Re: [PATCH v2] specify void prototype for functions with no parameters
Paul Eggert <[email protected]> Thu, 1 Sep 2022 18:18:10 -0500
| Newsgroups | gmane.comp.sysutils.autoconf.patches |
|---|---|
| Message-ID | <[email protected]> |
On 9/1/22 11:53, Khem Raj wrote: > > I ran into few problems. Some of them were latent issues[1] but some > are problems[2] especially using AC_CHECK_FUNCS when default compiler > is C++ compiler not C compiler Thanks for checking. How about the attached patch instead? It's closer to what you originally suggested. Zack, any thoughts on this sort of thing?
0001-Port-to-compilers-that-moan-about-K-R-func-decls.patch
(text/x-patch, 4.3 KB)
From 7a3bbca81b803ba116b83c82de378e840cc35f81 Mon Sep 17 00:00:00 2001 From: Paul Eggert <[email protected]> Date: Thu, 1 Sep 2022 16:19:50 -0500 Subject: [PATCH] Port to compilers that moan about K&R func decls MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit * lib/autoconf/c.m4 (AC_LANG_CALL, AC_LANG_FUNC_LINK_TRY): Use '(void)' rather than '()' in function prototypes, as the latter provokes fatal errors in some compilers nowadays. * lib/autoconf/functions.m4 (AC_FUNC_STRTOD): * tests/fortran.at (AC_F77_DUMMY_MAIN usage): * tests/semantics.at (AC_CHECK_DECLS): Don’t use () in a function decl. --- doc/autoconf.texi | 7 +++---- lib/autoconf/c.m4 | 6 +++--- lib/autoconf/functions.m4 | 3 --- tests/fortran.at | 8 ++++---- tests/semantics.at | 2 +- 5 files changed, 11 insertions(+), 15 deletions(-) diff --git a/doc/autoconf.texi b/doc/autoconf.texi index 67f31064..aa534ab7 100644 --- a/doc/autoconf.texi +++ b/doc/autoconf.texi @@ -5460,9 +5460,8 @@ the @samp{#undef malloc}): #include <config.h> #undef malloc -#include <sys/types.h> - -void *malloc (); +#include <stdlib.h> +#undef malloc /* Allocate an N-byte block of memory from the heap. If N is zero, allocate a 1-byte block. */ @@ -8297,7 +8296,7 @@ needed: # ifdef __cplusplus extern "C" # endif - int F77_DUMMY_MAIN () @{ return 1; @} + int F77_DUMMY_MAIN (void) @{ return 1; @} #endif @end example diff --git a/lib/autoconf/c.m4 b/lib/autoconf/c.m4 index abbb83fe..4751c7f5 100644 --- a/lib/autoconf/c.m4 +++ b/lib/autoconf/c.m4 @@ -133,7 +133,7 @@ m4_if([$2], [main], , #ifdef __cplusplus extern "C" #endif -char $2 ();])], [return $2 ();])]) +char $2 (void);])], [return $2 ();])]) # AC_LANG_FUNC_LINK_TRY(C)(FUNCTION) @@ -157,7 +157,7 @@ m4_define([AC_LANG_FUNC_LINK_TRY(C)], #define $1 innocuous_$1 /* System header to define __stub macros and hopefully few prototypes, - which can conflict with char $1 (); below. */ + which can conflict with char $1 (void); below. */ #include <limits.h> #undef $1 @@ -168,7 +168,7 @@ m4_define([AC_LANG_FUNC_LINK_TRY(C)], #ifdef __cplusplus extern "C" #endif -char $1 (); +char $1 (void); /* The GNU C library defines this for functions which it implements to always fail with ENOSYS. Some functions are actually named something starting with __ and the normal name is an alias. */ diff --git a/lib/autoconf/functions.m4 b/lib/autoconf/functions.m4 index 9f44a1ce..ee519a38 100644 --- a/lib/autoconf/functions.m4 +++ b/lib/autoconf/functions.m4 @@ -1613,9 +1613,6 @@ AC_DEFUN([AC_FUNC_STRTOD], AC_CACHE_CHECK(for working strtod, ac_cv_func_strtod, [AC_RUN_IFELSE([AC_LANG_SOURCE([[ ]AC_INCLUDES_DEFAULT[ -#ifndef strtod -double strtod (); -#endif int main (void) { diff --git a/tests/fortran.at b/tests/fortran.at index 75b50b1a..473b39f6 100644 --- a/tests/fortran.at +++ b/tests/fortran.at @@ -233,7 +233,7 @@ void FOOBAR_F77 (double *x, double *y); # ifdef __cplusplus extern "C" # endif - int F77_DUMMY_MAIN () { return 1; } + int F77_DUMMY_MAIN (void) { return 1; } #endif int main(int argc, char *argv[]) @@ -315,7 +315,7 @@ void FOOBAR_FC(double *x, double *y); # ifdef __cplusplus extern "C" # endif - int FC_DUMMY_MAIN () { return 1; } + int FC_DUMMY_MAIN (void) { return 1; } #endif int main (int argc, char *argv[]) @@ -561,7 +561,7 @@ void @foobar@ (int *x); # ifdef __cplusplus extern "C" # endif - int F77_DUMMY_MAIN () { return 1; } + int F77_DUMMY_MAIN (void) { return 1; } #endif int main(int argc, char *argv[]) @@ -637,7 +637,7 @@ void @foobar@ (int *x); # ifdef __cplusplus extern "C" # endif - int FC_DUMMY_MAIN () { return 1; } + int FC_DUMMY_MAIN (void) { return 1; } #endif int main(int argc, char *argv[]) diff --git a/tests/semantics.at b/tests/semantics.at index d24c4551..276d9744 100644 --- a/tests/semantics.at +++ b/tests/semantics.at @@ -207,7 +207,7 @@ AT_CHECK_MACRO([AC_CHECK_DECLS], [[extern int yes; enum { myenum }; extern struct mystruct_s { int x[20]; } mystruct; - extern int myfunc(); + extern int myfunc (int); #define mymacro1(arg) arg #define mymacro2]]) # Ensure we can detect missing declarations of functions whose -- 2.37.2