[Pixman] [PATCH 1/2] Always return a valid function from lookup_composite()

[Chris Wilson]

We never expect to fail to find the appropriate function as the
general_composite_rect should always match. So if somehow we fallthrough
the search, emit a _pixman_log_error() and return a dummy function.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 pixman/pixman-fast-path.c      |   16 ++++++----------
 pixman/pixman-glyph.c          |   26 ++++++++++++--------------
 pixman/pixman-implementation.c |   16 ++++++++++++----
 pixman/pixman-private.h        |    4 ++--
 pixman/pixman.c                |    8 ++++----
 5 files changed, 36 insertions(+), 34 deletions(-)

diff --git a/pixman/pixman-fast-path.c b/pixman/pixman-fast-path.c
index c625e0c..4c6435a 100644
--- a/pixman/pixman-fast-path.c
+++ b/pixman/pixman-fast-path.c
@@ -1258,12 +1258,12 @@ fast_composite_tiled_repeat (pixman_implementation_t *imp,
 	mask_flags = FAST_PATH_IS_OPAQUE;
     }
 
-    if (_pixman_implementation_lookup_composite (
-	    imp->toplevel, info->op,
-	    src_image->common.extended_format_code, src_flags,
-	    mask_format, mask_flags,
-	    dest_image->common.extended_format_code, info->dest_flags,
-	    &imp, &func))
+    _pixman_implementation_lookup_composite (
+	imp->toplevel, info->op,
+	src_image->common.extended_format_code, src_flags,
+	mask_format, mask_flags,
+	dest_image->common.extended_format_code, info->dest_flags,
+	&imp, &func);
     {
 	int32_t sx, sy;
 	int32_t width_remain;
@@ -1397,10 +1397,6 @@ fast_composite_tiled_repeat (pixman_implementation_t *imp,
 	if (need_src_extension)
 	    _pixman_image_fini (&extended_src_image);
     }
-    else
-    {
-	_pixman_log_error (FUNC, "Didn't find a suitable function ");
-    }
 }
 
 /* Use more unrolling for src_0565_0565 because it is typically CPU bound */
diff --git a/pixman/pixman-glyph.c b/pixman/pixman-glyph.c
index 5451f42..5a271b6 100644
--- a/pixman/pixman-glyph.c
+++ b/pixman/pixman-glyph.c
@@ -464,13 +464,12 @@ pixman_composite_glyphs_no_mask (pixman_op_t            op,
 		    glyph_format = glyph_img->common.extended_format_code;
 		    glyph_flags = glyph_img->common.flags;
 
-		    if (! _pixman_implementation_lookup_composite (
-			    get_implementation(), op,
-			    src->common.extended_format_code, src->common.flags,
-			    glyph_format, glyph_flags | extra,
-			    dest_format, dest_flags,
-			    &implementation, &func))
-			goto out;
+		    _pixman_implementation_lookup_composite (
+			get_implementation(), op,
+			src->common.extended_format_code, src->common.flags,
+			glyph_format, glyph_flags | extra,
+			dest_format, dest_flags,
+			&implementation, &func);
 		}
 
 		info.src_x = src_x + composite_box.x1 - dest_x;
@@ -574,13 +573,12 @@ add_glyphs (pixman_glyph_cache_t *cache,
 		white_src = TRUE;
 	    }
 
-	    if (! _pixman_implementation_lookup_composite (
-		    get_implementation(), PIXMAN_OP_ADD,
-		    src_format, info.src_flags,
-		    mask_format, info.mask_flags,
-		    dest_format, dest_flags,
-		    &implementation, &func))
-		goto out;
+	    _pixman_implementation_lookup_composite (
+		get_implementation(), PIXMAN_OP_ADD,
+		src_format, info.src_flags,
+		mask_format, info.mask_flags,
+		dest_format, dest_flags,
+		&implementation, &func);
 	}
 
 	glyph_box.x1 = glyphs[i].x - glyph->origin_x + off_x;
diff --git a/pixman/pixman-implementation.c b/pixman/pixman-implementation.c
index ec467a6..05cb5ea 100644
--- a/pixman/pixman-implementation.c
+++ b/pixman/pixman-implementation.c
@@ -65,7 +65,13 @@ typedef struct
 
 PIXMAN_DEFINE_THREAD_LOCAL (cache_t, fast_path_cache);
 
-pixman_bool_t
+static void
+dummy_composite_rect (pixman_implementation_t *imp,
+		      pixman_composite_info_t *info)
+{
+}
+
+void
 _pixman_implementation_lookup_composite (pixman_implementation_t  *toplevel,
 					 pixman_op_t               op,
 					 pixman_format_code_t      src_format,
@@ -142,7 +148,11 @@ _pixman_implementation_lookup_composite (pixman_implementation_t  *toplevel,
 	    ++info;
 	}
     }
-    return FALSE;
+
+    /* We should never reach this point */
+    _pixman_log_error (FUNC, "No known composite function\n");
+    *out_imp = NULL;
+    *out_func = dummy_composite_rect;
 
 update_cache:
     if (i)
@@ -160,8 +170,6 @@ update_cache:
 	cache->cache[0].fast_path.dest_flags = dest_flags;
 	cache->cache[0].fast_path.func = *out_func;
     }
-
-    return TRUE;
 }
 
 pixman_combine_32_func_t
diff --git a/pixman/pixman-private.h b/pixman/pixman-private.h
index e5ab873..3981873 100644
--- a/pixman/pixman-private.h
+++ b/pixman/pixman-private.h
@@ -497,7 +497,7 @@ pixman_implementation_t *
 _pixman_implementation_create (pixman_implementation_t *fallback,
 			       const pixman_fast_path_t *fast_paths);
 
-pixman_bool_t
+void
 _pixman_implementation_lookup_composite (pixman_implementation_t  *toplevel,
 					 pixman_op_t               op,
 					 pixman_format_code_t      src_format,
@@ -1052,7 +1052,7 @@ _pixman_log_error (const char *function, const char *message);
 
 #else
 
-#define _pixman_log_error(f,m) do { } while (0)				\
+#define _pixman_log_error(f,m) do { } while (0)
 
 #define return_if_fail(expr)						\
     do                                                                  \
diff --git a/pixman/pixman.c b/pixman/pixman.c
index 3fabed1..24c93c5 100644
--- a/pixman/pixman.c
+++ b/pixman/pixman.c
@@ -678,10 +678,10 @@ pixman_image_composite32 (pixman_op_t      op,
      */
     op = optimize_operator (op, src_flags, mask_flags, dest_flags);
 
-    if (_pixman_implementation_lookup_composite (
-	    get_implementation (), op,
-	    src_format, src_flags, mask_format, mask_flags, dest_format, dest_flags,
-	    &imp, &func))
+    _pixman_implementation_lookup_composite (
+	get_implementation (), op,
+	src_format, src_flags, mask_format, mask_flags, dest_format, dest_flags,
+	&imp, &func);
     {
 	pixman_composite_info_t info;
 	const pixman_box32_t *pbox;
-- 
1.7.10.4