DebugInfo: Split DWARF: Hash non-member function child DIEs

Significant missing hashing - as per the comment this was only meant to skip member functions (unspecified, but I think it's legible as member function declarations, not definitions) but was skipping all named subprograms (so only hashed child DIEs for member function definitions - because they didn't have a direct name, but only a name given indirectly in the DW_AT_specification-referenced DIE)
llvm · Jan 31, 2020 · b33e5f3 · b33e5f3
1 parent 792d9b5
commit b33e5f3
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Showing 4 changed files with 83 additions and 7 deletions.
diff --git a/llvm/lib/CodeGen/AsmPrinter/DIEHash.cpp b/llvm/lib/CodeGen/AsmPrinter/DIEHash.cpp
@@ -361,7 +361,7 @@ void DIEHash::computeHash(const DIE &Die) {
   for (auto &C : Die.children()) {
     // 7.27 Step 7
     // If C is a nested type entry or a member function entry, ...
-    if (isType(C.getTag()) || C.getTag() == dwarf::DW_TAG_subprogram) {
+    if (isType(C.getTag()) || (C.getTag() == dwarf::DW_TAG_subprogram && isType(C.getParent()->getTag()))) {
       StringRef Name = getDIEStringAttr(C, dwarf::DW_AT_name);
       // ... and has a DW_AT_name attribute
       if (!Name.empty()) {

diff --git a/llvm/test/DebugInfo/Inputs/fission-hash-local2.ll b/llvm/test/DebugInfo/Inputs/fission-hash-local2.ll
@@ -0,0 +1,29 @@
+; Function Attrs: norecurse nounwind readnone uwtable
+define dso_local void @_Z2f1v() local_unnamed_addr !dbg !7 {
+entry:
+  call void @llvm.dbg.value(metadata i32 9, metadata !11, metadata !DIExpression()), !dbg !13
+  ret void, !dbg !14
+}
+
+; Function Attrs: nounwind readnone speculatable willreturn
+declare void @llvm.dbg.value(metadata, metadata, metadata)
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4, !5}
+!llvm.ident = !{!6}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: !1, producer: "clang version 11.0.0 (git@github.com:llvm/llvm-project.git edc3f4f02e54c2ae1067f60f6a0ed6caf5b92ef6)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, splitDebugInlining: false, nameTableKind: None)
+!1 = !DIFile(filename: "hash.cpp", directory: "/usr/local/google/home/blaikie/dev/scratch")
+!2 = !{}
+!3 = !{i32 7, !"Dwarf Version", i32 4}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = !{i32 1, !"wchar_size", i32 4}
+!6 = !{!"clang version 11.0.0 (git@github.com:llvm/llvm-project.git edc3f4f02e54c2ae1067f60f6a0ed6caf5b92ef6)"}
+!7 = distinct !DISubprogram(name: "f1", linkageName: "_Z2f1v", scope: !1, file: !1, line: 1, type: !8, scopeLine: 1, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !10)
+!8 = !DISubroutineType(types: !9)
+!9 = !{null}
+!10 = !{!11}
+!11 = !DILocalVariable(name: "i", scope: !7, file: !1, line: 2, type: !12)
+!12 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!13 = !DILocation(line: 0, scope: !7)
+!14 = !DILocation(line: 3, column: 1, scope: !7)
diff --git a/llvm/test/DebugInfo/X86/fission-hash-local.ll b/llvm/test/DebugInfo/X86/fission-hash-local.ll
@@ -0,0 +1,47 @@
+; RUN: llc -split-dwarf-file=foo.dwo -O0 < %s -mtriple=x86_64-unknown-linux-gnu -filetype=obj -o - \
+; RUN:   | llvm-dwarfdump - | FileCheck --check-prefix=H1 %s
+; RUN: llc -split-dwarf-file=foo.dwo -O0 < %p/../Inputs/fission-hash-local2.ll -mtriple=x86_64-unknown-linux-gnu -filetype=obj -o - \
+; RUN:   | llvm-dwarfdump - | FileCheck --check-prefix=H2 %s
+
+; Testing that the location of a local variable in a global function is hashed
+; fission-hash-local2.ll is identical except for the value of the local
+; variable (local.ll uses the constant 7 in the llvm.dbg.value below, local2.ll
+; uses the constant 9) so it should have a different dwo_id, seen below.
+
+; Original source:
+; void f1() {
+;   int i = 7; // or 9
+; }
+
+; H1: DW_AT_GNU_dwo_id  (0x03a55a70550ee09b)
+; H2: DW_AT_GNU_dwo_id  (0x826fcafbddebc96b)
+
+; Function Attrs: norecurse nounwind readnone uwtable
+define dso_local void @_Z2f1v() local_unnamed_addr !dbg !7 {
+entry:
+  call void @llvm.dbg.value(metadata i32 7, metadata !11, metadata !DIExpression()), !dbg !13
+  ret void, !dbg !14
+}
+
+; Function Attrs: nounwind readnone speculatable willreturn
+declare void @llvm.dbg.value(metadata, metadata, metadata)
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4, !5}
+!llvm.ident = !{!6}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: !1, producer: "clang version 11.0.0 (git@github.com:llvm/llvm-project.git edc3f4f02e54c2ae1067f60f6a0ed6caf5b92ef6)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, splitDebugInlining: false, nameTableKind: None)
+!1 = !DIFile(filename: "hash.cpp", directory: "/usr/local/google/home/blaikie/dev/scratch")
+!2 = !{}
+!3 = !{i32 7, !"Dwarf Version", i32 4}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = !{i32 1, !"wchar_size", i32 4}
+!6 = !{!"clang version 11.0.0 (git@github.com:llvm/llvm-project.git edc3f4f02e54c2ae1067f60f6a0ed6caf5b92ef6)"}
+!7 = distinct !DISubprogram(name: "f1", linkageName: "_Z2f1v", scope: !1, file: !1, line: 1, type: !8, scopeLine: 1, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !10)
+!8 = !DISubroutineType(types: !9)
+!9 = !{null}
+!10 = !{!11}
+!11 = !DILocalVariable(name: "i", scope: !7, file: !1, line: 2, type: !12)
+!12 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!13 = !DILocation(line: 0, scope: !7)
+!14 = !DILocation(line: 3, column: 1, scope: !7)
diff --git a/llvm/test/DebugInfo/X86/sret.ll b/llvm/test/DebugInfo/X86/sret.ll
@@ -1,16 +1,16 @@
 ; RUN: llc -split-dwarf-file=foo.dwo -O0 %s -mtriple=x86_64-unknown-linux-gnu -filetype=obj -o %t
-; RUN: llvm-dwarfdump -v -all %t | FileCheck %s --check-prefix=CHECK-DWO
+; RUN: llvm-dwarfdump -debug-info %t | FileCheck %s --check-prefix=CHECK-DWO
 
 ; Based on the debuginfo-tests/sret.cpp code.
 
-; CHECK-DWO: DW_AT_GNU_dwo_id [DW_FORM_data8] (0x51ac5644b1937aa1)
-; CHECK-DWO: DW_AT_GNU_dwo_id [DW_FORM_data8] (0x51ac5644b1937aa1)
+; CHECK-DWO: DW_AT_GNU_dwo_id (0x7e62530711b94622)
+; CHECK-DWO: DW_AT_GNU_dwo_id (0x7e62530711b94622)
 
-; RUN: llc -O0 -fast-isel=true -mtriple=x86_64-apple-darwin -filetype=obj -o - %s | llvm-dwarfdump -v - | FileCheck %s
-; RUN: llc -O0 -fast-isel=false -mtriple=x86_64-apple-darwin -filetype=obj -o - %s | llvm-dwarfdump -v - | FileCheck %s
+; RUN: llc -O0 -fast-isel=true -mtriple=x86_64-apple-darwin -filetype=obj -o - %s | llvm-dwarfdump -debug-info - | FileCheck %s
+; RUN: llc -O0 -fast-isel=false -mtriple=x86_64-apple-darwin -filetype=obj -o - %s | llvm-dwarfdump -debug-info - | FileCheck %s
 ; CHECK: _ZN1B9AInstanceEv
 ; CHECK: DW_TAG_variable
-; CHECK-NEXT:   DW_AT_location [DW_FORM_sec_offset] (0x00000000
+; CHECK-NEXT:   DW_AT_location (0x00000000
 ; CHECK-NEXT:     [{{.*}}, {{.*}}): DW_OP_breg5 RDI+0
 ; CHECK-NEXT:     [{{.*}}, {{.*}}): DW_OP_breg6 RBP-24, DW_OP_deref)
 ; CHECK-NEXT:   DW_AT_name {{.*}}"a"