[CMake] Two bugs, Three patches, no weddings and no funeral. (Qt)

[John Biddiscombe]

I've just updated cmake from cvs and have set
QT_MAX_VERSION 3.9.9

and in environment
QTDIR=c:\qt\3.2.1

but cmake still pulls in qt4. I see from looking at the findQt module 
that a lot of checking is done on various variables, but the 
QT_MAX_VERSION has no effect because the first thing findQt does is to
  FIND_PROGRAM(QT_QMAKE_EXECUTABLE NAMES qmake PATHS $ENV{QTDIR}/bin)
and since qt4 put itself on my path when it was installed - it gets 
found, once this has been located, later we have
    EXEC_PROGRAM( ${QT_QMAKE_EXECUTABLE}
      ARGS "-query QT_INSTALL_HEADERS"
      OUTPUT_VARIABLE qt_headers )
which reports itself again as qt4 and ensures that other checks don't 
find qt 3.2.1

[I would like to use Qt3 even though Qt4 is installed (old projects, you 
know...). ]

The find Qt code from there on will never find Qt3 no matter what you 
ask it to do, so and despite a remarkably long piece of code which 
checks QT_MAX_VERSION against the version found (which doesn't seem to 
do anything), it can't override the qt4 with qt3 because it never found 
it. In fact, if v4 is installed, it's unlikely one can find v3 without 
some intervention.

I've therefore added a QT_SUGGESTED_PATH which can be set before calling 
FindQt. This will be searched before the other paths to help us get the 
version we want. [Only useful if you already know where it is, but one 
can add a gui option on a project by project as needs basis].
Unfortunately, even if we fooled cmake into finding Qt in our suggested 
place, later on, when FindQt3 is run, it also uses find_program - and so 
uic.exe and moc.exe from qt4 are picked up (groan!). I've added the 
suggested patch to them too.

But to cap it off,
    FIND_PROGRAM(QT_QMAKE_EXECUTABLE NAMES qmake PATHS 
${QT_USER_PATH}/bin $ENV{QTDIR}/bin)
should search qt user path before system paths (according to docs), but 
I had to add NO_SYSTEM_PATH for it to work. It turns out that 
systemtools is adding the sytem path before the user paths. Changing 
this may have repurcussions beyond this fix...

JB
Attached are patches (cvs write access gone for me it seems).


-------------- next part --------------
Index: Source/kwsys/SystemTools.cxx
===================================================================
RCS file: /cvsroot/CMake/CMake/Source/kwsys/SystemTools.cxx,v
retrieving revision 1.130
diff -u -r1.130 SystemTools.cxx
--- Source/kwsys/SystemTools.cxx	17 Aug 2005 21:04:23 -0000	1.130
+++ Source/kwsys/SystemTools.cxx	23 Aug 2005 16:29:00 -0000
@@ -1910,14 +1910,15 @@
     }
   kwsys_stl::vector<kwsys_stl::string> path;
   SystemTools::GetPath(path, "CMAKE_PROGRAM_PATH");
+
+  // add the additional paths
+  path.insert(path.end(), userPaths.begin(), userPaths.end());
   // Add the system search path to our path.
   if (!no_system_path)
     {
     SystemTools::GetPath(path);
     }
   
-  // now add the additional paths
-  path.insert(path.end(), userPaths.begin(), userPaths.end());
   
   for(kwsys_stl::vector<kwsys_stl::string>::const_iterator p = path.begin();
       p != path.end(); ++p)
-------------- next part --------------
Index: Modules/FindQt.cmake
===================================================================
RCS file: /cvsroot/CMake/CMake/Modules/FindQt.cmake,v
retrieving revision 1.39
diff -u -r1.39 FindQt.cmake
--- Modules/FindQt.cmake	10 Aug 2005 12:48:03 -0000	1.39
+++ Modules/FindQt.cmake	23 Aug 2005 16:09:37 -0000
@@ -6,6 +6,8 @@
 #                                       Qt > 3 projects have to (!) set QT_MAX_VERSION (maximum by Trolltech is "15.7.99")
 # QT_MIN_VERSION                ,minimum Qt version set by YOU (e.g. "2.2.3")
 #
+# QT_SUGGESTED_PATH                  ,Set this to a directory if you already know which version of Qt you want
+#                                and would like to override the detection of installed versions 
 # This modules sets
 # QT_INST_MAJOR_VERSION         ,major number of the installed Qt (e.g. Qt-Version = 4.2.6 => 4)
 # QT_INST_MINOR_VERSION         ,minor number of the installed Qt (e.g. Qt-Version = 4.2.6 => 2)
@@ -24,7 +26,11 @@
 
 # check for qmake
 IF(NOT QT_QMAKE_EXECUTABLE)
-  FIND_PROGRAM(QT_QMAKE_EXECUTABLE NAMES qmake PATHS $ENV{QTDIR}/bin)
+  IF(QT_SUGGESTED_PATH)
+    FIND_PROGRAM(QT_QMAKE_EXECUTABLE NAMES qmake PATHS ${QT_SUGGESTED_PATH}/bin $ENV{QTDIR}/bin NO_SYSTEM_PATH)
+  ELSE(QT_SUGGESTED_PATH)
+    FIND_PROGRAM(QT_QMAKE_EXECUTABLE NAMES qmake PATHS $ENV{QTDIR}/bin)
+  ENDIF(QT_SUGGESTED_PATH)
 ENDIF(NOT QT_QMAKE_EXECUTABLE)
 
 # compatibility to CMakeList.txt files for Qt3 projects
-------------- next part --------------
Index: Modules/FindQt3.cmake
===================================================================
RCS file: /cvsroot/CMake/CMake/Modules/FindQt3.cmake,v
retrieving revision 1.1
diff -u -r1.1 FindQt3.cmake
--- Modules/FindQt3.cmake	15 Jul 2005 16:14:47 -0000	1.1
+++ Modules/FindQt3.cmake	23 Aug 2005 16:18:48 -0000
@@ -95,6 +95,7 @@
 FIND_PROGRAM(QT_MOC_EXECUTABLE 
   NAMES moc moc-qt3
   PATHS
+  ${QT_SUGGESTED_PATH}/bin
   $ENV{QTDIR}/bin 
   /usr/local/qt/bin
   /usr/lib/qt/bin
@@ -109,6 +110,7 @@
 ENDIF(QT_MOC_EXECUTABLE)
 
 FIND_PROGRAM(QT_UIC_EXECUTABLE uic
+  ${QT_SUGGESTED_PATH}/bin
   $ENV{QTDIR}/bin 
   /usr/local/qt/bin
   /usr/lib/qt/bin