Add support for dependency files in custom targets.

2 files changed, 23 insertions, 3 deletions

diff --git a/mesonbuild/backend/backends.py b/mesonbuild/backend/backends.py
index 1f1c3ca..4d0af4b 100644
--- a/mesonbuild/backend/backends.py
+++ b/mesonbuild/backend/backends.py
@@ -551,6 +551,11 @@ class Backend():
             else:
                 if '@OUTDIR@' in i:
                     i = i.replace('@OUTDIR@', outdir)
+                elif '@DEPFILE@' in i:
+                    if target.depfile is None:
+                        raise MesonException('Custom target %s has @DEPFILE@ but no depfile keyword argument.' % target.name)
+                    dfilename = os.path.join(self.get_target_private_dir(target), target.depfile)
+                    i = i.replace('@DEPFILE@', dfilename)
                 elif '@PRIVATE_OUTDIR_' in i:
                     match = re.search('@PRIVATE_OUTDIR_(ABS_)?([-a-zA-Z0-9.@:]*)@', i)
                     source = match.group(0)
@@ -558,7 +563,6 @@ class Backend():
                         lead_dir = ''
                     else:
                         lead_dir = self.environment.get_build_dir()
-                    target_id = match.group(2)
                     i = i.replace(source,
                                   os.path.join(lead_dir,
                                                outdir))
diff --git a/mesonbuild/backend/ninjabackend.py b/mesonbuild/backend/ninjabackend.py
index 15f298b..eacfda4 100644
--- a/mesonbuild/backend/ninjabackend.py
+++ b/mesonbuild/backend/ninjabackend.py
@@ -366,7 +366,11 @@ int dummy;
         desc = 'Generating {0} with a {1} command.'
         if target.build_always:
             deps.append('PHONY')
-        elem = NinjaBuildElement(self.all_outputs, ofilenames, 'CUSTOM_COMMAND', srcs)
+        if target.depfile is None:
+            rulename = 'CUSTOM_COMMAND'
+        else:
+            rulename = 'CUSTOM_COMMAND_DEP'
+        elem = NinjaBuildElement(self.all_outputs, ofilenames, rulename, srcs)
         for i in target.depend_files:
             if isinstance(i, mesonlib.File):
                 deps.append(i.rel_to_builddir(self.build_to_src))
@@ -394,6 +398,11 @@ int dummy;
         else:
             cmd_type = 'custom'
 
+        if target.depfile is not None:
+            rel_dfile = os.path.join(self.get_target_private_dir(target), target.depfile)
+            abs_pdir = os.path.join(self.environment.get_build_dir(), self.get_target_private_dir(target))
+            os.makedirs(abs_pdir, exist_ok=True)
+            elem.add_item('DEPFILE', rel_dfile)
         elem.add_item('COMMAND', cmd)
         elem.add_item('description',  desc.format(target.name, cmd_type))
         elem.write(outfile)
@@ -636,7 +645,6 @@ int dummy;
             velem.write(outfile)
 
         # And then benchmarks.
-        benchmark_script = os.path.join(script_root, 'meson_benchmark.py')
         cmd = [sys.executable, self.environment.get_build_command(), '--internal', 'benchmark', benchmark_data]
         elem = NinjaBuildElement(self.all_outputs, 'benchmark', 'CUSTOM_COMMAND', ['all', 'PHONY'])
         elem.add_item('COMMAND', cmd)
@@ -657,6 +665,14 @@ int dummy;
         outfile.write(' command = $COMMAND\n')
         outfile.write(' description = $DESC\n')
         outfile.write(' restat = 1\n\n')
+        # Ninja errors out if you have deps = gcc but no depfile, so we must
+        # have two rules for custom commands.
+        outfile.write('rule CUSTOM_COMMAND_DEP\n')
+        outfile.write(' command = $COMMAND\n')
+        outfile.write(' description = $DESC\n')
+        outfile.write(' deps = gcc\n')
+        outfile.write(' depfile = $DEPFILE\n')
+        outfile.write(' restat = 1\n\n')
         outfile.write('rule REGENERATE_BUILD\n')
         c = (quote_char + ninja_quote(sys.executable) + quote_char,
              quote_char + ninja_quote(self.environment.get_build_command())  + quote_char,