gas/config/obj-coff-seh.h

   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
  81 typedef struct seh_prologue_element
  82 {
  83   int code;
  84   int info;
  85   offsetT off;
  86   symbolS *pc_addr;
  87 } seh_prologue_element;
  88
  89 typedef 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
 132 typedef 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.  */
 140 static void obj_coff_seh_stackalloc (int);
 141 static void obj_coff_seh_setframe (int);
 142 static void obj_coff_seh_endprologue (int);
 143 static void obj_coff_seh_save (int);
 144 static void obj_coff_seh_pushreg (int);
 145 static void obj_coff_seh_pushframe (int);
 146 static void obj_coff_seh_endproc  (int);
 147 static void obj_coff_seh_eh (int);
 148 static void obj_coff_seh_32 (int);
 149 static void obj_coff_seh_proc  (int);
 150 static void obj_coff_seh_handler (int);
 151 static 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