Bug 25998 – [GTK] Build failure: conflicting declaration 'typedef XID Cursor'

• Component: New Bugs
• Status: RESOLVED LATER

[Vincent Lefevre]

When building webkit r44078 under Mac OS X 10.4.11 (with GTK+ using X11 rendering, installed by MacPorts), I get the following error:

libtool: compile:  /usr/bin/g++-4.0 -DHAVE_CONFIG_H -I. -I./WebKitTools/DumpRenderTree -I./WebKitTools/DumpRenderTree/gtk/TestNetscapePlugin/ForwardingHeaders -I./WebCore -I./WebCore/bridge -I./WebCore/plugins -I./WebKitTools/DumpRenderTree/TestNetscapePlugIn.subproj -DBUILDING_CAIRO__=1 -DBUILDING_GTK__=1 -DWTF_CHANGES -DWTF_USE_ICU_UNICODE=1 -DNDEBUG -I./JavaScriptCore/ForwardingHeaders -I./JavaScriptCore/parser -I./JavaScriptCore/wtf -I./DerivedSources -I./JavaScriptCore -I./JavaScriptCore/API -I./JavaScriptCore/ForwardingHeaders -I./JavaScriptCore/interpreter -I./JavaScriptCore/bytecode -I./JavaScriptCore/bytecompiler -I./JavaScriptCore/debugger -I./JavaScriptCore/jit -I./JavaScriptCore/pcre -I./JavaScriptCore/profiler -I./JavaScriptCore/runtime -I./JavaScriptCore/wrec -I./JavaScriptCore/jit -I./JavaScriptCore/assembler -I./JavaScriptCore/wtf/unicode -I./JavaScriptCore/yarr -I./JavaScriptCore/pcre -I./JavaScriptCore/parser -I./JavaScriptCore/runtime -I/opt/local/include -O2 -O2 -MT WebKitTools/DumpRenderTree/gtk/TestNetscapePlugin/TestNetscapePlugin_libtestnetscapeplugin_la-TestNetscapePlugin.lo -MD -MP -MF WebKitTools/DumpRenderTree/gtk/TestNetscapePlugin/.deps/TestNetscapePlugin_libtestnetscapeplugin_la-TestNetscapePlugin.Tpo -c WebKitTools/DumpRenderTree/gtk/TestNetscapePlugin/TestNetscapePlugin.cpp  -fno-common -DPIC -o WebKitTools/DumpRenderTree/gtk/TestNetscapePlugin/.libs/TestNetscapePlugin_libtestnetscapeplugin_la-TestNetscapePlugin.o
/opt/local/include/X11/X.h:108: error: conflicting declaration 'typedef XID Cursor'
/System/Library/Frameworks/ApplicationServices.framework/Frameworks/QD.framework/Headers/Quickdraw.h:278: error: 'Cursor' has a previous declaration as 'typedef struct Cursor Cursor'
make[1]: *** [WebKitTools/DumpRenderTree/gtk/TestNetscapePlugin/TestNetscapePlugin_libtestnetscapeplugin_la-TestNetscapePlugin.lo] Error 1
make: *** [all] Error 2

It seems that Quickdraw.h (that is the cause of the error) is included via

    #include <ApplicationServices/ApplicationServices.h>

in WebCore/bridge/npapi.h.

[David Evans]

This bug applies to X11 builds Mac OS X systems and stems from the fact that
QuickDraw and X11 use the same names for a number of key types, namely,

Cursor
WindowPtr
Picture
Picture
BOOL
EventType

The problem is restricted to the file

WebKitTools/DumpRenderTree/gtk/TestNetscapePlugin/TestNetscapePlugin.cpp

in release versions version         1.1.9 onward


Attached is a patch against release 1.1.11 which solves the problem
by renaming the QuickTime types locally so as to not conflict with
their X11 counterparts.

This patch has been in use successfully with the MacPorts port webkit-gtk
since version 1.1.10.

[David Evans]

Created attachment 32683 [details]
Patch to fix QuickDraw/X11 namespace conflict

[Jan Alonzo]

(In reply to comment #2)
> Created an attachment (id=32683) [details]
> Patch to fix QuickTime/X11 namespace conflict

Hi Vincent. Your patch needs a ChangeLog. Please use WebKitTools/Scripts/prepare-ChangeLog to do it.

[David Evans]

Created attachment 32719 [details]
Revised patch with ChangeLog

Dave here, actually.  I'm one of the MacPorts maintainers for port webkit-gtk.

Attached is a revised patch with ChangeLog as requested.

[Holger Freyther]

Where is the QuickDraw dependency coming from? from the npapi.h? npruntime.h?

[Jan Alonzo]

(In reply to comment #5)
> Where is the QuickDraw dependency coming from? from the npapi.h? npruntime.h?

From npapi.h apparently (see comment #0)

[David Evans]

(In reply to comment #5)
> Where is the QuickDraw dependency coming from? from the npapi.h? npruntime.h?

in WebCore/bridge/npapi.h
included from WebKitTools/DumpRenderTree/gtk/TestNetscapePlugin/ForwardingHeaders/WebKit/npapi.h

#if defined(__APPLE_CC__) && !defined(__MACOS_CLASSIC__) && !defined(XP_UNIX)
#   define XP_MACOSX
#endif

#ifdef XP_MAC
    #include <Quickdraw.h>
    #include <Events.h>
#endif

#if defined(XP_MACOSX) && defined(__LP64__)
#define NP_NO_QUICKDRAW
#define NP_NO_CARBON
#endif

#ifdef XP_MACOSX
    #include <ApplicationServices/ApplicationServices.h>
    #include <OpenGL/OpenGL.h>
#ifndef NP_NO_CARBON
    #include <Carbon/Carbon.h>
#endif
#endif

[Holger Freyther]

(In reply to comment #7)
> (In reply to comment #5)
> > Where is the QuickDraw dependency coming from? from the npapi.h? npruntime.h?
> 
> in WebCore/bridge/npapi.h
> included from
> WebKitTools/DumpRenderTree/gtk/TestNetscapePlugin/ForwardingHeaders/WebKit/npapi.h
> 
> #if defined(__APPLE_CC__) && !defined(__MACOS_CLASSIC__) && !defined(XP_UNIX)
> #   define XP_MACOSX
> #endif
> 
> #ifdef XP_MAC
>     #include <Quickdraw.h>
>     #include <Events.h>
> #endif
> 
> #if defined(XP_MACOSX) && defined(__LP64__)
> #define NP_NO_QUICKDRAW
> #define NP_NO_CARBON
> #endif
> 
> #ifdef XP_MACOSX
>     #include <ApplicationServices/ApplicationServices.h>
>     #include <OpenGL/OpenGL.h>
> #ifndef NP_NO_CARBON
>     #include <Carbon/Carbon.h>
> #endif
> #endif


Could we define XP_UNIX when building the plugin? Any idea how to not get XP_MAC defined? I would pretty much prefer a solution that does not include Quickdraw.h and such in the first place.

[David Evans]

(In reply to comment #8)
> (In reply to comment #7)
> > (In reply to comment #5)
> 
> 
> Could we define XP_UNIX when building the plugin? Any idea how to not get
> XP_MAC defined? I would pretty much prefer a solution that does not include
> Quickdraw.h and such in the first place.

That would seem to need a wider code review to see what the impact might be.

Currently, the only build problem in this one file.

Note that it is possible to build with GTK+ on the Mac using either the
X11 or native quartz backends, so there may be legitimate needs for QuickDraw
that are not immediately apparent.  

In addition, I believe the Carbon and Applications Services frameworks probably
include QuickDraw indirectly although I haven't verified that as yet.

The namespace conflicts between QuickDraw and X11 are well known in the Apple
world and this fix is not original but is borrowed from usage in the XQuartz
project. As mentioned in the ChangeLog, jeremyhu from that group recommended the fix in the first place.

See 

http://cgit.freedesktop.org/xorg/xserver/tree/hw/xquartz/sanitizedCarbon.h

http://cgit.freedesktop.org/xorg/xserver/tree/hw/xquartz/sanitizedCocoa.h

[Holger Freyther]

(In reply to comment #9)
> (In reply to comment #8)
> > (In reply to comment #7)
> > > (In reply to comment #5)
> > 
> > 
> > Could we define XP_UNIX when building the plugin? Any idea how to not get
> > XP_MAC defined? I would pretty much prefer a solution that does not include
> > Quickdraw.h and such in the first place.
> 
> That would seem to need a wider code review to see what the impact might be.

Right, but it is a lot better than attempting undoing damage later.


> 
> Currently, the only build problem in this one file.
> 
> Note that it is possible to build with GTK+ on the Mac using either the
> X11 or native quartz backends, so there may be legitimate needs for QuickDraw
> that are not immediately apparent.

The plugin we are talking about is purely written for unix/X11 and Gtk+ does not support plugins on OSX yet, and once we do we will not use the Gtk+ plugin but the mac one (as it already supports the three different drawing models).

[David Evans]

(In reply to comment #10)
> (In reply to comment #9)
> > (In reply to comment #8)
> > > (In reply to comment #7)
> > > > (In reply to comment #5)
> > > 
> > > 
> > > Could we define XP_UNIX when building the plugin? Any idea how to not get
> > > XP_MAC defined? I would pretty much prefer a solution that does not include
> > > Quickdraw.h and such in the first place.
> > 
> > That would seem to need a wider code review to see what the impact might be.
> 
> Right, but it is a lot better than attempting undoing damage later.

Sorry, I didn't mean to get into an argument here. 

What specific damage do you see here?  Do you have an alternative patch
that allows webkit-gtk to build on Mac platforms.  Last that built
as is, was 1.7.

Perhaps a better solution is to not include npapi.h here which seems
to include much more than is necessary (mac native includes for instance) and only include what is necessary to make this code work.

> 
> 
> The plugin we are talking about is purely written for unix/X11 and Gtk+ does
> not support plugins on OSX yet, and once we do we will not use the Gtk+ plugin
> but the mac one (as it already supports the three different drawing models).

Is this available in 1.11 or just in trunk and if so where?  How is it
configured Ideally on a Mac platform configure should detect whether gtk-x11 is available or not and enable the correct plugin (gtk-x11 or mac native
if I understand correctly).

Sorry for sounding dense but I'm new to the webkit code base and am trying to
understand.

[Holger Freyther]

(In reply to comment #11)

> > Right, but it is a lot better than attempting undoing damage later.
> 
> Sorry, I didn't mean to get into an argument here. 
> 
> What specific damage do you see here?

At least some part of npapi.h believes we are supposed to use QuickDraw. This could mean that structs like  NPWindow, NPEvent, NPRegion... could have wrong sizes (e.g. missing a pointer we need on X11). We might be lucky and things just work... One proper fix is to make sure that our copy of npapi.h respects that we want to build for unix (Netscape's equivalent for using X11).





> Do you have an alternative patch

No, other patch... whenever I boot into OSX again I can come up with one, if you are willing to wait. The patch will be along the lines of defining XP_UNIX in the buildsystem and making sure that XP_MAC is not defined...


> > 
> > 
> > The plugin we are talking about is purely written for unix/X11 and Gtk+ does
> > not support plugins on OSX yet, and once we do we will not use the Gtk+ plugin
> > but the mac one (as it already supports the three different drawing models).
> 
> Is this available in 1.11 or just in trunk and if so where?  How is it
> configured Ideally on a Mac platform configure should detect whether gtk-x11 is
> available or not and enable the correct plugin (gtk-x11 or mac native
> if I understand correctly).
> 
> Sorry for sounding dense but I'm new to the webkit code base and am trying to
> understand.

There is no code for Gtk+ yet. If you look into WebCore/plugins/mac/ you will see the code used by Qt to support plugins on the mac. We would use the same code...and add #elif PLATFORM(GTK) to the nativeWindowFor and cgHandleFor method (and others were Qt specific code is) in the PluginViewMac.cpp.

[Eric Seidel (no email)]

Comment on attachment 32719 [details]
Revised patch with ChangeLog

Why do these need to be separate blocks?  Are both #ifdef blocks needed?

[Jan Alonzo]

Comment on attachment 32719 [details]
Revised patch with ChangeLog

r- for now per Holger's feedback on the ideal approach on this.

[Martin Robinson]

I'm sure there are many things to fix for OS X support. This patch has certainly bitrotted by now. I'm going to close this bug, but if anyone is interested in fixing trunk to build on OS X, open a new bug and CC me.