tests: Don't rely on build directory layout

Rather than having a hardcoded dependency on the build-directory layout,
use an explicit module-map environment variable, which rewrites requests
for modules and helper/libexec binaries to specific paths.

Pekka: This will help with migration to Meson where setting up the paths
according to autotools would be painful and unnecessary.

Emre: This should also help setting up the test suite after a
cross-compile.

Pekka: A caveat here is that this patch makes it slightly easier to load
external backends by abusing the module map. External backends are
specifically not supported in libweston.

Signed-off-by: Daniel Stone <daniels@collabora.com>

v2:

Fixed ivi_layout-test-plugin.c:wet_module_init().
Do not change the lookup name of ivi-layout.ivi.

Improved documentation of weston_module_path_from_env() and made it cope
with map strings that a) do not end with a semicolon, and b) have
multiple consecutive semicolons.

Let WESTON_MODULE_MAP be printed into the test log so that it is easier
to run tests manually.

Reviewed-by: Daniel Stone <daniels@collabora.com>
Reviewed-by: Emre Ucan <eucan@de.adit-jv.com>

Suggested by Emil: Use a variable for strlen(name).

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>

compositor/main.c

@@ -652,7 +652,6 @@ weston_create_listening_socket(struct wl_display *display, const char *socket_na
 WL_EXPORT void *
 wet_load_module_entrypoint(const char *name, const char *entrypoint)
 {
-	const char *builddir = getenv("WESTON_BUILD_DIR");
 	char path[PATH_MAX];
 	void *module, *init;
 	size_t len;
@@ -661,10 +660,8 @@ wet_load_module_entrypoint(const char *name, const char *entrypoint)
 		return NULL;
 
 	if (name[0] != '/') {
-		if (builddir)
-			len = snprintf(path, sizeof path, "%s/.libs/%s", builddir,
-				       name);
-		else
+		len = weston_module_path_from_env(name, path, sizeof path);
+		if (len == 0)
 			len = snprintf(path, sizeof path, "%s/%s", MODULEDIR,
 				       name);
 	} else {
@@ -701,7 +698,6 @@ wet_load_module_entrypoint(const char *name, const char *entrypoint)
 	return init;
 }
 
-
 WL_EXPORT int
 wet_load_module(struct weston_compositor *compositor,
 	        const char *name, int *argc, char *argv[])
@@ -732,6 +728,24 @@ wet_load_shell(struct weston_compositor *compositor,
 	return 0;
 }
 
+WL_EXPORT char *
+wet_get_binary_path(const char *name)
+{
+	char path[PATH_MAX];
+	size_t len;
+
+	len = weston_module_path_from_env(name, path, sizeof path);
+	if (len > 0)
+		return strdup(path);
+
+	len = snprintf(path, sizeof path, "%s/%s",
+		       weston_config_get_libexec_dir(), name);
+	if (len >= sizeof path)
+		return NULL;
+
+	return strdup(path);
+}
+
 static int
 load_modules(struct weston_compositor *ec, const char *modules,
 	     int *argc, char *argv[], int32_t *xwayland)

compositor/text-backend.c

@@ -1047,14 +1047,10 @@ text_backend_configuration(struct text_backend *text_backend)
 	struct weston_config *config = wet_get_config(text_backend->compositor);
 	struct weston_config_section *section;
 	char *client;
-	int ret;
 
 	section = weston_config_get_section(config,
 					    "input-method", NULL, NULL);
-	ret = asprintf(&client, "%s/weston-keyboard",
-		       weston_config_get_libexec_dir());
-	if (ret < 0)
-		client = NULL;
+	client = wet_get_binary_path("weston-keyboard");
 	weston_config_section_get_string(section, "path",
 					 &text_backend->input_method.path,
 					 client);

compositor/weston-screenshooter.c

@@ -117,12 +117,10 @@ screenshooter_binding(struct weston_keyboard *keyboard,
 {
 	struct screenshooter *shooter = data;
 	char *screenshooter_exe;
-	int ret;
 
-	ret = asprintf(&screenshooter_exe, "%s/%s",
-		       weston_config_get_libexec_dir(),
-		       "/weston-screenshooter");
-	if (ret < 0) {
+
+	screenshooter_exe = wet_get_binary_path("weston-screenshooter");
+	if (!screenshooter_exe) {
 		weston_log("Could not construct screenshooter path.\n");
 		return;
 	}

compositor/weston.h

@@ -77,6 +77,9 @@ int
 module_init(struct weston_compositor *compositor,
 	    int *argc, char *argv[]);
 
+char *
+wet_get_binary_path(const char *name);
+
 int
 wet_load_xwayland(struct weston_compositor *comp);
 

desktop-shell/shell.c

@@ -468,17 +468,12 @@ shell_configuration(struct desktop_shell *shell)
 {
 	struct weston_config_section *section;
 	char *s, *client;
-	int ret;
 	int allow_zap;
 
 	section = weston_config_get_section(wet_get_config(shell->compositor),
 					    "shell", NULL, NULL);
-	ret = asprintf(&client, "%s/%s", weston_config_get_libexec_dir(),
-		       WESTON_SHELL_CLIENT);
-	if (ret < 0)
-		client = NULL;
-	weston_config_section_get_string(section,
-					 "client", &s, client);
+	client = wet_get_binary_path(WESTON_SHELL_CLIENT);
+	weston_config_section_get_string(section, "client", &s, client);
 	free(client);
 	shell->client = s;
 

libweston/compositor.c

@@ -6573,10 +6573,60 @@ weston_version(int *major, int *minor, int *micro)
 	*micro = WESTON_VERSION_MICRO;
 }
 
+/**
+ * Attempts to find a module path from the module map specified in the
+ * environment. If found, writes the full path into the path variable.
+ *
+ * The module map is a string in environment variable WESTON_MODULE_MAP, where
+ * each entry is of the form "name=path" and entries are separated by
+ * semicolons. Whitespace is significant.
+ *
+ * \param name The name to search for.
+ * \param path Where the path is written to if found.
+ * \param path_len Allocated bytes at \c path .
+ * \returns The length of the string written to path on success, or 0 if the
+ * module was not specified in the environment map or path_len was too small.
+ */
+WL_EXPORT size_t
+weston_module_path_from_env(const char *name, char *path, size_t path_len)
+{
+	const char *mapping = getenv("WESTON_MODULE_MAP");
+	const char *end;
+	const int name_len = strlen(name);
+
+	if (!mapping)
+		return 0;
+
+	end = mapping + strlen(mapping);
+	while (mapping < end && *mapping) {
+		const char *filename, *next;
+
+		/* early out: impossibly short string */
+		if (end - mapping < name_len + 1)
+			return 0;
+
+		filename = &mapping[name_len + 1];
+		next = strchrnul(mapping, ';');
+
+		if (strncmp(mapping, name, name_len) == 0 &&
+		    mapping[name_len] == '=') {
+			size_t file_len = next - filename; /* no trailing NUL */
+			if (file_len >= path_len)
+				return 0;
+			strncpy(path, filename, file_len);
+			path[file_len] = '\0';
+			return file_len;
+		}
+
+		mapping = next + 1;
+	}
+
+	return 0;
+}
+
 WL_EXPORT void *
 weston_load_module(const char *name, const char *entrypoint)
 {
-	const char *builddir = getenv("WESTON_BUILD_DIR");
 	char path[PATH_MAX];
 	void *module, *init;
 	size_t len;
@@ -6585,10 +6635,8 @@ weston_load_module(const char *name, const char *entrypoint)
 		return NULL;
 
 	if (name[0] != '/') {
-		if (builddir)
-			len = snprintf(path, sizeof path, "%s/.libs/%s",
-				       builddir, name);
-		else
+		len = weston_module_path_from_env(name, path, sizeof path);
+		if (len == 0)
 			len = snprintf(path, sizeof path, "%s/%s",
 				       LIBWESTON_MODULEDIR, name);
 	} else {

libweston/compositor.h

@@ -2149,6 +2149,9 @@ weston_transformed_region(int width, int height,
 void *
 weston_load_module(const char *name, const char *entrypoint);
 
+size_t
+weston_module_path_from_env(const char *name, char *path, size_t path_len);
+
 int
 weston_parse_transform(const char *transform, uint32_t *out);
 

tests/ivi_layout-test-plugin.c

@@ -32,6 +32,7 @@
 #include <signal.h>
 #include <string.h>
 #include <assert.h>
+#include <limits.h>
 
 #include "compositor.h"
 #include "compositor/weston.h"
@@ -223,7 +224,6 @@ wet_module_init(struct weston_compositor *compositor,
 {
 	struct wl_event_loop *loop;
 	struct test_launcher *launcher;
-	const char *path;
 	const struct ivi_layout_interface *iface;
 
 	iface = ivi_layout_get_api(compositor);
@@ -233,20 +233,18 @@ wet_module_init(struct weston_compositor *compositor,
 		return -1;
 	}
 
-	path = getenv("WESTON_BUILD_DIR");
-	if (!path) {
-		weston_log("test setup failure: WESTON_BUILD_DIR not set\n");
-		return -1;
-	}
-
 	launcher = zalloc(sizeof *launcher);
 	if (!launcher)
 		return -1;
 
+	if (weston_module_path_from_env("ivi-layout.ivi", launcher->exe,
+					sizeof launcher->exe) == 0) {
+		weston_log("test setup failure: WESTON_MODULE_MAP not set\n");
+		return -1;
+	}
+
 	launcher->compositor = compositor;
 	launcher->layout_interface = iface;
-	snprintf(launcher->exe, sizeof launcher->exe,
-		 "%s/ivi-layout.ivi", path);
 
 	if (wl_global_create(compositor->wl_display,
 			     &weston_test_runner_interface, 1,

tests/weston-tests-env

@@ -25,6 +25,19 @@ MODDIR=$abs_builddir/.libs
 SHELL_PLUGIN=$MODDIR/desktop-shell.so
 TEST_PLUGIN=$MODDIR/weston-test.so
 
+WESTON_MODULE_MAP=
+for mod in cms-colord cms-static desktop-shell drm-backend fbdev-backend \
+	   fullscreen-shell gl-renderer headless-backend hmi-controller \
+	   ivi-shell rdp-compositor screen-share wayland-backend \
+	   weston-test-desktop-shell x11-backend xwayland; do
+	WESTON_MODULE_MAP="${WESTON_MODULE_MAP}${mod}.so=${abs_builddir}/.libs/${mod}.so;"
+done
+
+for exe in weston-desktop-shell weston-keyboard weston-screenshooter \
+	   weston-simple-im ivi-layout.ivi; do \
+	WESTON_MODULE_MAP="${WESTON_MODULE_MAP}${exe}=${abs_builddir}/${exe};"
+done
+
 CONFIG_FILE="${TEST_NAME}.ini"
 
 if [ -e "${abs_builddir}/${CONFIG_FILE}" ]; then
@@ -40,6 +53,7 @@ case $TEST_FILE in
 		SHELL_PLUGIN=$MODDIR/ivi-shell.so
 
 		set -x
+		WESTON_MODULE_MAP="${WESTON_MODULE_MAP}" \
 		WESTON_DATA_DIR=$abs_top_srcdir/data \
 		WESTON_BUILD_DIR=$abs_builddir \
 		WESTON_TEST_REFERENCE_PATH=$abs_top_srcdir/tests/reference \
@@ -53,6 +67,7 @@ case $TEST_FILE in
 		;;
 	*.la|*.so)
 		set -x
+		WESTON_MODULE_MAP="${WESTON_MODULE_MAP}" \
 		WESTON_DATA_DIR=$abs_top_srcdir/data \
 		WESTON_BUILD_DIR=$abs_builddir \
 		WESTON_TEST_REFERENCE_PATH=$abs_top_srcdir/tests/reference \
@@ -69,6 +84,7 @@ case $TEST_FILE in
 		SHELL_PLUGIN=$MODDIR/ivi-shell.so
 
 		set -x
+		WESTON_MODULE_MAP="${WESTON_MODULE_MAP}" \
 		WESTON_DATA_DIR=$abs_top_srcdir/data \
 		WESTON_BUILD_DIR=$abs_builddir \
 		WESTON_TEST_REFERENCE_PATH=$abs_top_srcdir/tests/reference \
@@ -84,6 +100,7 @@ case $TEST_FILE in
 		;;
 	*)
 		set -x
+		WESTON_MODULE_MAP="${WESTON_MODULE_MAP}" \
 		WESTON_DATA_DIR=$abs_top_srcdir/data \
 		WESTON_BUILD_DIR=$abs_builddir \
 		WESTON_TEST_REFERENCE_PATH=$abs_top_srcdir/tests/reference \