[PATCH] D87062: [DebugInfo] Add size to class declarations in debug info.

[Amy Huang via Phabricator via cfe-commits]

akhuang updated this revision to Diff 289602.
akhuang marked an inline comment as done.
akhuang added a comment.

remove assert; edit test case


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D87062/new/

https://reviews.llvm.org/D87062

Files:
  clang/lib/CodeGen/CGDebugInfo.cpp
  clang/test/CodeGenCXX/debug-info-class.cpp
  llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
  llvm/test/DebugInfo/X86/struct-fwd-decl.ll


Index: llvm/test/DebugInfo/X86/struct-fwd-decl.ll
===================================================================
--- /dev/null
+++ llvm/test/DebugInfo/X86/struct-fwd-decl.ll
@@ -0,0 +1,23 @@
+; RUN: llc -O0 -mtriple=x86_64-unknown-linux %s -o %t -filetype=obj
+; RUN: llvm-dwarfdump -debug-info %t | FileCheck %s
+; Test that size is not emitted for class declarations in DWARF, even if it exists.
+
+ at s = global i16 0, align 2, !dbg !0
+
+!llvm.dbg.cu = !{!4}
+!llvm.module.flags = !{!7}
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = !DIGlobalVariable(name: "s", scope: null, file: !2, line: 2, type: !3, isLocal: false, isDefinition: true)
+!2 = !DIFile(filename: "foo.cpp", directory: "/tmp")
+!3 = !DICompositeType(tag: DW_TAG_structure_type, name: "S", file: !2, line: 1, size: 16, align: 16, flags: DIFlagFwdDecl)
+!4 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !2, isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !5, retainedTypes: !5, globals: !6, imports: !5)
+!5 = !{}
+; CHECK: DW_TAG_structure_type
+; CHECK-NEXT: DW_AT_name
+; CHECK-NOT: DW_AT_byte_size
+; CHECK-NEXT: DW_AT_declaration
+; CHECK-NOT: DW_AT_byte_size
+; CHECK: NULL
+!6 = !{!0}
+!7 = !{i32 1, !"Debug Info Version", i32 3}
Index: llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
===================================================================
--- llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
+++ llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
@@ -1013,8 +1013,10 @@
       Tag == dwarf::DW_TAG_class_type || Tag == dwarf::DW_TAG_structure_type ||
       Tag == dwarf::DW_TAG_union_type) {
     // Add size if non-zero (derived types might be zero-sized.)
+    // Ignore the size if it's a non-enum forward decl.
     // TODO: Do we care about size for enum forward declarations?
-    if (Size)
+    if (Size &&
+        (!CTy->isForwardDecl() || Tag == dwarf::DW_TAG_enumeration_type))
       addUInt(Buffer, dwarf::DW_AT_byte_size, None, Size);
     else if (!CTy->isForwardDecl())
       // Add zero size if it is not a forward declaration.
Index: clang/test/CodeGenCXX/debug-info-class.cpp
===================================================================
--- clang/test/CodeGenCXX/debug-info-class.cpp
+++ clang/test/CodeGenCXX/debug-info-class.cpp
@@ -136,7 +136,7 @@
 // CHECK: [[C_DTOR]] = !DISubprogram(name: "~C"
 
 // CHECK: [[D:![0-9]+]] = !DICompositeType(tag: DW_TAG_structure_type, name: "D"
-// CHECK-NOT:              size:
+// CHECK-SAME:             size:
 // CHECK-SAME:             DIFlagFwdDecl
 // CHECK-NOT:              identifier:
 // CHECK-SAME:             ){{$}}
Index: clang/lib/CodeGen/CGDebugInfo.cpp
===================================================================
--- clang/lib/CodeGen/CGDebugInfo.cpp
+++ clang/lib/CodeGen/CGDebugInfo.cpp
@@ -1031,6 +1031,10 @@
   uint64_t Size = 0;
   uint32_t Align = 0;
 
+  const RecordDecl *D = RD->getDefinition();
+  if (D && D->isCompleteDefinition())
+    Size = CGM.getContext().getTypeSize(Ty);
+
   llvm::DINode::DIFlags Flags = llvm::DINode::FlagFwdDecl;
 
   // Add flag to nontrivial forward declarations. To be consistent with MSVC,


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