@node ax_cflags_no_writable_strings
@unnumberedsec ax_cflags_no_writable_strings

@majorheading Synopsis

@smallexample
AX_CFLAGS_NO_WRITABLE_STRINGS [(shellvar [,default, [A/NA]])]
@end smallexample

@majorheading Description

Try to find a compiler option that makes all string literals readonly.

The sanity check is done by looking at string.h which has a set of
strcpy definitions that should be defined with const-modifiers to not
emit a warning in all so many places.

For the GNU CC compiler it will be -fno-writable-strings -Wwrite-strings
The result is added to the shellvar being CFLAGS by default.

DEFAULTS:

@smallexample
 - $1 shell-variable-to-add-to : CFLAGS
 - $2 add-value-if-not-found : nothing
 - $3 action-if-found : add value to shellvariable
 - $4 action-if-not-found : nothing
@end smallexample

NOTE: These macros depend on AX_APPEND_FLAG.

@majorheading Source Code

Download the
@uref{http://git.savannah.gnu.org/gitweb/?p=autoconf-archive.git;a=blob_plain;f=m4/ax_cflags_no_writable_strings.m4,latest
version of @file{ax_cflags_no_writable_strings.m4}} or browse
@uref{http://git.savannah.gnu.org/gitweb/?p=autoconf-archive.git;a=history;f=m4/ax_cflags_no_writable_strings.m4,the
macro's revision history}.

@majorheading License

@w{Copyright @copyright{} 2008 Guido U. Draheim @email{guidod@@gmx.de}}

Copying and distribution of this file, with or without modification, are
permitted in any medium without royalty provided the copyright notice
and this notice are preserved.  This file is offered as-is, without any
warranty.