bazel 專案新增 automake/autoconf 專案解決辦法

摘要： 問題描述： 專案 A 是用 bazel 構建，專案 B 是用 automake / autoconf 或是 CMake 構建的，那麼如何在 專案 A 中使用專案 B 呢？ 方法一：clone B，然後在專案 B 中新增 WORKSPACE 和 BUILD，然後在 A 中引用 ...

問題描述：

專案 A 是用 bazel 構建，專案 B 是用 automake / autoconf 或是 CMake 構建的，那麼如何在 專案 A 中使用專案 B 呢？

方法一：clone B，然後在專案 B 中新增 WORKSPACE 和 BUILD，然後在 A 中引用 clone 並修改之後的專案 B

• 缺點：你需要維護 clone B，每次想要更新 B 都需要手動更新 clone B

一個更好的方法 ：

方法二：在 專案 A 中使用 new_git_repository 或是 http_archive 新增專案 B 並指定 BUILD 檔案，假設我們需要依賴專案 B：LAME MP3 Encoder

new_git_repository(
name = "org_lame",
build_file = "lame.BUILD",
commit = "3f89eaa001d9cc5a52e88f6b493c6eec750e9eab",
remote = "https://github.com/lifeiteng/lame.git",
)

# BUILD 檔案
licenses(["notice"])

cc_library(
name = "lame",
srcs = glob([
"libmp3lame/*.c",
"libmp3lame/vector/*.c",
"mpglib/*.c",
]),
hdrs = glob([
"include/*.h",
"libmp3lame/*.h",
"libmp3lame/vector/*.h",
"mpglib/*.h",
]),
copts = ["-Wno-sign-compare -DHAVE_CONFIG_H"],
includes = ["include", "libmp3lame", "mpglib", "."],
visibility = ["//visibility:public"],
)

萬事大吉？ 不是的 ，很多使用 automake/autoconf 的專案構建步驟

是 ofollow,noindex">lame-make

% ./configure# 生成 config.h
% make

或是 opus-make

% ./autogen.sh
 % ./configure# 生成 config.h
 % make

如果沒有 生成 config.h ，編譯通常會失敗，因此我們需要在 build_file ="lame.BUILD" 裡面顯式地生成 config.h， bazel 文件 Working with external dependencies 中沒有相關例子，那麼如何操作呢？

genrule(
name = "config_h",
srcs = [
"configure",
"libmp3lame/lame.c",
"install-sh",
"config.guess",
"config.rpath",
"config.sub",
] + glob(["**/*.in"]),
outs = ["config.h"],
cmd = "./$(location configure) " + 
"&& cp config.h $(location config.h)",
)

cc_library(
name = "liblame",
srcs = glob([
"libmp3lame/*.c",
"libmp3lame/vector/*.c",
"mpglib/*.c",
]),
hdrs = glob([
"include/*.h",
"libmp3lame/*.h",
"libmp3lame/vector/*.h",
"mpglib/*.h",
]) + [
"config.h",
],
copts = ["-Wno-sign-compare -DHAVE_CONFIG_H"],
includes = ["include", "libmp3lame", "mpglib", "."],
visibility = ["//visibility:public"],
)

或是

genrule(
name = "config_h",
srcs = [
"autogen.sh",
"configure.ac",
] + glob(["**/*.in", "m4/*.m4"]),
outs = ["config.h"],
cmd = "./$(location autogen.sh) " + 
"&& ./`dirname $(location autogen.sh)`/configure " +
"&& cp config.h $(location config.h)",
)

cc_library(
name = "libopus",
srcs = glob(
[
"src/*.c",
"celt/*.c",
"silk/*.c",
"silk/float/*.c",
],
exclude = [
"celt/opus_custom_demo.c",
"src/opus_demo.c",
"src/repacketizer_demo.c",
],
),
hdrs = glob(
[
"include/*.h",
"celt/*.h",
"silk/*.h",
"silk/float/*.h",
"src/*.h",
],
) + [
"config.h",
],
copts = ["-Wno-sign-compare -DHAVE_CONFIG_H"],
includes = ["include", "src", "silk/float", "silk", "celt", "."],
visibility = ["//visibility:public"],
)

這裡要注意的是動態確定 configure、autogen.sh 的位置： ./$(location configure) 或是 ./$(location autogen.sh) ，以及正確拷貝 config.h。

bazel-external-deps