Avoid double substitution with complete explicit template arguments.

Previously, when we got a function template with explicit arguments for all
of the template parameters, we still did "deduction", which of course
couldn't deduce anything, but did other deduction-time checking of
non-dependent conversions and such.  This broke down with the unevaluated
lambdas patch (to follow): substituting into the lambda multiple times, once
to get the function type for deduction and then again to generate the actual
decl, doesn't work, since different substitutions of a lambda produce
different types.  I believe that skipping the initial substitution when we
have all the arguments is still conformant, and produces better diagnostics
for some testcases.

	* pt.c (fn_type_unification): If we have a full set of explicit
	arguments, go straight to substitution.

From-SVN: r266055

6 files changed, 14 insertions, 20 deletions

diff --git a/gcc/testsuite/g++.dg/cpp0x/decltype48.C b/gcc/testsuite/g++.dg/cpp0x/decltype48.C
index 39fc4eb..7f5005b 100644
--- a/gcc/testsuite/g++.dg/cpp0x/decltype48.C
+++ b/gcc/testsuite/g++.dg/cpp0x/decltype48.C
@@ -6,7 +6,7 @@ template<typename T> struct baz { };
 template<typename T> T bar();
 
 template<typename T, typename ... U>
-baz<decltype(bar<Int>(bar<U>() ...))> // { dg-error "no match" }
+baz<decltype(bar<Int>(bar<U>() ...))> // { dg-error "" }
 foo();
 
 int main()
diff --git a/gcc/testsuite/g++.dg/cpp0x/diag1.C b/gcc/testsuite/g++.dg/cpp0x/diag1.C
index 9bf7cfe..1f8c4a4 100644
--- a/gcc/testsuite/g++.dg/cpp0x/diag1.C
+++ b/gcc/testsuite/g++.dg/cpp0x/diag1.C
@@ -23,7 +23,7 @@ struct TypeC
   //   TypeC::fn()
   // we don't want to see the template header, return type, or parameter bindings
   // for TypeB::fn.
-  template <int N> auto fn() -> decltype(b.fn<N>()); // { dg-bogus "typename|with" }
+  template <int N> auto fn() -> decltype(b.fn<N>()); // { dg-bogus "typename" }
 };
 
 int main()
diff --git a/gcc/testsuite/g++.dg/cpp0x/error4.C b/gcc/testsuite/g++.dg/cpp0x/error4.C
index bd73b2a7..1f365b7 100644
--- a/gcc/testsuite/g++.dg/cpp0x/error4.C
+++ b/gcc/testsuite/g++.dg/cpp0x/error4.C
@@ -12,7 +12,7 @@ struct S {
   template<typename U>
     static decltype(*declval<U>()) get(...); // { dg-error "operator*" }
 
-  typedef decltype(get<T>(declval<T>())) type; // { dg-error "no match" }
+  typedef decltype(get<T>(declval<T>())) type; // { dg-error "" }
 };
 
 struct X { };
diff --git a/gcc/testsuite/g++.dg/cpp0x/pr77655.C b/gcc/testsuite/g++.dg/cpp0x/pr77655.C
index ab2e942..8b4ffa6 100644
--- a/gcc/testsuite/g++.dg/cpp0x/pr77655.C
+++ b/gcc/testsuite/g++.dg/cpp0x/pr77655.C
@@ -3,7 +3,7 @@
 
 template <class F> void g(F);
 template <class... A>
-auto h(A &&... a) -> decltype(g(0, g<decltype(a)>(a)...)) {  // { dg-error "no matching" }
+auto h(A &&... a) -> decltype(g(0, g<decltype(a)>(a)...)) {  // { dg-error "" }
   h([] {});  // { dg-error "no matching" }
 }
 
diff --git a/gcc/testsuite/g++.dg/diagnostic/param-type-mismatch-2.C b/gcc/testsuite/g++.dg/diagnostic/param-type-mismatch-2.C
index f74f8d3..b19655d 100644
--- a/gcc/testsuite/g++.dg/diagnostic/param-type-mismatch-2.C
+++ b/gcc/testsuite/g++.dg/diagnostic/param-type-mismatch-2.C
@@ -134,21 +134,17 @@ int test_7 (int one, T two, float three); // { dg-line test_7_decl }
 int test_7 (int first, const char *second, float third)
 {
   return test_7 <const char **> (first, second, third); // { dg-line test_7_usage }
-  // { dg-error "no matching function" "" { target *-*-* } test_7_usage }
+  // { dg-message "cannot convert 'const char\\*' to 'const char\\*\\*'" "" { target *-*-* } test_7_usage }
   /* { dg-begin-multiline-output "" }
    return test_7 <const char **> (first, second, third);
-                                                      ^
+                                         ^~~~~~
+                                         |
+                                         const char*
      { dg-end-multiline-output "" } */
-  // { dg-message "candidate: 'template<class T> int test_7\\(int, T, float\\)'" "" { target *-*-* } test_7_decl }
+  // { dg-message "initializing argument 2 of 'int test_7\\(int, T, float\\) .with T = const char\\*\\*.'" "" { target *-*-* } test_7_decl }
   /* { dg-begin-multiline-output "" }
  int test_7 (int one, T two, float three);
-     ^~~~~~
-     { dg-end-multiline-output "" } */
-  // { dg-message "template argument deduction/substitution failed:" "" { target *-*-* } test_7_decl }
-  // { dg-message "cannot convert 'second' \\(type 'const char\\*'\\) to type 'const char\\*\\*'" "" { target *-*-* } test_7_usage }
-  /* { dg-begin-multiline-output "" }
-   return test_7 <const char **> (first, second, third);
-                                         ^~~~~~
+                      ~~^~~
      { dg-end-multiline-output "" } */
 }
 
diff --git a/gcc/testsuite/g++.dg/diagnostic/param-type-mismatch.C b/gcc/testsuite/g++.dg/diagnostic/param-type-mismatch.C
index 50bbd4a..cb5c360 100644
--- a/gcc/testsuite/g++.dg/diagnostic/param-type-mismatch.C
+++ b/gcc/testsuite/g++.dg/diagnostic/param-type-mismatch.C
@@ -130,18 +130,16 @@ int test_7 (int one, T two, float three);
 
 int test_7 (int first, int second, float third)
 {
-  return test_7 <const char *> (first, second, third); // { dg-error "no matching function" }
-  /* { dg-begin-multiline-output "" }
-   return test_7 <const char *> (first, second, third);
-                                                     ^
-     { dg-end-multiline-output "" } */
+  return test_7 <const char *> (first, second, third); // { dg-error "invalid conversion from 'int' to 'const char\\*'" }
   /* { dg-begin-multiline-output "" }
    return test_7 <const char *> (first, second, third);
                                         ^~~~~~
+                                        |
+                                        int
      { dg-end-multiline-output "" } */
   /* { dg-begin-multiline-output "" }
  int test_7 (int one, T two, float three);
-     ^~~~~~
+                      ~~^~~
      { dg-end-multiline-output "" } */
 }