glibc/include/libc-internal.h
Carlos O'Donell 93fe09cb5f Bug 20729: Fix building with -Os.
This commit adds a new DIAG_IGNORE_Os_NEEDS_COMMENT which is only
enabled when compiling with -Os. This allows developers working on
-Os enabled builds to mark false-positive warnings without impacting the
warnings emitted at -O2.

Then using the new DIAG_IGNORE_Os_NEEDS_COMMENT we fix 6 warnings
generated with GCC 5 to get -Os builds working again.
2016-10-29 23:50:56 -04:00

130 lines
5.3 KiB
C

/* This file contains a number of internal prototype declarations that
don't fit anywhere else. */
#ifndef _LIBC_INTERNAL
# define _LIBC_INTERNAL 1
#include <hp-timing.h>
/* Initialize the `__libc_enable_secure' flag. */
extern void __libc_init_secure (void);
/* This function will be called from _init in init-first.c. */
extern void __libc_global_ctors (void);
/* Discover the tick frequency of the machine if something goes wrong,
we return 0, an impossible hertz. */
extern int __profile_frequency (void);
libc_hidden_proto (__profile_frequency)
/* Hooks for the instrumenting functions. */
extern void __cyg_profile_func_enter (void *this_fn, void *call_site);
extern void __cyg_profile_func_exit (void *this_fn, void *call_site);
/* Get frequency of the system processor. */
extern hp_timing_t __get_clockfreq (void);
/* Free all allocated resources. */
extern void __libc_freeres (void);
libc_hidden_proto (__libc_freeres)
/* Free resources stored in thread-local variables on thread exit. */
extern void __libc_thread_freeres (void);
/* Define and initialize `__progname' et. al. */
extern void __init_misc (int, char **, char **);
# if IS_IN (rtld)
extern __typeof (__profile_frequency) __profile_frequency attribute_hidden;
# endif
/* 1 if 'type' is a pointer type, 0 otherwise. */
# define __pointer_type(type) (__builtin_classify_type ((type) 0) == 5)
/* __intptr_t if P is true, or T if P is false. */
# define __integer_if_pointer_type_sub(T, P) \
__typeof__ (*(0 ? (__typeof__ (0 ? (T *) 0 : (void *) (P))) 0 \
: (__typeof__ (0 ? (__intptr_t *) 0 : (void *) (!(P)))) 0))
/* __intptr_t if EXPR has a pointer type, or the type of EXPR otherwise. */
# define __integer_if_pointer_type(expr) \
__integer_if_pointer_type_sub(__typeof__ ((__typeof__ (expr)) 0), \
__pointer_type (__typeof__ (expr)))
/* Cast an integer or a pointer VAL to integer with proper type. */
# define cast_to_integer(val) ((__integer_if_pointer_type (val)) (val))
/* Align a value by rounding down to closest size.
e.g. Using size of 4096, we get this behavior:
{4095, 4096, 4097} = {0, 4096, 4096}. */
#define ALIGN_DOWN(base, size) ((base) & -((__typeof__ (base)) (size)))
/* Align a value by rounding up to closest size.
e.g. Using size of 4096, we get this behavior:
{4095, 4096, 4097} = {4096, 4096, 8192}.
Note: The size argument has side effects (expanded multiple times). */
#define ALIGN_UP(base, size) ALIGN_DOWN ((base) + (size) - 1, (size))
/* Same as ALIGN_DOWN(), but automatically casts when base is a pointer. */
#define PTR_ALIGN_DOWN(base, size) \
((__typeof__ (base)) ALIGN_DOWN ((uintptr_t) (base), (size)))
/* Same as ALIGN_UP(), but automatically casts when base is a pointer. */
#define PTR_ALIGN_UP(base, size) \
((__typeof__ (base)) ALIGN_UP ((uintptr_t) (base), (size)))
/* Ignore the value of an expression when a cast to void does not
suffice (in particular, for a call to a function declared with
attribute warn_unused_result). */
#define ignore_value(x) \
({ __typeof__ (x) __ignored_value = (x); (void) __ignored_value; })
/* The macros to control diagnostics are structured like this, rather
than a single macro that both pushes and pops diagnostic state and
takes the affected code as an argument, because the GCC pragmas
work by disabling the diagnostic for a range of source locations
and do not work when all the pragmas and the affected code are in a
single macro expansion. */
/* Push diagnostic state. */
#define DIAG_PUSH_NEEDS_COMMENT _Pragma ("GCC diagnostic push")
/* Pop diagnostic state. */
#define DIAG_POP_NEEDS_COMMENT _Pragma ("GCC diagnostic pop")
#define _DIAG_STR1(s) #s
#define _DIAG_STR(s) _DIAG_STR1(s)
/* Ignore the diagnostic OPTION. VERSION is the most recent GCC
version for which the diagnostic has been confirmed to appear in
the absence of the pragma (in the form MAJOR.MINOR for GCC 4.x,
just MAJOR for GCC 5 and later). Uses of this pragma should be
reviewed when the GCC version given is no longer supported for
building glibc; the version number should always be on the same
source line as the macro name, so such uses can be found with grep.
Uses should come with a comment giving more details of the
diagnostic, and an architecture on which it is seen if possibly
optimization-related and not in architecture-specific code. This
macro should only be used if the diagnostic seems hard to fix (for
example, optimization-related false positives). */
#define DIAG_IGNORE_NEEDS_COMMENT(version, option) \
_Pragma (_DIAG_STR (GCC diagnostic ignored option))
/* Similar to DIAG_IGNORE_NEEDS_COMMENT the following macro ignores the
diagnostic OPTION but only if optimizations for size are enabled.
This is required because different warnings may be generated for
different optimization levels. For example a key piece of code may
only generate a warning when compiled at -Os, but at -O2 you could
still want the warning to be enabled to catch errors. In this case
you would use DIAG_IGNORE_Os_NEEDS_COMMENT to disable the warning
only for -Os. */
#ifdef __OPTIMIZE_SIZE__
# define DIAG_IGNORE_Os_NEEDS_COMMENT(version, option) \
_Pragma (_DIAG_STR (GCC diagnostic ignored option))
#else
# define DIAG_IGNORE_Os_NEEDS_COMMENT(version, option)
#endif
#endif /* _LIBC_INTERNAL */