Introduce print_array function for consistent decoding of arrays
* defs.h (print_array): New prototype.
* util.c (print_array): New function.
diff --git a/defs.h b/defs.h
index fe2e46b..97ac973 100644
--- a/defs.h
+++ b/defs.h
@@ -515,6 +515,22 @@
extern int umovestr(struct tcb *, long, unsigned int, char *);
extern int upeek(int pid, long, long *);
+extern bool
+print_array(struct tcb *tcp,
+ const unsigned long start_addr,
+ const size_t nmemb,
+ void *const elem_buf,
+ const size_t elem_size,
+ int (*const umoven_func)(struct tcb *,
+ long,
+ unsigned int,
+ void *),
+ bool (*const print_func)(struct tcb *,
+ void *elem_buf,
+ size_t elem_size,
+ void *opaque_data),
+ void *const opaque_data);
+
#if defined ALPHA || defined IA64 || defined MIPS \
|| defined SH || defined SPARC || defined SPARC64
# define HAVE_GETRVAL2
diff --git a/util.c b/util.c
index a9bce99..454c7cf 100644
--- a/util.c
+++ b/util.c
@@ -1335,3 +1335,103 @@
}
return 0;
}
+
+/*
+ * Iteratively fetch and print up to nmemb elements of elem_size size
+ * from the array that starts at tracee's address start_addr.
+ *
+ * Array elements are being fetched to the address specified by elem_buf.
+ *
+ * The fetcher callback function specified by umoven_func should follow
+ * the same semantics as umoven_or_printaddr function.
+ *
+ * The printer callback function specified by print_func is expected
+ * to print something; if it returns false, no more iterations will be made.
+ *
+ * The pointer specified by opaque_data is passed to each invocation
+ * of print_func callback function.
+ *
+ * This function prints:
+ * - "NULL", if start_addr is NULL;
+ * - "[]", if nmemb is 0;
+ * - start_addr, if nmemb * elem_size overflows or wraps around;
+ * - nothing, if the first element cannot be fetched
+ * (if umoven_func returns non-zero), but it is assumed that
+ * umoven_func has printed the address it failed to fetch data from;
+ * - elements of the array, delimited by ", ", with the array itself
+ * enclosed with [] brackets.
+ *
+ * If abbrev(tcp) is true, then
+ * - the maximum number of elements printed equals to max_strlen;
+ * - "..." is printed instead of max_strlen+1 element
+ * and no more iterations will be made.
+ *
+ * This function returns true only if
+ * - umoven_func has been called at least once AND
+ * - umoven_func has not returned false.
+ */
+bool
+print_array(struct tcb *tcp,
+ const unsigned long start_addr,
+ const size_t nmemb,
+ void *const elem_buf,
+ const size_t elem_size,
+ int (*const umoven_func)(struct tcb *,
+ long,
+ unsigned int,
+ void *),
+ bool (*const print_func)(struct tcb *,
+ void *elem_buf,
+ size_t elem_size,
+ void *opaque_data),
+ void *const opaque_data)
+{
+ if (!start_addr) {
+ tprints("NULL");
+ return false;
+ }
+
+ if (!nmemb) {
+ tprints("[]");
+ return false;
+ }
+
+ const size_t size = nmemb * elem_size;
+ const unsigned long end_addr = start_addr + size;
+
+ if (end_addr <= start_addr || size / elem_size != nmemb) {
+ printaddr(start_addr);
+ return false;
+ }
+
+ const unsigned long abbrev_end =
+ (abbrev(tcp) && max_strlen < nmemb) ?
+ start_addr + elem_size * max_strlen : end_addr;
+ unsigned long cur;
+
+ for (cur = start_addr; cur < end_addr; cur += elem_size) {
+ if (cur != start_addr)
+ tprints(", ");
+
+ if (umoven_func(tcp, cur, elem_size, elem_buf))
+ break;
+
+ if (cur == start_addr)
+ tprints("[");
+
+ if (cur >= abbrev_end) {
+ tprints("...");
+ cur = end_addr;
+ break;
+ }
+
+ if (!print_func(tcp, elem_buf, elem_size, opaque_data)) {
+ cur = end_addr;
+ break;
+ }
+ }
+ if (cur != start_addr)
+ tprints("]");
+
+ return cur >= end_addr;
+}
