X-Git-Url: http://git.ozlabs.org/?a=blobdiff_plain;f=ccan%2Fmem%2Fmem.h;h=19f69c038c67efe1e11ac8ab5cec036123aa3b95;hb=c656dceb3f04c2e3da7af40824c97eff5119a0b9;hp=8d6bba943c8eab31243cadfdec3998cc1ed809f2;hpb=2c20abc2e2fdaf1888472968e811d00260dcf8fa;p=ccan

diff --git a/ccan/mem/mem.h b/ccan/mem/mem.h
index 8d6bba94..19f69c03 100644
--- a/ccan/mem/mem.h
+++ b/ccan/mem/mem.h
@@ -149,6 +149,19 @@ static inline bool memeqstr(const void *data, size_t length, const char *string)
 	return memeq(data, length, string, strlen(string));
 }
 
+/**
+ * memeqzero - Is a byte array all zeroes?
+ * @data: byte array
+ * @length: length of @data in bytes
+ *
+ * Example:
+ *	if (memeqzero(somebytes, bytes_len)) {
+ *		printf("somebytes == 0!\n");
+ *	}
+ */
+PURE_FUNCTION
+bool memeqzero(const void *data, size_t length);
+
 /**
  * memstarts_str - Does this byte array start with a string prefix?
  * @a: byte array
@@ -183,4 +196,100 @@ static inline bool memends(const void *s, size_t s_len, const void *suffix, size
 						suffix, suffix_len) == 0);
 }
 
+/**
+ * memends_str - Does this byte array end with a string suffix?
+ * @a: byte array
+ * @al: length in bytes
+ * @s: string suffix
+ *
+ * Example:
+ *	if (memends_str(somebytes, bytes_len, "It")) {
+ *		printf("somebytes ends with with 'It'\n");
+ *	}
+ */
+PURE_FUNCTION
+static inline bool memends_str(const void *a, size_t al, const char *s)
+{
+	return memends(a, al, s, strlen(s));
+}
+
+/**
+ * memoverlaps - Do two memory ranges overlap?
+ * @a: pointer to first memory range
+ * @al: length of first memory range
+ * @b: pointer to second memory range
+ * @al: length of second memory range
+ */
+CONST_FUNCTION
+static inline bool memoverlaps(const void *a_, size_t al,
+			       const void *b_, size_t bl)
+{
+	const char *a = a_;
+	const char *b = b_;
+
+	return (a < (b + bl)) && (b < (a + al));
+}
+
+/*
+ * memswap - Exchange two memory regions
+ * @a: first region
+ * @b: second region
+ * @n: length of the regions
+ *
+ * Undefined results if the two memory regions overlap.
+ */
+void memswap(void *a, void *b, size_t n);
+
+#if HAVE_VALGRIND_MEMCHECK_H
+#include <valgrind/memcheck.h>
+static inline void *memcheck_(const void *data, size_t len)
+{
+	VALGRIND_CHECK_MEM_IS_DEFINED(data, len);
+	return (void *)data;
+}
+#else
+static inline void *memcheck_(const void *data, size_t len)
+{
+	(void)len;
+	return (void *)data;
+}
+#endif
+
+#if HAVE_TYPEOF
+/**
+ * memcheck - check that a memory region is initialized
+ * @data: start of region
+ * @len: length in bytes
+ *
+ * When running under valgrind, this causes an error to be printed
+ * if the entire region is not defined.  Otherwise valgrind only
+ * reports an error when an undefined value is used for a branch, or
+ * written out.
+ *
+ * Example:
+ *	// Search for space, but make sure it's all initialized.
+ *	if (memchr(memcheck(somebytes, bytes_len), ' ', bytes_len)) {
+ *		printf("space was found!\n");
+ *	}
+ */
+#define memcheck(data, len) ((__typeof__((data)+0))memcheck_((data), (len)))
+#else
+#define memcheck(data, len) memcheck_((data), (len))
+#endif
+
+/**
+ * memtaint - mark a memory region unused
+ * @data: start of region
+ * @len: length in bytes
+ *
+ * This writes an "0xdeadbeef" eyecatcher repeatedly to the memory.
+ * When running under valgrind, it also tells valgrind that the memory is
+ * uninitialized, triggering valgrind errors if it is used for branches
+ * or written out (or passed to memcheck!) in future.
+ *
+ * Example:
+ *	// We'll reuse this buffer later, but be sure we don't access it.
+ *	memtaint(somebytes, bytes_len);
+ */
+void memtaint(void *data, size_t len);
 #endif /* CCAN_MEM_H */