Add a MetaPlatformInfo.

A metaplatform allow to regroup sereval platform together.
When a target is added to the platform, the target is dispatched/add to
all sub platforms.

As the step (metaplatformName, target) is not really added, we have to
track which steps are really added, so `add_targets` need to return the
list of added targets.

kiwixbuild/builder.py

@@ -18,17 +18,18 @@ class Builder:
         PlatformInfo.get_platform('neutral', self._targets)
 
         platform = PlatformInfo.get_platform(option('target_platform'), self._targets)
-        platform.add_targets(option('targets'), self._targets)
+        self.targetDefs = platform.add_targets(option('targets'), self._targets)
 
     def finalize_target_steps(self):
-        targetDef = (option('target_platform'), option('targets'))
-        dependencies = self.order_steps(targetDef)
-        dependencies = list(remove_duplicates(dependencies))
+        steps = []
+        for targetDef in self.targetDefs:
+            steps += self.order_steps(targetDef)
+        steps = list(remove_duplicates(steps))
 
         if option('build_nodeps'):
             add_target_step(targetDef, self._targets[targetDef])
         else:
-            for dep in dependencies:
+            for dep in steps:
                 if option('build_deps_only') and dep == targetDef:
                     continue
                 add_target_step(dep, self._targets[dep])

kiwixbuild/platforms/base.py

@@ -58,7 +58,7 @@ class PlatformInfo(metaclass=_MetaPlatform):
 
     def add_targets(self, targetName, targets):
         if (self.name, targetName) in targets:
-            return
+            return []
         targetClass = Dependency.all_deps[targetName]
         targets[('source', targetName)] = targetClass.Source
         targets[(self.name, targetName)] = targetClass.Builder
@@ -69,6 +69,7 @@ class PlatformInfo(metaclass=_MetaPlatform):
                 depPlatformName, depName = self.name, dep
             depPlatform = self.get_platform(depPlatformName, targets)
             depPlatform.add_targets(depName, targets)
+        return [(self.name, targetName)]
 
     def get_cross_config(self):
         return {}
@@ -102,3 +103,15 @@ class PlatformInfo(metaclass=_MetaPlatform):
     def clean_intermediate_directories(self):
         self.buildEnv.clean_intermediate_directories()
 
+
+
+class MetaPlatformInfo(PlatformInfo):
+    subPlatformNames = []
+
+    def add_targets(self, targetName, targets):
+        targetDefs = []
+        for platformName in self.subPlatformNames:
+            print("radd {}".format(platformName))
+            platform = self.get_platform(platformName, targets)
+            targetDefs += platform.add_targets(targetName, targets)
+        return targetDefs