damus-c: add bolt11 parser from CLN

We'll need this for our lightning invoice view

Signed-off-by: William Casarin <jb55@jb55.com>

damus-c/take.h

@@ -0,0 +1,136 @@
+/* CC0 (Public domain) - see LICENSE file for details */
+#ifndef CCAN_TAKE_H
+#define CCAN_TAKE_H
+#include "config.h"
+#include <stdbool.h>
+#include "str.h"
+
+#ifdef CCAN_TAKE_DEBUG
+#define TAKE_LABEL(p) __FILE__ ":" stringify(__LINE__) ":" stringify(p)
+#else
+#define TAKE_LABEL(p) NULL
+#endif
+
+/**
+ * TAKES - annotate a formal parameter as being take()-able
+ *
+ * This doesn't do anything, but useful for documentation.
+ *
+ * Example:
+ *    void print_string(const char *str TAKES);
+ *
+ */
+#define TAKES
+
+/**
+ * take - record a pointer to be consumed by the function its handed to.
+ * @p: the pointer to mark, or NULL.
+ *
+ * This marks a pointer object to be freed by the called function,
+ * which is extremely useful for chaining functions.  It works on
+ * NULL, for pass-through error handling.
+ */
+#define take(p) (take_typeof(p) take_((p), TAKE_LABEL(p)))
+
+/**
+ * taken - check (and un-take) a pointer was passed with take()
+ * @p: the pointer to check.
+ *
+ * A function which accepts take() arguments uses this to see if it
+ * should own the pointer; it will be removed from the take list, so
+ * this only returns true once.
+ *
+ * Example:
+ *    // Silly routine to add 1
+ *    static int *add_one(const int *num TAKES)
+ *    {
+ *        int *ret;
+ *        if (taken(num))
+ *            ret = (int *)num;
+ *        else
+ *            ret = malloc(sizeof(int));
+ *        if (ret)
+ *            *ret = (*num) + 1;
+ *        return ret;
+ *    }
+ */
+bool taken(const void *p);
+
+/**
+ * is_taken - check if a pointer was passed with take()
+ * @p: the pointer to check.
+ *
+ * This is like the above, but doesn't remove it from the taken list.
+ *
+ * Example:
+ *    // Silly routine to add 1: doesn't handle taken args!
+ *    static int *add_one_notake(const int *num)
+ *    {
+ *        int *ret = malloc(sizeof(int));
+ *        assert(!is_taken(num));
+ *        if (ret)
+ *            *ret = (*num) + 1;
+ *        return ret;
+ *    }
+ */
+bool is_taken(const void *p);
+
+/**
+ * taken_any - are there any taken pointers?
+ *
+ * Mainly useful for debugging take() leaks.  With CCAN_TAKE_DEBUG, returns
+ * the label where the pointer was passed to take(), otherwise returns
+ * a static char buffer with the pointer value in it.  NULL if none are taken.
+ *
+ * Example:
+ *    static void cleanup(void)
+ *    {
+ *        assert(!taken_any());
+ *    }
+ */
+const char *taken_any(void);
+
+/**
+ * take_cleanup - remove all taken pointers from list.
+ *
+ * This is useful in atexit() handlers for valgrind-style leak detection.
+ *
+ * Example:
+ *    static void cleanup2(void)
+ *    {
+ *        take_cleanup();
+ *    }
+ */
+void take_cleanup(void);
+
+/**
+ * take_allocfail - set function to call if we can't reallocated taken array.
+ * @fn: the function.
+ *
+ * If this is not set, then if the array reallocation fails, the
+ * pointer won't be marked taken().  If @fn returns, it is expected to
+ * free the pointer; we return NULL from take() and the function handles
+ * it like any allocation failure.
+ *
+ * Example:
+ *    static void free_on_fail(const void *p)
+ *    {
+ *        free((void *)p);
+ *    }
+ *
+ *    static void init(void)
+ *    {
+ *        take_allocfail(free_on_fail);
+ *    }
+ */
+void take_allocfail(void (*fn)(const void *p));
+
+/* Private functions */
+#if HAVE_TYPEOF
+#define take_typeof(ptr) (__typeof__(ptr))
+#else
+#define take_typeof(ptr)
+#endif
+
+void *take_(const void *p, const char *label);
+#endif /* CCAN_TAKE_H */