Re: [RFA/RFC] libdecnumber/gstdint.h is back :-(

[Joel Brobecker <brobecker@adacore.com>]

[-- Attachment #1: Type: text/plain, Size: 1601 bytes --]

> Why does ../libdecnumber/gstdint.h exist?  Is it because you're
> configuring in the source directory, and if so can we just tell people
> not to do that?

Yes, I like doing my builds in-tree. I tried changing my habits to
building out-of-tree, but having source files and generated files
in different trees is sometimes a pain, so I ended up reverting to
my old habits.  If this is going to cause too much trouble, then
I'll try to change my habits again. (Note: If this is the case,
then we need to adjust the README file, which still mentions both
options).

> Another option would be to add a check for _GL_STDINT_H to
> libdecnumber; I suspect they would not mind.

In the same category, here is the temporary change I installed
in our tree. I called it a horrible hack, but maybe that was an
overstatement...

> > What occured to me while thinking about all this is that the
> > root of the problem is that we have two incompatible files that
> > should be identical in practice. Since we are always building
> > libdecnumber, can we use libdecnumber's gstdint.h and ditch
> > gnulib's stdint.h?
> 
> This could be a problem if we pulled in gnulib modules that
> include <stdint.h> from a replacement header.  We already use
> it in the building of gnulib (str-two-way.h).

And I am also wondering about building gdbserver without configuring
GDB - that might be a problem too.

I can rework a little the comment, but what do you think of the idea?
I think it's similar to your suggestion, except that the knowledge is
kept on the "client" side rather than the library side.

Thanks,
-- 
Joel

[-- Attachment #2: stdint.diff --]
[-- Type: text/plain, Size: 1795 bytes --]

Modified: gdb/defs.h
===================================================================
--- gdb/defs.h	2008-09-13 01:57:56 UTC (rev 135288)
+++ gdb/defs.h	2008-09-13 04:09:52 UTC (rev 135289)
@@ -30,6 +30,31 @@
 #include <limits.h>
 #include <stdint.h>
 
+/* The libdecnumber library, on which GDB depends, includes a header file
+   called gstdint.h instead of relying directly on stdint.h.  GDB, on the
+   other hand, includes stdint.h directly, relying on the fact that gnulib
+   generates a copy if the system doesn't provide one or if it is missing
+   some features.  Unfortunately, gstdint.h and stdint.h cannot be included
+   at the same time, which may happen when we include a file from
+   libdecnumber.
+
+   The first time we encountered this problem, we thought we had resolved
+   it by having a file named gstdint.h in this directory that would simply
+   contain a #include of stdint.h, thus hoping to "redirect" the gstdint.h
+   include in libdecnumber.  Unfortunately, it turns out that this doesn't
+   work after all, mostly because libdecnumber includes gstdint.h using
+   the double quotes as opposed to the angle brackets.  The search path
+   in implementation defined, but it seems that the gstdint.h files in
+   libdecnumber is picked up after all, thus defeating our trick.
+
+   The following macro definition is a horrible hack that prevents
+   the effective inclusion of gstdint.h, as all the definitions it
+   provides are guarded against GCC_GENERATED_STDINT_H.  We already
+   have gnulib/stdint.h included, so it's ok to blank out gstdint.h.
+   It's horrible but it allows to fix the build issues it gstdint.h
+   causes while we work on a more suitable fix.  */
+#define GCC_GENERATED_STDINT_H 1
+
 #ifdef HAVE_STDDEF_H
 #include <stddef.h>
 #endif