this rule is missing dependency declarations for the following files included by 'bcd/hello.c':

[Yogur]

this rule is missing dependency declarations for the following files included by 'bcd/hello.c':

  '/home/yogur/my_project/abc/interface.h'.

but i have 

cc_library(

    name = "hello",

    srcs=["hello.c"],

    copts=["-Iabc"],

)

this error means that  the rule include the .h head file as hello.c #include "interface.h" 

why need i to declar the dependency?

in my project . i need to compile a lot of .c files whose dependency are very different. And all the dependency are in the same folder 

what shold i do ?~

thx for any help~

[Thiago Farina]

On Sat, Jul 25, 2015 at 4:57 AM, Yogur <yog...@gmail.com> wrote:

this rule is missing dependency declarations for the following files included by 'bcd/hello.c':

  '/home/yogur/my_project/abc/interface.h'.

but i have 

cc_library(

    name = "hello",

    srcs=["hello.c"],

    copts=["-Iabc"],

)

So you have the following:

$ cat /my_project/bcd/BUILD

cc_library(

  name= "hello",

  srcs=["hello.c"],

  copts=["-labc"],

)

Then interface.h is in /my_project/abc/, right?

How does it look like your abc BUILD file?

$ cat /my_project/abc/BUILD

?

I think in Bazel you have to be explicit about your dependencies.

--

Thiago Farina

[Yogur]

 Yes, interface.h is in /my_project/abc  there is no BUILD file.
the rule haved got it,and my .c file include the .h, why still I need to declar the dependency?

I mean , what the consideration that bazel do this ?

my temporary way to solve the problem is 

define a filegroup whose srcs is interface.h in the /my_project/abc/BUILD

then add the deps=["//my_project/abc:hello_deps"]  

it works，but i have to do the similar work many times.

so i want to konw if there is a simple solution？

[David Chen]

To confirm, from what I understand, your source tree currently looks like the following:

my_project/

  WORKSPACE

  abc/

    interface.h

  bcd/

    BUILD

    hello.c

In my_project/bcd/BUILD, you currently have:

cc_library(

    name = "hello",

    srcs = ["hello.c"],

    copts = ["-Iabc"],

)

And in my_project/bcd/hello.c, you currently have:

#include "interface.h"

Please let me know if I am missing anything.

------------------

Here are a few points to keep in mind about building C/C++ code with Bazel:

• The default include path for header files is the root of your source tree. As a result, in my_project/bcd/hello.c, your include should be:
  #include "abc/interface.h". However, this can be changed using the includes attribute of the cc_* rules.
• Usually, you should not use -I and -l flags directly to specify dependencies in your source tree. Instead, you should try to use deps when possible.
• If you haven't already, I highly recommend reading Bazel's C++ Basics documentation, which provides good explanations on building C/C++ projects with Bazel.

You have a few options here:

Option 1: Add a BUILD file for abc (recommended)

Your source tree would look like this:

my_project/

  WORKSPACE

  abc/

    BUILD

    interface.h

  bcd/

    BUILD

    hello.c

abc/BUILD:

cc_library(

    name = "abc",

    srcs = ["interface.h"],

    visibility = ["//visibility:public"],

)

bcd/hello.c:

#include "abc/interface.h"

...

In bcd/BUILD, specify a dependency on abc as follows:

cc_library(

    name = "hello",

    srcs = ["hello.c"],

    deps = ["//abc"],

)

This is the recommended approach because it provides a cleaner separation between different packages in your source tree, and it is more clear which library you are including different headers from.

Option 2: Use a common BUILD file at the root of your project

Your source tree would look like the following:

my_project/

  WORKSPACE

  BUILD

  abc/

    interface.h

  bcd/

    hello.c

In your root BUILD file, you can use the includes attribute to tell the rule to look for headers under abc/:

cc_library(

    name = "hello",

    srcs = ["bcd/hello.c"],

    includes = ["abc"],

)

bcd/hello.c:

#include "interface.h"

...

While this works, it is less ideal because there is a less clear separation between different modules.

In any case, I recommend reading the C++ Basics documentation if you haven't already. Keep in mind that many of the details there also apply to building C code since the cc_* rules can be used for building both C and C++ code.

Feel free to let me know if you have any more questions.

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[Yogur]

thank you very much!!!

I have read the C++ Basics documentation many times,and I have tried your two opitions.

my task is thanslate makefile to bazel BUILD , so i  can't  change the .c files。

  Each string of includes is prepended with -I and added to COPTS，so i think they have no difference.

the main reason of the way i choose is I care less the separation between different packages in  my source tree

I want to simpify the code to use copts  :)

now I have a deeper understand the difference of Bazel and Makefile

my way is define a filegroup containg the include .h files  in  abc/BUILD ，and add  the filegroup to the rule srcs，