diff options
| author | Zack Weinberg <zackw@panix.com> | 2023-04-02 21:54:31 -0400 |
|---|---|---|
| committer | Zack Weinberg <zackw@panix.com> | 2023-04-02 23:01:50 -0400 |
| commit | a7dc6d83c7d12b8409c512c3c10ad29f01e6c164 (patch) | |
| tree | 38cd1f6dd93d52b53dd2a1433e36b067ef1f5e16 | |
| parent | b5891a57b586ef6ff78bb752d62915b78cd58d7e (diff) | |
| download | autoconf-a7dc6d83c7d12b8409c512c3c10ad29f01e6c164.tar.gz | |
Fold AC_C_STRINGIZE into AC_PROG_CC.
Another of the last few uses of AC_EGREP_CPP is to check for the ISO C
“stringification” operator. As this is a feature of C89, let’s fold
the test into the extensive C89 tests we already have, and make
AC_C_STRINGIZE just lean on AC_PROG_CC, in the same way
AC_C_PROTOTYPES does.
* lib/autoconf/c.m4 (_AC_C_C89_TEST_GLOBALS): Add test of preprocessor
stringification and token pasting.
(AC_C_STRINGIZE): Just check ac_prog_cc_stdc.
| -rw-r--r-- | lib/autoconf/c.m4 | 31 |
1 files changed, 20 insertions, 11 deletions
diff --git a/lib/autoconf/c.m4 b/lib/autoconf/c.m4 index 33648b5b..c8c6a665 100644 --- a/lib/autoconf/c.m4 +++ b/lib/autoconf/c.m4 @@ -1143,6 +1143,21 @@ static char *f (char * (*g) (char **, int), char **p, ...) return s; } +/* C89 style stringification. */ +#define noexpand_stringify(a) #a +const char *stringified = noexpand_stringify(arbitrary+token=sequence); + +/* C89 style token pasting. Exercises some of the corner cases that + e.g. old MSVC gets wrong, but not very hard. */ +#define noexpand_concat(a,b) a##b +#define expand_concat(a,b) noexpand_concat(a,b) +extern int vA; +extern int vbee; +#define aye A +#define bee B +int *pvA = &expand_concat(v,aye); +int *pvbee = &noexpand_concat(v,bee); + /* OSF 4.0 Compaq cc is some sort of almost-ANSI by default. It has function prototypes and stuff, but not \xHH hex character constants. These do not provoke an error unfortunately, instead are silently treated @@ -2112,16 +2127,10 @@ fi # -------------- # Checks if '#' can be used to glue strings together at the CPP level. # Defines HAVE_STRINGIZE if positive. +# Obsolete - new code should assume C89 compliance. AC_DEFUN([AC_C_STRINGIZE], -[AC_CACHE_CHECK([for preprocessor stringizing operator], - [ac_cv_c_stringize], -[AC_EGREP_CPP([@%:@teststring], - [@%:@define x(y) #y - -char *s = x(teststring);], - [ac_cv_c_stringize=no], - [ac_cv_c_stringize=yes])]) -if test $ac_cv_c_stringize = yes; then +[AC_REQUIRE([AC_PROG_CC]) +if test "$ac_prog_cc_stdc" != no; then AC_DEFINE(HAVE_STRINGIZE, 1, [Define to 1 if cpp supports the ANSI @%:@ stringizing operator.]) fi @@ -2130,8 +2139,8 @@ fi # AC_C_PROTOTYPES # --------------- -# Check if the C compiler supports prototypes, included if it needs -# options. +# Check if the C compiler supports prototypes. +# Obsolete - new code should assume C89 compliance. AC_DEFUN([AC_C_PROTOTYPES], [AC_REQUIRE([AC_PROG_CC])dnl if test "$ac_prog_cc_stdc" != no; then |