I am trying to wrap a C library in Golang. I am trying to call a C function in an already compiled library. I have both a .a file and a .so library file.
Where do I need to place the library files and how do i tell cgo that I am using these libraries?
I am rather a novice when it comes to C. Any help would be greatly appreciated.
我正在尝试在Golang中包装C库。 我正在尝试在已编译的库中调用C函数。 我同时有一个 我需要在哪里放置库文件，如何告诉 我是C语言的新手。我们将不胜感激。
.a 文件和一个 .so 库文件。
cgo 我正在使用这些库？
I'll explain it with this sample:
First build libhello.a using ./libs/m.c:
微信扫一扫#include <stdint.h>
extern uint64_t Add(uint64_t a, uint64_t b) {
return a + b;
}
For this test sample libhello.a is inside ./libs/ :
m.go
└───libs
m.c
libhello.a
Then go build this m.go working sample:
package main
//#cgo LDFLAGS: -L${SRCDIR}/libs -lhello
//#include <stdint.h>
//extern uint64_t Add(uint64_t a, uint64_t b);
import "C"
import (
"fmt"
)
func main() {
fmt.Println(C.Add(C.uint64_t(10), C.uint64_t(20))) // 30
}
output:
30
When the cgo directives are parsed, any occurrence of the string ${SRCDIR} will be replaced by the absolute path to the directory containing the source file. This allows pre-compiled static libraries to be included in the package directory and linked properly. For example if package foo is in the directory /go/src/foo:
// #cgo LDFLAGS: -L${SRCDIR}/libs -lfooWill be expanded to:
// #cgo LDFLAGS: -L/go/src/foo/libs -lfoo