Extend builtin "attribute" syntax to include a notation for
printf-like functions, both builtin functions and those in the
C library. The function-call checker now queries this attribute do
determine if we have a printf-like function, rather than scanning
through the list of "known functions IDs". However, there are 5
functions they are not yet "builtins", so the function-call checker
handles them specifically still:

  - fprintf and vfprintf: the builtins mechanism cannot (yet)
    express FILE* arguments, so these can't be encoded.
  - NSLog: the builtins mechanism cannot (yet) express NSString*
    arguments, so this (and NSLogv) can't be encoded.
  - asprintf and vasprintf: these aren't part of the C99 standard
    library, so we really shouldn't be defining them as builtins in
    the general case (and we don't seem to have the machinery to make
    them builtins only on certain targets and depending on whether
    extensions are enabled).



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@64512 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/Rewriter/finally.m b/test/Rewriter/finally.m
index 903cdec..0d623dc 100644
--- a/test/Rewriter/finally.m
+++ b/test/Rewriter/finally.m
@@ -2,7 +2,8 @@
 
 int main() {
   @try {
-    printf("executing try");
+    printf("executing try"); // expected-warning{{implicitly declaring C library function 'printf' with type 'int (char const *, ...)'}} \
+        // expected-note{{please include the header <stdio.h> or explicitly provide a declaration for 'printf'}}
     return(0); // expected-warning{{rewriter doesn't support user-specified control flow semantics for @try/@finally (code may not execute properly)}}
   } @finally {
     printf("executing finally");