Persist core data to disk.

coredata.py

@@ -18,6 +18,8 @@
 # invocations of Meson. It is roughly the same thing as
 # cmakecache.
 
+import pickle
+
 class CoreData():
     
     def __init__(self, options):
@@ -31,3 +33,12 @@ class CoreData():
         self.buildtype = options.buildtype
         self.strip = options.strip
         self.coverage = options.coverage
+
+def load(filename):
+    obj = pickle.load(open(filename, 'rb'))
+    if not isinstance(obj, CoreData):
+        raise RuntimeError('Core data file is corrupted.')
+    return obj
+
+def save(obj, filename):
+    pickle.dump(obj, open(filename, 'wb'))

environment.py

@@ -227,16 +227,23 @@ def find_coverage_tools():
 header_suffixes = ['h', 'hh', 'hpp', 'hxx', 'H']
 
 class Environment():
+    private_dir = 'meson-private'
+    coredata_file = os.path.join(private_dir, 'coredata.dat')
+
     def __init__(self, source_dir, build_dir, main_script_file, options):
         assert(main_script_file[0] == '/')
         assert(not os.path.islink(main_script_file))
         self.source_dir = source_dir
         self.build_dir = build_dir
         self.meson_script_file = main_script_file
-        self.scratch_dir = os.path.join(build_dir, 'meson-private')
+        self.scratch_dir = os.path.join(build_dir, Environment.private_dir)
         os.makedirs(self.scratch_dir, exist_ok=True)
 
-        self.old_coredata = coredata.CoreData(options) # FIXME: read from disk
+        try:
+            cdf = os.path.join(self.get_build_dir(), Environment.coredata_file)
+            self.old_coredata = coredata.load(cdf)
+        except IOError:
+            self.old_coredata = coredata.CoreData(options)
         self.new_coredata = coredata.CoreData(self.old_coredata)
 
         self.default_c = ['cc']
@@ -250,6 +257,10 @@ class Environment():
         self.static_lib_prefix = 'lib'
         self.object_suffix = 'o'
 
+    def generating_finished(self):
+        cdf = os.path.join(self.get_build_dir(), Environment.coredata_file)
+        coredata.save(self.new_coredata, cdf)
+
     def get_script_dir(self):
         return os.path.dirname(self.meson_script_file)
 

meson.py

@@ -99,6 +99,7 @@ class MesonApp():
         else:
             raise RuntimeError('Unknown generator "%s".' % options.generator)
         g.generate()
+        env.generating_finished()
 
 if __name__ == '__main__':
     (options, args) = parser.parse_args(sys.argv)