From 607f14168a8e424fe9f82640be26667f5c80098d Mon Sep 17 00:00:00 2001
From: Douglas Gregor <dgregor@apple.com>
Date: Tue, 30 Mar 2010 20:35:20 +0000
Subject: [PATCH] Improve diagnostics when printing a template instantiation
 backtrace involving substitution of deduced template arguments into a class
 template partial specialization or function template, or when substituting
 explicitly-specific template arguments into a function template. We now print
 the actual deduced argument bindings so the user can see what got deduced.

llvm-svn: 99923
---
 clang/include/clang/Basic/DiagnosticSemaKinds.td |  8 ++++----
 clang/lib/Sema/SemaTemplateInstantiate.cpp       | 16 ++++++++++++++--
 .../SemaTemplate/instantiate-function-params.cpp |  2 +-
 3 files changed, 19 insertions(+), 7 deletions(-)

diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index 58c40cf3380f..61f1048e51c9 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -1385,13 +1385,13 @@ def note_default_function_arg_instantiation_here : Note<
   "for '%0' required here">;
 def note_explicit_template_arg_substitution_here : Note<
   "while substituting explicitly-specified template arguments into function "
-  "template %0, here">;
+  "template %0 %1">;
 def note_function_template_deduction_instantiation_here : Note<
-  "while substituting deduced template arguments into function template %0, "
-  "here">;
+  "while substituting deduced template arguments into function template %0 "
+  "%1">;
 def note_partial_spec_deduct_instantiation_here : Note<
   "during template argument deduction for class template partial "
-  "specialization %0, here">;
+  "specialization %0 %1">;
 def note_prior_template_arg_substitution : Note<
   "while substituting prior template arguments into %select{non-type|template}0"
   " template parameter%1 %2">;
diff --git a/clang/lib/Sema/SemaTemplateInstantiate.cpp b/clang/lib/Sema/SemaTemplateInstantiate.cpp
index 4da1fcb9242e..d08f483a6a08 100644
--- a/clang/lib/Sema/SemaTemplateInstantiate.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiate.cpp
@@ -394,7 +394,11 @@ void Sema::PrintInstantiationStack() {
         = cast<FunctionTemplateDecl>((Decl *)Active->Entity);
       Diags.Report(FullSourceLoc(Active->PointOfInstantiation, SourceMgr),
                    diag::note_explicit_template_arg_substitution_here)
-        << FnTmpl << Active->InstantiationRange;
+        << FnTmpl 
+        << getTemplateArgumentBindingsText(FnTmpl->getTemplateParameters(), 
+                                           Active->TemplateArgs, 
+                                           Active->NumTemplateArgs)
+        << Active->InstantiationRange;
       break;
     }
 
@@ -405,13 +409,21 @@ void Sema::PrintInstantiationStack() {
         Diags.Report(FullSourceLoc(Active->PointOfInstantiation, SourceMgr),
                      diag::note_partial_spec_deduct_instantiation_here)
           << Context.getTypeDeclType(PartialSpec)
+          << getTemplateArgumentBindingsText(
+                                         PartialSpec->getTemplateParameters(), 
+                                             Active->TemplateArgs, 
+                                             Active->NumTemplateArgs)
           << Active->InstantiationRange;
       } else {
         FunctionTemplateDecl *FnTmpl
           = cast<FunctionTemplateDecl>((Decl *)Active->Entity);
         Diags.Report(FullSourceLoc(Active->PointOfInstantiation, SourceMgr),
                      diag::note_function_template_deduction_instantiation_here)
-          << FnTmpl << Active->InstantiationRange;
+          << FnTmpl
+          << getTemplateArgumentBindingsText(FnTmpl->getTemplateParameters(), 
+                                             Active->TemplateArgs, 
+                                             Active->NumTemplateArgs)
+          << Active->InstantiationRange;
       }
       break;
 
diff --git a/clang/test/SemaTemplate/instantiate-function-params.cpp b/clang/test/SemaTemplate/instantiate-function-params.cpp
index 14c4d9f933a7..ea8dd7061988 100644
--- a/clang/test/SemaTemplate/instantiate-function-params.cpp
+++ b/clang/test/SemaTemplate/instantiate-function-params.cpp
@@ -7,7 +7,7 @@ template<typename T1> struct if_ {
 };
 template <class Model, void (Model::*)()> struct wrap_constraints { };
 template <class Model> 
-inline char has_constraints_(Model* ,  // expected-note 4{{while substituting}} \
+inline char has_constraints_(Model* ,  // expected-note 4{{while substituting deduced template arguments into function template 'has_constraints_' [with }} \
                              // expected-note 3{{candidate template ignored}}
                                wrap_constraints<Model,&Model::constraints>* = 0); // expected-note 4{{in instantiation}}