86 lines
3.1 KiB
C
86 lines
3.1 KiB
C
/* Code to enable profiling at program startup.
|
|
Copyright (C) 1995-2022 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Lesser General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2.1 of the License, or (at your option) any later version.
|
|
|
|
In addition to the permissions in the GNU Lesser General Public
|
|
License, the Free Software Foundation gives you unlimited
|
|
permission to link the compiled version of this file with other
|
|
programs, and to distribute those programs without any restriction
|
|
coming from the use of this file. (The GNU Lesser General Public
|
|
License restrictions do apply in other respects; for example, they
|
|
cover modification of the file, and distribution when not linked
|
|
into another program.)
|
|
|
|
Note that people who make modified versions of this file are not
|
|
obligated to grant this special exception for their modified
|
|
versions; it is their choice whether to do so. The GNU Lesser
|
|
General Public License gives permission to release a modified
|
|
version without this exception; this exception also makes it
|
|
possible to release a modified version which carries forward this
|
|
exception.
|
|
|
|
The GNU C Library is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with the GNU C Library; if not, see
|
|
<https://www.gnu.org/licenses/>. */
|
|
|
|
#include <sys/types.h>
|
|
#include <sys/gmon.h>
|
|
#include <stdlib.h>
|
|
#include <unistd.h>
|
|
#include <elf-initfini.h>
|
|
|
|
/* Use __executable_start as the lowest address to keep profiling records
|
|
if it provided by the linker. */
|
|
extern const char __executable_start[] __attribute__ ((visibility ("hidden")));
|
|
|
|
extern char etext[];
|
|
|
|
#if !ELF_INITFINI
|
|
/* Instead of defining __gmon_start__ globally in gcrt1.o, we make it
|
|
static and just put a pointer to it into the .preinit_array
|
|
section. */
|
|
# define GMON_START_ARRAY_SECTION ".preinit_array"
|
|
#endif
|
|
|
|
#ifdef GMON_START_ARRAY_SECTION
|
|
static void __gmon_start__ (void);
|
|
static void (*const gmon_start_initializer) (void)
|
|
__attribute__ ((used, section (GMON_START_ARRAY_SECTION))) = &__gmon_start__;
|
|
static
|
|
#else
|
|
/* We cannot use the normal constructor mechanism to call
|
|
__gmon_start__ because gcrt1.o appears before crtbegin.o in the link.
|
|
Instead crti.o calls it specially. */
|
|
extern void __gmon_start__ (void);
|
|
#endif
|
|
|
|
void
|
|
__gmon_start__ (void)
|
|
{
|
|
/* Protect from being called more than once. Since crti.o is linked
|
|
into every shared library, each of their init functions will call us. */
|
|
static int called;
|
|
|
|
if (called)
|
|
return;
|
|
|
|
called = 1;
|
|
|
|
/* Start keeping profiling records. */
|
|
__monstartup ((u_long) &__executable_start, (u_long) &etext);
|
|
|
|
/* Call _mcleanup before exiting; it will write out gmon.out from the
|
|
collected data. */
|
|
atexit (&_mcleanup);
|
|
}
|