Introduce a FunctionDecl::getReturnTypeSourceRange() utility

This source range is useful for all kinds of diagnostic QOI and refactoring
work, so let's make it more discoverable.

This commit also makes use of the new function to enhance various diagnostics
relating to return types and resolves an old FIXME.

llvm-svn: 212154

1 files changed, 17 insertions, 0 deletions

diff --git a/clang/lib/AST/Decl.cpp b/clang/lib/AST/Decl.cpp
index d910a669abf..702a2e32e3e 100644
--- a/clang/lib/AST/Decl.cpp
+++ b/clang/lib/AST/Decl.cpp
@@ -2687,6 +2687,23 @@ bool FunctionDecl::doesDeclarationForceExternallyVisibleDefinition() const {
   return FoundBody;
 }
 
+SourceRange FunctionDecl::getReturnTypeSourceRange() const {
+  const TypeSourceInfo *TSI = getTypeSourceInfo();
+  if (!TSI)
+    return SourceRange();
+
+  TypeLoc TL = TSI->getTypeLoc();
+  FunctionTypeLoc FunctionTL = TL.getAs<FunctionTypeLoc>();
+  if (!FunctionTL)
+    return SourceRange();
+
+  TypeLoc ResultTL = FunctionTL.getReturnLoc();
+  if (ResultTL.getUnqualifiedLoc().getAs<BuiltinTypeLoc>())
+    return ResultTL.getSourceRange();
+
+  return SourceRange();
+}
+
 /// \brief For an inline function definition in C, or for a gnu_inline function
 /// in C++, determine whether the definition will be externally visible.
 ///