Access Golang code from a C project in Visual Studio 2019

Question

I have a C project in Visual Studio 2019 and I would like to use certain functions written in Go within it.

I have a test file called ctest.go which has the following contents:

package main

import (
    "C"
    "fmt"
)

//export printInt
func printInt(x int) {
    fmt.Printf("Hello from go: %d", x)
}

func main() {}

I'm generating a static library with this command:

go build -buildmode=c-archive ctest.go

I end up with two files, ctest.a and ctest.h which I include in my VS project. I include ctest.h in my code and immediately get these errors:

identifier "__SIZE_TYPE__" is undefined
expected a ';'
expected a ';'

The generated header file contains the following lines which caused it:

typedef __SIZE_TYPE__ GoUintptr;
typedef float _Complex GoComplex64;
typedef double _Complex GoComplex128;

I replaced __SIZE_TYPE__ by size_t and just commented out the _Complex lines to stop the errors.

Now my VS project compiles while including the header file. But as soon as I try to use my go function like this:

printInt(5);

I get 2 warnings followed by 6 errors:

Warning LNK4078 multiple '.text' sections found with different attributes (60600060)    AWO F:\AWO\AWO\ctest.a(go.o)
Warning LNK4078 multiple '.text' sections found with different attributes (60600060)    AWO F:\AWO\AWO\ctest.a(go.o)
Error   LNK2019 unresolved external symbol __imp___iob referenced in function __cgo_preinit_init    AWO F:\AWO\AWO\ctest.a(000005.o)
Error   LNK2001 unresolved external symbol __imp___iob  AWO F:\AWO\AWO\ctest.a(000006.o)
Error   LNK2001 unresolved external symbol __imp___iob  AWO F:\AWO\AWO\ctest.a(000007.o)
Error   LNK2019 unresolved external symbol _fprintf referenced in function _x_cgo_sys_thread_create AWO F:\AWO\AWO\ctest.a(000005.o)
Error   LNK2001 unresolved external symbol _fprintf AWO F:\AWO\AWO\ctest.a(000007.o)
Error   LNK1120 2 unresolved externals  AWO F:\AWO\Debug\AWO.exe    1

This is where I'm stuck. I'm not sure what I'm doing wrong or should be doing differently to properly use the library generated with go.

I believe I am, I've added `ctest.a` to "Additional Dependencies" and its directory to "Additional Library Directories" — kpage, Sep 15 '19 at 14:25
There is a lot here https://stackoverflow.com/questions/6125683/call-go-functions-from-c — mevets, Sep 15 '19 at 14:34
I don't believe visual studio supports .a file format. Try compiling it as .lib and static. — Irelia, Sep 15 '19 at 15:57

score 0 · Answer 1 · edited Jul 20 '21 at 08:21

0

project properties -> linker -> input -> additional dependencies

legacy_stdio_definitions.lib;%(AdditionalDependencies)

add source code

C

FILE* __cdecl __iob_func(void)
{
    FILE _iob[] = { *stdin, *stdout, *stderr };
    return _iob;
}

C++

extern "C" { FILE __iob_func[3] = { *stdin,*stdout,*stderr }; }

edited Jul 20 '21 at 08:21

Josef

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answered Jul 20 '21 at 04:45

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Access Golang code from a C project in Visual Studio 2019

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