test: Silence gcc warnings

warning: cannot optimize possibly infinite loops

gcc does not detect that the "infinite" loops are actually just one or
two iterations, depending on the has_similar value being FALSE or
TRUE. It realizes it if the iteration variable and the iteration stop
value are both enum values.

3 files changed, 21 insertions, 13 deletions

diff --git a/test/cairo-test-private.h b/test/cairo-test-private.h
index 8c841493..e89eb70a 100644
--- a/test/cairo-test-private.h
+++ b/test/cairo-test-private.h
@@ -36,7 +36,12 @@
 
 CAIRO_BEGIN_DECLS
 
-cairo_bool_t
+typedef enum {
+    DIRECT,
+    SIMILAR
+} cairo_test_similar_t;
+
+cairo_test_similar_t
 cairo_test_target_has_similar (const cairo_test_context_t *ctx,
 			       const cairo_boilerplate_target_t *target);
 
diff --git a/test/cairo-test-runner.c b/test/cairo-test-runner.c
index c5d09456..87c6db0a 100644
--- a/test/cairo-test-runner.c
+++ b/test/cairo-test-runner.c
@@ -909,18 +909,18 @@ main (int argc, char **argv)
 			 target_error = FALSE,
 			 target_crashed = FALSE,
 			 target_skipped = TRUE;
-	    int has_similar;
+	    cairo_test_similar_t has_similar;
 
 	    target = ctx.targets_to_test[n];
 
 	    has_similar = runner.full_test ?
 			  cairo_test_target_has_similar (&ctx, target) :
-		          0;
+			  DIRECT;
 	    for (m = 0; m < runner.num_device_offsets; m++) {
 		int dev_offset = m * 25;
-		int similar;
+		cairo_test_similar_t similar;
 
-		for (similar = 0; similar <= has_similar; similar++) {
+		for (similar = DIRECT; similar <= has_similar; similar++) {
 		    status = _cairo_test_runner_draw (&runner, &ctx, target,
 						      similar, dev_offset);
 		    switch (status) {
diff --git a/test/cairo-test.c b/test/cairo-test.c
index 69af6ba8..e03f9f71 100644
--- a/test/cairo-test.c
+++ b/test/cairo-test.c
@@ -454,12 +454,12 @@ _cairo_test_mkdir (const char *path)
     return errno == EEXIST;
 }
 
-cairo_bool_t
+cairo_test_similar_t
 cairo_test_target_has_similar (const cairo_test_context_t *ctx,
 			       const cairo_boilerplate_target_t *target)
 {
     cairo_surface_t *surface;
-    cairo_bool_t has_similar;
+    cairo_test_similar_t has_similar;
     cairo_t * cr;
     cairo_surface_t *similar;
     cairo_status_t status;
@@ -468,16 +468,16 @@ cairo_test_target_has_similar (const cairo_test_context_t *ctx,
 
     /* ignore image intermediate targets */
     if (target->expected_type == CAIRO_SURFACE_TYPE_IMAGE)
-	return FALSE;
+	return DIRECT;
 
     if (getenv ("CAIRO_TEST_IGNORE_SIMILAR"))
-	return FALSE;
+	return DIRECT;
 
     xasprintf (&path, "%s/%s",
 	       _cairo_test_mkdir (CAIRO_TEST_OUTPUT_DIR) ? CAIRO_TEST_OUTPUT_DIR : ".",
 	       ctx->test_name);
 
-    has_similar = FALSE;
+    has_similar = DIRECT;
     do {
 	do {
 	    surface = (target->create_surface) (path,
@@ -502,7 +502,10 @@ cairo_test_target_has_similar (const cairo_test_context_t *ctx,
 	similar = cairo_get_group_target (cr);
 	status = cairo_surface_status (similar);
 
-	has_similar = cairo_surface_get_type (similar) == cairo_surface_get_type (surface);
+	if (cairo_surface_get_type (similar) == cairo_surface_get_type (surface))
+	    has_similar = SIMILAR;
+	else
+	    has_similar = DIRECT;
 
 	cairo_destroy (cr);
 	cairo_surface_destroy (surface);
@@ -1813,10 +1816,10 @@ _cairo_test_context_run (cairo_test_context_t *ctx)
 
 	for (j = 0; j < NUM_DEVICE_OFFSETS; j++) {
 	    int dev_offset = ((j + ctx->thread) % NUM_DEVICE_OFFSETS) * 25;
-	    int similar, has_similar;
+	    cairo_test_similar_t similar, has_similar;
 
 	    has_similar = cairo_test_target_has_similar (ctx, target);
-	    for (similar = 0; similar <= has_similar ; similar++) {
+	    for (similar = DIRECT; similar <= has_similar; similar++) {
 		cairo_status_t status;
 
 		status = _cairo_test_context_run_for_target (ctx,