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ceclipseeclipse-cdtglib

Eclipse CDT: Glib headers not parsed correctly

I am developing a C application, and using Eclipse CDT IDE, which I find great. The project uses Glib,Gtk,and GStreamer , so whenever I use some of their features in a file, I need to include:

#include <glib.h>
#include <gtk/gtk.h>
#include <gst/gst.h>

The code compiles without any error, since the PATH variable to search those headers is set correctly in a CMakeLists.txt. However, while working on the project, I found annoying errors highlighting in my code, regarding type definitions like gchar or GValue or GTKApplication; the error outlined is "symbol **** could not be resolved". These definitions are inside a header file that my Eclipse IDE cannot find (included by glib.h), if not at compile time (indeed the program compiles correctly). Instead, the type GError , defined in gst.h , is not highlighted as an error by the pre-compiler.

I would like then that my Eclipse IDE could search on nested headers (#include inside an #inlcude inside...) to find those type definition, in order so to not have those annoying errors highlighting. How can I do so? I would not like to have to include directly all files where the type definitions are done.

EDIT: As Jonah Graham outlined, the problem is not beacuse Eclispe does a "single-step research" on the headers, since it inspects includes inside other includes like any other IDE. It is a CMake bug with c and Eclipse

Thanks in advance.

Solution

  • The problem you are facing is a CMake bug*. CMake adds __cplusplus into the defined symbols unconditionally, which means that glib headers are not parsed properly when in C mode. You can see this clearly by opening gmacros.h around the definition for G_BEGIN_DECLS:

    enter image description here

    Because CMake told CDT __cplusplus is defined, it thinks G_BEGIN_DECLS is also defined, which makes code like this from gtypes.h parse incorrectly:

    G_BEGIN_DECLS

/* Provide type definitions for commonly used types.
 *  These are useful because a "gint8" can be adjusted
 *  to be 1 byte (8 bits) on all platforms. Similarly and
 *  more importantly, "gint32" can be adjusted to be
 *  4 bytes (32 bits) on all platforms.
 */

typedef char   gchar;
...

    Of course with no gchar defined, everything else is going to go badly.

    Luckily there is a quick workaround until the problem is resolved in CMake, remove __cplusplus from the info in CDT.

    1. Open Project Properties
    2. C/C++ Include Paths and Symbols
    3. Remove __cplusplus from the list and press OK

    enter image description here

    1. (sometimes necessary) Right-click on project -> Index -> Rebuild

    * There may be some other workarounds if you know CMake better. The bug says also it will be fixed for the next release of CMake.