Treating the unused equality comparisons as something other than part of

-Wunused was a mistake. It resulted in duplicate warnings and lots of
other hacks. Instead, this should be a special sub-category to
-Wunused-value, much like -Wunused-result is.

Moved to -Wunused-comparison, moved the implementation to piggy back on
the -Wunused-value implementation instead of rolling its own, different
mechanism for catching all of the "interesting" statements.

I like the unused-value mechanism for this better, but its currently
missing several top-level statements. For now, I've FIXME-ed out those
test cases. I'll enhance the generic infrastructure to catch these
statements in a subsequent patch.

This patch also removes the cast-to-void fixit hint. This hint isn't
available on any of the other -Wunused-value diagnostics, and if we want
it to be, we should add it generically rather than in one specific case.

llvm-svn: 137822

1 files changed, 6 insertions, 4 deletions

diff --git a/clang/test/SemaTemplate/resolve-single-template-id.cpp b/clang/test/SemaTemplate/resolve-single-template-id.cpp
index ef0a7630767..0c4656a8bc1 100644
--- a/clang/test/SemaTemplate/resolve-single-template-id.cpp
+++ b/clang/test/SemaTemplate/resolve-single-template-id.cpp
@@ -44,9 +44,10 @@ int main()
   !oneT<int>;  // expected-warning {{expression result unused}}
   +oneT<int>;  // expected-warning {{expression result unused}}
   -oneT<int>;  //expected-error {{invalid argument type}}
-  oneT<int> == 0;   // expected-warning {{expression result unused}}
-  0 == oneT<int>;   // expected-warning {{expression result unused}}
-  0 != oneT<int>;    // expected-warning {{expression result unused}}
+  oneT<int> == 0;   // expected-warning {{equality comparison result unused}} \
+                    // expected-note {{use '=' to turn this equality comparison into an assignment}}
+  0 == oneT<int>;   // expected-warning {{equality comparison result unused}}
+  0 != oneT<int>;    // expected-warning {{inequality comparison result unused}}
   (false ? one : oneT<int>);   // expected-warning {{expression result unused}}
   void (*p1)(int); p1 = oneT<int>;
   
@@ -67,7 +68,8 @@ int main()
 
   two < two; //expected-error {{cannot resolve overloaded function 'two' from context}}
   twoT<int> < twoT<int>; //expected-error {{cannot resolve overloaded function 'twoT' from context}}
-  oneT<int> == 0;   // expected-warning {{expression result unused}}
+  oneT<int> == 0;   // expected-warning {{equality comparison result unused}} \
+                    // expected-note {{use '=' to turn this equality comparison into an assignment}}
 
 }