compiler flags for HP-UX cc

[Bruno Haible]

Hi,

The INSTALL file recommends to use "cc -Ae" or "cc -Aa -D_HPUX_SOURCE" on
HP-UX, so that system headers define all needed types and function
declarations.

This is not enough. On HP-UX 11.11 the 'mbstate_t' type is not defined by
<wchar.h>, unless the _XOPEN_SOURCE flag is set to exactly 500.

$ uname -srm
HP-UX B.11.11 9000/785

$ cat > foo.c
#include <wchar.h>
int dummy;
mbstate_t state;

$ cc -Ae -c foo.c
cc: "foo.c", line 3: error 1000: Unexpected symbol: "state".
cc: "foo.c", line 3: warning 557: Missing declaration specifiers, "int" assumed.
$ cc -Ae -D_XOPEN_SOURCE=500 -c foo.c

$ cc -D_HPUX_SOURCE -c foo.c
cc: "foo.c", line 3: error 1000: Unexpected symbol: "state".
cc: "foo.c", line 3: warning 557: Missing declaration specifiers, "int" assumed.
$ cc -D_HPUX_SOURCE -D_XOPEN_SOURCE=500 -c foo.c

$ cc -Aa -D_HPUX_SOURCE -c foo.c
cc: "foo.c", line 3: error 1000: Unexpected symbol: "state".
cc: "foo.c", line 3: warning 557: Missing declaration specifiers, "int" assumed.
$ cc -Aa -D_HPUX_SOURCE -D_XOPEN_SOURCE=500 -c foo.c

Therefore I think autoconf should recommend to set, and itself default to
setting, -D_XOPEN_SOURCE=500. But *only* on HP-UX! The header files of glibc,
MacOS X, FreeBSD, OpenBSD, NetBSD, AIX, IRIX, OSF/1, Solaris, Cygwin, Haiku,
Interix are also sensitive to the _XOPEN_SOURCE flag.

Here is a proposed patch:

2008-12-20  Bruno Haible  <address@hidden>

        * doc/install.texi (Particular Systems): For HP-UX, also recommend
        -D_XOPEN_SOURCE=500. Needed for the declaration of mbstate_t on
        HP-UX 11.11.
        * lib/autoconf/c.m4 (_AC_PROG_CC_C89): Combine -Aa and -Ae with
        -D_XOPEN_SOURCE=500.

--- doc/install.texi.orig       2008-12-20 12:58:46.000000000 +0100
+++ doc/install.texi    2008-12-20 12:57:03.000000000 +0100
@@ -188,7 +188,7 @@
 use an ANSI C compiler:
 
 @example
-./configure CC="cc -Ae"
+./configure CC="cc -Ae -D_XOPEN_SOURCE=500"
 @end example
 
 @noindent
--- lib/autoconf/c.m4.orig      2008-12-20 12:58:46.000000000 +0100
+++ lib/autoconf/c.m4   2008-12-20 12:58:24.000000000 +0100
@@ -1003,11 +1003,12 @@
 dnl AIX circa 2003     -qlanglvl=extc89
 dnl old AIX            -qlanglvl=ansi
 dnl Ultrix, OSF/1, Tru64       -std
-dnl HP-UX 10.20 and later      -Ae
-dnl HP-UX older versions       -Aa -D_HPUX_SOURCE
+dnl HP-UX 10.20 and later      -Ae -D_XOPEN_SOURCE=500
+dnl HP-UX older versions       -Aa -D_HPUX_SOURCE -D_XOPEN_SOURCE=500
 dnl SVR4                       -Xc -D__EXTENSIONS__
 [-qlanglvl=extc89 -qlanglvl=ansi -std \
-       -Ae "-Aa -D_HPUX_SOURCE" "-Xc -D__EXTENSIONS__"], [$1], [$2])[]dnl
+ "-Ae -D_XOPEN_SOURCE=500 "-Aa -D_HPUX_SOURCE -D_XOPEN_SOURCE=500" 
+ "-Xc -D__EXTENSIONS__"], [$1], [$2])[]dnl
 ])# _AC_PROG_CC_C89

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