diff options
Diffstat (limited to 'private/crt32/misc/i386/longjmp.asm')
| -rw-r--r-- | private/crt32/misc/i386/longjmp.asm | 150 |
1 files changed, 150 insertions, 0 deletions
diff --git a/private/crt32/misc/i386/longjmp.asm b/private/crt32/misc/i386/longjmp.asm new file mode 100644 index 000000000..ae236afff --- /dev/null +++ b/private/crt32/misc/i386/longjmp.asm @@ -0,0 +1,150 @@ +;*** +;longjmp.asm +; +; Copyright (C) 1994 Microsoft Corporation. All rights reserved. +; +;Purpose: +; Contains setjmp(), longjmp() & raisex() routines; +; split from exsup.asm for granularity purposes. +; +;Notes: +; +;Revision History: +; 01-12-94 PML Split from setjmp.asm, added C9.0 generic EH +; callback for unwind. +; +;******************************************************************************* + +;hnt = -D_WIN32_ -Dsmall32 -Dflat32 -Mx $this; + +;Define small32 and flat32 since these are not defined in the NT build process +small32 equ 1 +flat32 equ 1 + +.xlist +include pversion.inc +?DFDATA = 1 +?NODATA = 1 +include cmacros.mas +include exsup.inc +.list + +BeginDATA + +COMM __setjmpexused:dword + +EndDATA + +assumes DS,DATA +assumes FS,DATA + +BeginCODE +if @Version LT 600 +;this needs to go here to work around a masm5 bug. (emits wrong fixup) +assumes CS,FLAT +endif + +; Following symbols defined in exsup.asm, sehsupp.c +extrn __except_list:near +extrn __global_unwind2:near +extrn __local_unwind2:near +extrn __rt_probe_read4@4:near + +; int +; longjmp ( +; IN jmp_buf env +; IN int val) +; +; Routine Description: +; +; Restore the stack and register environment saved by _setjmp. +; Reloads callee-save registers and stack pointer to that saved in +; the jmp_buf, then returns to the point of the _setjmp call. +; +; If exception unwinding is enabled, also reload the exception state +; from the jmp_buf by doing an unwind (both global and local) back +; to the old state. Do so by checking for a new-format (C9.0) +; jmp_buf, and call the EH longjmp unwinder saved therein if +; found, else assume a C8.0-vintage jmp_buf and SEH. +; +; Arguments: +; +; env - Address of the buffer holding the reload state +; val - Value to return from the _setjmp callsite (if nonzero) +; +; Return Value: +; +; None. longjmp does not return directly, but instead continues +; execution from the point of the _setjmp used to initialize the +; jmp_buf. That call will return the 'val' parameter if nonzero, +; else a one. + +cProc longjmp,<C,PUBLIC> +cBegin + mov ebx, [esp+4] ;get jmp_buf + + ;restore ebp before possible call to local_unwind-er + ; the call to global/local unwind will preserve this (callee save). + mov ebp, [ebx.saved_ebp] ;set up bp +ifdef _NTSDK + cmp __setjmpexused, 0 + je short _lj_no_unwind +endif + mov esi, [ebx.saved_xregistration] + cmp esi, dword ptr fs:__except_list + je short _lj_local_unwind + + push esi + call __global_unwind2 + add esp,4 + +_lj_local_unwind: + cmp esi, 0 + je short _lj_no_unwind + + ; Check if called with old or new format jmp_buf. Look for the + ; version cookie that's only present in the new format. + lea eax, [ebx.version_cookie] + push eax + call __rt_probe_read4@4 + or eax, eax + jz short _lj_old_unwind + mov eax, [ebx.version_cookie] + cmp eax, JMPBUF_COOKIE + jnz short _lj_old_unwind + + ; Called with a new-format jmp_buf. Call unwind function supplied + ; to the jmp_buf at setjmp time. + mov eax, [ebx.unwind_func] + or eax, eax + jz short _lj_no_unwind ;no local unwind necessary + push ebx + call eax + jmp short _lj_no_unwind + + ; Called with an old-format jmp_buf. Duplicate old longjmp behavior, + ; assuming there's a C8.0 SEH node at top. +_lj_old_unwind: + mov eax, [ebx.saved_trylevel] + push eax + push esi + call __local_unwind2 + add esp, 8 + +_lj_no_unwind: + mov edx, ebx + mov ebx, [edx.saved_ebx] ;recover registers... + mov edi, [edx.saved_edi] + mov esi, [edx.saved_esi] + + mov eax, [esp+8] ;load the return value + cmp eax, 1 ;make sure it's not 0 + adc eax, 0 + + mov esp, [edx.saved_esp] ;here, sp gets scorched + add esp, 4 ;punt the (old) return address + jmp [edx.saved_return] ;return +cEnd + +EndCODE +END |