* exception.h: Fold in content of include/exceptions.h.
* include/exceptions.h: Remove.
This commit is contained in:
		| @@ -1,3 +1,8 @@ | ||||
| 2013-10-27  Corinna Vinschen  <corinna@vinschen.de> | ||||
|  | ||||
| 	* exception.h: Fold in content of include/exceptions.h. | ||||
| 	* include/exceptions.h: Remove. | ||||
|  | ||||
| 2013-10-26  Corinna Vinschen  <corinna@vinschen.de> | ||||
|  | ||||
| 	* devices.in (dev_storage): Map /dev/dsp to \Device\Null. | ||||
|   | ||||
| @@ -1,6 +1,7 @@ | ||||
| /* exception.h | ||||
|  | ||||
|    Copyright 2010, 2011, 2012, 2013 Red Hat, Inc. | ||||
|    Copyright 1996, 1997, 1998, 2000, 2001, 2005, 2010, 2011, 1012, 2013 | ||||
|    Red Hat, Inc. | ||||
|  | ||||
| This software is a copyrighted work licensed under the terms of the | ||||
| Cygwin license.  Please consult the file "CYGWIN_LICENSE" for | ||||
| @@ -8,11 +9,102 @@ details. */ | ||||
|  | ||||
| #pragma once | ||||
|  | ||||
| #include <exceptions.h> | ||||
|  | ||||
| #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 int (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"); | ||||
| #endif | ||||
| #endif /* !__x86_64 */ | ||||
|  | ||||
| class exception | ||||
| { | ||||
| @@ -23,7 +115,7 @@ class exception | ||||
|   exception_list el; | ||||
|   exception_list *save; | ||||
|   static int handle (EXCEPTION_RECORD *, exception_list *, CONTEXT *, void *); | ||||
| #endif | ||||
| #endif /* __x86_64__ */ | ||||
| public: | ||||
|   exception () __attribute__ ((always_inline)) | ||||
|   { | ||||
| @@ -43,11 +135,11 @@ public: | ||||
|     el.handler = handle; | ||||
|     el.prev = _except_list; | ||||
|     _except_list = ⪙ | ||||
| #endif | ||||
| #endif /* __x86_64__ */ | ||||
|   }; | ||||
| #ifndef __x86_64__ | ||||
|   ~exception () __attribute__ ((always_inline)) { _except_list = save; } | ||||
| #endif | ||||
| #endif /* !__x86_64__ */ | ||||
| }; | ||||
|  | ||||
| class cygwin_exception | ||||
|   | ||||
| @@ -1,119 +0,0 @@ | ||||
| /* exceptions.h | ||||
|  | ||||
|    Copyright 1996, 1997, 1998, 2000, 2001, 2005, 2013 Red Hat, Inc. | ||||
|  | ||||
| This file is part of Cygwin. | ||||
|  | ||||
| This software is a copyrighted work licensed under the terms of the | ||||
| Cygwin license.  Please consult the file "CYGWIN_LICENSE" for | ||||
| details. */ | ||||
|  | ||||
| #ifndef _EXCEPTIONS_H | ||||
| #define _EXCEPTIONS_H | ||||
|  | ||||
| #ifndef __x86_64__ | ||||
|  | ||||
| #ifdef __cplusplus | ||||
| extern "C" { | ||||
| #endif /* __cplusplus */ | ||||
|  | ||||
| /* Documentation on the innards of exception handling (i.e. from the | ||||
|    perspective of a compiler implementor) apparently doesn't exist.  Sigh. | ||||
|    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 int (exception_handler) (EXCEPTION_RECORD *, struct _exception_list *, | ||||
| 				 CONTEXT *, void *); | ||||
|  | ||||
| typedef struct _exception_list | ||||
| { | ||||
|   struct _exception_list *prev; | ||||
|   exception_handler *handler; | ||||
| } exception_list; | ||||
|  | ||||
| #ifdef __cplusplus | ||||
| }; | ||||
| #endif /* __cplusplus */ | ||||
|  | ||||
| #endif /* __x86_64__ */ | ||||
|  | ||||
| #endif /* _EXCEPTIONS_H */ | ||||
| @@ -11,6 +11,9 @@ What changed: | ||||
|   Right now this excludes console windows on pre Windows 8, as well as almost | ||||
|   all virtual files under /proc. | ||||
|  | ||||
| - The header /usr/include/exceptions.h, containing implementation details for | ||||
|   32 bit Windows' exception handling only, has been removed. | ||||
|  | ||||
|  | ||||
| Bug fixes: | ||||
| ---------- | ||||
|   | ||||
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