[libgpiod][PATCH v2 2/2] tests: look for gpio-tools in more places

[Bartosz Golaszewski <brgl@xxxxxxxx>]

From: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>

Currently we only support running the test cases for gpio-tools from
the top-level source directory. Some users want to install the test
executable and run the tests from other locations (/bin, /usr/bin or
custom path).

This patch makes the test suite look in the source tree path first,
then check the directory in which the program resides and last iterate
over all directories in $PATH.

We only do that once at the beginning and then reuse the path later.

Cc: Anders Roxell <anders.roxell@xxxxxxxxxx>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
---
 tests/gpiod-test.c | 75 ++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 62 insertions(+), 13 deletions(-)

diff --git a/tests/gpiod-test.c b/tests/gpiod-test.c
index 4c51f4a..9cb9072 100644
--- a/tests/gpiod-test.c
+++ b/tests/gpiod-test.c
@@ -86,6 +86,7 @@ static struct {
 	pid_t main_pid;
 	int pipesize;
 	char *pipebuf;
+	char *toolpath;
 } globals;
 
 enum {
@@ -447,18 +448,6 @@ static void gpiotool_proc_dup_fds(int in_fd, int out_fd, int err_fd)
 	}
 }
 
-static char *gpiotool_proc_get_path(const char *tool)
-{
-	char *path, *progpath, *progdir;
-
-	progpath = xstrdup(program_invocation_name);
-	progdir = dirname(progpath);
-	path = xappend(NULL, "%s/../../tools/%s", progdir, tool);
-	free(progpath);
-
-	return path;
-}
-
 static NORETURN void gpiotool_proc_exec(const char *path, va_list va)
 {
 	size_t num_args;
@@ -545,10 +534,12 @@ void test_tool_run(char *tool, ...)
 	event_lock();
 	if (globals.test_ctx.event.running)
 		die("refusing to fork when the event thread is running");
+	if (!globals.toolpath)
+		die("asked to run tests for gpio-tools, but the executables were not found");
 
 	gpiotool_proc_make_pipes(in_fds, out_fds, err_fds);
-	path = gpiotool_proc_get_path(tool);
 
+	path = xappend(NULL, "%s/%s", globals.toolpath, tool);
 	rv = access(path, R_OK | X_OK);
 	if (rv)
 		die_perr("unable to execute '%s'", path);
@@ -768,6 +759,63 @@ static void check_gpio_mockup(void)
 	msg("gpio-mockup ok");
 }
 
+static void check_tool_path(void)
+{
+	/*
+	 * Let's check gpiodetect only and assume all the other tools are in
+	 * the same directory.
+	 */
+	static const char *const tool = "gpiodetect";
+
+	char *progpath, *progdir, *toolpath, *pathenv, *tok;
+
+	/* First check if we're running the from the top source directory. */
+	progpath = xstrdup(program_invocation_name);
+	progdir = dirname(progpath);
+
+	toolpath = xappend(NULL, "%s/../../tools/%s", progdir, tool);
+	if (access(toolpath, R_OK | X_OK) == 0) {
+		free(progpath);
+		goto out;
+	}
+	free(toolpath);
+
+	/* Is the tool in the same directory maybe? */
+	toolpath = xappend(NULL, "%s/%s", progdir, tool);
+	free(progpath);
+	if (access(toolpath, R_OK | X_OK) == 0)
+		goto out;
+	free(toolpath);
+
+	/* Next iterate over directories in $PATH. */
+	pathenv = getenv("PATH");
+	if (!pathenv)
+		return;
+
+	progpath = xstrdup(pathenv);
+	tok = strtok(progpath, ":");
+	while (tok) {
+		toolpath = xappend(NULL, "%s/%s", tok, tool);
+		if (access(toolpath, R_OK) == 0) {
+			free(progpath);
+			goto out;
+		}
+
+		free(toolpath);
+		tok = strtok(NULL, ":");
+	}
+
+	free(progpath);
+	toolpath = NULL;
+
+out:
+	if (toolpath) {
+		toolpath = dirname(toolpath);
+		msg("using gpio-tools from '%s'", toolpath);
+		globals.toolpath = toolpath;
+	}
+}
+
 static void load_module(struct _test_chip_descr *descr)
 {
 	unsigned int i;
@@ -1001,6 +1049,7 @@ int main(int argc TEST_UNUSED, char **argv TEST_UNUSED)
 
 	check_kernel();
 	check_gpio_mockup();
+	check_tool_path();
 
 	msg("running tests");
 
-- 
2.20.1