Changes to m4/modules/m4.c,v

[Eric Blake]

CVSROOT:        /sources/m4
Module name:    m4
Changes by:     Eric Blake <ericb>      06/08/21 12:46:24

Index: modules/m4.c
===================================================================
RCS file: /sources/m4/m4/modules/m4.c,v
retrieving revision 1.64
retrieving revision 1.65
diff -u -b -r1.64 -r1.65
--- modules/m4.c        9 Aug 2006 21:33:24 -0000       1.64
+++ modules/m4.c        21 Aug 2006 12:46:24 -0000      1.65
@@ -21,20 +21,14 @@
 #  include <config.h>
 #endif
 
-#if HAVE_STDLIB_H
-#  include <stdlib.h>
-#endif
-
-#if HAVE_UNISTD_H
-#  include <unistd.h>
-#endif
-
+#include <assert.h>
 #include <errno.h>
-#ifndef errno
-extern int errno;
-#endif
+#include <stdlib.h>
+#include <unistd.h>
 
-#include <assert.h>
+#if HAVE_SYS_WAIT_H
+# include <sys/wait.h>
+#endif
 
 #include <m4module.h>
 #include <modules/m4.h>
@@ -92,7 +86,7 @@
        BUILTIN(shift,          false,  false,  0,      -1 )    \
        BUILTIN(sinclude,       false,  true,   2,      2  )    \
        BUILTIN(substr,         false,  true,   3,      4  )    \
-       BUILTIN(syscmd,         false,  true,   2,      2  )    \
+       BUILTIN(syscmd,         false,  true,   -1,     2  )    \
        BUILTIN(sysval,         false,  false,  0,      -1 )    \
        BUILTIN(traceoff,       false,  false,  0,      -1 )    \
        BUILTIN(traceon,        false,  false,  0,      -1 )    \
@@ -427,11 +421,40 @@
    and "sysval".  */
 
 /* Exit code from last "syscmd" command.  */
-int  m4_sysval = 0;
+/* FIXME - we should preserve this value across freezing.  See
+   http://lists.gnu.org/archive/html/bug-m4/2006-06/msg00059.html
+   for ideas on how do to that.  */
+static int  m4_sysval = 0;
+
+/* Helper macros for readability.  */
+#if UNIX || defined WEXITSTATUS
+# define M4_SYSVAL_EXITBITS(status)                       \
+   (WIFEXITED (status) ? WEXITSTATUS (status) : 0)
+# define M4_SYSVAL_TERMSIGBITS(status)                    \
+   (WIFSIGNALED (status) ? WTERMSIG (status) << 8 : 0)
+
+#else /* ! UNIX && ! defined WEXITSTATUS */
+/* Platforms such as mingw do not support the notion of reporting
+   which signal terminated a process.  Furthermore if WEXITSTATUS was
+   not provided, then the exit value is in the low eight bits.  */
+# define M4_SYSVAL_EXITBITS(status) status
+# define M4_SYSVAL_TERMSIGBITS(status) 0
+#endif /* ! UNIX && ! defined WEXITSTATUS */
 
+/* Fallback definitions if <stdlib.h> or <sys/wait.h> are inadequate.  */
+/* FIXME - this may fit better as a gnulib module.  */
 #ifndef WEXITSTATUS
 # define WEXITSTATUS(status) (((status) >> 8) & 0xff)
 #endif
+#ifndef WTERMSIG
+# define WTERMSIG(status) ((status) & 0x7f)
+#endif
+#ifndef WIFSIGNALED
+# define WIFSIGNALED(status) (WTERMSIG (status) != 0)
+#endif
+#ifndef WIFEXITED
+# define WIFEXITED(status) (WTERMSIG (status) == 0)
+#endif
 
 void
 m4_set_sysval (int value)
@@ -451,14 +474,28 @@
 
 M4BUILTIN_HANDLER (syscmd)
 {
+  /* Calling with no arguments triggers a warning, but must also set
+     sysval to 0 as if the empty command had been executed.
+     Therefore, we must manually check min args ourselves rather than
+     relying on the macro calling engine.  */
+  if (m4_bad_argc (context, argc, argv, 2, -1))
+    {
+      m4_set_sysval (0);
+      return;
+    }
   m4_sysval_flush (context);
   m4_sysval = system (M4ARG (1));
+  /* FIXME - determine if libtool works for OS/2, in which case the
+     FUNC_SYSTEM_BROKEN section on the branch must be ported to work
+     around the bug in their EMX libc system().  */
 }
 
 
 M4BUILTIN_HANDLER (sysval)
 {
-  m4_shipout_int (obs, WEXITSTATUS (m4_sysval));
+  m4_shipout_int (obs, (m4_sysval == -1 ? 127
+                        : (M4_SYSVAL_EXITBITS (m4_sysval)
+                           | M4_SYSVAL_TERMSIGBITS (m4_sysval))));
 }