gas/config/obj-coff-seh.h

   1 /* seh pdata/xdata coff object file format
   2    Copyright (C) 2009-2014 Free Software Foundation, Inc.
   3
   4    This file is part of GAS.
   5
   6    GAS is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3, or (at your option)
   9    any later version.
  10
  11    GAS is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with GAS; see the file COPYING.  If not, write to the Free
  18    Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
  19    02110-1301, USA.  */
  20
  21 /* Short overview:
  22   There are at the moment three different function entry formats preset.
  23   The first is the MIPS one. The second version
  24   is for ARM, PPC, SH3, and SH4 mainly for Windows CE.
  25   The third is the IA64 and x64 version. Note, the IA64 isn't implemented yet,
  26   but to find information about it, please see specification about IA64 on
  27   http://download.intel.com/design/Itanium/Downloads/245358.pdf file.
  28
  29   The first version has just entries in the pdata section: BeginAddress,
  30   EndAddress, ExceptionHandler, HandlerData, and PrologueEndAddress. Each
  31   value is a pointer to the corresponding data and has size of 4 bytes.
  32
  33   The second variant has the following entries in the pdata section.
  34   BeginAddress, PrologueLength (8 bits), EndAddress (22 bits),
  35   Use-32-bit-instruction (1 bit), and Exception-Handler-Exists (1 bit).
  36   If the FunctionLength is zero, or the Exception-Handler-Exists bit
  37   is true, a PDATA_EH block is placed directly before function entry.
  38
  39   The third version has a function entry block of BeginAddress (RVA),
  40   EndAddress (RVA), and UnwindData (RVA). The description of the
  41   prologue, excepetion-handler, and additional SEH data is stored
  42   within the UNWIND_DATA field in the xdata section.
  43
  44   The pseudos:
  45   .seh_proc <fct_name>
  46   .seh_endprologue
  47   .seh_handler <handler>[,@unwind][,@except]    (x64)
  48   .seh_handler <handler>[,<handler_data>]       (others)
  49   .seh_handlerdata
  50   .seh_eh
  51   .seh_32/.seh_no32
  52   .seh_endproc
  53   .seh_setframe <reg>,<offset>
  54   .seh_stackalloc
  55   .seh_pushreg
  56   .seh_savereg
  57   .seh_savexmm
  58   .seh_pushframe
  59 */
  60
  61 /* architecture specific pdata/xdata handling.  */
  62 #define SEH_CMDS \
  63         {"seh_proc", obj_coff_seh_proc, 0}, \
  64         {"seh_endproc", obj_coff_seh_endproc, 0}, \
  65         {"seh_pushreg", obj_coff_seh_pushreg, 0}, \
  66         {"seh_savereg", obj_coff_seh_save, 1}, \
  67         {"seh_savexmm", obj_coff_seh_save, 2}, \
  68         {"seh_pushframe", obj_coff_seh_pushframe, 0}, \
  69         {"seh_endprologue", obj_coff_seh_endprologue, 0}, \
  70         {"seh_setframe", obj_coff_seh_setframe, 0}, \
  71         {"seh_stackalloc", obj_coff_seh_stackalloc, 0}, \
  72         {"seh_eh", obj_coff_seh_eh, 0}, \
  73         {"seh_32", obj_coff_seh_32, 1}, \
  74         {"seh_no32", obj_coff_seh_32, 0}, \
  75         {"seh_handler", obj_coff_seh_handler, 0}, \
  76         {"seh_handlerdata", obj_coff_seh_handlerdata, 0},
  77
  78 /* Type definitions.  */
  79
  80 typedef struct seh_prologue_element
  81 {
  82   int code;
  83   int info;
  84   offsetT off;
  85   symbolS *pc_addr;
  86 } seh_prologue_element;
  87
  88 typedef struct seh_context
  89 {
  90   struct seh_context *next;
  91
  92   /* Initial code-segment.  */
  93   segT code_seg;
  94   /* Function name.  */
  95   char *func_name;
  96   /* BeginAddress.  */
  97   symbolS *start_addr;
  98   /* EndAddress.  */
  99   symbolS *end_addr;
 100   /* Unwind data.  */
 101   symbolS *xdata_addr;
 102   /* PrologueEnd.  */
 103   symbolS *endprologue_addr;
 104   /* ExceptionHandler.  */
 105   expressionS handler;
 106   /* ExceptionHandlerData. (arm, mips)  */
 107   expressionS handler_data;
 108
 109   /* ARM .seh_eh directive seen.  */
 110   int handler_written;
 111
 112   /* WinCE specific data.  */
 113   int use_instruction_32;
 114   /* Was record already processed.  */
 115   int done;
 116
 117   /* x64 flags for the xdata header.  */
 118   int handler_flags;
 119   int subsection;
 120
 121   /* x64 framereg and frame offset information.  */
 122   int framereg;
 123   int frameoff;
 124
 125   /* Information about x64 specific unwind data fields.  */
 126   int elems_count;
 127   int elems_max;
 128   seh_prologue_element *elems;
 129 } seh_context;
 130
 131 typedef enum seh_kind {
 132   seh_kind_unknown = 0,
 133   seh_kind_mips = 1,  /* Used for MIPS and x86 pdata generation.  */
 134   seh_kind_arm = 2,   /* Used for ARM, PPC, SH3, and SH4 pdata (PDATA_EH) generation.  */
 135   seh_kind_x64 = 3    /* Used for IA64 and x64 pdata/xdata generation.  */
 136 } seh_kind;
 137
 138 /* Forward declarations.  */
 139 static void obj_coff_seh_stackalloc (int);
 140 static void obj_coff_seh_setframe (int);
 141 static void obj_coff_seh_endprologue (int);
 142 static void obj_coff_seh_save (int);
 143 static void obj_coff_seh_pushreg (int);
 144 static void obj_coff_seh_pushframe (int);
 145 static void obj_coff_seh_endproc  (int);
 146 static void obj_coff_seh_eh (int);
 147 static void obj_coff_seh_32 (int);
 148 static void obj_coff_seh_proc  (int);
 149 static void obj_coff_seh_handler (int);
 150 static void obj_coff_seh_handlerdata (int);
 151
 152 #define UNDSEC bfd_und_section_ptr
 153
 154 /* Check if x64 UNW_... macros are already defined.  */
 155 #ifndef PEX64_FLAG_NHANDLER
 156 /* We can't include here coff/pe.h header. So we have to copy macros
 157    from coff/pe.h here.  */
 158 #define PEX64_UNWCODE_CODE(VAL) ((VAL) & 0xf)
 159 #define PEX64_UNWCODE_INFO(VAL) (((VAL) >> 4) & 0xf)
 160
 161 /* The unwind info.  */
 162 #define UNW_FLAG_NHANDLER     0
 163 #define UNW_FLAG_EHANDLER     1
 164 #define UNW_FLAG_UHANDLER     2
 165 #define UNW_FLAG_FHANDLER     3
 166 #define UNW_FLAG_CHAININFO    4
 167
 168 #define UNW_FLAG_MASK         0x1f
 169
 170 /* The unwind codes.  */
 171 #define UWOP_PUSH_NONVOL      0
 172 #define UWOP_ALLOC_LARGE      1
 173 #define UWOP_ALLOC_SMALL      2
 174 #define UWOP_SET_FPREG        3
 175 #define UWOP_SAVE_NONVOL      4
 176 #define UWOP_SAVE_NONVOL_FAR  5
 177 #define UWOP_SAVE_XMM         6
 178 #define UWOP_SAVE_XMM_FAR     7
 179 #define UWOP_SAVE_XMM128      8
 180 #define UWOP_SAVE_XMM128_FAR  9
 181 #define UWOP_PUSH_MACHFRAME   10
 182
 183 #define PEX64_UWI_VERSION(VAL)  ((VAL) & 7)
 184 #define PEX64_UWI_FLAGS(VAL)    (((VAL) >> 3) & 0x1f)
 185 #define PEX64_UWI_FRAMEREG(VAL) ((VAL) & 0xf)
 186 #define PEX64_UWI_FRAMEOFF(VAL) (((VAL) >> 4) & 0xf)
 187 #define PEX64_UWI_SIZEOF_UWCODE_ARRAY(VAL) \
 188   ((((VAL) + 1) & ~1) * 2)
 189
 190 #define PEX64_OFFSET_TO_UNWIND_CODE 0x4
 191
 192 #define PEX64_OFFSET_TO_HANDLER_RVA (COUNTOFUNWINDCODES) \
 193   (PEX64_OFFSET_TO_UNWIND_CODE + \
 194    PEX64_UWI_SIZEOF_UWCODE_ARRAY(COUNTOFUNWINDCODES))
 195
 196 #define PEX64_OFFSET_TO_SCOPE_COUNT(COUNTOFUNWINDCODES) \
 197   (PEX64_OFFSET_TO_HANDLER_RVA(COUNTOFUNWINDCODES) + 4)
 198
 199 #define PEX64_SCOPE_ENTRY(COUNTOFUNWINDCODES, IDX) \
 200   (PEX64_OFFSET_TO_SCOPE_COUNT(COUNTOFUNWINDCODES) + \
 201    PEX64_SCOPE_ENTRY_SIZE * (IDX))
 202
 203 #endif
 204