vala: utilize depfiles

2 files changed, 22 insertions, 2 deletions

diff --git a/mesonbuild/backend/ninjabackend.py b/mesonbuild/backend/ninjabackend.py
index 02208ebc8..5fe753293 100644
--- a/mesonbuild/backend/ninjabackend.py
+++ b/mesonbuild/backend/ninjabackend.py
@@ -1807,6 +1807,8 @@ class NinjaBackend(backends.Backend):
                                     self.compiler_to_rule_name(valac),
                                     all_files + dependency_vapis)
         element.add_item('ARGS', args)
+        depfile = valac.depfile_for_object(os.path.join(self.get_target_dir(target), target.name))
+        element.add_item('DEPFILE', depfile)
         element.add_dep(extra_dep_files)
         self.add_build(element)
         self.create_target_source_introspection(target, valac, args, all_files, [])
@@ -2510,9 +2512,19 @@ class NinjaBackend(backends.Backend):
 
     def generate_vala_compile_rules(self, compiler) -> None:
         rule = self.compiler_to_rule_name(compiler)
-        command = compiler.get_exelist() + ['$ARGS', '$in']
+        command = compiler.get_exelist()
         description = 'Compiling Vala source $in'
-        self.add_rule(NinjaRule(rule, command, [], description, extra='restat = 1'))
+
+        depargs = compiler.get_dependency_gen_args('$out', '$DEPFILE')
+        depfile = '$DEPFILE' if depargs else None
+        depstyle = 'gcc' if depargs else None
+
+        args = depargs + ['$ARGS', '$in']
+
+        self.add_rule(NinjaRule(rule, command + args, [], description,
+                                depfile=depfile,
+                                deps=depstyle,
+                                extra='restat = 1'))
 
     def generate_cython_compile_rules(self, compiler: 'Compiler') -> None:
         rule = self.compiler_to_rule_name(compiler)
diff --git a/mesonbuild/compilers/vala.py b/mesonbuild/compilers/vala.py
index bbaefedb6..a3a196093 100644
--- a/mesonbuild/compilers/vala.py
+++ b/mesonbuild/compilers/vala.py
@@ -39,6 +39,14 @@ class ValaCompiler(Compiler):
     def get_optimization_args(self, optimization_level: str) -> T.List[str]:
         return []
 
+    def get_dependency_gen_args(self, outtarget: str, outfile: str) -> T.List[str]:
+        if version_compare(self.version, '>=0.47.2'):
+            return ['--depfile', outfile]
+        return []
+
+    def get_depfile_suffix(self) -> str:
+        return 'depfile'
+
     def get_debug_args(self, is_debug: bool) -> T.List[str]:
         return ['--debug'] if is_debug else []