[llvm] 8998f58 - Re-land D94976 after revert in e29552c5aff6
Jeremy Morse via llvm-commits
llvm-commits at lists.llvm.org
Thu Feb 4 03:17:43 PST 2021
Author: Jeremy Morse
Date: 2021-02-04T11:17:18Z
New Revision: 8998f5843503773c2f51fd475e2c77c687a65ee6
URL: https://github.com/llvm/llvm-project/commit/8998f5843503773c2f51fd475e2c77c687a65ee6
DIFF: https://github.com/llvm/llvm-project/commit/8998f5843503773c2f51fd475e2c77c687a65ee6.diff
LOG: Re-land D94976 after revert in e29552c5aff6
This modified patch avoids redirecting the unit in which a subprogram is
created if type units are enabled -- DIEs were getting children allocated
from different units memory pools. Original commit message:
[DWARF] Create subprogram's DIE in DISubprogram's unit
This is a fix for PR48790. Over in D70350, subprogram DIEs were permitted
to be shared between CUs. However, the creation of a subprogram DIE can be
triggered early, from other CUs. The subprogram definition is then created
in one CU, and when the function is actually emitted children are attached
to the subprogram that expect to be in another CU. This breaks internal CU
references in the children.
Fix this by redirecting the creation of subprogram DIEs in
getOrCreateContextDIE to the CU specified by it's DISubprogram definition.
This ensures that the subprogram DIE is always created in the correct CU.
Differential Revision: https://reviews.llvm.org/D94976
Added:
llvm/test/DebugInfo/X86/subprogram-across-cus.ll
Modified:
llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
Removed:
################################################################################
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
index 83700e837798..513be1d35d35 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
@@ -467,9 +467,6 @@ class DwarfDebug : public DebugHandlerBase {
/// Construct a DIE for this abstract scope.
void constructAbstractSubprogramScopeDIE(DwarfCompileUnit &SrcCU, LexicalScope *Scope);
- /// Construct a DIE for the subprogram definition \p SP and return it.
- DIE &constructSubprogramDefinitionDIE(const DISubprogram *SP);
-
/// Construct DIEs for call site entries describing the calls in \p MF.
void constructCallSiteEntryDIEs(const DISubprogram &SP, DwarfCompileUnit &CU,
DIE &ScopeDIE, const MachineFunction &MF);
@@ -773,6 +770,9 @@ class DwarfDebug : public DebugHandlerBase {
/// * DW_FORM_data4 for 32-bit DWARFv3 and DWARFv2.
dwarf::Form getDwarfSectionOffsetForm() const;
+ /// Construct a DIE for the subprogram definition \p SP and return it.
+ DIE &constructSubprogramDefinitionDIE(const DISubprogram *SP);
+
/// Returns the previous CU that was being updated
const DwarfCompileUnit *getPrevCU() const { return PrevCU; }
void setPrevCU(const DwarfCompileUnit *PrevCU) { this->PrevCU = PrevCU; }
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
index 2c44fcfa36fe..23b347f8c907 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
@@ -548,8 +548,17 @@ DIE *DwarfUnit::getOrCreateContextDIE(const DIScope *Context) {
return getOrCreateTypeDIE(T);
if (auto *NS = dyn_cast<DINamespace>(Context))
return getOrCreateNameSpace(NS);
- if (auto *SP = dyn_cast<DISubprogram>(Context))
- return getOrCreateSubprogramDIE(SP);
+ if (auto *SP = dyn_cast<DISubprogram>(Context)) {
+ assert(SP->isDefinition());
+ // When generating type units, each unit gets its own subprogram.
+ if (DD->generateTypeUnits())
+ return getOrCreateSubprogramDIE(SP);
+
+ // Subprogram definitions should be created in the Unit that they specify,
+ // which might not be "this" unit when type definitions move around under
+ // LTO.
+ return &DD->constructSubprogramDefinitionDIE(SP);
+ }
if (auto *M = dyn_cast<DIModule>(Context))
return getOrCreateModule(M);
return getDIE(Context);
diff --git a/llvm/test/DebugInfo/X86/subprogram-across-cus.ll b/llvm/test/DebugInfo/X86/subprogram-across-cus.ll
new file mode 100644
index 000000000000..345342aecf3c
--- /dev/null
+++ b/llvm/test/DebugInfo/X86/subprogram-across-cus.ll
@@ -0,0 +1,93 @@
+; RUN: llc %s -mtriple=x86_64-unknown-linux-gnu -filetype=obj -o %t
+; RUN: llvm-dwarfdump -verify %t
+; RUN: llvm-dwarfdump -debug-info %t | FileCheck %s
+; RUN: rm %t
+;
+;$ cat -n 1.cpp
+; 1 struct HHH;
+; 2 HHH *zzz;
+;
+;$ cat -n 2.cpp
+; 1 void __attribute__((optnone)) __attribute__((nodebug)) f1() { }
+; 2
+; 3 struct HHH {
+; 4 template <typename bbb>
+; 5 static int __attribute__((always_inline)) ccc() {
+; 6 f1();
+; 7 }
+; 8 };
+; 9
+; 10 int main() {
+; 11 struct local { };
+; 12 HHH::ccc<local>();
+; 13 }
+;
+; $ clang -flto -O2 -g 1.cpp 2.cpp -o a.out
+;
+; Given this input, LLVM attempts to create a DIE for subprogram "main" in the
+; wrong context. The definition of struct "HHH" is placed in the CU for 1.cpp.
+; While creating the template instance in "HHH", function "ccc" is referenced
+; via the struct local type, and "main" is created in the CU for 1.cpp, which
+; is incorrect.
+;
+; See PR48790 for more discussion and original compile commands.
+;
+; Check that there are no verifier failures, and that the SP for "main" appears
+; in the correct CU.
+; CHECK-LABEL: DW_TAG_compile_unit
+; CHECK: DW_AT_name ("1.cpp")
+; CHECK-NOT: DW_AT_name ("main")
+; CHECK-LABEL: DW_TAG_compile_unit
+; CHECK: DW_AT_name ("2.cpp")
+; CHECK: DW_TAG_subprogram
+; CHECK: DW_AT_name ("main")
+
+source_filename = "ld-temp.o"
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+; Function Attrs: noinline norecurse nounwind optnone uwtable mustprogress
+define internal fastcc void @_Z2f1v() unnamed_addr {
+entry:
+ ret void
+}
+
+; Function Attrs: norecurse noreturn nounwind uwtable mustprogress
+define dso_local i32 @main() local_unnamed_addr !dbg !17 {
+entry:
+ tail call fastcc void @_Z2f1v(), !dbg !21
+ unreachable, !dbg !21
+}
+
+!llvm.dbg.cu = !{!0, !9}
+!llvm.ident = !{!10, !10}
+!llvm.module.flags = !{!11, !12, !13, !14, !15, !16}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: !1, producer: "clang version 12.0.0 (git at github.com:llvm/llvm-project bc9ab9a5cd6bafc5e1293f3d5d51638f8f5cd26c)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, globals: !3, splitDebugInlining: false, nameTableKind: None)
+!1 = !DIFile(filename: "1.cpp", directory: "/tmp/bees")
+!2 = !{}
+!3 = !{!4}
+!4 = !DIGlobalVariableExpression(var: !5, expr: !DIExpression())
+!5 = distinct !DIGlobalVariable(name: "zzz", scope: !0, file: !1, line: 2, type: !6, isLocal: false, isDefinition: true)
+!6 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !7, size: 64)
+!7 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "HHH", file: !8, line: 3, size: 8, flags: DIFlagTypePassByValue, elements: !2, identifier: "_ZTS3HHH")
+!8 = !DIFile(filename: "2.cpp", directory: "/tmp/bees")
+!9 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: !8, producer: "clang version 12.0.0 (git at github.com:llvm/llvm-project bc9ab9a5cd6bafc5e1293f3d5d51638f8f5cd26c)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, splitDebugInlining: false, nameTableKind: None)
+!10 = !{!"clang version 12.0.0 (git at github.com:llvm/llvm-project bc9ab9a5cd6bafc5e1293f3d5d51638f8f5cd26c)"}
+!11 = !{i32 7, !"Dwarf Version", i32 4}
+!12 = !{i32 2, !"Debug Info Version", i32 3}
+!13 = !{i32 1, !"wchar_size", i32 4}
+!14 = !{i32 1, !"ThinLTO", i32 0}
+!15 = !{i32 1, !"EnableSplitLTOUnit", i32 1}
+!16 = !{i32 1, !"LTOPostLink", i32 1}
+!17 = distinct !DISubprogram(name: "main", scope: !8, file: !8, line: 10, type: !18, scopeLine: 10, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !9, retainedNodes: !2)
+!18 = !DISubroutineType(types: !19)
+!19 = !{!20}
+!20 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!21 = !DILocation(line: 6, column: 5, scope: !22, inlinedAt: !27)
+!22 = distinct !DISubprogram(name: "ccc<local>", linkageName: "_ZN3HHH3cccIZ4mainE5localEEiv", scope: !7, file: !8, line: 5, type: !18, scopeLine: 5, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition | DISPFlagOptimized, unit: !9, templateParams: !24, declaration: !23, retainedNodes: !2)
+!23 = !DISubprogram(name: "ccc<local>", linkageName: "_ZN3HHH3cccIZ4mainE5localEEiv", scope: !7, file: !8, line: 5, type: !18, scopeLine: 5, flags: DIFlagPrototyped | DIFlagStaticMember, spFlags: DISPFlagOptimized, templateParams: !24)
+!24 = !{!25}
+!25 = !DITemplateTypeParameter(name: "bbb", type: !26)
+!26 = !DICompositeType(tag: DW_TAG_structure_type, name: "local", scope: !17, file: !8, line: 11, size: 8, flags: DIFlagFwdDecl)
+!27 = distinct !DILocation(line: 12, column: 3, scope: !17)
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