ld: duplicate symbol at tip

[gta]

Hi,

I tried out tip and got this:

$ hg identify

71e92f075ee7 tip

$ go get github.com/jteeuwen/glfw

# github.com/jteeuwen/glfw

ld: duplicate symbol _setCharCB in $WORK/github.com/jteeuwen/glfw/_obj/callback.cgo2.o and $WORK/github.com/jteeuwen/glfw/_obj/_cgo_export.o for architecture x86_64

collect2: ld returned 1 exit status

$ uname -rs

Darwin 11.3.0

It works with the last weekly.

Can someone reproduce? Should I file an issue?

Ciao.

[Andrew Gerrand]

Did you rebuild the tree after updating to tip? ('go version')

[gta]

I'm pretty sure I did, but just in case I did it again :)

$ go version

go version weekly.2012-02-14 +71e92f075ee7

[gta]

followup

$ go version

go version weekly.2012-02-22 +96bd78e7d35e

$ go tool cgo glfw.go

$ ls _obj/

_cgo_.o         _cgo_defun.c    _cgo_export.c   _cgo_export.h   _cgo_flags      _cgo_gotypes.go _cgo_main.c     glfw.cgo1.go    glfw.cgo2.c

At this point  _cgo_export.h is:

/* Created by cgo - DO NOT EDIT. */

typedef unsigned int uint;

typedef signed char schar;

typedef unsigned char uchar;

typedef unsigned short ushort;

typedef long long int64;

typedef unsigned long long uint64;

typedef __SIZE_TYPE__ uintptr;

typedef struct { char *p; int n; } GoString;

typedef void *GoMap;

typedef void *GoChan;

typedef struct { void *t; void *v; } GoInterface;

$ go tool cgo callback.go

$ ls _obj/

_cgo_.o          _cgo_export.c    _cgo_flags       _cgo_main.c      callback.cgo2.c  glfw.cgo2.c

_cgo_defun.c     _cgo_export.h    _cgo_gotypes.go  callback.cgo1.go glfw.cgo1.go

_cgo_export.h now looks like:

/* Created by cgo - DO NOT EDIT. */

#line 7 "callback.go"

#include "glue.h"

extern void goWindowSizeCB(int, int);

extern int  goWindowCloseCB(void);

extern void goWindowRefreshCB(void);

extern void goMouseButtonCB(int, int);

extern void goMousePosCB(int, int);

extern void goMouseWheelCB(int);

extern void goKeyCB(int, int);

extern void goCharCB(int, int);

void setWindowSizeCB()    { glfwSetWindowSizeCallback(goWindowSizeCB); }

void setWindowCloseCB()   { glfwSetWindowCloseCallback(goWindowCloseCB); }

void setWindowRefreshCB() { glfwSetWindowRefreshCallback(goWindowRefreshCB); }

void setMouseButtonCB()   { glfwSetMouseButtonCallback(goMouseButtonCB); }

void setMousePosCB()      { glfwSetMousePosCallback(goMousePosCB); }

void setMouseWheelCB()    { glfwSetMouseWheelCallback(goMouseWheelCB); }

void setKeyCB()           { glfwSetKeyCallback(goKeyCB); }

void setCharCB()          { glfwSetCharCallback(goCharCB); }

typedef unsigned int uint;

typedef signed char schar;

typedef unsigned char uchar;

typedef unsigned short ushort;

typedef long long int64;

typedef unsigned long long uint64;

typedef __SIZE_TYPE__ uintptr;

typedef struct { char *p; int n; } GoString;

typedef void *GoMap;

typedef void *GoChan;

typedef struct { void *t; void *v; } GoInterface;

extern void goWindowSizeCB(int p0, int p1);

extern int goWindowCloseCB();

extern void goWindowRefreshCB();

extern void goMouseButtonCB(int p0, int p1);

extern void goMousePosCB(int p0, int p1);

extern void goMouseWheelCB(int p0);

extern void goKeyCB(int p0, int p1);

extern void goCharCB(int p0, int p1);

and the first 20 lines of callback.cgo2.c are:

#line 7 "callback.go"

#include "glue.h"

extern void goWindowSizeCB(int, int);

extern int  goWindowCloseCB(void);

extern void goWindowRefreshCB(void);

extern void goMouseButtonCB(int, int);

extern void goMousePosCB(int, int);

extern void goMouseWheelCB(int);

extern void goKeyCB(int, int);

extern void goCharCB(int, int);

void setWindowSizeCB()    { glfwSetWindowSizeCallback(goWindowSizeCB); }

void setWindowCloseCB()   { glfwSetWindowCloseCallback(goWindowCloseCB); }

void setWindowRefreshCB() { glfwSetWindowRefreshCallback(goWindowRefreshCB); }

void setMouseButtonCB()   { glfwSetMouseButtonCallback(goMouseButtonCB); }

void setMousePosCB()      { glfwSetMousePosCallback(goMousePosCB); }

void setMouseWheelCB()    { glfwSetMouseWheelCallback(goMouseWheelCB); }

void setKeyCB()           { glfwSetKeyCallback(goKeyCB); }

void setCharCB()          { glfwSetCharCallback(goCharCB); }

Any idea for a quick fix?

Ciao.

[Jim Teeuwen]

I've found the same issues myself. This seems to happen with all my cgo packages.

I have not had time to dive into it yet, so I can't say why this happens.

Agon filed a bug report on this issue: https://github.com/jteeuwen/glfw/issues/4

[gta]

I also filed this issue http://code.google.com/p/go/issues/detail?id=3116&colspec=ID%20Status%20Stars%20Priority%20Owner%20Reporter%20Summary

P.S. I hoep you don't mind using your code as example

[gwenn]

Maybe change 00a19a04b13e:
"If people are using //export and
putting non-header information in the preamble, they will need to
refactor their code."

On Feb 23, 5:05 pm, gta <giacomo.tart...@gmail.com> wrote:
> I also filed this
> issuehttp://code.google.com/p/go/issues/detail?id=3116&colspec=ID%20Status...

[Dorival Pedroso]

same problem here (with another package of mine)... 

[Dorival Pedroso]

Hi, I can confirm that the inferface(.h) files must be 'code-free' now; otherwise cgo produces 'multiple definition' s ...

I'm posting below an example code (calling Fortran <-> Go):

notes:

1) the code commented out in blue must be put in a c file;

2) I'm using global variables to communicate between Fortran and go because I'm still learning how to pass float64 arrays around ...;

3) I wonder if this code could be pretty coloured automatically here... ;-)

cheers.

dorival.

fortrancode.f

      subroutine FORTRANCODE(FCN,N,X,Y)

          ! FCN callback function: FCN(N,X,Y)

          ! N   size of arrays X and Y

          ! X   input array

          ! Y   output array = X**2.0D0

          implicit none

          external FCN

          integer N,I

          double precision X,Y

          dimension Y(N)

          call FCN(N,X,Y)

          write(6,'(a)') 'FORTRANCODE has finished'

      end subroutine

fcallback.h

#ifndef FCALLBACK_H

#define FCALLBACK_H

typedef void (*CFunction) (int *N, double *X, double *Y);

void fortrancode_(CFunction, int *N, double *X, double *Y);

int    *CC_N; // dimension

double *CC_X; // input vector (size=N)

double *CC_Y; // output vector (size=N)

/*

void cc_fcn(int *N, double *X, double *Y) {

    int i;

    for (i=0; i<(*N); ++i) { CC_X[i] = X[i]; }

    extern void go_fcn();

    go_fcn();

    for (i=0; i<(*N); ++i) { CC_Y[i] = Y[i]; }

}

void call_fortrancode() {

    fortrancode_(cc_fcn, CC_N, CC_X, CC_Y);

}

*/

void cc_fcn(int *N, double *X, double *Y);

void call_fortrancode();

#endif // FCALLBACK_H

fcallback.c

#include "fcallback.h"

void cc_fcn(int *N, double *X, double *Y) {

    int i;

    for (i=0; i<(*N); ++i) { CC_X[i] = X[i]; }

    extern void go_fcn();

    go_fcn();

    for (i=0; i<(*N); ++i) { CC_Y[i] = Y[i]; }

}

void call_fortrancode() {

    fortrancode_(cc_fcn, CC_N, CC_X, CC_Y);

}

gocallback.go

package main

/*

#cgo LDFLAGS: libfortrancode.so

#include "fcallback.h"

*/

import "C"

import (

"fmt"

"unsafe"

)

type Function func(n int, x, y []float64)

var (

GO_N   int       // dimension

GO_X   []float64 // input vector (size=N)

GO_Y   []float64 // output vector (size=N)

GO_FCN Function  // callback function

)

//export go_fcn

func go_fcn() {

GO_FCN(GO_N, GO_X, GO_X)

}

func powfcn(n int, x, y []float64) {

for i := 0; i < n; i++ {

y[i] = x[i] * x[i]

}

}

func main() {

// data

var n int = 10

x := make([]float64, n)

y := make([]float64, n)

for k, _ := range x {

x[k] = float64(k + 1)

}

// connect Go

GO_N, GO_X, GO_Y, GO_FCN = n, x, y, powfcn

// connect C

C.CC_N = (*C.int)(unsafe.Pointer(&GO_N))

C.CC_X = (*C.double)(unsafe.Pointer(&GO_X[0]))

C.CC_Y = (*C.double)(unsafe.Pointer(&GO_Y[0]))

// before: output

fmt.Printf("x(before) = %v\n", x)

fmt.Printf("y(before) = %v\n", x)

// call fortran code

C.call_fortrancode()

// after: output

fmt.Printf("x(after) = %v\n", x)

fmt.Printf("y(after) = %v\n", x)

}

CMakeLists.txt (for compiling a dynamic library with the Fortran code)

PROJECT(FORTRANCODE)

CMAKE_MINIMUM_REQUIRED(VERSION 2.8)

ENABLE_LANGUAGE(Fortran)

ADD_LIBRARY(fortrancode SHARED fortrancode.f)

[Dorival Pedroso]

hi, just to fix some typos:

this is correct => GO_FCN(GO_N, GO_X, GO_Y)

this is correct => fmt.Printf("y(before) = %v\n", y)

this is correct => fmt.Printf("y(after) = %v\n", y)

cheers.

dorival

[Jim Teeuwen]

The glfw repository has been updated with a fix.