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Diffstat (limited to 'winsup/cygwin/exception.h')
| -rw-r--r-- | winsup/cygwin/exception.h | 178 |
1 files changed, 0 insertions, 178 deletions
diff --git a/winsup/cygwin/exception.h b/winsup/cygwin/exception.h deleted file mode 100644 index 3686bb0b2..000000000 --- a/winsup/cygwin/exception.h +++ /dev/null @@ -1,178 +0,0 @@ -/* exception.h - - Copyright 1996, 1997, 1998, 2000, 2001, 2005, 2010, 2011, 1012, 2013, 2014 - Red Hat, Inc. - -This software is a copyrighted work licensed under the terms of the -Cygwin license. Please consult the file "CYGWIN_LICENSE" for -details. */ - -#pragma once - -#ifndef __x86_64__ -/* Documentation on the innards of 32 bit Windows exception handling (i.e. - from the perspective of a compiler implementor) apparently doesn't exist. - However, the following came from Onno Hovers <onno@stack.urc.tue.nl> - -The first pointer to the chain of handlers is in the thread environment block -at FS:[0]. This chain has the following format: - -typedef struct __EXCEPTION_FRAME -{ - struct __EXCEPTION_FRAME *Prev; /-* pointer to the previous frame *-/ - PEXCEPTION_HANDLER Handler; /-* handler function *-/ -} - -You register an exception handler in your compiler with this simple ASM -sequence: - PUSH _MyExceptionHandler - PUSH FS:[0] - MOV FS:[0],ESP -An exception frame MUST be on the stack! The frame may have more fields and -both Visual C++ and Borland C++ use more fields for themselves. - -When an exception occurs the system calls all handlers starting with the -handler at FS:0, and then the previous etc. until one handler returns -ExceptionContinueExecution, which is 0. If a handler does not want to handle -the exception it should just return ExceptionContinueSearch, which is 1. - -The handler has the following parameters: -ehandler ( - PEXCEPTION_RECORD erecord, - PEXCEPTION_FRAME myframe, - PCONTEXT context, /-* context before and after *-/ - PVOID dispatch) /-* something *-/ - -When a handler wants to handle the exception, it has some alternatives: - --one is to do do something about the exception condition, like emulating -an invalid instruction, mapping memory where there was a page fault, etc. -If the handler wants to have the context of the thread that causes the -exception changed, it should make that change in the context passed to the -handler. - --the second alternative is to call all exception handlers again, indicating -that you want them to clean up. This way all the __finally blocks get -executed. After doing that you change the context passed to the handler so -the code starts executing in the except block. For this purpose you could -call RtlUnwind. This (undocumented) function calls all exception handlers -up to but not including the exception frame passed to it. If NULL is passed -as exception frame RtlUnwind calls all exception handlers and then exits the -process. The parameters to RtlUnwind are: - -RtlUnwind ( - PEXCEPTION_FRAME endframe, - PVOID unusedEip, - PEXCEPTION_RECORD erecord, - DWORD returnEax) - -You should set unusedEip to the address where RtlUnwind should return like -this: - PUSH 0 - PUSH OFFSET ReturnUnwind - PUSH 0 - PUSH 0 - CALL RtlUnwind -ReturnUnwind: - ..... - -If no EXCEPTION_RECORD is passed, RtlUnwind makes a default exception -record. In any case, the ExceptionFlags part of this record has the -EH_UNWINDING (=2), flag set. (and EH_EXIT_UNWIND (=4), when NULL is passed as the end -frame.). - -The handler for a exception as well as a for unwinds may be executed in the -thread causing the exception, but may also be executed in another (special -exception) thread. So it is not wise to make any assumptions about that! - -As an alternative you may consider the SetUnhandledExceptionFilter API -to install your own exception filter. This one is documented. -*/ - -/* The January 1994 MSJ has an article entitled "Clearer, More Comprehensive - Error Processing with Win32 Structured Exception Handling". It goes into - a teensy bit of detail of the innards of exception handling (i.e. what we - have to do). */ - -typedef EXCEPTION_DISPOSITION (exception_handler) (EXCEPTION_RECORD *, - struct _exception_list *, - CONTEXT *, - void *); - -typedef struct _exception_list -{ - struct _exception_list *prev; - exception_handler *handler; -} exception_list; - -extern exception_list *_except_list asm ("%fs:0"); -typedef void *PDISPATCHER_CONTEXT; - -class exception -{ - exception_list el; - exception_list *save; - static EXCEPTION_DISPOSITION handle (EXCEPTION_RECORD *, exception_list *, - CONTEXT *, PDISPATCHER_CONTEXT); -public: - exception () __attribute__ ((always_inline)) - { - /* Install SEH handler. */ - save = _except_list; - el.handler = handle; - el.prev = _except_list; - _except_list = ⪙ - }; - ~exception () __attribute__ ((always_inline)) { _except_list = save; } -}; - -#else /* __x86_64__ */ - -#define exception_list void -typedef struct _DISPATCHER_CONTEXT *PDISPATCHER_CONTEXT; - -class exception -{ - static EXCEPTION_DISPOSITION myfault (EXCEPTION_RECORD *, exception_list *, - CONTEXT *, PDISPATCHER_CONTEXT); - static EXCEPTION_DISPOSITION handle (EXCEPTION_RECORD *, exception_list *, - CONTEXT *, PDISPATCHER_CONTEXT); -public: - exception () __attribute__ ((always_inline)) - { - /* Install SEH handler. */ - asm volatile ("\n\ - 1: \n\ - .seh_handler \ - _ZN9exception6handleEP17_EXCEPTION_RECORDPvP8_CONTEXTP19_DISPATCHER_CONTEXT, \ - @except \n\ - .seh_handlerdata \n\ - .long 1 \n\ - .rva 1b, 2f, 2f, 2f \n\ - .seh_code \n"); - }; - ~exception () __attribute__ ((always_inline)) - { - asm volatile ("\n\ - nop \n\ - 2: \n\ - nop \n"); - } -}; - -#endif /* !__x86_64__ */ - -class cygwin_exception -{ - PUINT_PTR framep; - PCONTEXT ctx; - EXCEPTION_RECORD *e; - HANDLE h; - void dump_exception (); - void open_stackdumpfile (); -public: - cygwin_exception (PUINT_PTR in_framep, PCONTEXT in_ctx = NULL, EXCEPTION_RECORD *in_e = NULL): - framep (in_framep), ctx (in_ctx), e (in_e), h (NULL) {} - void dumpstack (); - PCONTEXT context () const {return ctx;} -}; |