debug: Use a function to print output that can be replaced by a different callback

This patch adds the infrastructure and replaces the debug calls to fprintf
by calls to vrend_printf that internally may be redirected.

Signed-off-by: Gert Wollny <gert.wollny@collabora.com>
Reviewed-by: David Riley <davidriley@chromium.org>
Reviewed-by: Zach Reizner <zachr@chromium.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>

src/vrend_debug.c

@@ -162,3 +162,29 @@ int  vrend_debug_can_override(void)
 {
    return vrend_debug_flags & dbg_allow_guest_override;
 }
+
+static
+void vrend_default_debug_callback(const char *fmt, va_list va)
+{
+   vfprintf(stderr, fmt, va);
+}
+
+static virgl_debug_callback_type debug_callback = vrend_default_debug_callback;
+
+void vrend_printf(const char *fmt, ...)
+{
+   if (debug_callback) {
+      va_list va;
+      va_start(va, fmt);
+      debug_callback(fmt, va);
+      va_end(va);
+   }
+}
+
+virgl_debug_callback_type vrend_set_debug_callback(virgl_debug_callback_type cb)
+{
+   virgl_debug_callback_type retval = debug_callback;
+   debug_callback = cb;
+   return retval;
+}
+

src/vrend_debug.h

@@ -26,6 +26,7 @@
 #define vrend_debug_h
 
 #include "virgl_protocol.h"
+#include <stdarg.h>
 
 struct vrend_context;
 void vrend_print_context_name(struct vrend_context *ctx);
@@ -63,12 +64,18 @@ unsigned vrend_debug(struct vrend_context *ctx, enum virgl_debug_flags flag);
 
 void vrend_debug_add_flag(enum virgl_debug_flags flag);
 
+void vrend_printf(const char *fmt, ...);
+
+typedef void (*virgl_debug_callback_type)(const char *fmt, va_list ap);
+
+virgl_debug_callback_type vrend_set_debug_callback(virgl_debug_callback_type cb);
+
 #ifndef NDEBUG
 #define VREND_DEBUG(flag, ctx,  ...) \
    if (vrend_debug(ctx, flag)) \
       do { \
             vrend_print_context_name(ctx); \
-            fprintf(stderr, __VA_ARGS__); \
+            vrend_printf(__VA_ARGS__); \
       } while (0)
 
 #define VREND_DEBUG_EXT(flag, ctx, X) \

src/vrend_decode.c

@@ -796,7 +796,7 @@ static int vrend_decode_destroy_object(struct vrend_decode_ctx *ctx, int length)
 
    VREND_DEBUG_EXT(dbg_object, ctx->grctx,
                uint32_t obj = (get_buf_entry(ctx, 0) >> 8) & 0xFF;
-               fprintf(stderr, "  DESTROY %-17s handle:0x%x\n",
+               vrend_printf("  DESTROY %-17s handle:0x%x\n",
                        vrend_get_object_type_name(obj), handle));
 
    vrend_renderer_object_destroy(ctx->grctx, handle);

src/vrend_renderer.c

@@ -1894,7 +1894,7 @@ void debug_texture(const char *f, const struct vrend_resource *gt)
    const struct pipe_resource *pr = &gt->base;
 #define PRINT_TARGET(X) case X: fprintf(stderr, #X); break
    VREND_DEBUG_EXT(dbg_tex, NULL,
-               fprintf(stderr, "%s: ", f);
+               vrend_printf("%s: ", f);
                switch (tgsitargettogltarget(pr->target, pr->nr_samples)) {
                PRINT_TARGET(GL_TEXTURE_RECTANGLE_NV);
                PRINT_TARGET(GL_TEXTURE_1D);
@@ -1906,11 +1906,11 @@ void debug_texture(const char *f, const struct vrend_resource *gt)
                PRINT_TARGET(GL_TEXTURE_CUBE_MAP);
                PRINT_TARGET(GL_TEXTURE_CUBE_MAP_ARRAY);
                default:
-                  fprintf(stderr, "UNKNOWN");
+                  vrend_printf("UNKNOWN");
                }
-               fprintf(stderr, " id:%d pipe_type:%d ms:%d format:%s size: %dx%dx%d mip:%d\n",
+               vrend_printf(" id:%d pipe_type:%d ms:%d format:%s size: %dx%dx%d mip:%d\n",
-                       gt->id, pr->target, pr->nr_samples, util_format_name(pr->format),
+                            gt->id, pr->target, pr->nr_samples, util_format_name(pr->format),
-                       pr->width0, pr->height0, pr->depth0, pr->last_level);
+                            pr->width0, pr->height0, pr->depth0, pr->last_level);
                );
 #undef PRINT_TARGET
 }
@@ -8886,9 +8886,9 @@ unsigned vrend_context_has_debug_flag(struct vrend_context *ctx, enum virgl_debu
 void vrend_print_context_name(struct vrend_context *ctx)
 {
    if (ctx)
-      fprintf(stderr, "%s: ", ctx->debug_name);
+      vrend_printf("%s: ", ctx->debug_name);
    else
-      fprintf(stderr, "HOST: ");
+      vrend_printf("HOST: ");
 }
 
 void vrend_renderer_destroy_sub_ctx(struct vrend_context *ctx, int sub_ctx_id)