Teach the 'prefix' option to understand ${MODULE}/$MODULE.

This commit should make the 'prefix' option expand this variable to the
module's name, so one can easily install each module into a different
directory.

Reviewed-by: mpyne

doc/index.docbook

@@ -1904,11 +1904,13 @@ cannot figure out what you mean using <link linkend="conf-branch">branch</link>.
 <row id="conf-prefix">
 <entry>prefix</entry>
 <entry>Module setting overrides global</entry>
-<entry>This option controls where to install the module (normally the
+<entry><para>This option controls where to install the module (normally the
 <option><link linkend="conf-kdedir">kdedir</link></option> setting is used).
 Using this option allows you to install a module to a different directory than
 where the KDE Platform libraries are installed, such as if you were using
-&kdesrc-build; only to build applications.
+&kdesrc-build; only to build applications.</para>
+<para>You can use <varname>${MODULE}</varname> or <varname>$MODULE</varname>
+in the path to have them expanded to the module's name.</para>
 </entry>
 </row>
 

kdesrc-build

@@ -2999,6 +2999,27 @@ EOF
         return $destDir;
     }
 
+    # Subroutine to return the installation path of a given module (the value
+    # that is passed to the CMAKE_INSTALL_PREFIX CMake option).
+    # It is based on the "prefix" and, if it is not set, the "kdedir" option.
+    # The user may use '$MODULE' or '${MODULE}' in the "prefix" option to have
+    # them replaced by the name of the module in question.
+    sub installationPath
+    {
+        my $self = assert_isa(shift, 'Module');
+        my $path = $self->getOption('prefix');
+
+        if (!$path)
+        {
+            return $self->getOption('kdedir');
+        }
+
+        my $moduleName = $self->name();
+        $path =~ s/(\${MODULE})|(\$MODULE\b)/$moduleName/g;
+
+        return $path;
+    }
+
 
     1;
 }
@@ -6276,10 +6297,7 @@ sub safe_run_cmake
         push @commands, "-DCMAKE_CXX_FLAGS:STRING=$cxxflags";
     }
 
-    my $prefix = $module->getOption('prefix');
-
-    # If still no prefix, use KDEDIR
-    $prefix = $module->getOption('kdedir') unless $prefix;
+    my $prefix = $module->installationPath();
 
     push @commands, "-DCMAKE_INSTALL_PREFIX=$prefix";
 
@@ -6565,9 +6583,7 @@ sub update_module_environment
     my $module = assert_isa(shift, 'Module');
     my $kdedir = $module->getOption('kdedir');
     my $qtdir = $module->getOption('qtdir');
-    my $prefix = $module->getOption('prefix');
-
-    $prefix = $kdedir unless $prefix;
+    my $prefix = $module->installationPath();
 
     # Add global set-envs
     setup_module_environment ($module->buildContext());