FindQt3: Add Qt3_VERSION

This deprecates the QT_VERSION_STRING result variable.

The QT_VERSION_STRING was probably meant to be set also by FindQt4
module (for the deprecated FindQt) but at the time of writing isn't
implemented therefore replaced in the test.

Issue: #27088

Help/release/dev/find-modules.rst

@@ -84,6 +84,9 @@ Find Modules
   result variable.  The ``PostgreSQL_VERSION_STRING`` result variable is
   deprecated.
 
+* The :module:`FindQt3` module now provides a ``Qt3_VERSION`` result
+  variable.  The ``QT_VERSION_STRING`` result variable is deprecated.
+
 * The :module:`FindSDL_gfx`, :module:`FindSDL_image`, :module:`FindSDL_mixer`,
   :module:`FindSDL_net`, :module:`FindSDL_sound`, and :module:`FindSDL_ttf`
   modules now provide their respective ``<PackageName>_VERSION`` result

Modules/FindQt3.cmake

@@ -24,14 +24,20 @@ Result Variables
 This module defines the following variables:
 
 ``Qt3_FOUND``
-  Boolean indicating whether Qt3 has been found.
+  Boolean indicating whether (the requested version of) Qt3 has been found.
+
 ``QT_FOUND``
   Boolean indicating whether Qt3 has been found.  This variable is for
   compatibility with other Qt find modules.
-``QT_VERSION_STRING``
+
+``Qt3_VERSION``
+  .. versionadded:: 4.2
+
   The version of Qt3 that was found.
+
 ``QT_LIBRARIES``
   Libraries needed to link against for using Qt3.
+
 ``QT_DEFINITIONS``
   A list of compile definitions to use when compiling code that uses Qt3.
 
@@ -61,6 +67,17 @@ Hints
   To search for the multithreaded version of Qt3, set this variable to ``TRUE``
   before looking for Qt3.
 
+Deprecated Variables
+^^^^^^^^^^^^^^^^^^^^
+
+The following variables are provided for backward compatibility:
+
+``QT_VERSION_STRING``
+  .. deprecated:: 4.2
+    Use ``Qt3_VERSION``, which has the same value.
+
+  The version of Qt3 that was found.
+
 Examples
 ^^^^^^^^
 
@@ -138,7 +155,8 @@ if(QT_INCLUDE_DIR)
   # Under windows the qt library (MSVC) has the format qt-mtXYZ where XYZ is the
   # version X.Y.Z, so we need to remove the dots from version
   string(REGEX REPLACE "\\." "" qt_version_str_lib "${qt_version_str}")
-  set(QT_VERSION_STRING "${qt_version_str}")
+  set(Qt3_VERSION "${qt_version_str}")
+  set(QT_VERSION_STRING "${Qt3_VERSION}")
 endif()
 
 file(GLOB GLOB_PATHS_LIB /usr/lib/qt-3*/lib/)
@@ -265,7 +283,7 @@ if (CMAKE_FIND_PACKAGE_NAME STREQUAL "Qt")
 endif ()
 find_package_handle_standard_args(Qt3
                                   REQUIRED_VARS QT_QT_LIBRARY QT_INCLUDE_DIR QT_MOC_EXECUTABLE
-                                  VERSION_VAR QT_VERSION_STRING)
+                                  VERSION_VAR Qt3_VERSION)
 unset(FPHSA_NAME_MISMATCHED)
 set(QT_FOUND ${QT3_FOUND} )
 

Tests/CMakeOnly/CMakeLists.txt

@@ -94,4 +94,4 @@ endfunction()
 
 add_major_test(PythonLibs VERSIONS 2 3 VERSION_VAR PYTHONLIBS_VERSION_STRING)
 add_major_test(PythonInterp NOLANG VERSIONS 3 VERSION_VAR PYTHON_VERSION_STRING)
-add_major_test(Qt VERSIONS 3 4 VERSION_VAR QT_VERSION_STRING)
+add_major_test(Qt VERSIONS 3 4 VERSION_VAR Qt3_VERSION)