Mercurial > hg > CbC > CbC_gcc
annotate gcc/config/i386/w32-unwind.h @ 67:f6334be47118
update gcc from gcc-4.6-20100522 to gcc-4.6-20110318
| author | nobuyasu <dimolto@cr.ie.u-ryukyu.ac.jp> |
|---|---|
| date | Tue, 22 Mar 2011 17:18:12 +0900 |
| parents | a06113de4d67 |
| children |
| rev | line source |
|---|---|
|
67
f6334be47118
update gcc from gcc-4.6-20100522 to gcc-4.6-20110318
nobuyasu <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
1 /* Definitions for Dwarf2 EH unwind support for Windows32 targets |
|
f6334be47118
update gcc from gcc-4.6-20100522 to gcc-4.6-20110318
nobuyasu <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
2 Copyright (C) 2007, 2009, 2010 |
| 0 | 3 Free Software Foundation, Inc. |
| 4 Contributed by Pascal Obry <obry@adacore.com> | |
| 5 | |
| 6 This file is part of GCC. | |
| 7 | |
| 8 GCC is free software; you can redistribute it and/or modify it under | |
| 9 the terms of the GNU General Public License as published by the Free | |
| 10 Software Foundation; either version 3, or (at your option) any later | |
| 11 version. | |
| 12 | |
| 13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
| 14 WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
| 15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
| 16 for more details. | |
| 17 | |
| 18 Under Section 7 of GPL version 3, you are granted additional | |
| 19 permissions described in the GCC Runtime Library Exception, version | |
| 20 3.1, as published by the Free Software Foundation. | |
| 21 | |
| 22 You should have received a copy of the GNU General Public License and | |
| 23 a copy of the GCC Runtime Library Exception along with this program; | |
| 24 see the files COPYING3 and COPYING.RUNTIME respectively. If not, see | |
| 25 <http://www.gnu.org/licenses/>. */ | |
| 26 | |
| 27 | |
| 28 /* This file implements the md_fallback_frame_state_for routine for | |
| 29 Windows, triggered when the GCC table based unwinding process hits a | |
| 30 frame for which no unwind info has been registered. This typically | |
| 31 occurs when raising an exception from a signal handler, because the | |
| 32 handler is actually called from the OS kernel. | |
| 33 | |
| 34 The basic idea is to detect that we are indeed trying to unwind past a | |
| 35 signal handler and to fill out the GCC internal unwinding structures for | |
| 36 the OS kernel frame as if it had been directly called from the | |
| 37 interrupted context. | |
| 38 | |
| 39 This is all assuming that the code to set the handler asked the kernel | |
| 40 to pass a pointer to such context information. | |
| 41 | |
| 42 There is three main parts. | |
| 43 | |
| 44 1) The first thing to do is to check if we are in a signal context. If | |
| 45 not we can just return as there is nothing to do. We are probably on | |
| 46 some foreign code for which no unwind frame can be found. If this is | |
| 47 a call from the Windows signal handler, then: | |
| 48 | |
| 49 2) We must get the signal context information. | |
| 50 | |
| 51 * With the standard exception filter: | |
| 52 | |
| 53 This is on Windows pointed to by an EXCEPTION_POINTERS. We know that | |
| 54 the signal handle will call an UnhandledExceptionFilter with this | |
| 55 parameter. The spec for this routine is: | |
| 56 | |
| 57 LONG WINAPI UnhandledExceptionFilter(struct _EXCEPTION_POINTERS*); | |
| 58 | |
| 59 So the pointer to struct _EXCEPTION_POINTERS must be somewhere on the | |
| 60 stack. | |
| 61 | |
| 62 This was found experimentally to always be at offset 0 of the context | |
| 63 frame in all cases handled by this implementation. | |
| 64 | |
| 65 * With the SEH exception handler: | |
| 66 | |
| 67 In this case the signal context is directly on the stack as the SEH | |
| 68 exception handler has the following prototype: | |
| 69 | |
| 70 DWORD | |
| 71 SEH_error_handler (PEXCEPTION_RECORD ExceptionRecord, | |
| 72 PVOID EstablisherFrame, | |
| 73 PCONTEXT ContextRecord, | |
| 74 PVOID DispatcherContext) | |
| 75 | |
| 76 This was found experimentally to always be at offset 56 of the | |
| 77 context frame in all cases handled by this implementation. | |
| 78 | |
| 79 3) When we have the signal context we just have to save some registers | |
| 80 and set the return address based on the program counter (Eip). | |
| 81 | |
| 82 Note that this implementation follows closely the same principles as the | |
| 83 GNU/Linux and OSF ones. */ | |
| 84 | |
| 85 #define WIN32_MEAN_AND_LEAN | |
| 86 #include <windows.h> | |
| 87 /* Patterns found experimentally to be on a Windows signal handler */ | |
| 88 | |
| 89 /* In a standard exception filter */ | |
| 90 | |
| 91 #define SIG_PAT1 \ | |
| 92 (pc_[-2] == 0xff && pc_[-1] == 0xd0 /* call %eax */ \ | |
| 93 && pc_[0] == 0x83 && pc_[1] == 0xf8) /* cmp 0xdepl,%eax */ | |
| 94 | |
| 95 #define SIG_PAT2 \ | |
| 96 (pc_[-5] == 0xe8 && pc_[-4] == 0x68 /* call (depl16) */ \ | |
| 97 && pc_[0] == 0xc3) /* ret */ | |
| 98 | |
| 99 /* In a Win32 SEH handler */ | |
| 100 | |
| 101 #define SIG_SEH1 \ | |
| 102 (pc_[-5] == 0xe8 /* call addr */ \ | |
| 103 && pc_[0] == 0x83 && pc_[1] == 0xc4 /* add 0xval,%esp */ \ | |
| 104 && pc_[3] == 0xb8) /* mov 0xval,%eax */ | |
| 105 | |
| 106 #define SIG_SEH2 \ | |
| 107 (pc_[-5] == 0x8b && pc_[-4] == 0x4d /* mov depl(%ebp),%ecx */ \ | |
| 108 && pc_[0] == 0x64 && pc_[1] == 0x8b) /* mov %fs:(0),<reg> */ \ | |
| 109 | |
| 110 /* In the GCC alloca (stack probing) */ | |
| 111 | |
| 112 #define SIG_ALLOCA \ | |
| 113 (pc_[-1] == 0x83 /* orl $0x0,(%ecx) */ \ | |
| 114 && pc_[0] == 0x9 && pc_[1] == 0 \ | |
| 115 && pc_[2] == 0x2d && pc_[3] == 0 /* subl $0x1000,%eax */ \ | |
| 116 && pc_[4] == 0x10 && pc_[5] == 0) | |
| 117 | |
| 118 | |
| 119 #define MD_FALLBACK_FRAME_STATE_FOR i386_w32_fallback_frame_state | |
| 120 | |
| 121 static _Unwind_Reason_Code | |
| 122 i386_w32_fallback_frame_state (struct _Unwind_Context *context, | |
| 123 _Unwind_FrameState *fs) | |
| 124 | |
| 125 { | |
| 126 void * ctx_ra_ = (void *)(context->ra); /* return address */ | |
| 127 void * ctx_cfa_ = (void *)(context->cfa); /* context frame address */ | |
| 128 unsigned char * pc_ = (unsigned char *) ctx_ra_; | |
| 129 | |
| 130 /* In the test below we look for two specific patterns found | |
| 131 experimentally to be in the Windows signal handler. */ | |
| 132 if (SIG_PAT1 || SIG_PAT2 || SIG_SEH1 || SIG_SEH2) | |
| 133 { | |
| 134 PEXCEPTION_POINTERS weinfo_; | |
| 135 PCONTEXT proc_ctx_; | |
| 136 long new_cfa_; | |
| 137 | |
| 138 if (SIG_SEH1) | |
| 139 proc_ctx_ = (PCONTEXT) (*(int*)(ctx_cfa_ + 56)); | |
| 140 else if (SIG_SEH2) | |
| 141 proc_ctx_ = (PCONTEXT) (*(int*)(ctx_cfa_ + 8)); | |
| 142 else | |
| 143 { | |
| 144 weinfo_ = (PEXCEPTION_POINTERS) (*(int*)ctx_cfa_); | |
| 145 proc_ctx_ = weinfo_->ContextRecord; | |
| 146 } | |
| 147 | |
| 148 /* The new context frame address is the stack pointer. */ | |
| 149 new_cfa_ = proc_ctx_->Esp; | |
| 150 fs->regs.cfa_how = CFA_REG_OFFSET; | |
| 151 fs->regs.cfa_reg = __builtin_dwarf_sp_column(); | |
| 152 fs->regs.cfa_offset = new_cfa_ - (long) ctx_cfa_; | |
| 153 | |
|
67
f6334be47118
update gcc from gcc-4.6-20100522 to gcc-4.6-20110318
nobuyasu <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
154 /* Restore registers. */ |
| 0 | 155 fs->regs.reg[0].how = REG_SAVED_OFFSET; |
| 156 fs->regs.reg[0].loc.offset = (long)&proc_ctx_->Eax - new_cfa_; | |
| 157 fs->regs.reg[3].how = REG_SAVED_OFFSET; | |
| 158 fs->regs.reg[3].loc.offset = (long)&proc_ctx_->Ebx - new_cfa_; | |
| 159 fs->regs.reg[1].how = REG_SAVED_OFFSET; | |
| 160 fs->regs.reg[1].loc.offset = (long)&proc_ctx_->Ecx - new_cfa_; | |
| 161 fs->regs.reg[2].how = REG_SAVED_OFFSET; | |
| 162 fs->regs.reg[2].loc.offset = (long)&proc_ctx_->Edx - new_cfa_; | |
| 163 fs->regs.reg[6].how = REG_SAVED_OFFSET; | |
| 164 fs->regs.reg[6].loc.offset = (long)&proc_ctx_->Esi - new_cfa_; | |
| 165 fs->regs.reg[7].how = REG_SAVED_OFFSET; | |
| 166 fs->regs.reg[7].loc.offset = (long)&proc_ctx_->Edi - new_cfa_; | |
|
67
f6334be47118
update gcc from gcc-4.6-20100522 to gcc-4.6-20110318
nobuyasu <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
167 fs->regs.reg[5].how = REG_SAVED_OFFSET; |
|
f6334be47118
update gcc from gcc-4.6-20100522 to gcc-4.6-20110318
nobuyasu <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
168 fs->regs.reg[5].loc.offset = (long)&proc_ctx_->Ebp - new_cfa_; |
|
f6334be47118
update gcc from gcc-4.6-20100522 to gcc-4.6-20110318
nobuyasu <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
169 fs->regs.reg[8].how = REG_SAVED_OFFSET; |
|
f6334be47118
update gcc from gcc-4.6-20100522 to gcc-4.6-20110318
nobuyasu <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
170 fs->regs.reg[8].loc.offset = (long)&proc_ctx_->Eip - new_cfa_; |
|
f6334be47118
update gcc from gcc-4.6-20100522 to gcc-4.6-20110318
nobuyasu <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
171 fs->retaddr_column = 8; |
|
f6334be47118
update gcc from gcc-4.6-20100522 to gcc-4.6-20110318
nobuyasu <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
172 fs->signal_frame = 1; |
| 0 | 173 |
| 174 return _URC_NO_REASON; | |
| 175 } | |
| 176 | |
| 177 /* Unwinding through _alloca, propagating from a trap triggered by | |
| 178 one of it's probes prior to the real SP adjustment. The only | |
| 179 operations of interest performed is "pushl %ecx", followed by | |
| 180 ecx clobbering. */ | |
| 181 else if (SIG_ALLOCA) | |
| 182 { | |
| 183 /* Only one push between entry in _alloca and the probe trap. */ | |
| 184 long new_cfa_ = (long) ctx_cfa_ + 4; | |
| 185 | |
| 186 fs->regs.cfa_how = CFA_REG_OFFSET; | |
| 187 fs->regs.cfa_reg = __builtin_dwarf_sp_column(); | |
| 188 fs->regs.cfa_offset = new_cfa_ - (long) ctx_cfa_; | |
| 189 | |
| 190 /* The saved value of %ecx is at CFA - 4 */ | |
| 191 fs->regs.reg[1].how = REG_SAVED_OFFSET; | |
| 192 fs->regs.reg[1].loc.offset = -4; | |
| 193 | |
| 194 /* and what is stored at the CFA is the return address. */ | |
| 195 fs->retaddr_column = 8; | |
| 196 fs->regs.reg[8].how = REG_SAVED_OFFSET; | |
| 197 fs->regs.reg[8].loc.offset = 0; | |
|
67
f6334be47118
update gcc from gcc-4.6-20100522 to gcc-4.6-20110318
nobuyasu <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
198 fs->signal_frame = 1; |
|
f6334be47118
update gcc from gcc-4.6-20100522 to gcc-4.6-20110318
nobuyasu <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
199 |
| 0 | 200 return _URC_NO_REASON; |
| 201 } | |
| 202 else | |
| 203 return _URC_END_OF_STACK; | |
| 204 } |