From e251ebd1adf6d1fc73cf50af5982373abd49b033 Mon Sep 17 00:00:00 2001
From: Iakov Davydov <iakov.davydov@unil.ch>
Date: Tue, 10 May 2016 18:57:04 +0200
Subject: [PATCH] do not pass go pointers to the C code

This is a proposed solution for afbarnard/go-lbfgsb#4.
---
 lbfgsb.go             | 14 +++++++-------
 lbfgsb_go_interface.c |  8 ++++----
 lbfgsb_go_interface.h |  6 ++++--
 3 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/lbfgsb.go b/lbfgsb.go
index 53c14fe..9ceaa76 100644
--- a/lbfgsb.go
+++ b/lbfgsb.go
@@ -292,14 +292,14 @@ func (lbfgsb *Lbfgsb) Minimize(
 	upperBounds := makeCCopySlice_Float(lbfgsb.upperBounds, dim)
 
 	// Set up callbacks for function, gradient, and logging
-	callbackData_c := unsafe.Pointer(
-		&callbackData{objective: objective})
+	callbackData_c := uintptr(unsafe.Pointer(
+		&callbackData{objective: objective}))
 	var doLogging_c C.int                        // false
-	var logFunctionCallbackData_c unsafe.Pointer // null
+	var logFunctionCallbackData_c uintptr // null
 	if lbfgsb.logger != nil {
 		doLogging_c = C.int(1) // true
-		logFunctionCallbackData_c = unsafe.Pointer(
-			&logCallbackData{logger: lbfgsb.logger})
+		logFunctionCallbackData_c = uintptr(unsafe.Pointer(
+			&logCallbackData{logger: lbfgsb.logger}))
 	}
 
 	// Allocate arrays for return value
@@ -333,11 +333,11 @@ func (lbfgsb *Lbfgsb) Minimize(
 
 	// Call the actual L-BFGS-B procedure
 	statusCode_c := C.lbfgsb_minimize_c(
-		callbackData_c, dim_c,
+		(C.uintptr_t)(callbackData_c), dim_c,
 		boundsControl_c, lowerBounds_c, upperBounds_c,
 		approximationSize_c, fTolerance_c, gTolerance_c,
 		x0_c, minX_c, minF_c, minG_c, &iters_c, &evals_c,
-		printControl_c, doLogging_c, logFunctionCallbackData_c,
+		printControl_c, doLogging_c, (C.uintptr_t)(logFunctionCallbackData_c),
 		statusMessage_c, statusMessageLength_c,
 	)
 
diff --git a/lbfgsb_go_interface.c b/lbfgsb_go_interface.c
index 5f2959e..c7ed395 100644
--- a/lbfgsb_go_interface.c
+++ b/lbfgsb_go_interface.c
@@ -15,7 +15,7 @@
 
 int lbfgsb_minimize_c
 (
- void *callback_data,
+ uintptr_t callback_data,
  int dim,
  int *bounds_control,
  double *lower_bounds,
@@ -31,7 +31,7 @@ int lbfgsb_minimize_c
  int *evals,
  int fortran_print_control,
  int do_logging,
- void *log_function_callback_data,
+ uintptr_t log_function_callback_data,
  char *status_message,
  int status_message_length
  )
@@ -47,7 +47,7 @@ int lbfgsb_minimize_c
     (
      go_objective_function_callback,
      go_objective_gradient_callback,
-     callback_data,
+     (void *)callback_data,
      dim,
      bounds_control,
      lower_bounds,
@@ -63,7 +63,7 @@ int lbfgsb_minimize_c
      evals,
      fortran_print_control,
      log_function_pointer,
-     log_function_callback_data,
+     (void *)log_function_callback_data,
      status_message,
      status_message_length
      );
diff --git a/lbfgsb_go_interface.h b/lbfgsb_go_interface.h
index 21e063d..a3e847d 100644
--- a/lbfgsb_go_interface.h
+++ b/lbfgsb_go_interface.h
@@ -7,9 +7,11 @@
 #ifndef __LBFGSB_GO_INTERFACE_H__
 #define __LBFGSB_GO_INTERFACE_H__
 
+#include <stdint.h>
+
 int lbfgsb_minimize_c
 (
- void *callback_data,
+ uintptr_t callback_data,
  int dim,
  int *bounds_control,
  double *lower_bounds,
@@ -25,7 +27,7 @@ int lbfgsb_minimize_c
  int *evals,
  int fortran_print_control,
  int do_logging,
- void *log_function_callback_data,
+ uintptr_t log_function_callback_data,
  char *status_message,
  int status_message_length
  );