build: hack around compiler warning in g-ir-scanner

The autoconf macro for GIR passes $CFLAGS to g-ir-scanner.
g-ir-scanner extends those flags with the system-default which
includes -D_FORTIFY_SOURCE=2. Probably it should not do that,
but if you disable optimization, this results in a compler warning
in "/usr/include/features.h" [1]

    export CFLAGS='-O0'
    # Happens both with clang or gcc.
    #export CC=clang
    git clean -fdx
    ./autogen.sh
    make

Work around that by injecting -Wno-error to $CFLAGS when invoking
g-ir-scanner.

[1] Related: https://sourceware.org/bugzilla/show_bug.cgi?id=13979

diff --git a/m4/introspection.m4 b/m4/introspection.m4
index 589721c..efe0e9a 100644 (file)
--- a/m4/introspection.m4
+++ b/m4/introspection.m4
@@ -63,7 +63,7 @@ m4_define([_GOBJECT_INTROSPECTION_CHECK_INTERNAL],
        INTROSPECTION_LIBS=`$PKG_CONFIG --libs gobject-introspection-1.0`
        INTROSPECTION_MAKEFILE=`$PKG_CONFIG --variable=datadir gobject-introspection-1.0`/gobject-introspection-1.0/Makefile.introspection
     fi
-    AC_SUBST(INTROSPECTION_SCANNER)
+    AC_SUBST(INTROSPECTION_SCANNER, 'CFLAGS="${CFLAGS} -Wno-error" '"$INTROSPECTION_SCANNER")
     AC_SUBST(INTROSPECTION_COMPILER)
     AC_SUBST(INTROSPECTION_GENERATE)
     AC_SUBST(INTROSPECTION_GIRDIR)