使用Genrule输出的不同子集的Bazel规则

Question

I have a code generator that produces three output files:

• client.cpp
• server.cpp
• data.h

The genrule looks like this:

genrule(
  name = 'code_gen',
  tools = [ '//tools:code_gen.sh' ],
  outs = [ 'client.cpp', 'server.cpp', 'data.h' ],
  local = True,
  cmd = '$(location //tools:code_gen.sh) $(@D)')

The 'client.cpp' and 'server.cpp' each have their own cc_library rule.

My question is how to depend on the genrule but only use a specific output file.

What I did is create a macro that defined the genrule with specific outs set to the file required, but this resulted in multiple execution of the genrule :

gen.bzl :

def code_generator(
  name,
  out):
  native.genrule(
    name = name,
    tools = [ '//bazel:gen.sh' ],
    outs = [ out ],
    local = True,
    cmd = '$(location //bazel:gen.sh) $(@D)')

BUILD

load(':gen.bzl', 'code_generator')
code_generator('client_cpp', 'client.cpp')
code_generator('server_cpp', 'server.cpp')
code_generator('data_h', 'data.h')

cc_library(
  name = 'client',
  srcs = [ ':client_cpp' ],
  hdrs = [ ':data_h' ],
)

cc_library(
  name = 'server',
  srcs = [ ':server_cpp' ],
  hdrs = [ ':data_h' ],
)

Is there a way to depend on a genrule making it run once and then use only selected outputs from it?

Answer 1

您应该能够仅使用文件名（例如:server.cpp ）来依赖规则的特定输出。