Export the function that gets an address from a symbol name

[nrjatyunshan]

Export functions to make it easier for other languages ​​to load as libraries.

go build -buildmode=c-shared -o libGoReSym.so

then, use it in c

#include <stdio.h>
#include <dlfcn.h>
#include <assert.h>
#include <stddef.h>

typedef signed char GoInt8;
typedef unsigned char GoUint8;
typedef short GoInt16;
typedef unsigned short GoUint16;
typedef int GoInt32;
typedef unsigned int GoUint32;
typedef long long GoInt64;
typedef unsigned long long GoUint64;
typedef GoInt64 GoInt;
typedef GoUint64 GoUint;
typedef size_t GoUintptr;
typedef float GoFloat32;
typedef double GoFloat64;
typedef struct { const char *p; ptrdiff_t n; } GoString;
typedef void *GoMap;
typedef void *GoChan;
typedef struct { void *t; void *v; } GoInterface;
typedef struct { void *data; GoInt len; GoInt cap; } GoSlice;

struct Func
{
        GoUintptr addr;
        GoInt size;
};

int main()
{
        void *dlfile = dlopen("./libGoReSym.so", RTLD_LAZY);
        assert(dlfile);

        struct Func (*GetFuncBySym)(GoString, GoString) = dlsym(dlfile, "GetFuncBySym");
        assert(GetFuncBySym);

        GoString filename;
        GoString symname;

        filename.p = "GoReSym";
        filename.n = sizeof("GoReSym") - 1;

        symname.p = "runtime.casgstatus";
        symname.n = sizeof("runtime.casgstatus") - 1;

        struct Func func = GetFuncBySym(filename, symname);
        printf("addr=[%p]\n", func.addr);
        printf("size=[%d]\n", func.size);

        dlclose(dlfile);
        return 0;
}

output

addr=[0x43ae00]
size=[384]