[llvm] r234250 - DebugInfo: Allow isa<> on DIDescriptor and subclasses

[Duncan P. N. Exon Smith]

Author: dexonsmith
Date: Mon Apr  6 17:32:20 2015
New Revision: 234250

URL: http://llvm.org/viewvc/llvm-project?rev=234250&view=rev
Log:
DebugInfo: Allow isa<> on DIDescriptor and subclasses

Allow LLVM-style casting on `DIDescriptor` and its subclasses so they
can behave more like raw pointers.  I haven't bothered with tests since
I have a follow-up commit coming shortly that uses them extensively in
tree, and I'm hoping to kill `DIDescriptor` entirely before too long (so
they won't have time to bitrot).

Usage examples:

    DIDescriptor D = foo();
    if (DICompileUnit CU = dyn_cast<MDCompileUnit>(D))
      return bar(CU);
    else if (auto *SP = dyn_cast<MDSubprogram>(D))
      return baz(SP);
    return other(D);

Modified:
    llvm/trunk/include/llvm/IR/DebugInfo.h

Modified: llvm/trunk/include/llvm/IR/DebugInfo.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/IR/DebugInfo.h?rev=234250&r1=234249&r2=234250&view=diff
==============================================================================
--- llvm/trunk/include/llvm/IR/DebugInfo.h (original)
+++ llvm/trunk/include/llvm/IR/DebugInfo.h Mon Apr  6 17:32:20 2015
@@ -168,6 +168,35 @@ public:
   void replaceAllUsesWith(MDNode *D);
 };
 
+#define DECLARE_SIMPLIFY_DESCRIPTOR(DESC)                                      \
+  class DESC;                                                                  \
+  template <> struct simplify_type<const DESC>;                                \
+  template <> struct simplify_type<DESC>;
+DECLARE_SIMPLIFY_DESCRIPTOR(DIDescriptor)
+DECLARE_SIMPLIFY_DESCRIPTOR(DISubrange)
+DECLARE_SIMPLIFY_DESCRIPTOR(DIEnumerator)
+DECLARE_SIMPLIFY_DESCRIPTOR(DIScope)
+DECLARE_SIMPLIFY_DESCRIPTOR(DIType)
+DECLARE_SIMPLIFY_DESCRIPTOR(DIBasicType)
+DECLARE_SIMPLIFY_DESCRIPTOR(DIDerivedType)
+DECLARE_SIMPLIFY_DESCRIPTOR(DICompositeType)
+DECLARE_SIMPLIFY_DESCRIPTOR(DISubroutineType)
+DECLARE_SIMPLIFY_DESCRIPTOR(DIFile)
+DECLARE_SIMPLIFY_DESCRIPTOR(DICompileUnit)
+DECLARE_SIMPLIFY_DESCRIPTOR(DISubprogram)
+DECLARE_SIMPLIFY_DESCRIPTOR(DILexicalBlock)
+DECLARE_SIMPLIFY_DESCRIPTOR(DILexicalBlockFile)
+DECLARE_SIMPLIFY_DESCRIPTOR(DINameSpace)
+DECLARE_SIMPLIFY_DESCRIPTOR(DITemplateTypeParameter)
+DECLARE_SIMPLIFY_DESCRIPTOR(DITemplateValueParameter)
+DECLARE_SIMPLIFY_DESCRIPTOR(DIGlobalVariable)
+DECLARE_SIMPLIFY_DESCRIPTOR(DIVariable)
+DECLARE_SIMPLIFY_DESCRIPTOR(DIExpression)
+DECLARE_SIMPLIFY_DESCRIPTOR(DILocation)
+DECLARE_SIMPLIFY_DESCRIPTOR(DIObjCProperty)
+DECLARE_SIMPLIFY_DESCRIPTOR(DIImportedEntity)
+#undef DECLARE_SIMPLIFY_DESCRIPTOR
+
 /// \brief This is used to represent ranges, for array bounds.
 class DISubrange : public DIDescriptor {
 public:
@@ -1121,6 +1150,37 @@ public:
   StringRef getName() const { return get()->getName(); }
 };
 
+#define SIMPLIFY_DESCRIPTOR(DESC)                                              \
+  template <> struct simplify_type<const DESC> {                               \
+    typedef Metadata *SimpleType;                                              \
+    static SimpleType getSimplifiedValue(const DESC &DI) { return DI; }        \
+  };                                                                           \
+  template <> struct simplify_type<DESC> : simplify_type<const DESC> {};
+SIMPLIFY_DESCRIPTOR(DIDescriptor)
+SIMPLIFY_DESCRIPTOR(DISubrange)
+SIMPLIFY_DESCRIPTOR(DIEnumerator)
+SIMPLIFY_DESCRIPTOR(DIScope)
+SIMPLIFY_DESCRIPTOR(DIType)
+SIMPLIFY_DESCRIPTOR(DIBasicType)
+SIMPLIFY_DESCRIPTOR(DIDerivedType)
+SIMPLIFY_DESCRIPTOR(DICompositeType)
+SIMPLIFY_DESCRIPTOR(DISubroutineType)
+SIMPLIFY_DESCRIPTOR(DIFile)
+SIMPLIFY_DESCRIPTOR(DICompileUnit)
+SIMPLIFY_DESCRIPTOR(DISubprogram)
+SIMPLIFY_DESCRIPTOR(DILexicalBlock)
+SIMPLIFY_DESCRIPTOR(DILexicalBlockFile)
+SIMPLIFY_DESCRIPTOR(DINameSpace)
+SIMPLIFY_DESCRIPTOR(DITemplateTypeParameter)
+SIMPLIFY_DESCRIPTOR(DITemplateValueParameter)
+SIMPLIFY_DESCRIPTOR(DIGlobalVariable)
+SIMPLIFY_DESCRIPTOR(DIVariable)
+SIMPLIFY_DESCRIPTOR(DIExpression)
+SIMPLIFY_DESCRIPTOR(DILocation)
+SIMPLIFY_DESCRIPTOR(DIObjCProperty)
+SIMPLIFY_DESCRIPTOR(DIImportedEntity)
+#undef SIMPLIFY_DESCRIPTOR
+
 /// \brief Find subprogram that is enclosing this scope.
 DISubprogram getDISubprogram(const MDNode *Scope);