Enable GCC warnings in developer builds

However, do not fail; just issue the warnings.  Add an option
--enable-gcc-warnings=warn-only to configure, to implement this.
* INSTALL, etc/NEWS: Document this.
* configure.ac (gl_GCC_VERSION_IFELSE): New macro, from coreutils.
(gl_gcc_warnings, WERROR_CFLAGS): Use it to add new option.
Don’t treat --with-x-toolkit=no as a special case when configuring
warnings.

1 files changed, 5 insertions, 3 deletions

diff --git a/INSTALL b/INSTALL
index 6f516bd1dde..27af6d9c21f 100644
--- a/INSTALL
+++ b/INSTALL
@@ -318,9 +318,11 @@ Use --enable-gcc-warnings to enable compile-time checks that warn
 about possibly-questionable C code.  This is intended for developers
 and is useful with GNU-compatible compilers.  On a recent GNU system
 there should be no warnings; on older and on non-GNU systems the
-generated warnings may still be useful, though you may prefer building
-with 'make WERROR_CFLAGS=' so that the warnings are not treated as
-errors.
+generated warnings may still be useful, though you may prefer
+configuring with --enable-gcc-warnings=warn-only so they are not
+treated as errors.  The default is --enable-gcc-warnings=warn-only if
+it appears to be a developer build, and is --disable-gcc-warnings
+otherwise.
 
 Use --disable-silent-rules to cause 'make' to give more details about
 the commands it executes.  This can be helpful when debugging a build