zend_call_stack.h

/*
 +----------------------------------------------------------------------+
 | Zend Engine |
 +----------------------------------------------------------------------+
 | Copyright (c) Zend Technologies Ltd. (http://www.zend.com) |
 +----------------------------------------------------------------------+
 | This source file is subject to version 2.00 of the Zend license, |
 | that is bundled with this package in the file LICENSE, and is |
 | available through the world-wide-web at the following url: |
 | http://www.zend.com/license/2_00.txt. |
 | If you did not receive a copy of the Zend license and are unable to |
 | obtain it through the world-wide-web, please send a note to |
 | license@zend.com so we can mail you a copy immediately. |
 +----------------------------------------------------------------------+
 | Authors: Arnaud Le Blanc <arnaud.lb@gmail.com> |
 +----------------------------------------------------------------------+
*/

#ifndefZEND_CALL_STACK_H
#defineZEND_CALL_STACK_H

#include"zend.h"
#include"zend_portability.h"
#ifdef__APPLE__
# include<pthread.h>
#endif

#ifdefZEND_CHECK_STACK_LIMIT

typedefstruct_zend_call_stack {
void*base; /* high address of the stack */
size_tmax_size;
} zend_call_stack;

ZEND_APIvoidzend_call_stack_init(void);

ZEND_APIboolzend_call_stack_get(zend_call_stack*stack);

/** Returns an approximation of the current stack position */
staticzend_always_inlinevoid*zend_call_stack_position(void) {
#ifdefZEND_WIN32
return_AddressOfReturnAddress();
#elif defined(PHP_HAVE_BUILTIN_FRAME_ADDRESS)
return__builtin_frame_address(0);
#else
void*a;
void*pos= (void*)&a;
returnpos;
#endif
}

staticzend_always_inlineboolzend_call_stack_overflowed(void*stack_limit) {
return (uintptr_t) zend_call_stack_position() <= (uintptr_t) stack_limit;
}

staticinlinevoid*zend_call_stack_limit(void*base, size_tsize, size_treserved_size)
{
if (UNEXPECTED(size> (uintptr_t)base)) {
return (void*)0;
 }

base= (int8_t*)base-size;

if (UNEXPECTED(UINTPTR_MAX- (uintptr_t)base<reserved_size)) {
return (void*)UINTPTR_MAX;
 }

return (int8_t*)base+reserved_size;
}

staticinlinesize_tzend_call_stack_default_size(void)
{
#ifdef__linux__
return8*1024*1024;
#endif
#if defined(__FreeBSD__) || defined(__NetBSD__)
return4*1024*1024;
#endif
#if defined(__DragonFly__)
return2*1024*1024;
#endif
#ifdef__OpenBSD__
return512*1024;
#endif
#ifdef__APPLE__
// https://developer.apple.com/library/archive/documentation/Cocoa/Conceptual/Multithreading/CreatingThreads/CreatingThreads.html
if (pthread_main_np()) {
return8*1024*1024;
 }
return512*1024;
#endif
#ifdef__HAIKU__
return64*4096;
#endif
#ifdef__sun
return8*4096;
#endif

return2*1024*1024;
}

#endif/* ZEND_CHECK_STACK_LIMIT */
#endif/* ZEND_CALL_STACK_H */