gm2: Fix mc/mc.flex compilation on Solaris

The recent warning changes broke gm2 bootstrap on Solaris:

/vol/gcc/src/hg/master/local/gcc/m2/mc/mc.flex: In function 'handleFile':
/vol/gcc/src/hg/master/local/gcc/m2/mc/mc.flex:297:21: error: implicit
declaration of function 'alloca' [-Wimplicit-function-declaration]
  297 |   char *s = (char *)alloca (strlen (filename) + 2 + 1);
      |                     ^~~~~~

alloca needs <alloca.h> on Solaris, which isn't universally available.
Since mc.flex doesn't include any config header, I chose to switch to
__builtin_alloca instead.

/vol/gcc/src/hg/master/local/gcc/m2/mc/mc.flex:332:19: error: implicit
declaration of function 'index' [-Wimplicit-function-declaration]
  332 |   char   *p     = index(sdate, '\n');
      |                   ^~~~~

index is declared in <strings.h> on Solaris, again not a standard
header.  I simply switched to using strchr to avoid that issue.

Bootstrapped without regressions on i386-pc-solaris2.11,
sparc-sun-solaris2.11, x86_64-pc-linux-gnu, and
x86_64-apple-darwin23.1.0.

2023-12-03  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>

	gcc/m2:
	* mc/mc.flex [__GNUC__]: Define alloca as __builtin_alloca.
	(handleDate): Use strchr instead of index.

diff --git a/gcc/m2/mc/mc.flex b/gcc/m2/mc/mc.flex
index 4b37755bbc29ce339fbddb7a37e693072b60e332..8ba4e246f6326c77029a2e13317410a62952382f 100644 (file)
--- a/gcc/m2/mc/mc.flex
+++ b/gcc/m2/mc/mc.flex
@@ -28,6 +28,10 @@ along with GNU Modula-2; see the file COPYING3.  If not see
 #include <time.h>
 #include <ctype.h>
 
+#ifdef __GNUC__
+#define alloca __builtin_alloca
+#endif
+
 #if !defined(TRUE)
 #  define TRUE (1==1)
 #endif
@@ -329,7 +333,7 @@ handleDate (void)
   time_t  clock = time ((long *)0);
   char   *sdate = ctime (&clock);
   char   *s     = (char *)alloca (strlen (sdate)+2+1);
-  char   *p     = index(sdate, '\n');
+  char   *p     = strchr(sdate, '\n');
 
   if (p != NULL) {
     *p = (char) 0;