Don't accept %q length specifiers in the kernel (more precisely,

if compiling with -fformat-extensions). Gcc's format checker never
actually supported %q length specifiers.  It treats %q as an alias
for %ll, which is correct if quad_t is long long (e.g., on i386's)
and broken otherwise (e.g., on alphas).

quad_t's currently should be printed in the same way that they
already need to be printed to avoid compiler warnings on all
supported systems: cast them to a standard type that is at least
as large (long or long long) and use the length specifier for that
(%l or %ll).  This is problematic since long long isn't standard
yet.  C9x's intmax_t should be implemented soon.

Don't accept %L length specifiers in the kernel either.  The only
legitimate ones are for long doubles, but the kernel doesn't even
support plain doubles.  (gcc bogusly accepts %Ld as an alias for
%lld, and it sometimes prints "q" in error messages about "ll" and
"L" length specifiers, becauses it represents all these specifiers
as 'q'.)

Submitted by:	bde

1 files changed, 2 insertions, 1 deletions

diff --git a/contrib/gcc/c-common.c b/contrib/gcc/c-common.c
index 5e5b712..53a8bba 100644
--- a/contrib/gcc/c-common.c
+++ b/contrib/gcc/c-common.c
@@ -1615,7 +1615,8 @@ check_format_info (info, params)
 	{
 	  if (*format_chars == 'h' || *format_chars == 'l')
 	    length_char = *format_chars++;
-	  else if (*format_chars == 'q' || *format_chars == 'L')
+	  else if ((*format_chars == 'q' || *format_chars == 'L')
+		   && !flag_format_extensions)
 	    {
 	      length_char = *format_chars++;
 	      if (pedantic)