round: Don't override undeclared system function on IRIX 6.5.

* m4/check-math-lib.m4 (gl_CHECK_MATH_LIB): Accept an optional third
argument.
* m4/round.m4 (gl_FUNC_ROUND): Search for round() in the libraries
also when it is not declared. Set HAVE_ROUND. For replacement code,
test HAVE_ROUND, not HAVE_DECL_ROUND.
* modules/round (configure.ac): For replacement code, test HAVE_ROUND,
not HAVE_DECL_ROUND.
(Depends-on): Update conditions.
* modules/round-ieee (Depends-on): Update conditions.
* doc/posix-functions/round.texi: Mention the IRIX problem.

diff --git a/ChangeLog b/ChangeLog
index d49552d..faec45b 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,19 @@
 2012-03-07  Bruno Haible  <bruno@clisp.org>
 
+       round: Don't override undeclared system function on IRIX 6.5.
+       * m4/check-math-lib.m4 (gl_CHECK_MATH_LIB): Accept an optional third
+       argument.
+       * m4/round.m4 (gl_FUNC_ROUND): Search for round() in the libraries
+       also when it is not declared. Set HAVE_ROUND. For replacement code,
+       test HAVE_ROUND, not HAVE_DECL_ROUND.
+       * modules/round (configure.ac): For replacement code, test HAVE_ROUND,
+       not HAVE_DECL_ROUND.
+       (Depends-on): Update conditions.
+       * modules/round-ieee (Depends-on): Update conditions.
+       * doc/posix-functions/round.texi: Mention the IRIX problem.
+
+2012-03-07  Bruno Haible  <bruno@clisp.org>
+
        copysignf: Don't override undeclared system function on IRIX 6.5.
        * lib/math.in.h (copysignf): Test HAVE_DECL_COPYSIGNF, not
        HAVE_COPYSIGNF.

diff --git a/doc/posix-functions/round.texi b/doc/posix-functions/round.texi
index ca95e18..6eaa5e7 100644 (file)
--- a/doc/posix-functions/round.texi
+++ b/doc/posix-functions/round.texi
@@ -10,10 +10,10 @@ Portability problems fixed by either Gnulib module @code{round} or @code{round-i
 @itemize
 @item
 This function is missing on some platforms:
-FreeBSD 5.2.1, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, IRIX 6.5, OSF/1 4.0, Solaris 9, MSVC 9, Interix 3.5.
+FreeBSD 5.2.1, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, older IRIX 6.5, OSF/1 4.0, Solaris 9, MSVC 9, Interix 3.5.
 @item
 This function is not declared on some platforms:
-glibc 2.8, OSF/1 5.1.
+glibc 2.8, IRIX 6.5, OSF/1 5.1.
 @item
 This functions returns a wrong result for x = 1/2 - 2^-54 on some platforms:
 NetBSD 3.0, AIX 7.1.

diff --git a/m4/check-math-lib.m4 b/m4/check-math-lib.m4
index 0b77d8f..4f370eb 100644 (file)
--- a/m4/check-math-lib.m4
+++ b/m4/check-math-lib.m4
@@ -1,10 +1,10 @@
-# check-math-lib.m4 serial 3
+# check-math-lib.m4 serial 4
 dnl Copyright (C) 2007, 2009-2012 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.
 dnl
-dnl gl_CHECK_MATH_LIB (VARIABLE, EXPRESSION)
+dnl gl_CHECK_MATH_LIB (VARIABLE, EXPRESSION [, EXTRA-CODE])
 dnl
 dnl Sets the shell VARIABLE according to the libraries needed by EXPRESSION
 dnl to compile and link: to the empty string if no extra libraries are needed,
@@ -22,6 +22,7 @@ AC_DEFUN([gl_CHECK_MATH_LIB], [
          # define __NO_MATH_INLINES 1 /* for glibc */
          #endif
          #include <math.h>
+         $3
          double x;]],
       [$2])],
       [$1=$libm

diff --git a/m4/round.m4 b/m4/round.m4
index e2acf93..805eba9 100644 (file)
--- a/m4/round.m4
+++ b/m4/round.m4
@@ -1,4 +1,4 @@
-# round.m4 serial 14
+# round.m4 serial 15
 dnl Copyright (C) 2007, 2009-2012 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -8,23 +8,39 @@ AC_DEFUN([gl_FUNC_ROUND],
 [
   m4_divert_text([DEFAULTS], [gl_round_required=plain])
   AC_REQUIRE([gl_MATH_H_DEFAULTS])
+
   dnl Persuade glibc <math.h> to declare round().
   AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
-  AC_CHECK_DECLS([round], , , [[#include <math.h>]])
-  if test "$ac_cv_have_decl_round" = yes; then
-    gl_CHECK_MATH_LIB([ROUND_LIBM], [x = round (x);])
-    if test "$ROUND_LIBM" != missing; then
-      dnl Test whether round() produces correct results. On NetBSD 3.0, for
-      dnl x = 1/2 - 2^-54, the system's round() returns a wrong result.
-      AC_REQUIRE([AC_PROG_CC])
-      AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
-      AC_CACHE_CHECK([whether round works], [gl_cv_func_round_works],
-        [
-          save_LIBS="$LIBS"
-          LIBS="$LIBS $ROUND_LIBM"
-          AC_RUN_IFELSE([AC_LANG_SOURCE([[
+
+  gl_CHECK_MATH_LIB([ROUND_LIBM], [x = round (x);],
+    [extern
+     #ifdef __cplusplus
+     "C"
+     #endif
+     double round (double);
+    ])
+  if test "$ROUND_LIBM" != missing; then
+    HAVE_ROUND=1
+    dnl Also check whether it's declared.
+    dnl IRIX 6.5 has round() in libm but doesn't declare it in <math.h>.
+    AC_CHECK_DECLS([round], , [HAVE_DECL_ROUND=0], [[#include <math.h>]])
+
+    dnl Test whether round() produces correct results. On NetBSD 3.0, for
+    dnl x = 1/2 - 2^-54, the system's round() returns a wrong result.
+    AC_REQUIRE([AC_PROG_CC])
+    AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+    AC_CACHE_CHECK([whether round works], [gl_cv_func_round_works],
+      [
+        save_LIBS="$LIBS"
+        LIBS="$LIBS $ROUND_LIBM"
+        AC_RUN_IFELSE([AC_LANG_SOURCE([[
 #include <float.h>
 #include <math.h>
+extern
+#ifdef __cplusplus
+"C"
+#endif
+double round (double);
 #ifdef _MSC_VER
 # pragma fenv_access (off)
 #endif
@@ -43,20 +59,17 @@ int main()
   volatile double x = 0.5 - 0.5 / TWO_MANT_DIG;
   exit (x < 0.5 && round (x) != 0.0);
 }]])], [gl_cv_func_round_works=yes], [gl_cv_func_round_works=no],
-          [case "$host_os" in
-             netbsd* | aix*) gl_cv_func_round_works="guessing no";;
-             *)              gl_cv_func_round_works="guessing yes";;
-           esac
-          ])
-          LIBS="$save_LIBS"
+        [case "$host_os" in
+           netbsd* | aix*) gl_cv_func_round_works="guessing no";;
+           *)              gl_cv_func_round_works="guessing yes";;
+         esac
         ])
-      case "$gl_cv_func_round_works" in
-        *no) ROUND_LIBM=missing ;;
-      esac
-    fi
-    if test "$ROUND_LIBM" = missing; then
-      REPLACE_ROUND=1
-    fi
+        LIBS="$save_LIBS"
+      ])
+    case "$gl_cv_func_round_works" in
+      *no) REPLACE_ROUND=1 ;;
+    esac
+
     m4_ifdef([gl_FUNC_ROUND_IEEE], [
       if test $gl_round_required = ieee && test $REPLACE_ROUND = 0; then
         AC_CACHE_CHECK([whether round works according to ISO C 99 with IEC 60559],
@@ -70,6 +83,11 @@ int main()
 # define __NO_MATH_INLINES 1 /* for glibc */
 #endif
 #include <math.h>
+extern
+#ifdef __cplusplus
+"C"
+#endif
+double round (double);
 ]gl_DOUBLE_MINUS_ZERO_CODE[
 ]gl_DOUBLE_SIGNBIT_CODE[
 static double dummy (double f) { return 0; }
@@ -94,9 +112,10 @@ int main (int argc, char *argv[])
       fi
     ])
   else
+    HAVE_ROUND=0
     HAVE_DECL_ROUND=0
   fi
-  if test $HAVE_DECL_ROUND = 0 || test $REPLACE_ROUND = 1; then
+  if test $HAVE_ROUND = 0 || test $REPLACE_ROUND = 1; then
     dnl Find libraries needed to link lib/round.c.
     gl_FUNC_FLOOR_LIBS
     gl_FUNC_CEIL_LIBS

diff --git a/modules/round b/modules/round
index 6fe95a2..c057822 100644 (file)
--- a/modules/round
+++ b/modules/round
@@ -11,12 +11,12 @@ m4/ceil.m4
 Depends-on:
 math
 extensions
-float           [test $HAVE_DECL_ROUND = 0 || test $REPLACE_ROUND = 1]
-floor           [test $HAVE_DECL_ROUND = 0 || test $REPLACE_ROUND = 1]
+float           [test $HAVE_ROUND = 0 || test $REPLACE_ROUND = 1]
+floor           [test $HAVE_ROUND = 0 || test $REPLACE_ROUND = 1]
 
 configure.ac:
 gl_FUNC_ROUND
-if test $HAVE_DECL_ROUND = 0 || test $REPLACE_ROUND = 1; then
+if test $HAVE_ROUND = 0 || test $REPLACE_ROUND = 1; then
   AC_LIBOBJ([round])
 fi
 gl_MATH_MODULE_INDICATOR([round])

diff --git a/modules/round-ieee b/modules/round-ieee
index 407e781..f0f00ff 100644 (file)
--- a/modules/round-ieee
+++ b/modules/round-ieee
@@ -8,8 +8,8 @@ m4/signbit.m4
 
 Depends-on:
 round
-floor-ieee      [test $HAVE_DECL_ROUND = 0 || test $REPLACE_ROUND = 1]
-ceil-ieee       [test $HAVE_DECL_ROUND = 0 || test $REPLACE_ROUND = 1]
+floor-ieee      [test $HAVE_ROUND = 0 || test $REPLACE_ROUND = 1]
+ceil-ieee       [test $HAVE_ROUND = 0 || test $REPLACE_ROUND = 1]
 
 configure.ac:
 gl_FUNC_ROUND_IEEE