Fix a long standard problem with clang retaining "too much" sugar

information about types.  We often print diagnostics where we say 
"foo_t" is bad, but the user doesn't know how foo_t is declared 
(because it is a typedef).  Fix this by expanding sugar when present
in a diagnostic (and not one of a few special cases, like vectors).

Before:
t.m:5:2: error: invalid operands to binary expression ('typeof(P)' and 'typeof(F)')
 MAX(P, F);
 ^~~~~~~~~
t.m:1:78: note: instantiated from:
#define MAX(A,B)    ({ __typeof__(A) __a = (A); __typeof__(B) __b = (B); __a < __b ? __b : __a; })
                                                                             ^

After:
t.m:5:2: error: invalid operands to binary expression ('typeof(P)' (aka 'struct mystruct') and 'typeof(F)' (aka 'float'))
 MAX(P, F);
 ^~~~~~~~~
t.m:1:78: note: instantiated from:
#define MAX(A,B)    ({ __typeof__(A) __a = (A); __typeof__(B) __b = (B); __a < __b ? __b : __a; })
                                                                             ^

llvm-svn: 65081

1 files changed, 9 insertions, 0 deletions

diff --git a/clang/test/Sema/exprs.c b/clang/test/Sema/exprs.c
index 4ddb976eb2e..ba411c528da 100644
--- a/clang/test/Sema/exprs.c
+++ b/clang/test/Sema/exprs.c
@@ -64,3 +64,12 @@ void test10(int n,...) {
   }               s;
   double x = s.a[0];  // should not get another error here.
 }
+
+
+#define MYMAX(A,B)    __extension__ ({ __typeof__(A) __a = (A); __typeof__(B) __b = (B); __a < __b ? __b : __a; })
+
+struct mystruct {int A; };
+void foo(struct mystruct P, float F) {
+  MYMAX(P, F);  // expected-error {{invalid operands to binary expression ('typeof(P)' (aka 'struct mystruct') and 'typeof(F)' (aka 'float'))}}
+}
+