Can extract objects from targets and use them in other targets.

backends.py

@@ -174,13 +174,24 @@ class Backend():
         for obj in target.get_objects():
             if isinstance(obj, str):
                 o = os.path.join(self.build_to_src, target.get_subdir(), obj)
+                obj_list.append(o)
+            elif isinstance(obj, build.ExtractedObjects):
+                obj_list += self.determine_ext_objs(obj)
             else:
                 raise MesonException('Unknown data type in object list.')
-            obj_list.append(o)
         elem = self.generate_link(target, outfile, outname, obj_list)
         self.generate_shlib_aliases(target, self.get_target_dir(target), outfile, elem)
         self.processed_targets[name] = True
 
+    def determine_ext_objs(self, extobj):
+        result = []
+        targetdir = self.get_target_private_dir(extobj.target)
+        suffix = '.' + self.environment.get_object_suffix()
+        for osrc in extobj.srclist:
+            objname = os.path.join(targetdir, os.path.basename(osrc) + suffix)
+            result.append(objname)
+        return result
+
     def process_target_dependencies(self, target, outfile):
         for t in target.get_dependencies():
             tname = t.get_basename()

build.py

@@ -90,6 +90,11 @@ class IncludeDirs():
     def get_incdirs(self):
         return self.incdirs
 
+class ExtractedObjects():
+    def __init__(self, target, srclist):
+        self.target = target
+        self.srclist = srclist
+
 class BuildTarget():
     def __init__(self, name, subdir, is_cross, sources, objects, environment, kwargs):
         self.name = name
@@ -114,8 +119,12 @@ class BuildTarget():
     def process_objectlist(self, objects):
         assert(isinstance(objects, list))
         for s in objects:
+            if hasattr(s, 'held_object'):
+                s = s.held_object
             if isinstance(s, str):
                 self.objects.append(s)
+            elif isinstance(s, ExtractedObjects):
+                self.objects.append(s)
             else:
                 raise InvalidArguments('Bad object in target %s.' % self.name)
 
@@ -136,22 +145,38 @@ class BuildTarget():
     def get_original_kwargs(self):
         return self.kwargs
 
+    def unpack_holder(self, d):
+        if not isinstance(d, list):
+            d = [d]
+        newd = []
+        for i in d:
+            if hasattr(i, 'el'):
+                newd.append(i.el)
+            elif hasattr(i, 'held_object'):
+                newd.append(i.held_object)
+            else:
+                newd.append(i)
+        return newd
+
     def copy_kwargs(self, kwargs):
         self.kwargs = copy.copy(kwargs)
         # This sucks quite badly. Arguments
         # are holders but they can't be pickled
         # so unpack those known.
         if 'deps' in self.kwargs:
-            d = self.kwargs['deps']
+            self.kwargs['deps'] = self.unpack_holder(self.kwargs['deps'])
-            if not isinstance(d, list):
+        if 'link_with' in self.kwargs:
-                d = [d]
+            self.kwargs['link_with'] = self.unpack_holder(self.kwargs['link_with'])
-            newd = []
+
-            for i in d:
+    def extract_objects(self, srclist):
-                if hasattr(i, 'el'):
+        obj_src = []
-                    newd.append(i.el)
+        for src in srclist:
-                else:
+            if not isinstance(src, str):
-                    newd.append(i)
+                raise coredata.MesonException('Extraction arguments must be strings.')
-            self.kwargs['deps'] = newd
+            if src not in self.sources:
+                raise coredata.MesonException('Tried to extract unknown source %s.' % src)
+            obj_src.append(src)
+        return ExtractedObjects(self, obj_src)
 
     def get_rpaths(self):
         return self.get_transitive_rpaths()
@@ -172,8 +197,8 @@ class BuildTarget():
         for linktarget in llist:
             # Sorry for this hack. Keyword targets are kept in holders
             # in kwargs. Unpack here without looking at the exact type.
-            if hasattr(linktarget, "target"):
+            if hasattr(linktarget, "held_object"):
-                linktarget = linktarget.target
+                linktarget = linktarget.held_object
             self.link(linktarget)
         c_pchlist = kwargs.get('c_pch', [])
         if not isinstance(c_pchlist, list):
@@ -263,6 +288,8 @@ class BuildTarget():
         [self.add_external_dep(dep) for dep in args]
 
     def link(self, target):
+        if hasattr(target, 'held_object'):
+            target = target.held_object
         if not isinstance(target, StaticLibrary) and \
         not isinstance(target, SharedLibrary):
             print(target)
@@ -321,8 +348,8 @@ class Generator():
         if len(args) != 1:
             raise InvalidArguments('Generator requires one and only one positional argument')
         
-        if hasattr(args[0], 'target'):
+        if hasattr(args[0], 'held_object'):
-            exe = args[0].target
+            exe = args[0].held_object
             if not isinstance(exe, Executable):
                 raise InvalidArguments('First generator argument must be an executable.')
         elif hasattr(args[0], 'ep'):

interpreter.py

@@ -311,12 +311,23 @@ class Man(InterpreterObject):
     def get_sources(self):
         return self.sources
 
+class GeneratedObjectsHolder(InterpreterObject):
+    def __init__(self, held_object):
+        super().__init__()
+        self.held_object = held_object
+
 class BuildTargetHolder(InterpreterObject):
     def __init__(self, targetttype, name, subdir, is_cross, sources, objects, environment, kwargs):
-        self.target = targetttype(name, subdir, is_cross, sources, objects, environment, kwargs)
+        super().__init__()
-    
+        self.held_object = targetttype(name, subdir, is_cross, sources, objects, environment, kwargs)
+        self.methods.update({'extract_objects' : self.extract_objects_method})
+
     def is_cross(self):
-        return self.target.is_cross()
+        return self.held_object.is_cross()
+
+    def extract_objects_method(self, args, kwargs):
+        gobjs = self.held_object.extract_objects(args)
+        return GeneratedObjectsHolder(gobjs)
 
 class ExecutableHolder(BuildTargetHolder):
     def __init__(self, name, subdir, is_cross, sources, objects, environment, kwargs):
@@ -849,7 +860,7 @@ class Interpreter():
             if ' ' in k:
                 raise InterpreterException('Env var key must not have spaces in it.')
             env[k] = val
-        t = Test(args[0], args[1].target, par, cmd_args, env)
+        t = Test(args[0], args[1].held_object, par, cmd_args, env)
         self.build.tests.append(t)
         mlog.debug('Adding test "', mlog.bold(args[0]), '".', sep='')
 
@@ -953,6 +964,8 @@ class Interpreter():
             return args.get_value()
         if isinstance(args, str):
             return args
+        if isinstance(args, InterpreterObject):
+            return args
         result = []
         for a in args:
             if isinstance(a, list):
@@ -992,7 +1005,7 @@ class Interpreter():
             raise InvalidCode('Tried to create target "%s", but a target of that name already exists.' % name)
         self.check_sources_exist(os.path.join(self.environment.source_dir, self.subdir), sources)
         l = targetclass(name, self.subdir, is_cross, sources, objs, self.environment, kwargs)
-        self.build.targets[name] = l.target
+        self.build.targets[name] = l.held_object
         if self.environment.is_cross_build() and l.is_cross:
             txt = ' cross build '
         else:

test cases/common/25 object extraction/lib.c

@@ -0,0 +1,3 @@
+int func() {
+    return 42;
+}

test cases/common/25 object extraction/main.c

@@ -0,0 +1,5 @@
+int func();
+
+int main(int argc, char **argv) {
+    return func() == 42 ? 0 : 1;
+}

test cases/common/25 object extraction/meson.build

@@ -0,0 +1,7 @@
+project('object extraction', 'c')
+
+lib = shared_library('somelib', 'lib.c')
+obj = lib.extract_objects('lib.c')
+
+e = executable('main', 'main.c', objects : obj)
+test('extraction test', e)