] .text._ZN1a1bEv PROGBITS
|
||||
; CHECK-ELF-DAG: [{{.*}}] .debug_types.dwo PROGBITS
|
||||
; CHECK-ELF-DAG: [{{.*}}] xray_instr_map PROGBITS {{.*}} {{.*}} {{.*}} {{.*}} WAL [[FSECT]]
|
||||
target triple = "x86_64-pc-linux"
|
||||
|
||||
%class.a = type { i8 }
|
||||
|
||||
; Function Attrs: nounwind readnone uwtable
|
||||
define i32 @_ZN1a1bEv(%class.a* nocapture readnone) local_unnamed_addr #0 align 2 !dbg !8 {
|
||||
tail call void @llvm.dbg.value(metadata %class.a* %0, metadata !17, metadata !DIExpression()), !dbg !19
|
||||
br label %2, !dbg !20
|
||||
|
||||
; <label>:2: ; preds = %2, %1
|
||||
br label %2, !dbg !21, !llvm.loop !25
|
||||
}
|
||||
|
||||
|
||||
; Function Attrs: nounwind readnone speculatable
|
||||
declare void @llvm.dbg.value(metadata, metadata, metadata) #1
|
||||
|
||||
attributes #0 = { nounwind readnone uwtable "xray-instruction-threshold"="200" }
|
||||
attributes #1 = { nounwind readnone speculatable }
|
||||
|
||||
!llvm.dbg.cu = !{!0}
|
||||
!llvm.module.flags = !{!3, !4, !5, !6}
|
||||
!llvm.ident = !{!7}
|
||||
|
||||
!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version trunk (trunk r312634)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, splitDebugInlining: false, debugInfoForProfiling: true)
|
||||
!1 = !DIFile(filename: "input.cc", directory: "/usr/local/google/home/dberris/tmp")
|
||||
!2 = !{}
|
||||
!3 = !{i32 2, !"Debug Info Version", i32 3}
|
||||
!4 = !{i32 1, !"wchar_size", i32 4}
|
||||
!5 = !{i32 7, !"PIC Level", i32 2}
|
||||
!6 = !{i32 7, !"PIE Level", i32 2}
|
||||
!7 = !{!"clang version trunk (trunk r312634)"}
|
||||
!8 = distinct !DISubprogram(name: "b", linkageName: "_ZN1a1bEv", scope: !9, file: !1, line: 4, type: !12, isLocal: false, isDefinition: true, scopeLine: 4, flags: DIFlagPrototyped, isOptimized: true, unit: !0, declaration: !11, variables: !16)
|
||||
!9 = distinct !DICompositeType(tag: DW_TAG_class_type, name: "a", file: !1, line: 1, size: 8, elements: !10, identifier: "_ZTS1a")
|
||||
!10 = !{!11}
|
||||
!11 = !DISubprogram(name: "b", linkageName: "_ZN1a1bEv", scope: !9, file: !1, line: 2, type: !12, isLocal: false, isDefinition: false, scopeLine: 2, flags: DIFlagPrototyped, isOptimized: true)
|
||||
!12 = !DISubroutineType(types: !13)
|
||||
!13 = !{!14, !15}
|
||||
!14 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
|
||||
!15 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !9, size: 64, flags: DIFlagArtificial | DIFlagObjectPointer)
|
||||
!16 = !{!17}
|
||||
!17 = !DILocalVariable(name: "this", arg: 1, scope: !8, type: !18, flags: DIFlagArtificial | DIFlagObjectPointer)
|
||||
!18 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !9, size: 64)
|
||||
!19 = !DILocation(line: 0, scope: !8)
|
||||
!20 = !DILocation(line: 5, column: 3, scope: !8)
|
||||
!21 = !DILocation(line: 5, column: 3, scope: !22)
|
||||
!22 = !DILexicalBlockFile(scope: !23, file: !1, discriminator: 2)
|
||||
!23 = distinct !DILexicalBlock(scope: !24, file: !1, line: 5, column: 3)
|
||||
!24 = distinct !DILexicalBlock(scope: !8, file: !1, line: 5, column: 3)
|
||||
!25 = distinct !{!25, !26, !27}
|
||||
!26 = !DILocation(line: 5, column: 3, scope: !24)
|
||||
!27 = !DILocation(line: 6, column: 5, scope: !24)
|
||||
Loading…
Reference in New Issue