--- /dev/null
+#include <stdio.h>
+#include <string.h>
+#include "config.h"
+
+/**
+ * failtest - unit test helpers for testing malloc and other failures.
+ *
+ * The failtest module overrides various standard functions, and forks
+ * your unit test at those points to test failure paths. The failing
+ * child are expected to fail (eg. when malloc fails), but should not
+ * leak memory or crash.
+ *
+ * The unit test is a normal CCAN tap-style test, except it should
+ * start by calling failtest_init() and end by calling
+ * failtest_exit().
+ *
+ * You can control what functions fail: see failtest_hook.
+ *
+ * Example:
+ * #include <stdio.h>
+ * #include <stdlib.h>
+ * #include <string.h>
+ * #include <ccan/tap/tap.h>
+ * #include <ccan/failtest/failtest_override.h>
+ * #include <ccan/failtest/failtest.h>
+ *
+ * int main(int argc, char *argv[])
+ * {
+ * void *a, *b;
+ *
+ * failtest_init(argc, argv);
+ * plan_tests(3);
+ *
+ * // Simple malloc test.
+ * a = malloc(100);
+ * if (ok1(a)) {
+ * // Fill the memory.
+ * memset(a, 'x', 100);
+ * b = realloc(a, 200);
+ * if (ok1(b)) {
+ * // Fill the rest of the memory.
+ * memset(b + 100, 'y', 100);
+ * // Check it got a copy of a as expected.
+ * ok1(strspn(b, "x") == 100);
+ * free(b);
+ * } else {
+ * // Easy to miss: free a on realloc failure!
+ * free(a);
+ * }
+ * }
+ * failtest_exit(exit_status());
+ * }
+ *
+ * License: LGPL
+ * Author: Rusty Russell <rusty@rustcorp.com.au>
+ */
+int main(int argc, char *argv[])
+{
+ if (argc != 2)
+ return 1;
+
+ if (strcmp(argv[1], "depends") == 0) {
+ printf("ccan/compiler\n");
+ printf("ccan/read_write_all\n");
+ return 0;
+ }
+
+ return 1;
+}