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Common Trace Format - Standards, Extensions and Libraries Mathieu Desnoyers September 26, 2010

This document describes the CTF library dependencies on standards, extensions and libraries.

Standards

C99

This library is C99 compliant. A non-documented non-compliance should be reported as a bug. See the ISO/IEC 9899:TC2 publication:

http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1124.pdf

IEEE 754-2008

The IEEE 754-2008 standard is used for binary floating point arithmetic representation. See:

http://grouper.ieee.org/groups/754/

GNU/C extensions

This library uses some widely GNU/C extensions widely adopted by compilers. For detail, see:

http://gcc.gnu.org/onlinedocs/gcc/C-Extensions.html#C-Extensions

Non-standard Dependencies

In some cases, standards do not provide the required primitives to write portable code; these are listed here.

Non-standard endian.h

endian.h is used to provide the following definitions:

#define LITTLE_ENDIAN	1234
#define BIG_ENDIAN	4321
#define BYTE_ORDER	/* Your architecture: BIG_ENDIAN or LITTLE_ENDIAN */

Bitfields

The ISO/IEC 9899 standard leaves bitfields implementation defined, which is unacceptable for portability of this library. Section 6.7.2.1 - "Structure and union specifiers", Semantic 10 specifically indicates that padding and order of bit-fields allocation within a unit is implementation-defined.

This is why this library provides the bitfield.h header (under the MIT license), which specifies bitfields write primitives that uses the same field order as the GNU/C compiler, but does not require any padding for fields spreading across units. This is therefore a superset of the GNU/C bitfields, which can be dealt with by detecting C structure padding manually given the bit offset and bit-field size as well as the unit size.

Libraries

The GLib library of C routines

The library glib 2 is used for its basic data structures. See

http://library.gnome.org/devel/glib/2.24/glib-data-types.html