[glib] gio/tests: fix race when generating code

[Ross Burton <rburton src gnome org>]

commit 299ca6dc1e54797e6fc5264c7b19b08bd726ca83
Author: Ross Burton <ross burton intel com>
Date:   Tue Feb 4 13:15:08 2014 +0000

    gio/tests: fix race when generating code
    
    There is a race condition in the makefile that can result in build failures like this in parallel builds:
    
    | ./gdbus-test-codegen-generated.h:7:0: error: unterminated #ifndef
    |  #ifndef __GDBUS_TEST_CODEGEN_GENERATED_H__
    
    This is because a rule like this:
    
    x.c x.h: prerequisites
        @commands
    
    doesn't consider x.c and x.h together. Instead, it expands to two rules, one to
    generate x.c and one to generate x.h, which happen to run the same commands.  In
    the worst case they execute in parallel, overwriting each other's output.
    
    Signed-off-by: Ross Burton <ross burton intel com>
    
    https://bugzilla.gnome.org/show_bug.cgi?id=723616

 gio/tests/Makefile.am |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)
---
diff --git a/gio/tests/Makefile.am b/gio/tests/Makefile.am
index 0beb239..270faf6 100644
--- a/gio/tests/Makefile.am
+++ b/gio/tests/Makefile.am
@@ -436,7 +436,7 @@ gmenumodel_SOURCES                       = $(gdbus_sessionbus_sources) gmenumode
 gnotification_SOURCES                    = $(gdbus_sessionbus_sources) gnotification.c 
gnotification-server.h gnotification-server.c
 
 gdbus-test-codegen.o: gdbus-test-codegen-generated.h
-gdbus-test-codegen-generated.h gdbus-test-codegen-generated.c: test-codegen.xml Makefile 
$(top_builddir)/gio/gdbus-2.0/codegen/gdbus-codegen
+gdbus-test-codegen-generated.h: test-codegen.xml Makefile $(top_builddir)/gio/gdbus-2.0/codegen/gdbus-codegen
        $(AM_V_GEN) UNINSTALLED_GLIB_SRCDIR=$(top_srcdir) \
                UNINSTALLED_GLIB_BUILDDIR=$(top_builddir) \
                $(PYTHON) $(top_builddir)/gio/gdbus-2.0/codegen/gdbus-codegen \
@@ -455,6 +455,8 @@ gdbus-test-codegen-generated.h gdbus-test-codegen-generated.c: test-codegen.xml
                --annotate "org.project.Bar::TestSignal[array_of_strings]" Key8 Value8 \
                $(srcdir)/test-codegen.xml \
                $(NULL)
+gdbus-test-codegen-generated.c: gdbus-test-codegen-generated.h
+       @: # Generated as side-effect of .h
 
 EXTRA_DIST += test-codegen.xml
 CLEANFILES += gdbus-test-codegen-generated.[ch] gdbus-test-codegen-generated-doc-*.xml