tempdir and sandboxes are now separate entities

clar now has the concept of a _temporary directory_, which is the
temporary directory for the entirety of a `clar` invocation (a set of
test runs) and a sandbox, which is the temporary directory for a single
test invocation.

This allows us to ensure that a well-written test (that only writes into
its sandbox) doesn't poison the well for future test invocations if it
fails to clean up its sandbox.

clar.c

@@ -199,8 +199,10 @@ static void clar_print_onabortv(const char *msg, va_list argp);
 static void clar_print_onabort(const char *msg, ...);
 
 /* From clar_sandbox.c */
-static void clar_unsandbox(void);
-static void clar_sandbox(void);
+static void clar_tempdir_init(void);
+static void clar_tempdir_shutdown(void);
+static int clar_sandbox_create(const char *suite_name, const char *test_name);
+static int clar_sandbox_cleanup(void);
 
 /* From summary.h */
 static struct clar_summary *clar_summary_init(const char *filename);
@@ -304,6 +306,8 @@ clar_run_test(
 
 	CL_TRACE(CL_TRACE__TEST__BEGIN);
 
+	clar_sandbox_create(suite->name, test->name);
+
 	_clar.last_report->start = time(NULL);
 	clar_time_now(&start);
 
@@ -331,6 +335,8 @@ clar_run_test(
 	if (cleanup->ptr != NULL)
 		cleanup->ptr();
 
+	clar_sandbox_cleanup();
+
 	CL_TRACE(CL_TRACE__TEST__END);
 
 	_clar.tests_ran++;
@@ -604,7 +610,7 @@ clar_test_init(int argc, char **argv)
 	if (_clar.write_summary)
 	    _clar.summary = clar_summary_init(_clar.summary_filename);
 
-	clar_sandbox();
+	clar_tempdir_init();
 }
 
 int
@@ -636,7 +642,7 @@ clar_test_shutdown(void)
 		_clar.total_errors
 	);
 
-	clar_unsandbox();
+	clar_tempdir_shutdown();
 
 	if (_clar.write_summary && clar_summary_shutdown(_clar.summary) < 0)
 		clar_abort("Failed to write the summary file '%s: %s.\n",

clar.h

@@ -8,11 +8,14 @@
 #define __CLAR_TEST_H__
 
 #include <stdlib.h>
+#include <limits.h>
 
-#ifdef CLAR_WIN32_LONGPATHS
+#if defined(_WIN32) && defined(CLAR_WIN32_LONGPATHS)
 # define CLAR_MAX_PATH 4096
-#else
+#elif defined(_WIN32)
 # define CLAR_MAX_PATH MAX_PATH
+#else
+# define CLAR_MAX_PATH PATH_MAX
 #endif
 
 #ifndef CLAR_SELFTEST
@@ -46,6 +49,7 @@ void clar_test_shutdown(void);
 int clar_test(int argc, char *argv[]);
 
 const char *clar_sandbox_path(void);
+const char *clar_tempdir_path(void);
 
 void cl_set_cleanup(void (*cleanup)(void *), void *opaque);
 void cl_fs_cleanup(void);

clar/fixtures.h

@@ -28,7 +28,7 @@ const char *cl_fixture(const char *fixture_name)
 
 void cl_fixture_sandbox(const char *fixture_name)
 {
-	fs_copy(cl_fixture(fixture_name), _clar_path);
+	fs_copy(cl_fixture(fixture_name), clar_sandbox_path());
 }
 
 const char *cl_fixture_basename(const char *fixture_name)
@@ -45,6 +45,6 @@ const char *cl_fixture_basename(const char *fixture_name)
 
 void cl_fixture_cleanup(const char *fixture_name)
 {
-	fs_rm(fixture_path(_clar_path, cl_fixture_basename(fixture_name)));
+	fs_rm(fixture_path(clar_sandbox_path(), cl_fixture_basename(fixture_name)));
 }
 #endif

clar/fs.h

@@ -290,7 +290,7 @@ void
 cl_fs_cleanup(void)
 {
 #ifdef CLAR_FIXTURE_PATH
-	fs_rm(fixture_path(_clar_path, "*"));
+	fs_rm(fixture_path(clar_tempdir_path(), "*"));
 #else
 	((void)fs_copy); /* unused */
 #endif
@@ -512,7 +512,7 @@ fs_rm(const char *path)
 void
 cl_fs_cleanup(void)
 {
-	clar_unsandbox();
-	clar_sandbox();
+	clar_tempdir_shutdown();
+	clar_tempdir_init();
 }
 #endif

clar/sandbox.h

@@ -2,7 +2,17 @@
 #include <sys/syslimits.h>
 #endif
 
-static char _clar_path[CLAR_MAX_PATH];
+/*
+ * The tempdir is the temporary directory for the entirety of the clar
+ * process execution. The sandbox is an individual temporary directory
+ * for the execution of an individual test. Sandboxes are deleted
+ * entirely after test execution to avoid pollution across tests.
+ */
+
+static char _clar_tempdir[CLAR_MAX_PATH];
+static size_t _clar_tempdir_len;
+
+static char _clar_sandbox[CLAR_MAX_PATH];
 
 static int
 is_valid_tmp_path(const char *path)
@@ -108,17 +118,17 @@ static int canonicalize_tmp_path(char *buffer)
 #endif
 }
 
-static void clar_unsandbox(void)
+static void clar_tempdir_shutdown(void)
 {
-	if (_clar_path[0] == '\0')
+	if (_clar_tempdir[0] == '\0')
 		return;
 
 	cl_must_pass(chdir(".."));
 
-	fs_rm(_clar_path);
+	fs_rm(_clar_tempdir);
 }
 
-static int build_sandbox_path(void)
+static int build_tempdir_path(void)
 {
 #ifdef CLAR_TMPDIR
 	const char path_tail[] = CLAR_TMPDIR "_XXXXXX";
@@ -128,57 +138,116 @@ static int build_sandbox_path(void)
 
 	size_t len;
 
-	if (find_tmp_path(_clar_path, sizeof(_clar_path)) < 0 ||
-	    canonicalize_tmp_path(_clar_path) < 0)
+	if (find_tmp_path(_clar_tempdir, sizeof(_clar_tempdir)) < 0 ||
+	    canonicalize_tmp_path(_clar_tempdir) < 0)
 		return -1;
 
-	len = strlen(_clar_path);
+	len = strlen(_clar_tempdir);
 
 	if (len + strlen(path_tail) + 1 > CLAR_MAX_PATH)
 		return -1;
 
-	if (_clar_path[len - 1] != '/')
-		_clar_path[len++] = '/';
+	if (_clar_tempdir[len - 1] != '/')
+		_clar_tempdir[len++] = '/';
 
-	strncpy(_clar_path + len, path_tail, sizeof(_clar_path) - len);
+	strncpy(_clar_tempdir + len, path_tail, sizeof(_clar_tempdir) - len);
 
 #if defined(__MINGW32__)
-	if (_mktemp(_clar_path) == NULL)
+	if (_mktemp(_clar_tempdir) == NULL)
 		return -1;
 
-	if (mkdir(_clar_path, 0700) != 0)
+	if (mkdir(_clar_tempdir, 0700) != 0)
 		return -1;
 #elif defined(_WIN32)
-	if (_mktemp_s(_clar_path, sizeof(_clar_path)) != 0)
+	if (_mktemp_s(_clar_tempdir, sizeof(_clar_tempdir)) != 0)
 		return -1;
 
-	if (mkdir(_clar_path, 0700) != 0)
+	if (mkdir(_clar_tempdir, 0700) != 0)
 		return -1;
 #elif defined(__sun) || defined(__TANDEM)
-	if (mktemp(_clar_path) == NULL)
+	if (mktemp(_clar_tempdir) == NULL)
 		return -1;
 
-	if (mkdir(_clar_path, 0700) != 0)
+	if (mkdir(_clar_tempdir, 0700) != 0)
 		return -1;
 #else
-	if (mkdtemp(_clar_path) == NULL)
+	if (mkdtemp(_clar_tempdir) == NULL)
 		return -1;
 #endif
 
+	_clar_tempdir_len = strlen(_clar_tempdir);
 	return 0;
 }
 
-static void clar_sandbox(void)
+static void clar_tempdir_init(void)
+{
+	if (_clar_tempdir[0] == '\0' && build_tempdir_path() < 0)
+		clar_abort("Failed to build tempdir path.\n");
+
+	if (chdir(_clar_tempdir) != 0)
+		clar_abort("Failed to change into tempdir '%s': %s.\n",
+			   _clar_tempdir, strerror(errno));
+}
+
+static void append(char *dst, const char *src)
+{
+	char *d;
+	const char *s;
+
+	for (d = dst; *d; d++)
+		;
+
+	for (s = src; *s; d++, s++)
+		if (*s == ':')
+			*d = '_';
+		else
+			*d = *s;
+
+	*d = '\0';
+}
+
+static int clar_sandbox_create(const char *suite_name, const char *test_name)
 {
-	if (_clar_path[0] == '\0' && build_sandbox_path() < 0)
-		clar_abort("Failed to build sandbox path.\n");
+	cl_assert(_clar_sandbox[0] == '\0');
 
-	if (chdir(_clar_path) != 0)
-		clar_abort("Failed to change into sandbox directory '%s': %s.\n",
-			   _clar_path, strerror(errno));
+	cl_assert(strlen(_clar_tempdir) + strlen(suite_name) + strlen(test_name) + 2 < CLAR_MAX_PATH);
+
+	strcpy(_clar_sandbox, _clar_tempdir);
+	_clar_sandbox[_clar_tempdir_len] = '/';
+	_clar_sandbox[_clar_tempdir_len + 1] = '\0';
+
+	append(_clar_sandbox, suite_name);
+	append(_clar_sandbox, "__");
+	append(_clar_sandbox, test_name);
+
+	if (mkdir(_clar_sandbox, 0700) != 0)
+		return -1;
+
+	if (chdir(_clar_sandbox) != 0)
+		return -1;
+
+	return 0;
+}
+
+static int clar_sandbox_cleanup(void)
+{
+	cl_assert(_clar_sandbox[0] != '\0');
+
+	fs_rm(_clar_sandbox);
+	_clar_sandbox[0] = '\0';
+
+	if (chdir(_clar_tempdir) != 0)
+		return -1;
+
+	return 0;
+}
+
+const char *clar_tempdir_path(void)
+{
+	return _clar_tempdir;
 }
 
 const char *clar_sandbox_path(void)
 {
-	return _clar_path;
+	return _clar_sandbox;
 }