How Can I Call Go Code from Within a C Program?

Integrating Go with Existing C Projects: Calling Go Code from C

Since the release of Go 1.5, the possibility of integrating Go with existing C projects has emerged. This guide aims to address the query of how to evoke Go code from within a C program.

Go 1.5 introduced the -buildmode=c-archive option, facilitating the generation of C-callable archives. However, generating the necessary header files may pose challenges. To resolve this issue, it's crucial to mark functions as exported CGo symbols.

To illustrate, consider the following Go code in foo.go:

package main

import (
    "C"
    "fmt"
)

//export PrintInt
func PrintInt(x int) {
    fmt.Println(x)
}

func main() {}

To compile this code as a C-callable static library, execute the following command:

go build -buildmode=c-archive foo.go

This command will produce an archive (foo.a) and a header file (foo.h). The header file will contain declarations such as:

typedef long long GoInt64;
typedef GoInt64 GoInt;
extern void PrintInt(GoInt p0);

With these declarations, it's now possible to invoke the exported function from a C program:

#include "foo.h"

int main(int argc, char **argv) {
    PrintInt(42);
    return 0;
}

To compile this C program:

gcc -pthread foo.c foo.a -o foo

The -pthread option is necessary as the Go runtime utilizes threads. Upon execution, the program will output 42.

By following these steps, you can effectively use Go code within existing C projects, benefiting from the higher-level features of Go while maintaining the low-level access provided by C.

The above is the detailed content of How Can I Call Go Code from Within a C Program?. For more information, please follow other related articles on the PHP Chinese website!