去用C库构建，遇到stdlib.h中重复的成员

Question

I am doing some protocol stack programming with golang. I put codec thing in C. And build C with a simple CMake configuration as below:

cmake_minimum_required (VERSION 2.8)

project (Demo1)

aux_source_directory(. DIR_SRCS)


add_library(codecLib SHARED ${DIR_SRCS})

and Link the shared library with this kind code

//#cgo CFLAGS:-I./codec/

//#cgo LDFLAGS: ./codec/build -lcodecLib

//#include <protocol.h>

import "C"

import "fmt"

at last, I met following error while building it with command "CGO_ENABLED=1 GOOS=linux GOARCH=amd64 go build",

In file included from /usr/include/stdlib.h:42:0,
from _cgo_export.c:2:
/usr/include/x86_64-linux-gnu/bits/waitstatus.h:79:15: error: duplicate member ‘__w_retcode’
  unsigned int __w_retcode:8;
               ^
/usr/include/x86_64-linux-gnu/bits/waitstatus.h:80:15: error: duplicate member ‘__w_coredump’
  unsigned int __w_coredump:1;
               ^
/usr/include/x86_64-linux-gnu/bits/waitstatus.h:81:15: error: duplicate member ‘__w_termsig’
  unsigned int __w_termsig:7;
               ^
/usr/include/x86_64-linux-gnu/bits/waitstatus.h:93:15: error: duplicate member ‘__w_stopsig’
  unsigned int __w_stopsig:8; /* Stopping signal.  */
               ^
/usr/include/x86_64-linux-gnu/bits/waitstatus.h:94:15: error: duplicate member ‘__w_stopval’
  unsigned int __w_stopval:8; /* W_STOPPED if stopped.  */

I didn't find the solution yet. I appreciate for the solution.

Answer 1

The problem you're having is probably due to GOLang not parsing the pre-processor commands in the GNU C Library properly (or at all). It could also be due to an issue with your importing endian.h, or requiring some other C/GO/CGO import or define.

Here's an excerpt from waitstatus.h (or see the full file on GitHub):

# if    __BYTE_ORDER == __LITTLE_ENDIAN 
    unsigned int __w_termsig:7;
    unsigned int __w_coredump:1;
    unsigned int __w_retcode:8;
    unsigned int:16;
# endif /* Little endian. */ 
# if    __BYTE_ORDER == __BIG_ENDIAN 
    unsigned int:16; 
    unsigned int __w_retcode:8; 
    unsigned int __w_coredump:1; 
    unsigned int __w_termsig:7; 
# endif /* Big endian.  */

You'll notice that the same variables are announced twice - one for each Endian. GOLang is erroring because of this. You could resolve this by manually editing the file if you know which endian you're compiling for.