Created attachment 316289 [details]
sources demonstrating the issue

Description of problem:
Best described with an example code:
#define TEST_DATA_CONST1 10
#define TEST_DATA_CONST2 *10
#define TEST_DATA_CONST3 (TEST_DATA_CONST1 TEST_DATA_CONST2)

If the above code is a part of the header file (attached) that is GI-introspected, only the TEST_DATA_CONST1 is "exported" (defined in the namespace).

Version-Release number of selected component (if applicable):
gobject-introspection-devel-1.42.0-1.fc21.x86_64

How reproducible:
100 %

Steps to Reproduce:
1. use the test_data.c and test_data.h files to create a GI-introspected library
2. try to get the TEST_DATA_CONST3 e.g. from python

$ gcc -fPIC -c -o test_data.o `pkg-config --cflags glib-2.0 gobject-2.0` test_data.c
$ gcc -shared -o test_data.so `pkg-config --libs glib-2.0 gobject-2.0` test_data.o
$ LD_LIBRARY_PATH=. g-ir-scanner `pkg-config --libs --cflags glib-2.0 gobject-2.0` --identifier-prefix=Test --symbol-prefix=test --namespace Test --nsversion=1.0 --library test_data --warn-all -o Test-1.0.gir test_data.c test_data.h
$ g-ir-compiler Test-1.0.gir > Test-1.0.typelib
$ GI_TYPELIB_PATH=. LD_LIBRARY_PATH=. ipython

Actual results:
no TestData.CONST3 in the TestData module/namespace

Expected results:
TestData.CONST3 in the TestData module/namespace as it is a valid constant and preprocessor expands it to the right value just fine