1 2 /*--------------------------------------------------------------------*/ 3 /*--- A minimal setjmp/longjmp facility. pub_tool_libcsetjmp.h ---*/ 4 /*--------------------------------------------------------------------*/ 5 6 /* 7 This file is part of Valgrind, a dynamic binary instrumentation 8 framework. 9 10 Copyright (C) 2010-2012 Mozilla Inc 11 12 This program is free software; you can redistribute it and/or 13 modify it under the terms of the GNU General Public License as 14 published by the Free Software Foundation; either version 2 of the 15 License, or (at your option) any later version. 16 17 This program is distributed in the hope that it will be useful, but 18 WITHOUT ANY WARRANTY; without even the implied warranty of 19 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 20 General Public License for more details. 21 22 You should have received a copy of the GNU General Public License 23 along with this program; if not, write to the Free Software 24 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 25 02111-1307, USA. 26 27 The GNU General Public License is contained in the file COPYING. 28 */ 29 30 /* Contributed by Julian Seward <jseward (at) acm.org> */ 31 32 #ifndef __PUB_TOOL_LIBCSETJMP_H 33 #define __PUB_TOOL_LIBCSETJMP_H 34 35 //-------------------------------------------------------------------- 36 // PURPOSE: Provides a minimal setjmp/longjmp facility, that saves/ 37 // restores integer registers, but not necessarily anything more. 38 //-------------------------------------------------------------------- 39 40 41 /* This provides an extremely minimal setjmp/longjmp facility, in 42 which only the host's integer registers are saved/restored. Or at 43 least, that is the minimal guaranteed functionality. 44 45 Until Apr 2011 we used __builtin_setjmp and __builtin_longjmp, but 46 it appears that that is not always correctly implemented. See 47 https://bugs.kde.org/show_bug.cgi?id=259977. So this module wraps 48 those functions up and facilitates replacing them with our own 49 implementations where necessary. 50 */ 51 52 /* --- !!! --- EXTERNAL HEADERS start --- !!! --- */ 53 #include <setjmp.h> 54 /* --- !!! --- EXTERNAL HEADERS end --- !!! --- */ 55 56 57 /* Don't use jmp_buf, __builtin_setjmp or __builtin_longjmp directly. 58 They don't always work reliably. Instead use these macros, which 59 provide the opportunity to supply alternative implementations as 60 necessary. 61 62 Note that the abstraction is done with macros (ick) rather than 63 functions and typedefs, since wrapping __builtin_setjmp up in a 64 second function (eg, VG_(minimal_setjmp)) doesn't seem to work for 65 whatever reason -- returns via a VG_(minimal_longjmp) go wrong. 66 67 VG_MINIMAL_SETJMP stores the current integer register state in the 68 supplied argument, and returns zero. VG_MINIMAL_LONGJMP resumes 69 with the previously saved state, and returns a nonzero, word-sized 70 value. The caller must test all bits of the value in order to make 71 a zero/non-zero determination. 72 */ 73 74 #if defined(VGP_ppc32_linux) 75 76 #define VG_MINIMAL_JMP_BUF(_name) UInt _name [32+1+1] 77 __attribute__((returns_twice)) 78 UWord VG_MINIMAL_SETJMP(VG_MINIMAL_JMP_BUF(_env)); 79 __attribute__((noreturn)) 80 void VG_MINIMAL_LONGJMP(VG_MINIMAL_JMP_BUF(_env)); 81 82 83 #elif defined(VGP_ppc64_linux) 84 85 #define VG_MINIMAL_JMP_BUF(_name) ULong _name [32+1+1] 86 __attribute__((returns_twice)) 87 UWord VG_MINIMAL_SETJMP(VG_MINIMAL_JMP_BUF(_env)); 88 __attribute__((noreturn)) 89 void VG_MINIMAL_LONGJMP(VG_MINIMAL_JMP_BUF(_env)); 90 91 92 #elif defined(VGP_amd64_linux) || defined(VGP_amd64_darwin) 93 94 #define VG_MINIMAL_JMP_BUF(_name) ULong _name [16+1] 95 __attribute__((returns_twice)) 96 UWord VG_MINIMAL_SETJMP(VG_MINIMAL_JMP_BUF(_env)); 97 __attribute__((noreturn)) 98 void VG_MINIMAL_LONGJMP(VG_MINIMAL_JMP_BUF(_env)); 99 100 101 #elif defined(VGP_x86_linux) || defined(VGP_x86_darwin) 102 103 #define VG_MINIMAL_JMP_BUF(_name) UInt _name [8+1] 104 __attribute__((returns_twice)) 105 __attribute__((regparm(1))) // this is critical; don't delete 106 UWord VG_MINIMAL_SETJMP(VG_MINIMAL_JMP_BUF(_env)); 107 __attribute__((noreturn)) 108 __attribute__((regparm(1))) // ditto 109 void VG_MINIMAL_LONGJMP(VG_MINIMAL_JMP_BUF(_env)); 110 111 112 #else 113 114 /* The default implementation. */ 115 #define VG_MINIMAL_JMP_BUF(_name) jmp_buf _name 116 #define VG_MINIMAL_SETJMP(_env) ((UWord)(__builtin_setjmp((_env)))) 117 #define VG_MINIMAL_LONGJMP(_env) __builtin_longjmp((_env),1) 118 119 #endif 120 121 #endif // __PUB_TOOL_LIBCSETJMP_H 122 123 /*--------------------------------------------------------------------*/ 124 /*--- end pub_tool_libcsetjmp.h ---*/ 125 /*--------------------------------------------------------------------*/ 126
