vkd3d-shader: Allow writing log output via a custom callback.

When using PE vkd3d through Wine, debug output may be swallowed by writing to
Win32 stderr. Avoid this by providing a way to hook up vkd3d log output to Wine
output.

Signed-off-by: Zebediah Figura <zfigura@codeweavers.com>
Signed-off-by: Giovanni Mascellani <gmascellani@codeweavers.com>
Signed-off-by: Henri Verbeet <hverbeet@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>

include/private/vkd3d_debug.h

@@ -47,6 +47,7 @@ enum vkd3d_dbg_level
 enum vkd3d_dbg_level vkd3d_dbg_get_level(void);
 
 void vkd3d_dbg_printf(enum vkd3d_dbg_level level, const char *function, const char *fmt, ...) VKD3D_PRINTF_FUNC(3, 4);
+void vkd3d_dbg_set_log_callback(PFN_vkd3d_log callback);
 
 const char *vkd3d_dbg_sprintf(const char *fmt, ...) VKD3D_PRINTF_FUNC(1, 2);
 const char *vkd3d_dbg_vsprintf(const char *fmt, va_list args);

include/vkd3d_shader.h

@@ -1806,6 +1806,18 @@ VKD3D_SHADER_API void vkd3d_shader_free_shader_signature(struct vkd3d_shader_sig
 VKD3D_SHADER_API int vkd3d_shader_preprocess(const struct vkd3d_shader_compile_info *compile_info,
         struct vkd3d_shader_code *out, char **messages);
 
+/**
+ * Set a callback to be called when vkd3d-shader outputs debug logging.
+ *
+ * If NULL, or if this function has not been called, libvkd3d-shader will print
+ * all enabled log output to stderr.
+ *
+ * \param callback Callback function to set.
+ *
+ * \since 1.4
+ */
+VKD3D_SHADER_API void vkd3d_shader_set_log_callback(PFN_vkd3d_log callback);
+
 #endif  /* VKD3D_SHADER_NO_PROTOTYPES */
 
 /** Type of vkd3d_shader_get_version(). */
@@ -1859,6 +1871,9 @@ typedef void (*PFN_vkd3d_shader_free_shader_signature)(struct vkd3d_shader_signa
 typedef void (*PFN_vkd3d_shader_preprocess)(struct vkd3d_shader_compile_info *compile_info,
         struct vkd3d_shader_code *out, char **messages);
 
+/** Type of vkd3d_shader_set_log_callback(). \since 1.4 */
+typedef void (*PFN_vkd3d_shader_set_log_callback)(PFN_vkd3d_log callback);
+
 #ifdef __cplusplus
 }
 #endif  /* __cplusplus */

include/vkd3d_types.h

@@ -19,6 +19,8 @@
 #ifndef __VKD3D_TYPES_H
 #define __VKD3D_TYPES_H
 
+#include <stdarg.h>
+
 #ifdef __cplusplus
 extern "C" {
 #endif  /* __cplusplus */
@@ -53,6 +55,8 @@ enum vkd3d_result
     VKD3D_FORCE_32_BIT_ENUM(VKD3D_RESULT),
 };
 
+typedef void (*PFN_vkd3d_log)(const char *format, va_list args);
+
 #ifdef _WIN32
 # define VKD3D_IMPORT __declspec(dllimport)
 # define VKD3D_EXPORT __declspec(dllexport)

libs/vkd3d-common/debug.c

@@ -68,6 +68,25 @@ enum vkd3d_dbg_level vkd3d_dbg_get_level(void)
     return level;
 }
 
+static PFN_vkd3d_log log_callback;
+
+static void vkd3d_dbg_voutput(const char *fmt, va_list args)
+{
+    if (log_callback)
+        log_callback(fmt, args);
+    else
+        vfprintf(stderr, fmt, args);
+}
+
+static void vkd3d_dbg_output(const char *fmt, ...)
+{
+    va_list args;
+
+    va_start(args, fmt);
+    vkd3d_dbg_voutput(fmt, args);
+    va_end(args);
+}
+
 void vkd3d_dbg_printf(enum vkd3d_dbg_level level, const char *function, const char *fmt, ...)
 {
     va_list args;
@@ -77,12 +96,17 @@ void vkd3d_dbg_printf(enum vkd3d_dbg_level level, const char *function, const ch
 
     assert(level < ARRAY_SIZE(debug_level_names));
 
-    fprintf(stderr, "%s:%s: ", debug_level_names[level], function);
+    vkd3d_dbg_output("%s:%s ", debug_level_names[level], function);
     va_start(args, fmt);
-    vfprintf(stderr, fmt, args);
+    vkd3d_dbg_voutput(fmt, args);
     va_end(args);
 }
 
+void vkd3d_dbg_set_log_callback(PFN_vkd3d_log callback)
+{
+    log_callback = callback;
+}
+
 static char *get_buffer(void)
 {
     static char buffers[VKD3D_DEBUG_BUFFER_COUNT][VKD3D_DEBUG_BUFFER_SIZE];

libs/vkd3d-shader/vkd3d_shader.map

@@ -17,6 +17,7 @@ global:
     vkd3d_shader_preprocess;
     vkd3d_shader_scan;
     vkd3d_shader_serialize_root_signature;
+    vkd3d_shader_set_log_callback;
 
 local: *;
 };

libs/vkd3d-shader/vkd3d_shader_main.c

@@ -1550,3 +1550,8 @@ int vkd3d_shader_preprocess(const struct vkd3d_shader_compile_info *compile_info
     vkd3d_shader_message_context_cleanup(&message_context);
     return ret;
 }
+
+void vkd3d_shader_set_log_callback(PFN_vkd3d_log callback)
+{
+    vkd3d_dbg_set_log_callback(callback);
+}