[DebugInfo] Improvements to representation of enumeration types (PR36168)

This patch:

* fixes an incorrect sign-extension of unsigned values, when emitting
  debug info metadata for enumerators
* the enumerators metadata is created with a flag, which determines
  interpretation of the value bits (signed or unsigned)
* the enumerations metadata contains the underlying integer type and a
  flag, indicating whether this is a C++ "fixed enum"

Differential Revision: https://reviews.llvm.org/D42736

llvm-svn: 324490

1 files changed, 7 insertions, 5 deletions

diff --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp
index e766ccc203b..9d12130376f 100644
--- a/clang/lib/CodeGen/CGDebugInfo.cpp
+++ b/clang/lib/CodeGen/CGDebugInfo.cpp
@@ -2492,9 +2492,12 @@ llvm::DIType *CGDebugInfo::CreateTypeDefinition(const EnumType *Ty) {
   // Create elements for each enumerator.
   SmallVector<llvm::Metadata *, 16> Enumerators;
   ED = ED->getDefinition();
+  bool IsSigned = ED->getIntegerType()->isSignedIntegerType();
   for (const auto *Enum : ED->enumerators()) {
-    Enumerators.push_back(DBuilder.createEnumerator(
-        Enum->getName(), Enum->getInitVal().getSExtValue()));
+    const auto &InitVal = Enum->getInitVal();
+    auto Value = IsSigned ? InitVal.getSExtValue() : InitVal.getZExtValue();
+    Enumerators.push_back(
+        DBuilder.createEnumerator(Enum->getName(), Value, !IsSigned));
   }
 
   // Return a CompositeType for the enum itself.
@@ -2503,11 +2506,10 @@ llvm::DIType *CGDebugInfo::CreateTypeDefinition(const EnumType *Ty) {
   llvm::DIFile *DefUnit = getOrCreateFile(ED->getLocation());
   unsigned Line = getLineNumber(ED->getLocation());
   llvm::DIScope *EnumContext = getDeclContextDescriptor(ED);
-  llvm::DIType *ClassTy =
-      ED->isFixed() ? getOrCreateType(ED->getIntegerType(), DefUnit) : nullptr;
+  llvm::DIType *ClassTy = getOrCreateType(ED->getIntegerType(), DefUnit);
   return DBuilder.createEnumerationType(EnumContext, ED->getName(), DefUnit,
                                         Line, Size, Align, EltArray, ClassTy,
-                                        FullName);
+                                        FullName, ED->isFixed());
 }
 
 llvm::DIMacro *CGDebugInfo::CreateMacro(llvm::DIMacroFile *Parent,