sandboxed-api/cmake/SapiUtil.cmake
Christian Blichmann f44cca6c98 Fix path to generated proto sources when embedding
When embedding SAPI in an external CMake project, the version of
`protobuf_generate_cpp` that we lifted from upstream protobuf produces
the wrong generated file paths.

For example, given this project structure:

```
/parent/
+-- myproject/
+-- myproject_build/  <- CMake build directory
+-- sandboxed-api/    <- Checkout from GitHub
```

And a CMake file in `myproject/CMakeLists.txt` that embeds SAPI like
this:

```
cmake_minimum_required(VERSION 3.12)
project(SandboxedTest LANGUAGES CXX)
set(CMAKE_CXX_STANDARD 17)
set(CMAKE_CXX_STANDARD_REQUIRED ON)

add_subdirectory(
  ${PROJECT_SOURCE_DIR}/../sandboxed-api
  ${PROJECT_BINARY_DIR}/sandboxed-api
)
```

Then `protobuf_generate_cpp` correctly invokes the protoc compiler to
generate
`/parent/myproject_build/sandboxed-api/sandboxed_api/proto_arg.proto.pb.cc'.
However, the path of the generated source file that is passed to the C++
compiler will be
`/parent/myproject_build/sandboxed-api/sandboxed_api/../../myproject_build/sandboxed-api/sandboxed_api/proto_arg.pb.cc`.
Note the duplicated project build directory component in the
canonicalized version:
`/parent/myproject_build/myproject_build/sandboxed-api/sandboxed_api/proto_arg.pb.cc`.

This change simple omits the computation of any relative file paths and
simply uses `_pb_PROTOC_OUT_DIR` which defauls to
`CMAKE_CURRENT_BINARY_DIR`, which should always contain the correct
path.

Signed-off-by: Christian Blichmann <mail@blichmann.eu>
2020-03-18 18:47:02 +01:00

202 lines
7.1 KiB
CMake

# Copyright 2019 Google LLC
#
# 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.
# Creates an alias for SOURCE, called DESTINATION.
#
# On platforms that support them, this rule will effectively create a symlink.
#
# SOURCE may be relative to CMAKE_CURRENT_SOURCE_DIR, or absolute.
# DESTINATION may relative to CMAKE_CURRENT_BINARY_DIR, or absolute.
#
# Adapted from https://github.com/google/binexport/blob/master/util.cmake
function(create_directory_symlink SOURCE DESTINATION)
get_filename_component(_destination_parent "${DESTINATION}" DIRECTORY)
file(MAKE_DIRECTORY "${_destination_parent}")
if(WIN32)
file(TO_NATIVE_PATH "${SOURCE}" _native_source)
file(TO_NATIVE_PATH "${DESTINATION}" _native_destination)
execute_process(COMMAND $ENV{ComSpec} /c
mklink /J "${_native_destination}" "${_native_source}" ERROR_QUIET)
else()
execute_process(COMMAND ${CMAKE_COMMAND} -E
create_symlink "${SOURCE}" "${DESTINATION}")
endif()
endfunction()
# Implements list(JOIN ...) for CMake < 3.12.
function(list_join LIST SEP OUTPUT)
foreach(item IN LISTS ${LIST})
set(_concat "${_concat}${SEP}${item}")
endforeach()
string(LENGTH "${SEP}" _len)
string(SUBSTRING "${_concat}" ${_len} -1 _concat)
set(${OUTPUT} "${_concat}" PARENT_SCOPE)
endfunction()
# Helper function that behaves just like Protobuf's protobuf_generate_cpp(),
# except that it strips import paths. This is necessary, because CMake's
# protobuf rules don't work well with imports across different directories.
function(sapi_protobuf_generate_cpp SRCS HDRS)
cmake_parse_arguments(_pb "" "EXPORT_MACRO" "" ${ARGN})
if(NOT _pb_UNPARSED_ARGUMENTS)
message(FATAL_ERROR "sapi_protobuf_generate_cpp() missing proto files")
return()
endif()
foreach(_file IN LISTS _pb_UNPARSED_ARGUMENTS)
file(READ "${_file}" _pb_orig)
string(REGEX REPLACE "import \".*/([^/]+\\.proto)\""
"import \"\\1\"" _pb_repl "${_pb_orig}")
set(_file "${CMAKE_CURRENT_BINARY_DIR}/${_file}")
file(WRITE "${_file}" "${_pb_repl}")
list(APPEND _pb_files "${_file}")
endforeach()
set(_outvar)
sapi_protobuf_generate(APPEND_PATH
LANGUAGE cpp
EXPORT_MACRO ${_pb_EXPORT_MACRO}
OUT_VAR _outvar
PROTOS ${_pb_files})
set(${SRCS})
set(${HDRS})
foreach(_file IN LISTS _outvar)
if(_file MATCHES "cc$")
list(APPEND ${SRCS} ${_file})
else()
list(APPEND ${HDRS} ${_file})
endif()
endforeach()
set(${SRCS} ${${SRCS}} PARENT_SCOPE)
set(${HDRS} ${${HDRS}} PARENT_SCOPE)
endfunction()
# Runs the protocol buffer compiler on the given proto files. Compatible
# with the upstream version and included here so we can add_subdirectory()
# the protobuf source tree.
# One difference to the protobuf version is that this function handles
# relative paths differently, which is relevant when Sandboxed API is
# embedded in another project.
# TODO(cblichmann): We should try and upstream this behavior.
function(sapi_protobuf_generate)
set(_options APPEND_PATH)
set(_singleargs LANGUAGE OUT_VAR EXPORT_MACRO PROTOC_OUT_DIR TARGET)
set(_multiargs PROTOS IMPORT_DIRS GENERATE_EXTENSIONS)
cmake_parse_arguments(_pb "${_options}" "${_singleargs}" "${_multiargs}"
"${ARGN}")
if(NOT _pb_PROTOS AND NOT _pb_TARGET)
message(FATAL_ERROR "sapi_protobuf_generate missing targets or sources")
return()
endif()
if(NOT _pb_OUT_VAR AND NOT _pb_TARGET)
message(FATAL_ERROR "sapi_protobuf_generate missing target or output var")
return()
endif()
if(NOT _pb_LANGUAGE)
set(_pb_LANGUAGE cpp)
else()
string(TOLOWER ${_pb_LANGUAGE} _pb_LANGUAGE)
endif()
if(NOT _pb_PROTOC_OUT_DIR)
set(_pb_PROTOC_OUT_DIR ${CMAKE_CURRENT_BINARY_DIR})
endif()
if(_pb_EXPORT_MACRO AND _pb_LANGUAGE STREQUAL cpp)
set(_dll_export_decl "dllexport_decl=${_pb_EXPORT_MACRO}:")
endif()
if(NOT _pb_GENERATE_EXTENSIONS)
if(_pb_LANGUAGE STREQUAL cpp)
set(_pb_GENERATE_EXTENSIONS .pb.h .pb.cc)
elseif(_pb_LANGUAGE STREQUAL python)
set(_pb_GENERATE_EXTENSIONS _pb2.py)
else()
message(FATAL_ERROR
"sapi_protobuf_generate given unknown language ${_pb_LANGUAGE}")
return()
endif()
endif()
if(_pb_TARGET)
get_target_property(_source_list ${_pb_TARGET} SOURCES)
foreach(_file IN LISTS _source_list)
if(_file MATCHES "proto$")
list(APPEND _pb_PROTOS "${_file}")
endif()
endforeach()
endif()
if(NOT _pb_PROTOS)
message(FATAL_ERROR
"sapi_protobuf_generate could not find any .proto files")
return()
endif()
# Create an include path for each file specified
foreach(_file ${_pb_PROTOS})
get_filename_component(_abs_file ${_file} ABSOLUTE)
get_filename_component(_abs_path ${_abs_file} PATH)
list(FIND _protobuf_include_path "${_abs_path}" _contains_already)
if(${_contains_already} EQUAL -1)
list(APPEND _protobuf_include_path -I ${_abs_path})
endif()
endforeach()
foreach(_dir IN LISTS _pb_IMPORT_DIRS)
get_filename_component(_abs_path "${_dir}" ABSOLUTE)
list(FIND _protobuf_include_path "${_abs_path}" _contains_already)
if(${_contains_already} EQUAL -1)
list(APPEND _protobuf_include_path -I "${_abs_path}")
endif()
endforeach()
set(_generated_srcs_all)
foreach(_proto IN LISTS _pb_PROTOS)
get_filename_component(_abs_file ${_proto} ABSOLUTE)
get_filename_component(_abs_dir ${_abs_file} DIRECTORY)
get_filename_component(_basename ${_proto} NAME_WE)
set(_generated_srcs)
foreach(_ext ${_pb_GENERATE_EXTENSIONS})
# Use _pb_PROTOC_OUT_DIR directly without computing a relative path
list(APPEND _generated_srcs "${_pb_PROTOC_OUT_DIR}/${_basename}${_ext}")
endforeach()
list(APPEND _generated_srcs_all ${_generated_srcs})
add_custom_command(OUTPUT ${_generated_srcs}
COMMAND protobuf::protoc
ARGS --${_pb_LANGUAGE}_out
${_dll_export_decl}${_pb_PROTOC_OUT_DIR}
${_protobuf_include_path}
${_abs_file}
DEPENDS ${_abs_file} protobuf::protoc
COMMENT "Running ${_pb_LANGUAGE} protoc on ${_proto}"
VERBATIM)
endforeach()
set_source_files_properties(${_generated_srcs_all}
PROPERTIES GENERATED TRUE)
if(_pb_OUT_VAR)
set(${_pb_OUT_VAR} ${_generated_srcs_all} PARENT_SCOPE)
endif()
if(_pb_TARGET)
target_sources(${_pb_TARGET} PRIVATE ${_generated_srcs_all})
endif()
endfunction()