X-Git-Url: https://git.liburcu.org/?a=blobdiff_plain;f=src%2Fcommon%2Fmacros.h;h=e2d0fcf3eae8e61fd1c7030e5f807e3d1b92bdf6;hb=e909777bf000d0fd8f0116569b3fb31676b228be;hp=308d3d57a14d5ff9ad7911383af9f40f0477c4da;hpb=4616a46c3c3866553a1c3e07546135e4f7ea50a3;p=lttng-tools.git

diff --git a/src/common/macros.h b/src/common/macros.h
index 308d3d57a..e2d0fcf3e 100644
--- a/src/common/macros.h
+++ b/src/common/macros.h
@@ -20,6 +20,8 @@
 #define _MACROS_H
 
 #include <stdlib.h>
+#include <string.h>
+#include <common/compat/string.h>
 
 /*
  * Takes a pointer x and transform it so we can use it to access members
@@ -61,7 +63,7 @@ void *zmalloc(size_t len)
 #endif
 
 #ifndef max_t
-#define max_t(type, a, b)	((type) max(a, b))
+#define max_t(type, a, b)	max((type) a, (type) b)
 #endif
 
 #ifndef min
@@ -72,8 +74,48 @@ void *zmalloc(size_t len)
 #define LTTNG_PACKED __attribute__((__packed__))
 #endif
 
-#ifndef LTTNG_HIDDEN
+/*
+ * LTTNG_HIDDEN: set the hidden attribute for internal functions
+ * On Windows, symbols are local unless explicitly exported,
+ * see https://gcc.gnu.org/wiki/Visibility
+ */
+#if defined(_WIN32) || defined(__CYGWIN__)
+#define LTTNG_HIDDEN
+#else
 #define LTTNG_HIDDEN __attribute__((visibility("hidden")))
 #endif
 
+#define member_sizeof(type, field)	sizeof(((type *) 0)->field)
+
+/*
+ * Get an aligned pointer to a value. This is meant
+ * as a helper to pass an aligned pointer to a member in a packed structure
+ * to a function.
+ */
+#define ALIGNED_CONST_PTR(value) (((const typeof(value) []) { value }))
+
+/*
+ * lttng_strncpy returns 0 on success, or nonzero on failure.
+ * It checks that the @src string fits into @dst_len before performing
+ * the copy. On failure, no copy has been performed.
+ *
+ * dst_len includes the string's trailing NULL.
+ */
+static inline
+int lttng_strncpy(char *dst, const char *src, size_t dst_len)
+{
+	if (lttng_strnlen(src, dst_len) == dst_len) {
+		/* Fail since copying would result in truncation. */
+		return -1;
+	}
+	strncpy(dst, src, dst_len);
+	/*
+	 * Be extra careful and put final \0 at the end after strncpy(),
+	 * even though we checked the length before. This makes Coverity
+	 * happy.
+	 */
+	dst[dst_len - 1] = '\0';
+	return 0;
+}
+
 #endif /* _MACROS_H */