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/* ---------------------------------------------- */
/* chkstk86.s */
/* ---------------------------------------------- */
#ifndef __x86_64__
/* ---------------------------------------------- */
.globl __chkstk
__chkstk:
xchg (%esp),%ebp /* store ebp, get ret.addr */
push %ebp /* push ret.addr */
lea 4(%esp),%ebp /* setup frame ptr */
push %ecx /* save ecx */
mov %ebp,%ecx
P0:
sub $4096,%ecx
test %eax,(%ecx)
sub $4096,%eax
cmp $4096,%eax
jge P0
sub %eax,%ecx
test %eax,(%ecx)
mov %esp,%eax
mov %ecx,%esp
mov (%eax),%ecx /* restore ecx */
jmp *4(%eax)
/* ---------------------------------------------- */
#else
/* ---------------------------------------------- */
.globl __chkstk
__chkstk:
xchg (%rsp),%rbp /* store ebp, get ret.addr */
push %rbp /* push ret.addr */
lea 8(%rsp),%rbp /* setup frame ptr */
push %rcx /* save ecx */
mov %rbp,%rcx
movslq %eax,%rax
P0:
sub $4096,%rcx
test %rax,(%rcx)
sub $4096,%rax
cmp $4096,%rax
jge P0
sub %rax,%rcx
test %rax,(%rcx)
mov %rsp,%rax
mov %rcx,%rsp
mov (%rax),%rcx /* restore ecx */
jmp *8(%rax)
/* ---------------------------------------------- */
/* setjmp/longjmp support */
.globl tinyc_getbp
tinyc_getbp:
mov %rbp,%rax
ret
/* ---------------------------------------------- */
#endif
/* ---------------------------------------------- */
/* ---------------------------------------------- */
#ifndef __x86_64__
/* ---------------------------------------------- */
/*
int _except_handler3(
PEXCEPTION_RECORD exception_record,
PEXCEPTION_REGISTRATION registration,
PCONTEXT context,
PEXCEPTION_REGISTRATION dispatcher
);
int __cdecl _XcptFilter(
unsigned long xcptnum,
PEXCEPTION_POINTERS pxcptinfoptrs
);
struct _sehrec {
void *esp; // 0
void *exception_pointers; // 1
void *prev; // 2
void *handler; // 3
void *scopetable; // 4
int trylevel; // 5
void *ebp // 6
};
// this is what the assembler code below means:
__try
{
// ...
}
__except (_XcptFilter(GetExceptionCode(), GetExceptionInformation()))
{
exit(GetExceptionCode());
}
*/
.globl _exception_info
_exception_info:
mov 1*4-24(%ebp),%eax
ret
.globl _exception_code
_exception_code:
call _exception_info
mov (%eax),%eax
mov (%eax),%eax
ret
seh_filter:
call _exception_info
push %eax
call _exception_code
push %eax
call _XcptFilter
add $ 8,%esp
ret
seh_except:
mov 0*4-24(%ebp),%esp
call _exception_code
push %eax
call _exit
// msvcrt wants scopetables aligned and in read-only segment (using .text)
.align 4
seh_scopetable:
.long -1
.long seh_filter
.long seh_except
seh_handler:
jmp _except_handler3
.globl ___try__
___try__:
.globl __try__
__try__:
push %ebp
mov 8(%esp),%ebp
// void *esp;
lea 12(%esp),%eax
mov %eax,0*4(%ebp)
// void *exception_pointers;
xor %eax,%eax
mov %eax,1*4(%ebp)
// void *prev;
mov %fs:0,%eax
mov %eax,2*4(%ebp)
// void *handler;
mov $ seh_handler,%eax
mov %eax,3*4(%ebp)
// void *scopetable;
mov $ seh_scopetable,%eax
mov %eax,4*4(%ebp)
// int trylevel;
xor %eax,%eax
mov %eax,5*4(%ebp)
// register new SEH
lea 2*4(%ebp),%eax
mov %eax,%fs:0
pop %ebp
ret
/* ---------------------------------------------- */
#else
/* ---------------------------------------------- */
/* SEH on x86-64 not implemented */
/* ---------------------------------------------- */
#endif
/* ---------------------------------------------- */
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