blob: 37b8e20ccc2649b5e26511bb8a5be5126926ab83 [file] [log] [blame]
Scons Builder for nanopb .proto definitions.
This tool will locate the nanopb generator and use it to generate .pb.c and
.pb.h files from the .proto files.
Basic example
# Build myproto.pb.c and myproto.pb.h from myproto.proto
myproto = env.NanopbProto("myproto")
# Link nanopb core to the program
env.Append(CPPPATH = "$NANOB")
myprog = env.Program(["myprog.c", myproto, "$NANOPB/pb_encode.c", "$NANOPB/pb_decode.c"])
Configuration options
Normally, this script is used in the test environment of nanopb and it locates
the nanopb generator by a relative path. If this script is used in another
application, the path to nanopb root directory has to be defined:
env.SetDefault(NANOPB = "path/to/nanopb")
Additionally, the path to protoc and the options to give to protoc can be
defined manually:
env.SetDefault(PROTOC = "path/to/protoc")
env.SetDefault(PROTOCFLAGS = "--plugin=protoc-gen-nanopb=path/to/protoc-gen-nanopb")
import SCons.Action
import SCons.Builder
import SCons.Util
from SCons.Script import Dir, File
import os.path
import platform
warningbase = SCons.Warnings.SConsWarning
except AttributeError:
warningbase = SCons.Warnings.Warning
class NanopbWarning(warningbase):
def _detect_nanopb(env):
'''Find the path to nanopb root directory.'''
if 'NANOPB' in env:
# Use nanopb dir given by user
return env['NANOPB']
p = os.path.abspath(os.path.join(os.path.dirname(__file__), '..', '..', '..'))
if os.path.isdir(p) and os.path.isfile(os.path.join(p, 'pb.h')):
# Assume we are running under tests/site_scons/site_tools
return p
raise SCons.Errors.StopError(NanopbWarning,
"Could not find the nanopb root directory")
def _detect_python(env):
'''Find Python executable to use.'''
if 'PYTHON' in env:
return env['PYTHON']
p = env.WhereIs('python3')
if p:
return env['ESCAPE'](p)
p = env.WhereIs('py.exe')
if p:
return env['ESCAPE'](p) + " -3"
return env['ESCAPE'](sys.executable)
def _detect_nanopb_generator(env):
'''Return command for running'''
generator_cmd = os.path.join(env['NANOPB'], 'generator-bin', 'nanopb_generator' + env['PROGSUFFIX'])
if os.path.exists(generator_cmd):
# Binary package
return env['ESCAPE'](generator_cmd)
# Source package
return env['PYTHON'] + " " + env['ESCAPE'](os.path.join(env['NANOPB'], 'generator', ''))
def _detect_protoc(env):
'''Find the path to the protoc compiler.'''
if 'PROTOC' in env:
# Use protoc defined by user
return env['PROTOC']
n = _detect_nanopb(env)
p1 = os.path.join(n, 'generator-bin', 'protoc' + env['PROGSUFFIX'])
if os.path.exists(p1):
# Use protoc bundled with binary package
return env['ESCAPE'](p1)
p = os.path.join(n, 'generator', 'protoc')
if os.path.exists(p):
# Use the grcpio-tools protoc wrapper
if env['PLATFORM'] == 'win32':
return env['ESCAPE'](p + '.bat')
return env['ESCAPE'](p)
p = env.WhereIs('protoc')
if p:
# Use protoc from path
return env['ESCAPE'](p)
raise SCons.Errors.StopError(NanopbWarning,
"Could not find the protoc compiler")
def _detect_protocflags(env):
'''Find the options to use for protoc.'''
if 'PROTOCFLAGS' in env:
return env['PROTOCFLAGS']
p = _detect_protoc(env)
n = _detect_nanopb(env)
p1 = os.path.join(n, 'generator', 'protoc' + env['PROGSUFFIX'])
p2 = os.path.join(n, 'generator-bin', 'protoc' + env['PROGSUFFIX'])
if p in [env['ESCAPE'](p1), env['ESCAPE'](p2)]:
# Using the bundled protoc, no options needed
return ''
e = env['ESCAPE']
if env['PLATFORM'] == 'win32':
return e('--plugin=protoc-gen-nanopb=' + os.path.join(n, 'generator', 'protoc-gen-nanopb.bat'))
return e('--plugin=protoc-gen-nanopb=' + os.path.join(n, 'generator', 'protoc-gen-nanopb'))
def _nanopb_proto_actions(source, target, env, for_signature):
esc = env['ESCAPE']
# Make protoc build inside the SConscript directory
prefix = os.path.dirname(str(source[-1]))
srcfile = esc(os.path.relpath(str(source[0]), prefix))
include_dirs = '-I.'
for d in env['PROTOCPATH']:
d = env.GetBuildPath(d)
if not os.path.isabs(d): d = os.path.relpath(d, prefix)
include_dirs += ' -I' + esc(d)
# when generating .pb.cpp sources, instead of pb.h generate .pb.hpp headers
source_extension = os.path.splitext(str(target[0]))[1]
header_extension = '.h' + source_extension[2:]
nanopb_flags = env['NANOPBFLAGS']
if nanopb_flags:
nanopb_flags = '--source-extension=%s,--header-extension=%s,%s:.' % (source_extension, header_extension, nanopb_flags)
nanopb_flags = '--source-extension=%s,--header-extension=%s:.' % (source_extension, header_extension)
return SCons.Action.CommandAction('$PROTOC $PROTOCFLAGS %s --nanopb_out=%s %s' % (include_dirs, nanopb_flags, srcfile),
chdir = prefix)
def _nanopb_proto_emitter(target, source, env):
basename = os.path.splitext(str(source[0]))[0]
source_extension = os.path.splitext(str(target[0]))[1]
header_extension = '.h' + source_extension[2:]
target.append(basename + '.pb' + header_extension)
# This is a bit of a hack. protoc include paths work the sanest
# when the working directory is the same as the source root directory.
# To get that directory in _nanopb_proto_actions, we add SConscript to
# the list of source files.
if os.path.exists(basename + '.options'):
source.append(basename + '.options')
return target, source
_nanopb_proto_builder = SCons.Builder.Builder(
generator = _nanopb_proto_actions,
suffix = '.pb.c',
src_suffix = '.proto',
emitter = _nanopb_proto_emitter)
_nanopb_proto_cpp_builder = SCons.Builder.Builder(
generator = _nanopb_proto_actions,
suffix = '.pb.cpp',
src_suffix = '.proto',
emitter = _nanopb_proto_emitter)
def generate(env):
'''Add Builder for nanopb protos.'''
env['NANOPB'] = _detect_nanopb(env)
env['PROTOC'] = _detect_protoc(env)
env['PROTOCFLAGS'] = _detect_protocflags(env)
env['PYTHON'] = _detect_python(env)
env['NANOPB_GENERATOR'] = _detect_nanopb_generator(env)
env.SetDefault(NANOPBFLAGS = '')
env.SetDefault(PROTOCPATH = [".", os.path.join(env['NANOPB'], 'generator', 'proto')])
env['BUILDERS']['NanopbProto'] = _nanopb_proto_builder
env['BUILDERS']['NanopbProtoCpp'] = _nanopb_proto_cpp_builder
def exists(env):
return _detect_protoc(env) and _detect_protoc_opts(env)