Add tests for GL_EXTENSION_STRING vs. old idTech2 / idTech3 games

As people dig up other games, we can (and should) easily add them.

v2: Fix some comments and reduce the limit from 4k to 2k.  Suggested by
Roland.

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Roland Scheidegger <sroland@vmware.com>
Cc: Federico Dossena <info@fdossena.com>

2 files changed, 156 insertions, 0 deletions

diff --git a/tests/general/CMakeLists.gl.txt b/tests/general/CMakeLists.gl.txt
index ceec9f0b6..83189fc42 100644
--- a/tests/general/CMakeLists.gl.txt
+++ b/tests/general/CMakeLists.gl.txt
@@ -65,6 +65,7 @@ if (UNIX)
 	target_link_libraries (hiz m)
 endif (UNIX)
 piglit_add_executable (early-z early-z.c)
+piglit_add_executable (idtech-extension-strings idtech-extension-strings.c)
 piglit_add_executable (infinite-spot-light infinite-spot-light.c)
 piglit_add_executable (isbufferobj isbufferobj.c)
 piglit_add_executable (linestipple linestipple.c)
diff --git a/tests/general/idtech-extension-strings.c b/tests/general/idtech-extension-strings.c
new file mode 100644
index 000000000..83eaed8ce
--- /dev/null
+++ b/tests/general/idtech-extension-strings.c
@@ -0,0 +1,155 @@
+/*
+ * Copyright © 2018 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ */
+
+/**
+ * \file idtech-extension-strings.c
+ * Verify extensions used by idTech2 and idTech3 games occur in the first 2k
+ *
+ * For a long time idTech2- and idTech3-based games contained a bug in
+ * extension string handling.  The engine would copy the extension string
+ * returned by the driver into a buffer on the stack.  The engine would not be
+ * able to detect the existence of any extensions that occured after the size
+ * of the buffer.
+ *
+ * A 2011 Wine bug
+ * (https://www.winehq.org/pipermail/wine-bugs/2011-June/280463.html) suggests
+ * that the limit for at least Return to Castle Wofenstein is 4k.  Some other
+ * evidence suggests that other games may have limits as low as 2k.
+ *
+ * Based on this evidence, my guess is that the buffer is 2k, but extension
+ * strings longer than 4k caused enough of a stack over run to lead to a
+ * crash.
+ *
+ * There are separate subtests for each game that has a different set of
+ * extension strings.  This acts as a catalog of sorts for which games use
+ * which extensions.  It also makes it clear which games have been tested.
+ */
+#include "piglit-util-gl.h"
+
+PIGLIT_GL_TEST_CONFIG_BEGIN
+
+	config.supports_gl_compat_version = 10;
+
+	config.window_visual = PIGLIT_GL_VISUAL_RGB;
+
+PIGLIT_GL_TEST_CONFIG_END
+
+enum piglit_result
+piglit_display(void)
+{
+	/* UNREACHABLE */
+	return PIGLIT_FAIL;
+}
+
+/* List of extensions scraped from the Quake3 demo found in
+ * linuxq3ademo-1.11-6.x86.gz.sh.  The Return to Castle Wolfenstein demo found
+ * in wolfspdemo-linux-1.1b.x86.run had the same list.
+ */
+const char *const q3demo_list[] = {
+	"GL_S3_s3tc",
+	"GL_EXT_texture_env_add",
+	"GL_ARB_multitexture",
+	"GL_EXT_compiled_vertex_array",
+};
+
+/* List of extensions used by the game "Star Trek Voyager" provided by
+ * Federico Dossena.
+ */
+const char *const star_trek_voyager_list[] = {
+	"GL_S3_s3tc",
+	"GL_EXT_texture_compression_s3tc",
+	"GL_EXT_texture_env_add"
+	"GL_EXT_texture_filter_anisotropic",
+	"GL_EXT_texture_edge_clamp",
+	"GL_ARB_multitexture",
+	"GL_EXT_compiled_vertex_array",
+
+	/* GL_ARB_texture_compression wasn't listed in the output of the
+	 * application, but since GL_EXT_texture_compression_s3tc is layered
+	 * on top of it, it really should check for it too...
+	 */
+	"GL_ARB_texture_compression",
+};
+
+static bool
+check_extension_list(const char *application_name,
+		     const char *extension_string,
+		     const char *const list[],
+		     unsigned num_extensions)
+{
+	bool pass = true;
+
+	for (unsigned i = 0; i < num_extensions; i++) {
+		const unsigned len = strlen(list[i]);
+		const char *ptr = strstr(extension_string, list[i]);
+
+		while (ptr != NULL && ptr[len] != '\0' && ptr[len] != ' ')
+			ptr = strstr(ptr + len, list[i]);
+
+		if (ptr == NULL) {
+			if (!piglit_automatic) {
+				printf("Extension %s is not supported.\n",
+				       list[i]);
+			}
+
+			continue;
+		}
+
+		const ptrdiff_t offset = (ptr - extension_string) + len;
+		if (offset >= 2048) {
+			printf("Extension %s is at offset %ld.  Too far!\n",
+			       list[i], (long) offset);
+			pass = false;
+		} else if (!piglit_automatic) {
+			printf("Extension %s is at offset %ld.\n",
+			       list[i], (long) offset);
+		}
+	}
+
+	piglit_report_subtest_result(pass ? PIGLIT_PASS : PIGLIT_FAIL,
+				     application_name);
+	return pass;
+}
+
+void
+piglit_init(int argc, char **argv)
+{
+	bool pass = true;
+	const char *const extension_string =
+		(const char *) glGetString(GL_EXTENSIONS);
+
+	pass = check_extension_list("linuxq3ademo-1.11-6.x86.gz.sh",
+				    extension_string,
+				    q3demo_list,
+				    ARRAY_SIZE(q3demo_list))
+		&& pass;
+
+	pass = check_extension_list("Star Trek: Voyager - Elite Force",
+				    extension_string,
+				    star_trek_voyager_list,
+				    ARRAY_SIZE(star_trek_voyager_list))
+		&& pass;
+
+	piglit_report_result(pass ? PIGLIT_PASS : PIGLIT_FAIL);
+}