waf-tools/clang_compilation_database.py

   1 #!/usr/bin/env python
   2 # encoding: utf-8
   3 # Christoph Koke, 2013
   4
   5 """
   6 Writes the c and cpp compile commands into build/compile_commands.json
   7 see http://clang.llvm.org/docs/JSONCompilationDatabase.html
   8
   9 Usage:
  10
  11     def configure(conf):
  12         conf.load('compiler_cxx')
  13         ...
  14         conf.load('clang_compilation_database')
  15 """
  16
  17 import sys, os, json, shlex, pipes
  18 from waflib import Logs, TaskGen, Task
  19
  20 Task.Task.keep_last_cmd = True
  21
  22 @TaskGen.feature('c', 'cxx')
  23 @TaskGen.after_method('process_use')
  24 def collect_compilation_db_tasks(self):
  25         "Add a compilation database entry for compiled tasks"
  26         try:
  27                 clang_db = self.bld.clang_compilation_database_tasks
  28         except AttributeError:
  29                 clang_db = self.bld.clang_compilation_database_tasks = []
  30                 self.bld.add_post_fun(write_compilation_database)
  31
  32         tup = tuple(y for y in [Task.classes.get(x) for x in ('c', 'cxx')] if y)
  33         for task in getattr(self, 'compiled_tasks', []):
  34                 if isinstance(task, tup):
  35                         clang_db.append(task)
  36
  37 def write_compilation_database(ctx):
  38         "Write the clang compilation database as JSON"
  39         database_file = ctx.bldnode.make_node('compile_commands.json')
  40         Logs.info('Build commands will be stored in %s' % database_file.path_from(ctx.path))
  41         try:
  42                 root = json.load(database_file)
  43         except IOError:
  44                 root = []
  45         clang_db = dict((x['file'], x) for x in root)
  46         for task in getattr(ctx, 'clang_compilation_database_tasks', []):
  47                 try:
  48                         cmd = task.last_cmd
  49                 except AttributeError:
  50                         continue
  51                 directory = getattr(task, 'cwd', ctx.variant_dir)
  52                 f_node = task.inputs[0]
  53                 filename = os.path.relpath(f_node.abspath(), directory)
  54                 entry = {
  55                         "directory": directory,
  56                         "arguments": cmd,
  57                         "file": filename,
  58                 }
  59                 clang_db[filename] = entry
  60         root = list(clang_db.values())
  61         database_file.write(json.dumps(root, indent=2))
  62
  63 # Override the runnable_status function to do a dummy/dry run when the file doesn't need to be compiled.
  64 # This will make sure compile_commands.json is always fully up to date.
  65 # Previously you could end up with a partial compile_commands.json if the build failed.
  66 for x in ('c', 'cxx'):
  67         if x not in Task.classes:
  68                 continue
  69
  70         t = Task.classes[x]
  71
  72         def runnable_status(self):
  73                 def exec_command(cmd, **kw):
  74                         pass
  75
  76                 run_status = self.old_runnable_status()
  77                 if run_status == Task.SKIP_ME:
  78                         setattr(self, 'old_exec_command', getattr(self, 'exec_command', None))
  79                         setattr(self, 'exec_command', exec_command)
  80                         self.run()
  81                         setattr(self, 'exec_command', getattr(self, 'old_exec_command', None))
  82                 return run_status
  83
  84         setattr(t, 'old_runnable_status', getattr(t, 'runnable_status', None))
  85         setattr(t, 'runnable_status', runnable_status)