因此,该组中有很多内容建议您可以在Go中执行此操作(尽管CGO文档中没有):
package bridge
import "fmt"
// #cgo CFLAGS: -I/Users/doug/projects/c/go-bridge/include
// #cgo LDFLAGS: /Users/doug/projects/c/go-bridge/build/libgb.a
// #include <junk.h>
import "C"
func Run() {
fmt.Printf("Invoking c library...\n")
C.x(10)
fmt.Printf("Done\n")
}
然而,它似乎不起作用:
/var/folders/.../bridge.a(bridge.cgo2.o)(__TEXT/__text): x: not defined
使用动态库似乎可以很好地执行此操作,并且判断生成的文件时,其中实际上包含符号‘x’:
/var/folders/rg/hj4s3qlj3sz1d1b5p50ws0vc0000gn/T/go-build442792776/bridge/_obj/_cgo_.o:
0000000100001048 S _NXArgc
0000000100001050 S _NXArgv
0000000100001060 S ___progname
0000000100000dc0 T __cgo_2d7eefe3d6d4_Cfunc_x
0000000100000da0 T __cgo_allocate
0000000100000db0 T __cgo_panic
0000000100000000 T __mh_execute_header
0000000100000d90 T _crosscall2
0000000100001058 S _environ
U _exit
0000000100000d80 T _main
U _puts
0000000100001000 s _pvars
0000000100000de0 T _x <------- Exists
U dyld_stub_binder
0000000100000d40 T start
但显然只是bridge.cgo2.o中的一个标记:
/var/folders/rg/hj4s3qlj3sz1d1b5p50ws0vc0000gn/T/go-build442792776/bridge.a(bridge.cgo2.o):
0000000000000368 s EH_frame0
0000000000000000 T __cgo_2d7eefe3d6d4_Cfunc_x
0000000000000380 S __cgo_2d7eefe3d6d4_Cfunc_x.eh
U _x
我做错了什么?
对于ref,c标头:
int x(int y);
和代码:
#include <junk.h>
#include <stdio.h>
int x(int y) {
printf("Hello World\n");
return y;
}
--
编辑:
不,-L和-l也不起作用;实际上在Google组上有一些具体的讨论,这个(-l/blah/blah.a)不适用于CGO,正确的语法is实际上是省略-l,只列出.a文件……不过,嘿,如果有用的话,我肯定会用的.但事实并非如此:
dougs-mini:go doug$ go run test.go
# bridge
ld: library not found for -l/Users/doug/projects/c/go-bridge/build/libgb.a
collect2: ld returned 1 exit status
dougs-mini:go doug$ ls -l /Users/doug/projects/c/go-bridge/build/libgb.a
-rw-r--r-- 1 doug staff 872 25 May 14:02 /Users/doug/projects/c/go-bridge/build/libgb.a
详细版本:
dougs-mini:go doug$ go build -work -x test.go
WORK=/var/folders/rg/hj4s3qlj3sz1d1b5p50ws0vc0000gn/T/go-build354497708
mkdir -p $WORK/bridge/_obj/
cd /Users/doug/projects/c/go-bridge/go/src/bridge
/Users/doug/projects/go/go/pkg/tool/darwin_amd64/cgo -objdir $WORK/bridge/_obj/ -- -I/Users/doug/projects/c/go-bridge/include -I $WORK/bridge/_obj/ bridge.go
/Users/doug/projects/go/go/pkg/tool/darwin_amd64/6c -FVw -I $WORK/bridge/_obj/ -I /Users/doug/projects/go/go/pkg/darwin_amd64 -o $WORK/bridge/_obj/_cgo_defun.6 -DGOOS_darwin -DGOARCH_amd64 $WORK/bridge/_obj/_cgo_defun.c
gcc -I . -g -O2 -fPIC -m64 -pthread -fno-common -I/Users/doug/projects/c/go-bridge/include -I $WORK/bridge/_obj/ -o $WORK/bridge/_obj/_cgo_main.o -c $WORK/bridge/_obj/_cgo_main.c
gcc -I . -g -O2 -fPIC -m64 -pthread -fno-common -I/Users/doug/projects/c/go-bridge/include -I $WORK/bridge/_obj/ -o $WORK/bridge/_obj/_cgo_export.o -c $WORK/bridge/_obj/_cgo_export.c
gcc -I . -g -O2 -fPIC -m64 -pthread -fno-common -I/Users/doug/projects/c/go-bridge/include -I $WORK/bridge/_obj/ -o $WORK/bridge/_obj/bridge.cgo2.o -c $WORK/bridge/_obj/bridge.cgo2.c
gcc -I . -g -O2 -fPIC -m64 -pthread -fno-common -o $WORK/bridge/_obj/_cgo_.o $WORK/bridge/_obj/_cgo_main.o $WORK/bridge/_obj/_cgo_export.o $WORK/bridge/_obj/bridge.cgo2.o -l/Users/doug/projects/c/go-bridge/build/libgb.a
# bridge
ld: library not found for -l/Users/doug/projects/c/go-bridge/build/libgb.a
collect2: ld returned 1 exit status
值得注意的是,try 这样链接(使用-l)时的失败是gcc无法链接的典型情况,因为您试图组合一组对象文件.
例如:
gcc -I . -g -O2 -fPIC -m64 -pthread -fno-common -o ... -l/path/libgb.a
永远不会在gcc下编译;您可以像这样链接静态库:
gcc -I . -g -O2 -fPIC -m64 -pthread -fno-common -o ... /path/libgb.a
也就是说.我绝对不是漏掉了a-l或-L.