mirror of
https://github.com/irungentoo/toxcore.git
synced 2024-03-22 13:30:51 +08:00
44 lines
1.2 KiB
C
44 lines
1.2 KiB
C
/*
|
|
* C language compatibility macros for varying compiler support.
|
|
*/
|
|
#ifndef CCOMPAT_H
|
|
#define CCOMPAT_H
|
|
|
|
// Marking GNU extensions to avoid warnings.
|
|
#if defined(__GNUC__)
|
|
#define GNU_EXTENSION __extension__
|
|
#else
|
|
#define GNU_EXTENSION
|
|
#endif
|
|
|
|
// Variable length arrays.
|
|
// VLA(type, name, size) allocates a variable length array with automatic
|
|
// storage duration. VLA_SIZE(name) evaluates to the runtime size of that array
|
|
// in bytes.
|
|
//
|
|
// If C99 VLAs are not available, an emulation using alloca (stack allocation
|
|
// "function") is used. Note the semantic difference: alloca'd memory does not
|
|
// get freed at the end of the declaration's scope. Do not use VLA() in loops or
|
|
// you may run out of stack space.
|
|
#if !defined(_MSC_VER) && __STDC_VERSION__ >= 199901L
|
|
// C99 VLAs.
|
|
#define VLA(type, name, size) type name[size]
|
|
#define SIZEOF_VLA sizeof
|
|
#else
|
|
|
|
// Emulation using alloca.
|
|
#ifdef _WIN32
|
|
#include <malloc.h>
|
|
#else
|
|
#include <alloca.h>
|
|
#endif
|
|
|
|
#define VLA(type, name, size) \
|
|
const size_t name##_size = (size) * sizeof(type); \
|
|
type *const name = (type *)alloca(name##_size)
|
|
#define SIZEOF_VLA(name) name##_size
|
|
|
|
#endif
|
|
|
|
#endif /* CCOMPAT_H */
|