When printing a non-viable overload candidate that failed due to

conflicting deduced template argument values, give a more specific
reason along with those values, e.g.,

test/SemaTemplate/overload-candidates.cpp:4:10: note: candidate template
      ignored: deduced conflicting types for parameter 'T' ('int' vs. 'long')
const T& min(const T&, const T&); 
         ^




git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@103339 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 40 insertions, 0 deletions

diff --git a/lib/AST/TemplateBase.cpp b/lib/AST/TemplateBase.cpp
index e9b1725641..0bf9f2fb7c 100644
--- a/lib/AST/TemplateBase.cpp
+++ b/lib/AST/TemplateBase.cpp
@@ -18,6 +18,7 @@
 #include "clang/AST/DeclTemplate.h"
 #include "clang/AST/Expr.h"
 #include "clang/AST/TypeLoc.h"
+#include "clang/Basic/Diagnostic.h"
 
 using namespace clang;
 
@@ -119,3 +120,42 @@ SourceRange TemplateArgumentLoc::getSourceRange() const {
   // Silence bonus gcc warning.
   return SourceRange();
 }
+
+const DiagnosticBuilder &clang::operator<<(const DiagnosticBuilder &DB,
+                                           const TemplateArgument &Arg) {
+  switch (Arg.getKind()) {
+  case TemplateArgument::Null:
+    return DB;
+      
+  case TemplateArgument::Type:
+    return DB << Arg.getAsType();
+      
+  case TemplateArgument::Declaration:
+    return DB << Arg.getAsDecl();
+      
+  case TemplateArgument::Integral:
+    return DB << Arg.getAsIntegral()->toString(10);
+      
+  case TemplateArgument::Template:
+    return DB << Arg.getAsTemplate();
+      
+  case TemplateArgument::Expression: {
+    // This shouldn't actually ever happen, so it's okay that we're
+    // regurgitating an expression here.
+    // FIXME: We're guessing at LangOptions!
+    llvm::SmallString<32> Str;
+    llvm::raw_svector_ostream OS(Str);
+    LangOptions LangOpts;
+    LangOpts.CPlusPlus = true;
+    PrintingPolicy Policy(LangOpts);
+    Arg.getAsExpr()->printPretty(OS, 0, Policy);
+    return DB << OS.str();
+  }
+      
+  case TemplateArgument::Pack:
+    // FIXME: Format arguments in a list!
+    return DB << "<parameter pack>";
+  }
+  
+  return DB;
+}