* regex.m4 (gl_REGEX): Check whether off_t can be used in a switch

statement, to work around an HP-UX 10.20 compiler bug reported by
Peter O'Gorman.

diff --git a/m4/ChangeLog b/m4/ChangeLog
index b797738de5ebf78d114972c56ce7cc861e729cc4..d285d7c296f2f10220083f59e85a6bf3e353060b 100644 (file)
--- a/m4/ChangeLog
+++ b/m4/ChangeLog
@@ -1,3 +1,9 @@
+2005-12-01  Paul Eggert  <eggert@cs.ucla.edu>
+
+       * regex.m4 (gl_REGEX): Check whether off_t can be used in a switch
+       statement, to work around an HP-UX 10.20 compiler bug reported by
+       Peter O'Gorman.
+
 2005-11-10  Paul Eggert  <eggert@cs.ucla.edu>
 
        * gethrxtime.m4 (gl_PREREQ_GETHRXTIME): Don't require AC_HEADER_TIME

diff --git a/m4/regex.m4 b/m4/regex.m4
index d7e22109020d6c1ff7e7d247679253b8c23595d0..8ea4fe94bb8f5f66b63d99ed66b1ccacf217040a 100644 (file)
--- a/m4/regex.m4
+++ b/m4/regex.m4
@@ -1,4 +1,4 @@
-#serial 30
+#serial 31
 
 # Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2003, 2004, 2005 Free
 # Software Foundation, Inc.
@@ -15,8 +15,29 @@ AC_PREREQ([2.50])
 AC_DEFUN([gl_REGEX],
 [
   AC_REQUIRE([AC_SYS_LARGEFILE]) dnl for a sufficently-wide off_t
-  AC_DEFINE([_REGEX_LARGE_OFFSETS], 1,
-    [Define if you want regoff_t to be at least as wide POSIX requires.])
+
+  AC_CACHE_CHECK([whether off_t can be used in a switch statement],
+    [gl_cv_type_off_t_switch],
+    [AC_COMPILE_IFELSE(
+      [AC_LANG_PROGRAM(
+         [AC_INCLUDES_DEFAULT],
+        [[off_t o = -1;
+          switch (o)
+            {
+            case -2:
+              return 1;
+            case -1:
+              return 2;
+            default:
+              return 0;
+            }
+        ]])],
+      [gl_cv_type_off_t_switch=yes],
+      [gl_cv_type_off_t_switch=no])])
+  if test $gl_cv_type_off_t_switch = yes; then
+    AC_DEFINE([_REGEX_LARGE_OFFSETS], 1,
+      [Define if you want regoff_t to be at least as wide POSIX requires.])
+  fi
 
   AC_LIBSOURCES(
     [regcomp.c, regex.c, regex.h,