Fix a couple of Dwarf bugs.

- Emit DW_AT_byte_size for struct and union of size zero.
- Emit DW_AT_declaration for forward type declaration.

llvm-svn: 60812

2 files changed, 22 insertions, 8 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfWriter.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfWriter.cpp
index 9ca9e28010a..4476be3bb3f 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfWriter.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfWriter.cpp
@@ -1774,14 +1774,25 @@ private:
       }
     }
 
-    // Add size if non-zero (derived types don't have a size.)
-    if (Size) AddUInt(&Buffer, DW_AT_byte_size, 0, Size);
-
     // Add name if not anonymous or intermediate type.
     if (!Name.empty()) AddString(&Buffer, DW_AT_name, DW_FORM_string, Name);
 
-    // Add source line info if available.
-    AddSourceLine(&Buffer, TyDesc->getFile(), TyDesc->getLine());
+    // Add size if non-zero (derived types might be zero-sized.)
+    if (Size)
+      AddUInt(&Buffer, DW_AT_byte_size, 0, Size);
+    else if (isa<CompositeTypeDesc>(TyDesc)) {
+      // If TyDesc is a composite type, then add size even if it's zero unless
+      // it's a forward declaration.
+      if (TyDesc->isForwardDecl())
+        AddUInt(&Buffer, DW_AT_declaration, DW_FORM_flag, 1);
+      else
+        AddUInt(&Buffer, DW_AT_byte_size, 0, 0);
+    }
+
+    // Add source line info if available and TyDesc is not a forward
+    // declaration.
+    if (!TyDesc->isForwardDecl())
+      AddSourceLine(&Buffer, TyDesc->getFile(), TyDesc->getLine());
   }
 
   /// NewCompileUnit - Create new compile unit and it's debug information entry.
diff --git a/llvm/lib/CodeGen/MachineModuleInfo.cpp b/llvm/lib/CodeGen/MachineModuleInfo.cpp
index 9e0e9025a4b..f93f27c934d 100644
--- a/llvm/lib/CodeGen/MachineModuleInfo.cpp
+++ b/llvm/lib/CodeGen/MachineModuleInfo.cpp
@@ -906,7 +906,8 @@ void BasicTypeDesc::dump() {
        << "Context(" << getContext() << "), "
        << "Name(\"" << getName() << "\"), "
        << "Size(" << getSize() << "), "
-       << "Encoding(" << Encoding << ")\n";
+       << "Encoding(" << Encoding << "),"
+       << "Flags(" << Flags << ")\n";
 }
 #endif
 
@@ -965,7 +966,8 @@ void DerivedTypeDesc::dump() {
        << "Size(" << getSize() << "), "
        << "File(" << getFile() << "), "
        << "Line(" << getLine() << "), "
-       << "FromType(" << FromType << ")\n";
+       << "FromType(" << FromType << "),"
+       << "Flags(" << Flags << ")\n";
 }
 #endif
 
@@ -1023,7 +1025,8 @@ void CompositeTypeDesc::dump() {
        << "File(" << getFile() << "), "
        << "Line(" << getLine() << "), "
        << "FromType(" << getFromType() << "), "
-       << "Elements.size(" << Elements.size() << ")\n";
+       << "Elements.size(" << Elements.size() << "),"
+       << "Flags(" << Flags << ")\n";
 }
 #endif