core: docs: Add support to generate compile_commands.json

Thanks to ninja-build, all we need to do is to run one command [1] and
we can get a compile_commands.json from a ninja.build file.

This commit adds a new argument (-j or --compdb) to let users generate a
compile_commands.json file.

[1] https://ninja-build.org/manual.html#_extra_tools

architectds/architectds.py

@@ -177,14 +177,15 @@ class GenericBinary():
         clean = '-c' in args or '--clean' in args
         graph = '-g' in args or '--graph' in args
         help_ = '-h' in args or '--help' in args
+        compdb = '-j' in args or '--compdb' in args
         ninja = '-n' in args or '--ninja' in args
 
         # Build ROM if the script has been called with no arguments.
-        if not build and not clean and not graph and not ninja and not help_:
+        if not (build or clean or compdb or graph or ninja or help_):
             build = True
 
         # If there is any argument that requires the ninja file, generate it.
-        if build or graph:
+        if build or compdb or graph:
             ninja = True
 
         if help_:
@@ -192,11 +193,12 @@ class GenericBinary():
             print('')
             print('Options:')
             print('')
-            print('  -b / --build : Generate ninja file and build ROM.')
-            print('  -c / --clean : Clean build outputs and ninja file.')
-            print('  -g / --graph : Generate dependency graph as a PNG file.')
-            print('  -n / --ninja : Generate ninja file.')
-            print('  -h / --help  : Show this message.')
+            print('  -b / --build  : Generate ninja file and build ROM.')
+            print('  -c / --clean  : Clean build outputs and ninja file.')
+            print('  -g / --graph  : Generate dependency graph as a PNG file.')
+            print('  -n / --ninja  : Only generate ninja file.')
+            print('  -j / --compdb : Generate compile_commands.json.')
+            print('  -h / --help   : Show this message.')
             print('')
             print('If no option is used, the tool will act the same as if')
             print('--build had been used.')
@@ -224,6 +226,13 @@ class GenericBinary():
             my_env["BLOCKSDS"] = BLOCKSDS
             subprocess.run(['ninja', '-f', ninja_file_path], env=my_env)
 
+        if compdb:
+            print('[*] COMPDB')
+            proc = subprocess.run(['ninja', '-f', ninja_file_path, '-t', 'compdb'],
+                                  encoding='utf-8', stdout=subprocess.PIPE)
+            with open('compile_commands.json', 'w') as f:
+                f.write(proc.stdout)
+
         if graph:
             print('[*] GRAPH')
             ninja_process = subprocess.Popen(

readme.rst

@@ -276,6 +276,8 @@ arguments passed to the python script:
 
 - ``python3 build.py --clean``: Clean all build files.
 
+- ``python3 build.py --compdb``: Generate a ``compile_commands.json`` file.
+
 - ``python3 build.py --graph``: If you have ``graphviz`` installed in your
   system, this will generate a PNG file with the dependency graph of your
   project.