[Spice-devel] [PATCH 6/8] use AC_DEFINE instead of hardcoding preprocessor flags

[Christophe Fergeau]

Now that all source files include config.h, we can use AC_DEFINE
to enable/disable optional features (opengl, cegui). This is
cleaner than directly appending -Dxxx directives to the preprocessor
flags. This also guarantees that everything will be appropriately
rebuilt when using the same source tree to build first with opengl
support and then without (the config.h timestamp will change,
triggering a rebuild of the files including it)
---
 configure.ac |    7 ++++---
 1 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/configure.ac b/configure.ac
index 7e77672..23c814f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -173,13 +173,13 @@ if test "x$enable_gui" = "xyes"; then
     [
         AC_SUBST(CEGUI06_CFLAGS)
         AC_SUBST(CEGUI06_LIBS)
-        CEGUI06_CFLAGS+="-DUSE_GUI"
+        AC_DEFINE([USE_GUI], [1], [Define to build with CEGUI support])
     ],
     [
         PKG_CHECK_MODULES(CEGUI, CEGUI >= 0.6.0 CEGUI < 0.7.0)
         AC_SUBST(CEGUI_CFLAGS)
         AC_SUBST(CEGUI_LIBS)
-        CEGUI_CFLAGS+="-DUSE_GUI"
+        AC_DEFINE([USE_GUI], [1], [Define to build with CEGUI support])
     ])
 fi
 
@@ -232,7 +232,8 @@ SPICE_REQUIRES+=" openssl"
 if test "x$enable_opengl" = "xyes"; then
    AC_CHECK_LIB(GL, glBlendFunc, GL_LIBS="$GL_LIBS -lGL", enable_opengl=no)
    AC_CHECK_LIB(GLU, gluSphere, GL_LIBS="$GL_LIBS -lGLU", enable_opengl=no)
-   GL_CFLAGS="-DGL_GLEXT_PROTOTYPES -DUSE_OGL"
+   AC_DEFINE([USE_OGL], [1], [Define to build with OpenGL support])
+   AC_DEFINE([GL_GLEXT_PROTOTYPES], [], [Enable GLExt prototypes])
 
    if test "x$enable_opengl" = "xno"; then
       AC_MSG_ERROR([GL libraries not available])
-- 
1.7.4.4