Re: test failures building 5.93 and hpux compiler patch

[Paul Eggert]

"Peter O'Gorman" <address@hidden> writes:

> The HP-UX 10.20 compiler is documented to fail on switch statements with
> 64 bit values, so yes, that test causes it to crash. However, the
> problem only occurs with re_search which returns a regoff_t which is an
> off_t which is, correctly, 64 bits. Please don't use this test in
> configure.

I wasn't thinking of changing off_t's width, as that would cause many
programs to mishandle large files on HP-UX 10.20.  I was thinking
merely of changing regoff_t's width, as that will merely cause
programs to mishandle strings larger than 2 GiB when processing
regular expressions -- an acceptable limitation, I think, for that old
platform.

In an attempt to fix this problem I installed the following patch in
both coreutils and gnulib.

2005-12-01  Paul Eggert  <address@hidden>

        * m4/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.

Index: regex.m4
===================================================================
RCS file: /cvsroot/gnulib/gnulib/m4/regex.m4,v
retrieving revision 1.46
diff -p -u -r1.46 regex.m4
--- regex.m4    23 Sep 2005 21:18:20 -0000      1.46
+++ regex.m4    2 Dec 2005 00:29:31 -0000
@@ -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,