Support proto files in subdirectories of the package directory (#436)

The existing code assumed that all input .proto files were in the same directory as the BUILD file for the build rule. This isn't always the case, since it's perfectly legal to reference files in a subdirectory that doesn't have its own BUILD file.

Signed-off-by: Alex Konradi <akonradi@google.com>

bazel/protobuf.bzl

@@ -21,16 +21,30 @@ def _path_ignoring_repository(f):
         # before "external/workspace", so we need to add the starting index of "external/workspace"
         return f.path[f.path.find(f.owner.workspace_root) + len(f.owner.workspace_root) + 1:]
 
-def _protoc_cc_output_files(proto_file_sources):
+def _package_relative_path(ctx, file):
+    # Remove the path prefix common to both the BUILD file that defines the
+    # package and the input file.
+    path_parts = file.short_path.split("/")
+    for piece in ctx.build_file_path.split("/"):
+        if path_parts[0] != piece:
+            break
+        path_parts.pop(0)
+
+    return "/".join(path_parts)
+
+def _protoc_cc_output_files(ctx, proto_file_sources):
     cc_hdrs = []
     cc_srcs = []
 
     for p in proto_file_sources:
-        basename = p.basename[:-len(".proto")]
+        # The returned path needs to be relative to the package directory.
+        file_path = _package_relative_path(ctx, p)
 
-        cc_hdrs.append(basename + ".pb.validate.h")
+        if p.basename.endswith(".proto"):
+            file_path = file_path[:-len(".proto")]
 
-        cc_srcs.append(basename + ".pb.validate.cc")
+        cc_hdrs.append(file_path + ".pb.validate.h")
+        cc_srcs.append(file_path + ".pb.validate.cc")
 
     return cc_hdrs + cc_srcs
 
@@ -51,7 +65,7 @@ def _protoc_gen_validate_cc_impl(ctx):
     """Generate C++ protos using protoc-gen-validate plugin"""
     protos = _proto_sources(ctx)
 
-    cc_files = _protoc_cc_output_files(protos)
+    cc_files = _protoc_cc_output_files(ctx, protos)
     out_files = [ctx.actions.declare_file(out) for out in cc_files]
 
     dir_out = _output_dir(ctx)
@@ -69,20 +83,23 @@ def _protoc_gen_validate_cc_impl(ctx):
         package_command = "true",
     )
 
-def _protoc_python_output_files(proto_file_sources):
+def _protoc_python_output_files(ctx, proto_file_sources):
     python_srcs = []
 
     for p in proto_file_sources:
-        basename = p.basename[:-len(".proto")]
+        # The returned path needs to be relative to the package directory.
+        file_path = _package_relative_path(ctx, p)
+        if file_path.endswith(".proto"):
+            file_path = file_path[:-len(".proto")]
 
-        python_srcs.append(basename.replace("-", "_") + "_pb2.py")
+        python_srcs.append(file_path.replace("-", "_") + "_pb2.py")
     return python_srcs
 
 def _protoc_gen_validate_python_impl(ctx):
     """Generate Python protos using protoc-gen-validate plugin"""
     protos = _proto_sources(ctx)
 
-    python_files = _protoc_python_output_files(protos)
+    python_files = _protoc_python_output_files(ctx, protos)
     out_files = [ctx.actions.declare_file(out) for out in python_files]
 
     dir_out = _output_dir(ctx)

tests/harness/cases/BUILD

@@ -24,6 +24,7 @@ proto_library(
         "oneofs.proto",
         "repeated.proto",
         "strings.proto",
+        "subdirectory/in_subdirectory.proto",
         "wkt_any.proto",
         "wkt_duration.proto",
         "wkt_timestamp.proto",

tests/harness/cases/subdirectory/in_subdirectory.proto

@@ -0,0 +1,7 @@
+syntax = "proto3";
+
+package tests.harness.cases;
+option go_package = "cases";
+
+import "validate/validate.proto";
+