diff options
Diffstat (limited to 'misc')
| -rw-r--r-- | misc/scons/site_tools/compilation_db.py | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/misc/scons/site_tools/compilation_db.py b/misc/scons/site_tools/compilation_db.py new file mode 100644 index 0000000000..87db32adc9 --- /dev/null +++ b/misc/scons/site_tools/compilation_db.py @@ -0,0 +1,177 @@ +# Copyright 2015 MongoDB Inc. +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. + +import json +import SCons +import itertools + +# Implements the ability for SCons to emit a compilation database for the MongoDB project. See +# http://clang.llvm.org/docs/JSONCompilationDatabase.html for details on what a compilation +# database is, and why you might want one. The only user visible entry point here is +# 'env.CompilationDatabase'. This method takes an optional 'target' to name the file that +# should hold the compilation database, otherwise, the file defaults to compile_commands.json, +# which is the name that most clang tools search for by default. + +# TODO: Is there a better way to do this than this global? Right now this exists so that the +# emitter we add can record all of the things it emits, so that the scanner for the top level +# compilation database can access the complete list, and also so that the writer has easy +# access to write all of the files. But it seems clunky. How can the emitter and the scanner +# communicate more gracefully? +__COMPILATION_DB_ENTRIES = [] + +# We make no effort to avoid rebuilding the entries. Someday, perhaps we could and even +# integrate with the cache, but there doesn't seem to be much call for it. +class __CompilationDbNode(SCons.Node.Python.Value): + def __init__(self, value): + SCons.Node.Python.Value.__init__(self, value) + self.Decider(changed_since_last_build_node) + + +def changed_since_last_build_node(child, target, prev_ni, node): + """ Dummy decider to force always building""" + return True + + +def makeEmitCompilationDbEntry(comstr): + """ + Effectively this creates a lambda function to capture: + * command line + * source + * target + :param comstr: unevaluated command line + :return: an emitter which has captured the above + """ + user_action = SCons.Action.Action(comstr) + + def EmitCompilationDbEntry(target, source, env): + """ + This emitter will be added to each c/c++ object build to capture the info needed + for clang tools + :param target: target node(s) + :param source: source node(s) + :param env: Environment for use building this node + :return: target(s), source(s) + """ + + dbtarget = __CompilationDbNode(source) + + entry = env.__COMPILATIONDB_Entry( + target=dbtarget, + source=[], + __COMPILATIONDB_UTARGET=target, + __COMPILATIONDB_USOURCE=source, + __COMPILATIONDB_UACTION=user_action, + __COMPILATIONDB_ENV=env, + ) + + # TODO: Technically, these next two lines should not be required: it should be fine to + # cache the entries. However, they don't seem to update properly. Since they are quick + # to re-generate disable caching and sidestep this problem. + env.AlwaysBuild(entry) + env.NoCache(entry) + + __COMPILATION_DB_ENTRIES.append(dbtarget) + + return target, source + + return EmitCompilationDbEntry + + +def CompilationDbEntryAction(target, source, env, **kw): + """ + Create a dictionary with evaluated command line, target, source + and store that info as an attribute on the target + (Which has been stored in __COMPILATION_DB_ENTRIES array + :param target: target node(s) + :param source: source node(s) + :param env: Environment for use building this node + :param kw: + :return: None + """ + + command = env["__COMPILATIONDB_UACTION"].strfunction( + target=env["__COMPILATIONDB_UTARGET"], source=env["__COMPILATIONDB_USOURCE"], env=env["__COMPILATIONDB_ENV"], + ) + + entry = { + "directory": env.Dir("#").abspath, + "command": command, + "file": str(env["__COMPILATIONDB_USOURCE"][0]), + } + + target[0].write(entry) + + +def WriteCompilationDb(target, source, env): + entries = [] + + for s in __COMPILATION_DB_ENTRIES: + entries.append(s.read()) + + with open(str(target[0]), "w") as target_file: + json.dump(entries, target_file, sort_keys=True, indent=4, separators=(",", ": ")) + + +def ScanCompilationDb(node, env, path): + return __COMPILATION_DB_ENTRIES + + +def generate(env, **kwargs): + + static_obj, shared_obj = SCons.Tool.createObjBuilders(env) + + env["COMPILATIONDB_COMSTR"] = kwargs.get("COMPILATIONDB_COMSTR", "Building compilation database $TARGET") + + components_by_suffix = itertools.chain( + itertools.product( + env["CPPSUFFIXES"], + [ + (static_obj, SCons.Defaults.StaticObjectEmitter, "$CXXCOM"), + (shared_obj, SCons.Defaults.SharedObjectEmitter, "$SHCXXCOM"), + ], + ), + ) + + for entry in components_by_suffix: + suffix = entry[0] + builder, base_emitter, command = entry[1] + + # Ensure we have a valid entry + # used to auto ignore header files + if suffix in builder.emitter: + emitter = builder.emitter[suffix] + builder.emitter[suffix] = SCons.Builder.ListEmitter([emitter, makeEmitCompilationDbEntry(command),]) + + env["BUILDERS"]["__COMPILATIONDB_Entry"] = SCons.Builder.Builder( + action=SCons.Action.Action(CompilationDbEntryAction, None), + ) + + env["BUILDERS"]["__COMPILATIONDB_Database"] = SCons.Builder.Builder( + action=SCons.Action.Action(WriteCompilationDb, "$COMPILATIONDB_COMSTR"), + target_scanner=SCons.Scanner.Scanner(function=ScanCompilationDb, node_class=None), + ) + + def CompilationDatabase(env, target): + result = env.__COMPILATIONDB_Database(target=target, source=[]) + + env.AlwaysBuild(result) + env.NoCache(result) + + return result + + env.AddMethod(CompilationDatabase, "CompilationDatabase") + + +def exists(env): + return True |