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);

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234250 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/IR/DebugInfo.h b/include/llvm/IR/DebugInfo.h
index f022edddb0e41bc7aa7ad4af3df303dd46b141cc..1972526b340e82b38a2b0426f8ab36d199e96858 100644 (file)
--- a/include/llvm/IR/DebugInfo.h
+++ b/include/llvm/IR/DebugInfo.h
@@ -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);