strerror: Avoid "guessing no" when cross-compiling to glibc systems.

* m4/strerror.m4 (gl_FUNC_STRERROR): Require AC_CANONICAL_HOST. When
cross-compiling to a glibc platform, set gl_cv_func_working_strerror
to "guessing yes".
(gl_FUNC_STRERROR_0): Require AC_CANONICAL_HOST. When cross-compiling
to a glibc platform, set gl_cv_func_strerror_0_works to "guessing yes".

diff --git a/ChangeLog b/ChangeLog
index f44d6ef..e32d9f1 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,14 @@
 2012-05-05  Bruno Haible  <bruno@clisp.org>
 
+       strerror: Avoid "guessing no" when cross-compiling to glibc systems.
+       * m4/strerror.m4 (gl_FUNC_STRERROR): Require AC_CANONICAL_HOST. When
+       cross-compiling to a glibc platform, set gl_cv_func_working_strerror
+       to "guessing yes".
+       (gl_FUNC_STRERROR_0): Require AC_CANONICAL_HOST. When cross-compiling
+       to a glibc platform, set gl_cv_func_strerror_0_works to "guessing yes".
+
+2012-05-05  Bruno Haible  <bruno@clisp.org>
+
        canonicalize[-lgpl]: Avoid "guessing no" when cross-compiling to glibc.
        * m4/canonicalize.m4 (gl_FUNC_REALPATH_WORKS): Require
        AC_CANONICAL_HOST. When cross-compiling to a glibc system, set

diff --git a/m4/strerror.m4 b/m4/strerror.m4
index 6bf14ef..1c96e52 100644 (file)
--- a/m4/strerror.m4
+++ b/m4/strerror.m4
@@ -1,4 +1,4 @@
-# strerror.m4 serial 16
+# strerror.m4 serial 17
 dnl Copyright (C) 2002, 2007-2012 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -9,6 +9,7 @@ AC_DEFUN([gl_FUNC_STRERROR],
   AC_REQUIRE([gl_HEADER_STRING_H_DEFAULTS])
   AC_REQUIRE([gl_HEADER_ERRNO_H])
   AC_REQUIRE([gl_FUNC_STRERROR_0])
+  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
   m4_ifdef([gl_FUNC_STRERROR_R_WORKS], [
     AC_REQUIRE([gl_FUNC_STRERROR_R_WORKS])
   ])
@@ -22,14 +23,22 @@ AC_DEFUN([gl_FUNC_STRERROR],
            [[if (!*strerror (-2)) return 1;]])],
         [gl_cv_func_working_strerror=yes],
         [gl_cv_func_working_strerror=no],
-        [dnl Be pessimistic on cross-compiles for now.
-         gl_cv_func_working_strerror="guessing no"])
+        [case "$host_os" in
+                   # Guess yes on glibc systems.
+           *-gnu*) gl_cv_func_working_strerror="guessing yes" ;;
+                   # If we don't know, assume the worst.
+           *)      gl_cv_func_working_strerror="guessing no" ;;
+         esac
+        ])
     ])
-    if test "$gl_cv_func_working_strerror" != yes; then
-      dnl The system's strerror() fails to return a string for out-of-range
-      dnl integers. Replace it.
-      REPLACE_STRERROR=1
-    fi
+    case "$gl_cv_func_working_strerror" in
+      *yes) ;;
+      *)
+        dnl The system's strerror() fails to return a string for out-of-range
+        dnl integers. Replace it.
+        REPLACE_STRERROR=1
+        ;;
+    esac
     m4_ifdef([gl_FUNC_STRERROR_R_WORKS], [
       dnl If the system's strerror_r or __xpg_strerror_r clobbers strerror's
       dnl buffer, we must replace strerror.
@@ -48,6 +57,7 @@ dnl Detect if strerror(0) passes (that is, does not set errno, and does not
 dnl return a string that matches strerror(-1)).
 AC_DEFUN([gl_FUNC_STRERROR_0],
 [
+  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
   REPLACE_STRERROR_0=0
   AC_CACHE_CHECK([whether strerror(0) succeeds],
    [gl_cv_func_strerror_0_works],
@@ -67,12 +77,20 @@ AC_DEFUN([gl_FUNC_STRERROR_0],
            return result;]])],
       [gl_cv_func_strerror_0_works=yes],
       [gl_cv_func_strerror_0_works=no],
-      [dnl Be pessimistic on cross-compiles for now.
-       gl_cv_func_strerror_0_works="guessing no"])
+      [case "$host_os" in
+                 # Guess yes on glibc systems.
+         *-gnu*) gl_cv_func_strerror_0_works="guessing yes" ;;
+                 # If we don't know, assume the worst.
+         *)      gl_cv_func_strerror_0_works="guessing no" ;;
+       esac
+      ])
   ])
-  if test "$gl_cv_func_strerror_0_works" != yes; then
-    REPLACE_STRERROR_0=1
-    AC_DEFINE([REPLACE_STRERROR_0], [1], [Define to 1 if strerror(0)
-      does not return a message implying success.])
-  fi
+  case "$gl_cv_func_strerror_0_works" in
+    *yes) ;;
+    *)
+      REPLACE_STRERROR_0=1
+      AC_DEFINE([REPLACE_STRERROR_0], [1], [Define to 1 if strerror(0)
+        does not return a message implying success.])
+      ;;
+  esac
 ])