Can generate custom rules for dependencies.

backends.py

@@ -418,12 +418,30 @@ class NinjaBackend(Backend):
             datafile.write(self.get_target_filename(t.get_exe()) + '\n')
         datafile.close()
 
+    def generate_dep_gen_rules(self, outfile):
+        outfile.write('# Rules for external dependency generators.\n\n')
+        processed = {}
+        for dep in self.environment.coredata.deps.values():
+            name = dep.get_name()
+            if name in processed:
+                continue
+            processed[name] = True
+            for rule in dep.get_generate_rules():
+                outfile.write('rule %s\n' % rule.name)
+                command = ' '.join([ninja_quote(x) for x in rule.cmd_list])
+                command = command.replace('@INFILE@', '$in').replace('@OUTFILE@', '$out')
+                outfile.write(' command = %s\n' % command)
+                desc = rule.description.replace('@INFILE@', '$in')
+                outfile.write(' description = %s\n' % desc)
+            outfile.write('\n')
+
     def generate_rules(self, outfile):
         outfile.write('# Rules for compiling.\n\n')
         self.generate_compile_rules(outfile)
         outfile.write('# Rules for linking.\n\n')
         self.generate_static_link_rules(outfile)
         self.generate_dynamic_link_rules(outfile)
+        self.generate_dep_gen_rules(outfile)
         outfile.write('# Other rules\n\n')
         outfile.write('rule CUSTOM_COMMAND\n')
         outfile.write(' command = $COMMAND\n')

dependencies.py

@@ -28,6 +28,14 @@ class DependencyException(MesonException):
     def __init__(self, *args, **kwargs):
         MesonException.__init__(self, *args, **kwargs)
 
+class CustomRule:
+    def __init__(self, cmd_list, name_templ, src_keyword, name, description):
+        self.cmd_list = cmd_list
+        self.name_templ = name_templ
+        self.src_keyword = src_keyword
+        self.name = name
+        self.description = description
+
 class Dependency():
     def __init__(self):
         self.name = "null"
@@ -49,6 +57,11 @@ class Dependency():
     def get_name(self):
         return self.name
 
+    # Rules for commands to execute before compilation
+    # such as Qt's moc preprocessor.
+    def get_generate_rules(self):
+        return []
+
 class PkgConfigDependency(Dependency):
     pkgconfig_found = False
 
@@ -316,6 +329,13 @@ class Qt5Dependency(Dependency):
                 return False
         return True
 
+    def get_generate_rules(self):
+        moc_rule = CustomRule([self.moc.get_command(), '@INFILE@', '-o', '@OUTFILE@'],
+                              'moc_%BASENAME%.cpp','moc_headers', 'moc_compile',
+                              'Compiling @INFILE@ with the moc preprocessor')
+        return [moc_rule]
+
+
 def get_dep_identifier(name, kwargs):
     elements = [name]
     modlist = kwargs.get('modules', [])

test cases/frameworks/4 qt5/mainWindow.h

@@ -1,3 +1,4 @@
+#include <QObject>
 #include <QMainWindow>
 #include "ui_mainWindow.h"