如何在Conan.io中使用Bazel作为构建工具

Question

我想使用柯南进行包管理，并使用Bazel作为我的C++代码的构建工具。我使用柯南的原因是因为JFrog Artifactory支持它，我正在使用它作为Artifactory Repository。

要做到这一点，我想出了以下方案：

$/home/mytimer=> ls -lrt 
    0 Sep 25 11:57 WORKSPACE 

4096年09月25 12:00编译/ 4096年09月25 12:02主/

$/home/mytimer=> ls -l main 
total 4 
60 Sep 25 12:02 BUILD 
61 Sep 25 11:56 conanfile.txt 
955 Sep 25 11:56 timer.cpp 

$/home/mytimer=> ls -l build 

total 8 
1266 Sep 25 12:00 conanbuildinfo.gcc 
1875 Sep 25 12:00 conaninfo.txt 

（这是后我执行柯南--install ../main）

$/home/mytimer=> cat cat main/conanfile.txt 
[requires] 
Poco/1.7.8p3@pocoproject/stable 

[generators] 
gcc 



$/home/mytimer=>cat build/conanbuildinfo.gcc 
-DPOCO_STATIC=ON -DPOCO_NO_AUTOMATIC_LIBS -I"/home/.conan/data/Poco/1.7.8p3/pocoproject/stable/package/da23483d46b7229cbae8615ce1ea2594635f3a5f/include" -I"/home/.conan/data/OpenSSL/1.0.2l/conan/stable/package/c8dc3f0797f6d24f3c80634ae2854ddf9ee34334/include" -I"/home/.conan/data/zlib/1.2.11/conan/stable/package/82b1dd29b2e9143665c77ef477100c690d719cbf/include" -Wl,-rpath="/home/.conan/data/Poco/1.7.8p3/pocoproject/stable/package/da23483d46b7229cbae8615ce1ea2594635f3a5f/lib" -Wl,-rpath="/home/.conan/data/OpenSSL/1.0.2l/conan/stable/package/c8dc3f0797f6d24f3c80634ae2854ddf9ee34334/lib" -Wl,-rpath="/home/.conan/data/zlib/1.2.11/conan/stable/package/82b1dd29b2e9143665c77ef477100c690d719cbf/lib" -L"/home/.conan/data/Poco/1.7.8p3/pocoproject/stable/package/da23483d46b7229cbae8615ce1ea2594635f3a5f/lib" -L"/home/.conan/data/OpenSSL/1.0.2l/conan/stable/package/c8dc3f0797f6d24f3c80634ae2854ddf9ee34334/lib" -L"/home/.conan/data/zlib/1.2.11/conan/stable/package/82b1dd29b2e9143665c77ef477100c690d719cbf/lib" -lPocoUtil -lPocoMongoDB -lPocoNet -lPocoNetSSL -lPocoCrypto -lPocoData -lPocoDataSQLite -lPocoZip -lPocoXML -lPocoJSON -lPocoFoundation -lpthread -lrt -lssl -lcrypto -ldl -lz -D_GLIBCXX_USE_CXX11_ABI=0 -m64 -s -DNDEBUGdevc 

$/home/mytimer=> cat build/conaninfo.txt 
[settings] 
arch=x86_64 
build_type=Release 
compiler=gcc 
compiler.libcxx=libstdc++ 
compiler.version=6.3 
os=Linux 

[requires] 
Poco/1.Y.Z 

[options] 


[full_settings] 
arch=x86_64 
build_type=Release 
compiler=gcc 
compiler.libcxx=libstdc++ 
compiler.version=6.3 
os=Linux 

[full_requires] 
OpenSSL/1.0.2l@conan/stable:c8dc3f0797f6d24f3c80634ae2854ddf9ee34334 
Poco/1.7.8p3@pocoproject/stable:da23483d46b7229cbae8615ce1ea2594635f3a5f 
zlib/1.2.11@conan/stable:82b1dd29b2e9143665c77ef477100c690d719cbf 

[full_options] 
OpenSSL:386=False 
OpenSSL:no_asm=False 
OpenSSL:no_bf=False 
OpenSSL:no_cast=False 
OpenSSL:no_des=False 
OpenSSL:no_dh=False 
OpenSSL:no_dsa=False 
OpenSSL:no_hmac=False 
OpenSSL:no_md2=False 
OpenSSL:no_md5=False 
OpenSSL:no_mdc2=False 
OpenSSL:no_rc2=False 
OpenSSL:no_rc4=False 
OpenSSL:no_rc5=False 
OpenSSL:no_rsa=False 
OpenSSL:no_sha=False 
OpenSSL:no_sse2=False 
OpenSSL:no_threads=False 
OpenSSL:no_zlib=False 
OpenSSL:shared=False 
Poco:cxx_14=False 
Poco:enable_apacheconnector=False 
Poco:enable_cppparser=False 
Poco:enable_crypto=True 
Poco:enable_data=True 
Poco:enable_data_mysql=False 
Poco:enable_data_odbc=False 
Poco:enable_data_sqlite=True 
Poco:enable_json=True 
Poco:enable_mongodb=True 
Poco:enable_net=True 
Poco:enable_netssl=True 
Poco:enable_netssl_win=True 
Poco:enable_pagecompiler=False 
Poco:enable_pagecompiler_file2page=False 
Poco:enable_pdf=False 
Poco:enable_pocodoc=False 
Poco:enable_sevenzip=False 
Poco:enable_tests=False 
Poco:enable_util=True 
Poco:enable_xml=True 
Poco:enable_zip=True 
Poco:force_openssl=True 
Poco:poco_unbundled=False 
Poco:shared=False 
zlib:shared=False 

[scope] 
dev=True 

[recipe_hash] 


[env] 

$/home/mytimer=> cat main/BUILD 
cc_binary(
name = "timer", 
srcs = ["timer.cpp"], 
) 

================================ ====================== ============== 现在，我想使用bazel构建工具来构建mytimer项目，如下所示： $/home/mytimer => bazel build - （某些选项）//main：timer

这个选项应该是什么，以便bazel可以读取conanbuildinfo.gcc并使用它创建可执行文件？

Answer 1

我用巴泽尔的genrule（）功能来解决我这样的问题：

$/home/mytimer=> cat main/BUILD 
genrule(
    name = "timer", 
    outs = ["timer.out"], 
    cmd = "g++ /home/mytimer/main/timer.cpp@/home/mytimer/build/conanbuildinfo.gcc -o $@ ", 
) 
/home/mytime=> bazel build -s //main:timer 
WARNING: ignoring http_proxy in environment. 
WARNING: Output base '/home/.cache/bazel/_bazel_user/274fa1325d85b25c2722794ea' is on NFS. This may lead to surprising failures and undetermined behavior. 
INFO: Found 1 target... 
>>>>> # //main:timer [action 'Executing genrule //main:timer'] 
(cd /home/.cache/bazel/_bazel_user/274fa1325d85b25c2722614/execroot/__main__ && \ 
    exec env - \ 
    LD_LIBRARY_PATH=<library paths> 
    PATH=<all other paths> 
    /bin/bash -c 'source external/bazel_tools/tools/genrule/genrule-setup.sh; g++ /home/bazel/examples/cpp-tutorial/mytimer/main/timer.cpp @/home/bazel/examples/cpp-tutorial/mytimer/build/conanbuildinfo.gcc -o bazel-out/local-fastbuild/genfiles/main/timer.out ') 
Target //main:timer up-to-date: 
    bazel-genfiles/main/timer.out 
INFO: Elapsed time: 1.050s, Critical Path: 0.50s 

/home/mytime=> ls -lrt bazel-out/local-fastbuild/genfiles/main/ 
total 212 
212000 Sep 26 14:42 timer.out 
/home/mytime=> ./bazel-out/local-fastbuild/genfiles/main/timer.out 
Callback called after 249 milliseconds. 
Callback called after 749 milliseconds. 
Callback called after 1249 milliseconds. 
Callback called after 1749 milliseconds. 
Callback called after 2249 milliseconds. 
Callback called after 2749 milliseconds. 
^C 

因此，通过使用genrule（）功能，我们可以在巴泽尔执行任何shell命令。虽然这不是一种所谓的“bazel”方法来生成工件（genzle（）to bazel与C/C++中的“goto”命令相同），但在这种情况下，我没有看到任何其他选项来解决此问题。

Answer 2

您也可以为此创建一个自定义规则：https://docs.bazel.build/versions/master/skylark/rules.html。理想情况下，您可以使用Skylark API来遵循C++规则，以防止重新实现C++规则已经做的所有事情，但不幸的是，API尚未完成（2017年10月）。我认为最好的跟踪错误是https://github.com/bazelbuild/bazel/issues/1624。