Implement filter expression to bytecode compiler in liblttng-ctl

[lttng-tools.git] / src / lib / lttng-ctl / align.h

diff --git a/src/lib/lttng-ctl/align.h b/src/lib/lttng-ctl/align.h
new file mode 100644 (file)
index 0000000..813bade
--- /dev/null
+++ b/src/lib/lttng-ctl/align.h
@@ -0,0 +1,64 @@
+#ifndef _LTTNG_ALIGN_H
+#define _LTTNG_ALIGN_H
+
+/*
+ * align.h
+ *
+ * (C) Copyright 2010-2011 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ */
+
+#include <lttng/bug.h>
+#include <unistd.h>
+#include <limits.h>
+
+#ifndef PAGE_SIZE      /* Cygwin limits.h defines its own PAGE_SIZE */
+#define PAGE_SIZE              sysconf(_SC_PAGE_SIZE)
+#endif
+
+#define PAGE_MASK              (~(PAGE_SIZE - 1))
+#define __ALIGN_MASK(v, mask)  (((v) + (mask)) & ~(mask))
+#define ALIGN(v, align)                __ALIGN_MASK(v, (__typeof__(v)) (align) - 1)
+#define PAGE_ALIGN(addr)       ALIGN(addr, PAGE_SIZE)
+
+/**
+ * offset_align - Calculate the offset needed to align an object on its natural
+ *                alignment towards higher addresses.
+ * @align_drift:  object offset from an "alignment"-aligned address.
+ * @alignment:    natural object alignment. Must be non-zero, power of 2.
+ *
+ * Returns the offset that must be added to align towards higher
+ * addresses.
+ */
+#define offset_align(align_drift, alignment)                                  \
+       ({                                                                     \
+               LTTNG_BUILD_RUNTIME_BUG_ON((alignment) == 0                    \
+                                  || ((alignment) & ((alignment) - 1)));      \
+               (((alignment) - (align_drift)) & ((alignment) - 1));           \
+       })
+
+/**
+ * offset_align_floor - Calculate the offset needed to align an object
+ *                      on its natural alignment towards lower addresses.
+ * @align_drift:  object offset from an "alignment"-aligned address.
+ * @alignment:    natural object alignment. Must be non-zero, power of 2.
+ *
+ * Returns the offset that must be substracted to align towards lower addresses.
+ */
+#define offset_align_floor(align_drift, alignment)                            \
+       ({                                                                     \
+               LTTNG_BUILD_RUNTIME_BUG_ON((alignment) == 0                    \
+                                  || ((alignment) & ((alignment) - 1)));      \
+               (((align_drift) - (alignment)) & ((alignment) - 1);            \
+       })
+
+#endif /* _LTTNG_ALIGN_H */