Question

我修改了stage3 cpp bazelbuild示例，以通过copts使用额外的包含路径

https://github.com/mnieber/examples/commit/a8b784ddf5698563a31401b9ac3531636b3536ef

但是，这会产生编译器错误（请注意，尽管-Ilib/foo被用作gcc的选项）：

bazel build --verbose_failures //main:hello-world
INFO: Analysed target //main:hello-world (1 packages loaded).
INFO: Found 1 target...
ERROR: /home/maarten/sources/examples/cpp-tutorial/stage3/lib/BUILD:1:1: C++ compilation of rule '//lib:hello-time' failed (Exit 1): gcc failed: error executing command 
  (cd /home/maarten/.cache/bazel/_bazel_maarten/62d72ea3bd73864cf884808e7d850715/execroot/__main__ && \
  exec env - \
    LD_LIBRARY_PATH=/usr/local/lib \
    PATH=/home/maarten/projects/xmlparser/dodo_commands/env/bin:/home/maarten/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin:/home/dodo/env/bin:/home/maarten/.dodo_commands/bin \
    PWD=/proc/self/cwd \
  /usr/bin/gcc -U_FORTIFY_SOURCE -fstack-protector -Wall -B/usr/bin -B/usr/bin -Wunused-but-set-parameter -Wno-free-nonheap-object -fno-omit-frame-pointer '-std=c++0x' -MD -MF bazel-out/k8-fastbuild/bin/lib/_objs/hello-time/hello-time.pic.d '-frandom-seed=bazel-out/k8-fastbuild/bin/lib/_objs/hello-time/hello-time.pic.o' -fPIC -iquote . -iquote bazel-out/k8-fastbuild/genfiles -iquote bazel-out/k8-fastbuild/bin -iquote external/bazel_tools -iquote bazel-out/k8-fastbuild/genfiles/external/bazel_tools -iquote bazel-out/k8-fastbuild/bin/external/bazel_tools -Ilib/foo -fno-canonical-system-headers -Wno-builtin-macro-redefined '-D__DATE__="redacted"' '-D__TIMESTAMP__="redacted"' '-D__TIME__="redacted"' -c lib/hello-time.cc -o bazel-out/k8-fastbuild/bin/lib/_objs/hello-time/hello-time.pic.o)

Use --sandbox_debug to see verbose messages from the sandbox
lib/hello-time.cc:2:21: fatal error: bar/baz.h: No such file or directory
compilation terminated.
Target //main:hello-world failed to build

有人可以解释为什么找不到bar/baz.h吗？

Answer 1

cc_library中的cpp-tutorial/stage3/lib/BUILD没有声明对头文件的依赖，因此Bazel不会将该文件放入沙箱中，因此编译失败（应该如此）。

您不需要多余的copts。相反，您必须在{hello-time“规则的bar/baz.h中添加hdrs，或者，如果” bar“是一个单独的程序包（它具有BUILD文件），然后添加一个” cc_library ”，其中hdrs包括baz.h并依赖于“ hello-time”中的该库的规则。

Answer 2

我在Bazel邮件列表中得到了这个答案（简短版本：此头文件需要添加到cc_library( name = "hello-time", srcs = [ "foo/bar/baz.h", "hello-time.cc", ], hdrs = ["hello-time.h"], copts = ["-Ilib/foo"], visibility = ["//main:__pkg__"], )，有点令人惊讶）：

问题在于，您没有在cc_library的源文件中以任何方式声明头文件baz.h。因此，在沙箱中执行操作（默认设置）时，该文件不可见。该构建已经可以在没有沙箱的情况下运行了（尝试使用--spawn_strategy = standalone标志运行它）。

因此，在源代码中声明baz.h：

{{1}}

尽管使用copts添加了额外的include目录，Bazel为什么仍找不到我的include文件？

2 个答案: