Re: [PATCH] sparse: Add GCC pre-defined macros for user-space

[Pekka Enberg <penberg@cs.helsinki.fi>]

Hi Josh,

On Sat, Aug 15, 2009 at 11:26:31PM +0300, Pekka Enberg wrote:
> > --- a/lib.c
> > +++ b/lib.c
> > @@ -788,6 +788,14 @@ void create_builtin_stream(void)
> >  		add_pre_buffer("#define __OPTIMIZE__ 1\n");
> >  	if (optimize_size)
> >  		add_pre_buffer("#define __OPTIMIZE_SIZE__ 1\n");
> > +
> > +	/* GCC defines these for limits.h */
> > +	add_pre_buffer("#weak_define __SHRT_MAX__ %d\n", __SHRT_MAX__);
> > +	add_pre_buffer("#weak_define __SCHAR_MAX__ %d\n", __SCHAR_MAX__);
> > +	add_pre_buffer("#weak_define __INT_MAX__ %d\n", __INT_MAX__);
> > +	add_pre_buffer("#weak_define __LONG_MAX__ %ld\n", __LONG_MAX__);
> > +	add_pre_buffer("#weak_define __LONG_LONG_MAX__ %lld\n", __LONG_LONG_MAX__);
> > +	add_pre_buffer("#weak_define __WCHAR_MAX__ %d\n", __WCHAR_MAX__);

On Sat, 2009-08-15 at 15:36 -0700, Josh Triplett wrote:
> These defines need to have the right type suffixes.  GCC defines
> __LONG_LONG_MAX__ with an LL suffix, and __LONG_MAX__ with an L suffix.
> You could either add the appropriate suffixes, or better yet, stringize
> the constants and print them as strings.

Right. Is there a macro in sparse to do the stringification? I didn't
find one and the best I could come up is this.

Thanks for the help so far!

			Pekka

From c96297f4e246f6ba052c99edde3475daa19686a4 Mon Sep 17 00:00:00 2001
From: Pekka Enberg <penberg@cs.helsinki.fi>
Date: Sat, 15 Aug 2009 23:22:24 +0300
Subject: [PATCH] Define GCC builtin defines for limits.h

Sparse produces a bunch of warnings like this when compiling against
glibc:

  /usr/lib/gcc/i486-linux-gnu/4.3.2//include-fixed/limits.h:33:22: warning: undefined preprocessor identifier '__INT_MAX__'
  /usr/lib/gcc/i486-linux-gnu/4.3.2//include-fixed/limits.h:64:5: warning: undefined preprocessor identifier '__SHRT_MAX__'
  /usr/lib/gcc/i486-linux-gnu/4.3.2//include-fixed/limits.h:64:21: warning: undefined preprocessor identifier '__INT_MAX__'
  /usr/include/bits/xopen_lim.h:95:6: warning: undefined preprocessor identifier '__INT_MAX__'
  /usr/include/bits/xopen_lim.h:98:7: warning: undefined preprocessor identifier '__INT_MAX__'

Fix that up by adding some add_pre_buffer() calls to
create_builtin_define(). For future reference, GCC defines the builtins
in the c_cpp_builtins() function in gcc/c-cppbuiltin.c.

Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
---
 lib.c |    8 ++++++++
 lib.h |    3 +++
 2 files changed, 11 insertions(+), 0 deletions(-)

diff --git a/lib.c b/lib.c
index 42affcd..fb7e9bc 100644
--- a/lib.c
+++ b/lib.c
@@ -788,6 +788,14 @@ void create_builtin_stream(void)
 		add_pre_buffer("#define __OPTIMIZE__ 1\n");
 	if (optimize_size)
 		add_pre_buffer("#define __OPTIMIZE_SIZE__ 1\n");
+
+	/* GCC defines these for limits.h */
+	add_pre_buffer("#weak_define __SHRT_MAX__ " STRINGIFY(__SHRT_MAX__) "\n");
+	add_pre_buffer("#weak_define __SCHAR_MAX__ " STRINGIFY(__SCHAR_MAX__) "\n");
+	add_pre_buffer("#weak_define __INT_MAX__ " STRINGIFY(__INT_MAX__) "\n");
+	add_pre_buffer("#weak_define __LONG_MAX__ " STRINGIFY(__LONG_MAX__) "\n");
+	add_pre_buffer("#weak_define __LONG_LONG_MAX__ " STRINGIFY(__LONG_LONG_MAX__) "\n");
+	add_pre_buffer("#weak_define __WCHAR_MAX__ " STRINGIFY(__WCHAR_MAX__) "\n");
 }
 
 static struct symbol_list *sparse_tokenstream(struct token *token)
diff --git a/lib.h b/lib.h
index b22fa93..62f7433 100644
--- a/lib.h
+++ b/lib.h
@@ -17,6 +17,9 @@
 #include "compat.h"
 #include "ptrlist.h"
 
+#define __STRINGIFY(x) #x
+#define STRINGIFY(x) __STRINGIFY(x)
+
 extern int verbose, optimize, optimize_size, preprocessing;
 extern int die_if_error;
 extern int repeat_phase, merge_phi_sources;
-- 
1.5.6.3