1# Copyright 2023 The BoringSSL Authors
2#
3# Licensed under the Apache License, Version 2.0 (the "License");
4# you may not use this file except in compliance with the License.
5# You may obtain a copy of the License at
6#
7#     https://www.apache.org/licenses/LICENSE-2.0
8#
9# Unless required by applicable law or agreed to in writing, software
10# distributed under the License is distributed on an "AS IS" BASIS,
11# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12# See the License for the specific language governing permissions and
13# limitations under the License.
14
15# Go is an optional dependency. It's a necessary dependency if running tests or
16# the FIPS build, which will check these.
17find_program(GO_EXECUTABLE go)
18
19function(require_go)
20  if(NOT GO_EXECUTABLE)
21    message(FATAL_ERROR "Could not find Go")
22  endif()
23endfunction()
24
25function(go_executable dest package)
26  require_go()
27  set(godeps "${PROJECT_SOURCE_DIR}/util/godeps.go")
28  if(NOT CMAKE_GENERATOR STREQUAL "Ninja")
29    # The DEPFILE parameter to add_custom_command only works with Ninja. Query
30    # the sources at configure time. Additionally, everything depends on go.mod.
31    # That affects what external packages to use.
32    #
33    # TODO(davidben): Starting CMake 3.20, it also works with Make. Starting
34    # 3.21, it works with Visual Studio and Xcode too.
35    execute_process(COMMAND ${GO_EXECUTABLE} run ${godeps} -format cmake
36                            -pkg ${package}
37                    WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
38                    OUTPUT_VARIABLE sources
39                    RESULT_VARIABLE godeps_result)
40    add_custom_command(OUTPUT ${dest}
41                       COMMAND ${GO_EXECUTABLE} build
42                               -o ${CMAKE_CURRENT_BINARY_DIR}/${dest} ${package}
43                       WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
44                       DEPENDS ${sources} ${PROJECT_SOURCE_DIR}/go.mod)
45  else()
46    # Ninja expects the target in the depfile to match the output. This is a
47    # relative path from the build directory.
48    binary_dir_relative_path(${dest} target)
49
50    set(depfile "${CMAKE_CURRENT_BINARY_DIR}/${dest}.d")
51    add_custom_command(OUTPUT ${dest}
52                       COMMAND ${GO_EXECUTABLE} build
53                               -o ${CMAKE_CURRENT_BINARY_DIR}/${dest} ${package}
54                       COMMAND ${GO_EXECUTABLE} run ${godeps} -format depfile
55                               -target ${target} -pkg ${package} -out ${depfile}
56                       WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
57                       DEPENDS ${godeps} ${PROJECT_SOURCE_DIR}/go.mod
58                       DEPFILE ${depfile})
59  endif()
60endfunction()
61
62