Thanks, Glenn, it's the column positions of the warning on line 9.

Flymake expects the warning to come after the note, but on 
gcc 4 it comes before. No biggie, I'll just skip it based on the 
output of gcc -v.

On Fri, Oct 20, 2017 at 12:55 AM, Glenn Morris <rgm@gnu.org> wrote:

And here's the output with gcc 5.3 on the same system, where the test passes:

cc    -c -o errors-and-warnings.o errors-and-warnings.c
In file included from errors-and-warnings.c:3:0:
some-problems.h:3:1: warning: data definition has no type or storage class
 strange;
 ^
some-problems.h:3:1: warning: type defaults to 'int' in declaration of 'strange' [-Wimplicit-int]
some-problems.h:5:1: error: unknown type name 'sint'
 sint main();
 ^
errors-and-warnings.c: In function 'main':
errors-and-warnings.c:9:12: warning: overflow in implicit constant conversion [-Woverflow]
   char c = 1000; /* a note and a warning */
            ^
errors-and-warnings.c:11:8: error: redeclaration of 'c' with no linkage
   char c; if (bla == (void*)3); /* an error, and two warnings */
        ^
errors-and-warnings.c:9:8: note: previous definition of 'c' was here
   char c = 1000; /* a note and a warning */
        ^
errors-and-warnings.c:11:19: warning: comparison between pointer and integer
   char c; if (bla == (void*)3); /* an error, and two warnings */
                   ^




--
João Távora