1/* seh pdata/xdata coff object file format 2 Copyright 2009 3 Free Software Foundation, Inc. 4 5 This file is part of GAS. 6 7 GAS is free software; you can redistribute it and/or modify 8 it under the terms of the GNU General Public License as published by 9 the Free Software Foundation; either version 3, or (at your option) 10 any later version. 11 12 GAS is distributed in the hope that it will be useful, 13 but WITHOUT ANY WARRANTY; without even the implied warranty of 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 GNU General Public License for more details. 16 17 You should have received a copy of the GNU General Public License 18 along with GAS; see the file COPYING. If not, write to the Free 19 Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA 20 02110-1301, USA. */ 21 22/* Short overview: 23 There are at the moment three different function entry formats preset. 24 The first is the MIPS one. The second version 25 is for ARM, PPC, SH3, and SH4 mainly for Windows CE. 26 The third is the IA64 and x64 version. Note, the IA64 isn't implemented yet, 27 but to find information about it, please see specification about IA64 on 28 http://download.intel.com/design/Itanium/Downloads/245358.pdf file. 29 30 The first version has just entries in the pdata section: BeginAddress, 31 EndAddress, ExceptionHandler, HandlerData, and PrologueEndAddress. Each 32 value is a pointer to the corresponding data and has size of 4 bytes. 33 34 The second variant has the following entries in the pdata section. 35 BeginAddress, PrologueLength (8 bits), EndAddress (22 bits), 36 Use-32-bit-instruction (1 bit), and Exception-Handler-Exists (1 bit). 37 If the FunctionLength is zero, or the Exception-Handler-Exists bit 38 is true, a PDATA_EH block is placed directly before function entry. 39 40 The third version has a function entry block of BeginAddress (RVA), 41 EndAddress (RVA), and UnwindData (RVA). The description of the 42 prologue, excepetion-handler, and additional SEH data is stored 43 within the UNWIND_DATA field in the xdata section. 44 45 The pseudos: 46 .seh_proc <fct_name> 47 .seh_endprologue 48 .seh_handler <handler>[,@unwind][,@except] (x64) 49 .seh_handler <handler>[,<handler_data>] (others) 50 .seh_handlerdata 51 .seh_eh 52 .seh_32/.seh_no32 53 .seh_endproc 54 .seh_setframe <reg>,<offset> 55 .seh_stackalloc 56 .seh_pushreg 57 .seh_savereg 58 .seh_savexmm 59 .seh_pushframe 60*/ 61 62/* architecture specific pdata/xdata handling. */ 63#define SEH_CMDS \ 64 {"seh_proc", obj_coff_seh_proc, 0}, \ 65 {"seh_endproc", obj_coff_seh_endproc, 0}, \ 66 {"seh_pushreg", obj_coff_seh_pushreg, 0}, \ 67 {"seh_savereg", obj_coff_seh_save, 1}, \ 68 {"seh_savexmm", obj_coff_seh_save, 2}, \ 69 {"seh_pushframe", obj_coff_seh_pushframe, 0}, \ 70 {"seh_endprologue", obj_coff_seh_endprologue, 0}, \ 71 {"seh_setframe", obj_coff_seh_setframe, 0}, \ 72 {"seh_stackalloc", obj_coff_seh_stackalloc, 0}, \ 73 {"seh_eh", obj_coff_seh_eh, 0}, \ 74 {"seh_32", obj_coff_seh_32, 1}, \ 75 {"seh_no32", obj_coff_seh_32, 0}, \ 76 {"seh_handler", obj_coff_seh_handler, 0}, \ 77 {"seh_handlerdata", obj_coff_seh_handlerdata, 0}, 78 79/* Type definitions. */ 80 81typedef struct seh_prologue_element 82{ 83 int code; 84 int info; 85 offsetT off; 86 symbolS *pc_addr; 87} seh_prologue_element; 88 89typedef struct seh_context 90{ 91 struct seh_context *next; 92 93 /* Initial code-segment. */ 94 segT code_seg; 95 /* Function name. */ 96 char *func_name; 97 /* BeginAddress. */ 98 symbolS *start_addr; 99 /* EndAddress. */ 100 symbolS *end_addr; 101 /* Unwind data. */ 102 symbolS *xdata_addr; 103 /* PrologueEnd. */ 104 symbolS *endprologue_addr; 105 /* ExceptionHandler. */ 106 expressionS handler; 107 /* ExceptionHandlerData. (arm, mips) */ 108 expressionS handler_data; 109 110 /* ARM .seh_eh directive seen. */ 111 int handler_written; 112 113 /* WinCE specific data. */ 114 int use_instruction_32; 115 /* Was record already processed. */ 116 int done; 117 118 /* x64 flags for the xdata header. */ 119 int handler_flags; 120 int subsection; 121 122 /* x64 framereg and frame offset information. */ 123 int framereg; 124 int frameoff; 125 126 /* Information about x64 specific unwind data fields. */ 127 int elems_count; 128 int elems_max; 129 seh_prologue_element *elems; 130} seh_context; 131 132typedef enum seh_kind { 133 seh_kind_unknown = 0, 134 seh_kind_mips = 1, /* Used for MIPS and x86 pdata generation. */ 135 seh_kind_arm = 2, /* Used for ARM, PPC, SH3, and SH4 pdata (PDATA_EH) generation. */ 136 seh_kind_x64 = 3 /* Used for IA64 and x64 pdata/xdata generation. */ 137} seh_kind; 138 139/* Forward declarations. */ 140static void obj_coff_seh_stackalloc (int); 141static void obj_coff_seh_setframe (int); 142static void obj_coff_seh_endprologue (int); 143static void obj_coff_seh_save (int); 144static void obj_coff_seh_pushreg (int); 145static void obj_coff_seh_pushframe (int); 146static void obj_coff_seh_endproc (int); 147static void obj_coff_seh_eh (int); 148static void obj_coff_seh_32 (int); 149static void obj_coff_seh_proc (int); 150static void obj_coff_seh_handler (int); 151static void obj_coff_seh_handlerdata (int); 152 153#define UNDSEC (asection *) &bfd_und_section 154 155/* Check if x64 UNW_... macros are already defined. */ 156#ifndef PEX64_FLAG_NHANDLER 157/* We can't include here coff/pe.h header. So we have to copy macros 158 from coff/pe.h here. */ 159#define PEX64_UNWCODE_CODE(VAL) ((VAL) & 0xf) 160#define PEX64_UNWCODE_INFO(VAL) (((VAL) >> 4) & 0xf) 161 162/* The unwind info. */ 163#define UNW_FLAG_NHANDLER 0 164#define UNW_FLAG_EHANDLER 1 165#define UNW_FLAG_UHANDLER 2 166#define UNW_FLAG_FHANDLER 3 167#define UNW_FLAG_CHAININFO 4 168 169#define UNW_FLAG_MASK 0x1f 170 171/* The unwind codes. */ 172#define UWOP_PUSH_NONVOL 0 173#define UWOP_ALLOC_LARGE 1 174#define UWOP_ALLOC_SMALL 2 175#define UWOP_SET_FPREG 3 176#define UWOP_SAVE_NONVOL 4 177#define UWOP_SAVE_NONVOL_FAR 5 178#define UWOP_SAVE_XMM 6 179#define UWOP_SAVE_XMM_FAR 7 180#define UWOP_SAVE_XMM128 8 181#define UWOP_SAVE_XMM128_FAR 9 182#define UWOP_PUSH_MACHFRAME 10 183 184#define PEX64_UWI_VERSION(VAL) ((VAL) & 7) 185#define PEX64_UWI_FLAGS(VAL) (((VAL) >> 3) & 0x1f) 186#define PEX64_UWI_FRAMEREG(VAL) ((VAL) & 0xf) 187#define PEX64_UWI_FRAMEOFF(VAL) (((VAL) >> 4) & 0xf) 188#define PEX64_UWI_SIZEOF_UWCODE_ARRAY(VAL) \ 189 ((((VAL) + 1) & ~1) * 2) 190 191#define PEX64_OFFSET_TO_UNWIND_CODE 0x4 192 193#define PEX64_OFFSET_TO_HANDLER_RVA (COUNTOFUNWINDCODES) \ 194 (PEX64_OFFSET_TO_UNWIND_CODE + \ 195 PEX64_UWI_SIZEOF_UWCODE_ARRAY(COUNTOFUNWINDCODES)) 196 197#define PEX64_OFFSET_TO_SCOPE_COUNT(COUNTOFUNWINDCODES) \ 198 (PEX64_OFFSET_TO_HANDLER_RVA(COUNTOFUNWINDCODES) + 4) 199 200#define PEX64_SCOPE_ENTRY(COUNTOFUNWINDCODES, IDX) \ 201 (PEX64_OFFSET_TO_SCOPE_COUNT(COUNTOFUNWINDCODES) + \ 202 PEX64_SCOPE_ENTRY_SIZE * (IDX)) 203 204#endif 205 206