[Piglit] [PATCH] glsl: Enhance built-in-constants to test extensions too

[Ian Romanick]

From: Ian Romanick <ian.d.romanick at intel.com>

v2: Use an array of pointers to char for required_extensions (using
strndup) instead of the previous static buffer cleverness.  Also replace
the previous cleverness for generating the GLSL extension enables with
something less clever and easier to understand.  Both suggested by Eric.

v3: Decallocated the extension strings in the non-error case.  There are
still some PIGLIT_SKIP cases that could leak, but meh.  Noticed by Topi.

Signed-off-by: Ian Romanick <ian.d.romanick at intel.com>
Reviewed-by: Eric Anholt <eric at anholt.net>
Cc: Topi Pohjolainen <topi.pohjolainen at intel.com>
---
 tests/shaders/built-in-constants.c | 82 +++++++++++++++++++++++++++++++++++++-
 1 file changed, 81 insertions(+), 1 deletion(-)

diff --git a/tests/shaders/built-in-constants.c b/tests/shaders/built-in-constants.c
index af87107..06850b5 100644
--- a/tests/shaders/built-in-constants.c
+++ b/tests/shaders/built-in-constants.c
@@ -39,6 +39,22 @@ unsigned num_tests = 0;
 int required_glsl_version = 0;
 char *required_glsl_version_string = NULL;
 
+/**
+ * List of extensions required by the current test set.
+ */
+char *required_extensions[32];
+unsigned num_required_extensions = 0;
+
+/**
+ * Array of extension enables for the shader code
+ *
+ * For each used entry in \c required_extensions, there is text in
+ * this string of the form "#extension ...: require\n".
+ */
+#define MAX_EXTENSION_ENABLE_LINE_LEN 80
+char extension_enables[ARRAY_SIZE(required_extensions)
+		       * MAX_EXTENSION_ENABLE_LINE_LEN];
+unsigned extension_enables_len = 0;
 
 static const char *const uniform_template =
 	"uniform float f[%s %s %d ? 1 : -1];\n"
@@ -131,6 +147,7 @@ parse_file(const char *filename)
 	/* The format of the test file is:
 	 *
 	 * major.minor
+	 * GL_ARB_some_extension
 	 * gl_MaxFoo 8
 	 * gl_MaxBar 16
 	 * gl_MinAsdf -2
@@ -152,6 +169,32 @@ parse_file(const char *filename)
 	if (line[0] != '\0')
 		line++;
 
+	/* Process the list of required extensions.
+	 */
+	while (strncmp("GL_", line, 3) == 0) {
+		char *end_of_line = strchrnul(line, '\n');
+		const ptrdiff_t len = end_of_line - line;
+
+		assert(end_of_line[0] == '\n' || end_of_line[0] == '\0');
+
+		if (num_required_extensions >= ARRAY_SIZE(required_extensions)) {
+			fprintf(stderr, "Too many required extensions!\n");
+			piglit_report_result(PIGLIT_FAIL);
+		}
+
+		/* Copy the new extension to the list.
+		 */
+		required_extensions[num_required_extensions] =
+			strndup(line, len);
+		num_required_extensions++;
+
+		/* Advance to the next input line.
+		 */
+		line = end_of_line;
+		if (line[0] == '\n')
+			line++;
+	}
+
 	while (line[0] != '\0') {
 		char *endptr;
 
@@ -254,16 +297,53 @@ piglit_init(int argc, char **argv)
 	if (glsl_version < required_glsl_version)
 		piglit_report_result(PIGLIT_SKIP);
 
+	/* Process the list of required extensions.  While doing this,
+	 * generate the GLSL code that will enable those extensions in the
+	 * shaders.
+	 */
+	for (i = 0; i < num_required_extensions; i++) {
+		int len;
+
+		if (!piglit_is_extension_supported(required_extensions[i])) {
+			printf("%s not supported\n", required_extensions[i]);
+			piglit_report_result(PIGLIT_SKIP);
+		}
+
+		if ((extension_enables_len + MAX_EXTENSION_ENABLE_LINE_LEN)
+		    >= sizeof(extension_enables)) {
+			printf("Extension enables too long.\n");
+			piglit_report_result(PIGLIT_FAIL);
+		}
+
+		len = snprintf(&extension_enables[extension_enables_len],
+			       MAX_EXTENSION_ENABLE_LINE_LEN,
+			       "#extension %s: require\n",
+			       required_extensions[i]);
+
+		/* After the last use of the extension string, free it.
+		 */
+		free(required_extensions[i]);
+
+		if (len <= 0) {
+			printf("Extension enable snprintf failed.\n");
+			piglit_report_result(PIGLIT_FAIL);
+		}
+
+		extension_enables_len += len;
+	}
+
 	/* Generate the version declaration that will be used by all of the
 	 * shaders in the test run.
 	 */
 	asprintf(&version_string,
 		 "#version %d %s\n"
+		 "%s"
 		 "#ifdef GL_ES\n"
 		 "precision mediump float;\n"
 		 "#endif\n",
 		 required_glsl_version,
-		 required_glsl_version == 300 ? "es" : "");
+		 required_glsl_version == 300 ? "es" : "",
+		 extension_enables);
 
 	/* Create the shaders that will be used for the real part of the test.
 	 */
-- 
1.8.1.4