Can use outputs of targets as inputs of custom targets.

build.py

@@ -203,7 +203,7 @@ class BuildTarget():
         for i in self.link_targets:
             result += i.get_rpaths()
         return result
-    
+
     def get_custom_install_dir(self):
         return self.custom_install_dir
 
@@ -567,6 +567,7 @@ class CustomTarget:
     def __init__(self, name, subdir, kwargs):
         self.name = name
         self.subdir = subdir
+        self.dependencies = []
         self.process_kwargs(kwargs)
 
     def process_kwargs(self, kwargs):
@@ -586,10 +587,15 @@ class CustomTarget:
         for i, c in enumerate(cmd):
             if hasattr(c, 'ep'):
                 c = c.ep
+            if hasattr(c, 'held_object'):
+                c = c.held_object
             if isinstance(c, str):
                 final_cmd.append(c)
             elif isinstance(c, dependencies.ExternalProgram):
                 final_cmd.append(c.get_command())
+            elif isinstance(c, BuildTarget) or isinstance(c, CustomTarget):
+                self.dependencies.append(c)
+                final_cmd.append(os.path.join(c.get_subdir(), c.get_filename()))
             else:
                 raise InvalidArguments('Argument %s in "command" is invalid.' % i)
         self.command = final_cmd
@@ -609,14 +615,14 @@ class CustomTarget:
         return self.name
 
     def get_dependencies(self):
-        return []
+        return self.dependencies
 
     def should_install(self):
         return self.install
 
     def get_custom_install_dir(self):
         return self.install_dir
-    
+
     def get_subdir(self):
         return self.subdir
 

ninjabackend.py

@@ -136,7 +136,8 @@ class NinjaBackend(backends.Backend):
 
     def generate_custom_target(self, target, outfile):
         ofilename = os.path.join(target.subdir, target.output)
-        elem = NinjaBuildElement(ofilename, 'CUSTOM_COMMAND', '')
+        deps = [os.path.join(i.get_subdir(), i.get_filename()) for i in target.get_dependencies()]
+        elem = NinjaBuildElement(ofilename, 'CUSTOM_COMMAND', deps)
         elem.add_item('COMMAND', target.command)
         elem.write(outfile)
         self.processed_targets[target.name] = True

test cases/common/57 custom target chain/data_source.txt

@@ -0,0 +1 @@
+This is a text only input file.

test cases/common/57 custom target chain/installed_files.txt

@@ -0,0 +1 @@
+subdir/data2.dat

test cases/common/57 custom target chain/meson.build

@@ -0,0 +1,21 @@
+project('custom target', 'c')
+
+python = find_program('python3')
+
+comp = '@0@/@1@'.format(meson.current_source_dir(), 'my_compiler.py')
+comp2 = '@0@/@1@'.format(meson.current_source_dir(), 'my_compiler2.py')
+infile = '@0@/@1@'.format(meson.current_source_dir(), 'data_source.txt')
+outfile = '@0@/@1@'.format(meson.current_build_dir(), 'data.dat')
+outfile2 = '@0@/@1@'.format(meson.current_build_dir(), 'data2.dat')
+
+mytarget = custom_target('bindat',
+output : 'data.dat',
+command : [python, comp, infile, outfile],
+)
+
+mytarget2 = custom_target('bindat2',
+output : 'data2.dat',
+command : [python, comp2, mytarget, outfile2],
+install : true,
+install_dir : 'subdir'
+)

test cases/common/57 custom target chain/my_compiler.py

@@ -0,0 +1,14 @@
+#!/usr/bin/python3
+
+import sys
+
+if __name__ == '__main__':
+    if len(sys.argv) != 3:
+        print(sys.argv[0], 'input_file output_file')
+        sys.exit(1)
+    ifile = open(sys.argv[1]).read()
+    if ifile != 'This is a text only input file.\n':
+        print('Malformed input')
+        sys.exit(1)
+    ofile = open(sys.argv[2], 'w')
+    ofile.write('This is a binary output file.\n')

test cases/common/57 custom target chain/my_compiler2.py

@@ -0,0 +1,14 @@
+#!/usr/bin/python3
+
+import sys
+
+if __name__ == '__main__':
+    if len(sys.argv) != 3:
+        print(sys.argv[0], 'input_file output_file')
+        sys.exit(1)
+    ifile = open(sys.argv[1]).read()
+    if ifile != 'This is a binary output file.\n':
+        print('Malformed input')
+        sys.exit(1)
+    ofile = open(sys.argv[2], 'w')
+    ofile.write('This is a different binary output file.\n')