tools/include/uapi/asm-generic/bitsperlong.h

Source file repositories/reference/linux-study-clean/tools/include/uapi/asm-generic/bitsperlong.h

File Facts

System
Linux kernel
Corpus path
tools/include/uapi/asm-generic/bitsperlong.h
Extension
.h
Size
1107 bytes
Lines
32
Domain
Support Tooling And Documentation
Bucket
tools
Inferred role
Support Tooling And Documentation: implementation source
Status
source implementation candidate

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

#ifndef _UAPI__ASM_GENERIC_BITS_PER_LONG
#define _UAPI__ASM_GENERIC_BITS_PER_LONG

#ifndef __BITS_PER_LONG
/*
 * In order to keep safe and avoid regression, only unify uapi
 * bitsperlong.h for some archs which are using newer toolchains
 * that have the definitions of __CHAR_BIT__ and __SIZEOF_LONG__.
 * See the following link for more info:
 * https://lore.kernel.org/linux-arch/b9624545-2c80-49a1-ac3c-39264a591f7b@app.fastmail.com/
 */
#if defined(__CHAR_BIT__) && defined(__SIZEOF_LONG__)
#define __BITS_PER_LONG (__CHAR_BIT__ * __SIZEOF_LONG__)
#else
/*
 * There seems to be no way of detecting this automatically from user
 * space, so 64 bit architectures should override this in their
 * bitsperlong.h. In particular, an architecture that supports
 * both 32 and 64 bit user space must not rely on CONFIG_64BIT
 * to decide it, but rather check a compiler provided macro.
 */
#define __BITS_PER_LONG 32
#endif
#endif

#ifndef __BITS_PER_LONG_LONG
#define __BITS_PER_LONG_LONG 64
#endif

#endif /* _UAPI__ASM_GENERIC_BITS_PER_LONG */

Annotation

Implementation Notes