X-Git-Url: https://git.ozlabs.org/?a=blobdiff_plain;f=ccan%2Fmem%2Fmem.h;h=68a4aa3c18885c207a9fd11828bc5174bead6905;hb=e8d1e7304feb9318a841ad4a7d5a8773271ab814;hp=1afe508b3a097beefdbf93660165c7146fdb3f25;hpb=4ad5144790a12523f8a7c24c469a34907b6942a6;p=ccan

diff --git a/ccan/mem/mem.h b/ccan/mem/mem.h
index 1afe508b..68a4aa3c 100644
--- a/ccan/mem/mem.h
+++ b/ccan/mem/mem.h
@@ -200,4 +200,66 @@ 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)
+{
+	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
 #endif /* CCAN_MEM_H */