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Subject: |
24.0.50; Compiling on solaris2.10 with gcc doesn't define alloca |
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Date: |
Tue, 11 May 2010 11:57:17 +0100 |
On this system, <stdlib.h> is provided by Sun and therefore
doesn't define alloca, unlike on a typical GNU/linux system where
<stdlib.h> contains the following:
| #if defined __USE_GNU || defined __USE_BSD || defined __USE_MISC
| # include <alloca.h>
| #endif /* Use GNU, BSD, or misc. */
When compiling emacs with gcc, alloca is therefore undefined.
The culprit is this snippet in configure.in:
| #ifndef __GNUC__
| # ifdef HAVE_ALLOCA_H
| # include <alloca.h>
| # else /* AIX files deal with #pragma. */
| # ifndef alloca /* predefined by HP cc +Olibcalls */
| char *alloca ();
| # endif
| # endif /* HAVE_ALLOCA_H */
| #endif /* __GNUC__ */
On this system, configure correctly defines both HAVE_ALLOCA_H
and HAVE_ALLOCA, but since the inclusion is guarded by __GNUC__
not being defined, we never include <alloca.h>.
I think the correct fix is to unconditionally define alloca if
__GNUC__ is detected, see patch below. Note that this is closer
to how autoconf checks for the presence of the alloca function.
Possible changelog entry:
2010-05-11 Lawrence Mitchell <address@hidden>
* configure.in: Unconditionally define alloca if __GNUC__ is
detected.
diff --git a/configure.in b/configure.in
index 8a7d9be..98b6abb 100644
--- a/configure.in
+++ b/configure.in
@@ -3360,6 +3360,9 @@ extern char *getenv ();
char *alloca ();
# endif
# endif /* HAVE_ALLOCA_H */
+#else
+# undef alloca
+# define alloca __builtin_alloca
#endif /* __GNUC__ */
#ifndef HAVE_SIZE_T
typedef unsigned size_t;
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--- Begin Message ---
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Subject: |
Re: bug#6170: 24.0.50; Compiling on solaris2.10 with gcc doesn't define alloca |
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Date: |
Wed, 02 Jun 2010 05:24:36 -0400 |
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User-agent: |
Gnus/5.11 (Gnus v5.11) Emacs/22.1 (gnu/linux) |
Lawrence Mitchell <address@hidden> writes:
> Dan Nicolaescu wrote:
>> Lawrence Mitchell <address@hidden> writes:
>
>>> On this system, <stdlib.h> is provided by Sun and therefore
>>> doesn't define alloca, unlike on a typical GNU/linux system where
>>> <stdlib.h> contains the following:
>
>>> | #if defined __USE_GNU || defined __USE_BSD || defined __USE_MISC
>>> | # include <alloca.h>
>>> | #endif /* Use GNU, BSD, or misc. */
>
>>> When compiling emacs with gcc, alloca is therefore undefined.
>>> The culprit is this snippet in configure.in:
>
>>> | #ifndef __GNUC__
>>> | # ifdef HAVE_ALLOCA_H
>>> | # include <alloca.h>
>>> | # else /* AIX files deal with #pragma. */
>>> | # ifndef alloca /* predefined by HP cc +Olibcalls */
>>> | char *alloca ();
>>> | # endif
>>> | # endif /* HAVE_ALLOCA_H */
>>> | #endif /* __GNUC__ */
>
>
>> "info autoconf" says that this is the proper way to do it:
>
>> #ifdef HAVE_ALLOCA_H
>> # include <alloca.h>
>> #elif defined __GNUC__
>> # define alloca __builtin_alloca
>> #elif defined _AIX
>> # define alloca __alloca
>> #elif defined _MSC_VER
>> # include <malloc.h>
>> # define alloca _alloca
>> #else
>> # include <stddef.h>
>> # ifdef __cplusplus
>> extern "C"
>> # endif
>> void *alloca (size_t);
>> #endif
>
>> Not sure we need the last #else part, or the _MSC_VER part...
>
> Is there any movement on getting this fix, or something like it,
> installed? It doesn't seem like a controversial change.
Should be fixed now.
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