(PKG_CHECK_MODULES, C_SWITCH_X_SITE): Use -isystem rather than -I,
when including system files with GCC.
* etc/NEWS: Mention --enable-gcc-warnings.
+ * INSTALL (DETAILED BUILDING AND INSTALLATION): Likewise.
* lib/Makefile.am (AM_CFLAGS): New macro.
* m4/manywarnings.m4, m4/warnings.m4: New files, from gnulib.
even on hosts where a narrower type would do. With this option, on a
typical 32-bit host, Emacs integers have 62 bits instead of 30.
+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.
+
The `--prefix=PREFIXDIR' option specifies where the installation process
should put emacs and its data files. This defaults to `/usr/local'.
- Emacs (and the other utilities users run) go in PREFIXDIR/bin