Merge pull request #1233 from davidzchen/python-path

Remove hack for building Python support with Bazel.

BUILD

@@ -22,7 +22,6 @@ load(
     "protobuf",
     "cc_proto_library",
     "py_proto_library",
-    "internal_copied_filegroup",
     "internal_protobuf_py_tests",
 )
 
@@ -484,25 +483,7 @@ java_library(
 # Python support
 ################################################################################
 
-# Hack:
-# protoc generated files contain imports like:
-#   "from google.protobuf.xxx import yyy"
-# However, the sources files of the python runtime are not directly under
-# "google/protobuf" (they are under python/google/protobuf).  We workaround
-# this by copying runtime source files into the desired location to workaround
-# the import issue. Ideally py_library should support something similiar to the
-# "include" attribute in cc_library to inject the PYTHON_PATH for all libraries
-# that depend on the target.
-#
-# If you use python protobuf as a third_party library in your bazel managed
-# project:
-# 1) Please import the whole package to //google/protobuf in your
-# project. Otherwise, bazel disallows generated files out of the current
-# package, thus we won't be able to copy protobuf runtime files into
-# //google/protobuf/.
-# 2) The runtime also requires "six" for Python2/3 compatibility, please see the
-# WORKSPACE file and bind "six" to your workspace as well.
-internal_copied_filegroup(
+py_library(
     name = "python_srcs",
     srcs = glob(
         [
@@ -514,7 +495,7 @@ internal_copied_filegroup(
             "python/google/protobuf/internal/test_util.py",
         ],
     ),
-    include = "python",
+    imports = ["python"],
 )
 
 cc_binary(
@@ -527,7 +508,7 @@ cc_binary(
     linkstatic = 1,
     deps = select({
         "//conditions:default": [],
-        ":use_fast_cpp_protos": ["//util/python:python_headers"],
+        ":use_fast_cpp_protos": ["//external:python_headers"],
     }),
 )
 
@@ -553,7 +534,7 @@ cc_binary(
         ":protobuf",
     ] + select({
         "//conditions:default": [],
-        ":use_fast_cpp_protos": ["//util/python:python_headers"],
+        ":use_fast_cpp_protos": ["//external:python_headers"],
     }),
 )
 
@@ -584,23 +565,14 @@ py_proto_library(
     }),
     default_runtime = "",
     protoc = ":protoc",
-    py_extra_srcs = [":python_srcs"],
-    py_libs = ["//external:six"],
+    py_libs = [
+        ":python_srcs",
+        "//external:six"
+    ],
     srcs_version = "PY2AND3",
     visibility = ["//visibility:public"],
 )
 
-internal_copied_filegroup(
-    name = "python_test_srcs",
-    srcs = glob(
-        [
-            "python/google/protobuf/internal/*_test.py",
-            "python/google/protobuf/internal/test_util.py",
-        ],
-    ),
-    include = "python",
-)
-
 py_proto_library(
     name = "python_common_test_protos",
     srcs = LITE_TEST_PROTOS + TEST_PROTOS,
@@ -624,7 +596,13 @@ py_proto_library(
 
 py_library(
     name = "python_tests",
-    srcs = [":python_test_srcs"],
+    srcs = glob(
+        [
+            "python/google/protobuf/internal/*_test.py",
+            "python/google/protobuf/internal/test_util.py",
+        ],
+    ),
+    imports = ["python"],
     srcs_version = "PY2AND3",
     deps = [
         ":protobuf_python",

WORKSPACE

@@ -12,6 +12,11 @@ new_http_archive(
     build_file = "six.BUILD",
 )
 
+bind(
+    name = "python_headers",
+    actual = "//util/python:python_headers",
+)
+
 bind(
     name = "gtest",
     actual = "@gmock_archive//:gtest",

protobuf.bzl

@@ -117,10 +117,10 @@ def cc_proto_library(
         deps=[],
         cc_libs=[],
         include=None,
-        protoc="//google/protobuf:protoc",
+        protoc="//:protoc",
         internal_bootstrap_hack=False,
         use_grpc_plugin=False,
-        default_runtime="//google/protobuf:protobuf",
+        default_runtime="//:protobuf",
         **kargs):
   """Bazel rule to create a C++ protobuf library from proto source files
 
@@ -199,35 +199,6 @@ def cc_proto_library(
       includes=includes,
       **kargs)
 
-def internal_copied_filegroup(
-        name,
-        srcs,
-        include,
-        **kargs):
-  """Bazel rule to fix sources file to workaround with python path issues.
-
-  Args:
-    name: the name of the internal_copied_filegroup rule, which will be the
-        name of the generated filegroup.
-    srcs: the source files to be copied.
-    include: the expected import root of the source.
-    **kargs: extra arguments that will be passed into the filegroup.
-  """
-  outs = [_RelativeOutputPath(s, include) for s in srcs]
-
-  native.genrule(
-      name=name+"_genrule",
-      srcs=srcs,
-      outs=outs,
-      cmd=" && ".join(["cp $(location %s) $(location %s)" %
-                       (s, _RelativeOutputPath(s, include))
-                       for s in srcs]))
-
-  native.filegroup(
-      name=name,
-      srcs=outs,
-      **kargs)
-
 def py_proto_library(
         name,
         srcs=[],
@@ -235,8 +206,8 @@ def py_proto_library(
         py_libs=[],
         py_extra_srcs=[],
         include=None,
-        default_runtime="//google/protobuf:protobuf_python",
-        protoc="//google/protobuf:protoc",
+        default_runtime="//:protobuf_python",
+        protoc="//:protoc",
         **kargs):
   """Bazel rule to create a Python protobuf library from proto source files
 
@@ -276,15 +247,6 @@ def py_proto_library(
       visibility=["//visibility:public"],
   )
 
-  if include != None:
-    # Copy the output files to the desired location to make the import work.
-    internal_copied_filegroup_name=name + "_internal_copied_filegroup"
-    internal_copied_filegroup(
-        name=internal_copied_filegroup_name,
-        srcs=outs,
-        include=include)
-    outs=[internal_copied_filegroup_name]
-
   if default_runtime and not default_runtime in py_libs + deps:
     py_libs += [default_runtime]
 
@@ -292,6 +254,7 @@ def py_proto_library(
       name=name,
       srcs=outs+py_extra_srcs,
       deps=py_libs+deps,
+      imports=includes,
       **kargs)
 
 def internal_protobuf_py_tests(
@@ -308,8 +271,7 @@ def internal_protobuf_py_tests(
 
   """
   for m in modules:
-    s = _RelativeOutputPath(
-        "python/google/protobuf/internal/%s.py" % m, "python")
+    s = "python/google/protobuf/internal/%s.py" % m
     native.py_test(
         name="py_%s" % m,
         srcs=[s],

util/python/BUILD

 # This is a placeholder for python headers. Projects needing to use
 # fast cpp protos in protobuf's python interface should build with
 # --define=use_fast_cpp_protos=true, and in addition, provide
-# //util/python:python_headers dependency that in turn provides Python.h.
+# //external:python_headers dependency that in turn provides Python.h.
+#
+# Projects that include protobuf using a Bazel external repository will need to
+# add a workspace rule to their WORKSPACE files to add an external workspace
+# that includes the Python headers. For example, the protobuf WORKSPACE file
+# includes the following local_repository rule that points to this directory:
+#
+# new_local_repository(
+#   name = "python",
+#   path = __workspace_dir__ + "/util/python",
+# )
 cc_library(
     name = "python_headers",
     visibility = ["//visibility:public"],