Apply patch from Richard Trieu to fix PR9548:

When two different types has the same text representation in the same
diagnostic message, print an a.k.a. after the type if the a.k.a. gives extra
information about the type.

class versa_string;

typedef versa_string string;

namespace std {template <typename T> class vector;}

using std::vector;

void f(vector<string> v);

namespace std {
class basic_string;
typedef basic_string string;
template <typename T> class vector {};
void g() {
  vector<string> v;
  f(v);
}
}

Old message:
----------------
test.cc:15:3: error: no matching function for call to 'f'
  f(&v);
  ^
test.cc:7:6: note: candidate function not viable: no known conversion from
      'vector<string>' to 'vector<string>' for 1st argument
void f(vector<string> v);
     ^
1 error generated.

New message:
---------------
test.cc:15:3: error: no matching function for call to 'f'
  f(v);
  ^
test.cc:7:6: note: candidate function not viable: no known conversion from
      'vector<string>' (aka 'std::vector<std::basic_string>') to
      'vector<string>' (aka 'std::vector<versa_string>') for 1st argument
void f(vector<string> v);
     ^
1 error generated.

llvm-svn: 134904

1 files changed, 11 insertions, 3 deletions

diff --git a/clang/lib/Basic/Diagnostic.cpp b/clang/lib/Basic/Diagnostic.cpp
index e0ef53d00de..ae363a0df0d 100644
--- a/clang/lib/Basic/Diagnostic.cpp
+++ b/clang/lib/Basic/Diagnostic.cpp
@@ -26,7 +26,8 @@ static void DummyArgToStringFn(Diagnostic::ArgumentKind AK, intptr_t QT,
                                const Diagnostic::ArgumentValue *PrevArgs,
                                unsigned NumPrevArgs,
                                llvm::SmallVectorImpl<char> &Output,
-                               void *Cookie) {
+                               void *Cookie,
+                               llvm::SmallVectorImpl<intptr_t> &QualTypeVals) {
   const char *Str = "<can't format argument>";
   Output.append(Str, Str+strlen(Str));
 }
@@ -544,7 +545,14 @@ FormatDiagnostic(const char *DiagStr, const char *DiagEnd,
   /// ConvertArgToString, allowing the implementation to avoid redundancies in
   /// obvious cases.
   llvm::SmallVector<Diagnostic::ArgumentValue, 8> FormattedArgs;
-  
+
+  /// QualTypeVals - Pass a vector of arrays so that QualType names can be
+  /// compared to see if more information is needed to be printed.
+  llvm::SmallVector<intptr_t, 2> QualTypeVals;
+  for (unsigned i = 0, e = getNumArgs(); i < e; ++i)
+    if (getArgKind(i) == Diagnostic::ak_qualtype)
+      QualTypeVals.push_back(getRawArg(i));
+
   while (DiagStr != DiagEnd) {
     if (DiagStr[0] != '%') {
       // Append non-%0 substrings to Str if we have one.
@@ -675,7 +683,7 @@ FormatDiagnostic(const char *DiagStr, const char *DiagEnd,
                                      Modifier, ModifierLen,
                                      Argument, ArgumentLen,
                                      FormattedArgs.data(), FormattedArgs.size(),
-                                     OutStr);
+                                     OutStr, QualTypeVals);
       break;
     }