Can specify explicit dependencies for custom targets.

build.py

@@ -668,11 +668,14 @@ class CustomTarget:
                     'command' : True,
                     'install' : True,
                     'install_dir' : True,
-                    'build_always' : True}
+                    'build_always' : True,
+                    'depends' : True}
+
     def __init__(self, name, subdir, kwargs):
         self.name = name
         self.subdir = subdir
         self.dependencies = []
+        self.extra_depends = []
         self.process_kwargs(kwargs)
         self.extra_files = []
         self.install_rpath = ''
@@ -744,6 +747,15 @@ class CustomTarget:
         self.build_always = kwargs.get('build_always', False)
         if not isinstance(self.build_always, bool):
             raise InvalidArguments('Argument build_always must be a boolean.')
+        extra_deps = kwargs.get('depends', [])
+        if not isinstance(extra_deps, list):
+            extra_deps = [extra_deps]
+        for ed in extra_deps:
+            while hasattr(ed, 'held_object'):
+                ed = ed.held_object
+            if not isinstance(ed, CustomTarget) and not isinstance(ed, BuildTarget):
+                raise InvalidArguments('Can only depend on toplevel targets.')
+            self.extra_depends.append(ed)
 
     def get_basename(self):
         return self.name

ninjabackend.py

@@ -283,6 +283,12 @@ class NinjaBackend(backends.Backend):
         if target.build_always:
             deps.append('PHONY')
         elem = NinjaBuildElement(ofilenames, 'CUSTOM_COMMAND', deps)
+        for d in target.extra_depends:
+            tmp = d.get_filename()
+            if not isinstance(tmp, list):
+                tmp = [tmp]
+            for fname in tmp:
+                elem.add_dep(os.path.join(d.get_subdir(), fname))
         cmd = []
         for i in target.command:
             for (j, src) in enumerate(srcs):

test cases/common/78 ctarget dependency/gen1.py

@@ -0,0 +1,10 @@
+#!/usr/bin/env python3
+
+import time, sys
+
+# Make sure other script runs first if dependency
+# is missing.
+time.sleep(0.5)
+
+contents = open(sys.argv[1], 'r').read()
+open(sys.argv[2], 'w').write(contents)

test cases/common/78 ctarget dependency/gen2.py

@@ -0,0 +1,9 @@
+#!/usr/bin/env python3
+
+import sys
+from glob import glob
+
+files = glob('*.tmp')
+assert(len(files) == 1)
+
+open(sys.argv[1], 'w').write(open(files[0], 'r').read())

test cases/common/78 ctarget dependency/input.dat

@@ -0,0 +1 @@
+This is a piece of text.

test cases/common/78 ctarget dependency/meson.build

@@ -0,0 +1,20 @@
+project('custom target dependency', 'c')
+
+# Sometimes custom targets do not take input files
+# but instead do globbing or some similar wackiness.
+# In this case we need to be able to specify a
+# manual dependency between two custom targets,
+# if one needs to be run before the other.
+
+g1 = find_program('gen1.py')
+g2 = find_program('gen2.py')
+
+c1 = custom_target('medput',
+input : 'input.dat',
+output : 'medput.tmp',
+command : [g1, '@INPUT@', '@OUTPUT@'])
+
+custom_target('output',
+output : 'output.dat',
+command : [g2, '@OUTPUT@'],
+depends : c1)