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>[,<handler-data>]]
  49   .seh_eh
  50   .seh_32/.seh_no32
  51   .seh_endproc
  52   .seh_setframe <reg>,<offset>
  53   .seh_stackalloc
  54   .seh_pushreg
  55   .seh_savereg
  56   .seh_savemm
  57   .seh_savexmm
  58   .seh_pushframe
  59   .seh_scope
  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_push, 0}, \
  67         {"seh_savereg", obj_coff_seh_save, 0}, \
  68         {"seh_savemm", obj_coff_seh_save, 1}, \
  69         {"seh_savexmm", obj_coff_seh_save, 2}, \
  70         {"seh_pushframe", obj_coff_seh_push, 1}, \
  71         {"seh_endprologue", obj_coff_seh_endprologue, 0}, \
  72         {"seh_setframe", obj_coff_seh_setframe, 0}, \
  73         {"seh_stackalloc", obj_coff_seh_stack_alloc, 0}, \
  74         {"seh_handler", obj_coff_seh_handler, 0}, \
  75         {"seh_eh", obj_coff_seh_eh, 0}, \
  76         {"seh_32", obj_coff_seh_32, 1}, \
  77         {"seh_no32", obj_coff_seh_32, 0}, \
  78         {"seh_scope", obj_coff_seh_scope, 0},
  79
  80 /* Type definitions.  */
  81
  82 typedef struct seh_prologue_element
  83 {
  84   symbolS *pc_addr;
  85   char *pc_symbol;
  86   int kind;
  87   int reg;
  88   bfd_vma offset;
  89 } seh_prologue_element;
  90
  91 typedef struct seh_scope_elem {
  92   char *begin_addr;
  93   char *end_addr;
  94   char *handler_addr;
  95   char *jump_addr;
  96 } seh_scope_elem;
  97
  98 typedef struct seh_context
  99 {
 100   struct seh_context *next;
 101   /* Was record alread processed.  */
 102   int done;
 103   /* Function name.  */
 104   char *func_name;
 105   /* BeginAddress.  */
 106   char *start_symbol;
 107   symbolS *start_addr;
 108   bfd_vma start_offset;
 109   /* EndAddress.  */
 110   char *end_symbol;
 111   symbolS *end_addr;
 112   bfd_vma end_offset;
 113   /* PrologueEnd.  */
 114   char *endprologue_symbol;
 115   symbolS *endprologue_addr;
 116   bfd_vma endprologue_offset;
 117   /* ExceptionHandler.  */
 118   char *handler_name;
 119   /* ExceptionHandlerData.  */
 120   char *handler_data_name;
 121   int handler_written;
 122   /* WinCE specific data.  */
 123   int use_instruction_32;
 124
 125   /* the bfd to store data within.  */
 126   bfd *abfd;
 127   /* the current section to generate data within.  */
 128   asection *section;
 129   /* Relocations for section.  */
 130   unsigned int count_reloc;
 131   /* Symbols within section.  */
 132   unsigned int count_syms;
 133   /* Iterator for text lable generation.  */
 134   unsigned int tlbl_count;
 135   /* Iterator for xdata lable generation.  */
 136   unsigned int xlbl_count;
 137   /* The name of the first xdata label.  */
 138   char *xdata_first;
 139   /* FIelds used for x64 generation of chained information.  */
 140   char **xdata_names;
 141   char **xdata_pcsyms;
 142   int *xdata_elm_start;
 143   /* Size and offset within current generated xdata section.  */
 144   size_t xdata_sz;
 145   size_t xdata_offset;
 146   /* x64 framereg and frame offset information.  */
 147   int framereg;
 148   bfd_vma frameoff;
 149   /* Information about x64 specific unwind data fields.  */
 150   size_t elems_count;
 151   size_t elems_max;
 152   seh_prologue_element *elems;
 153   size_t scope_max;
 154   size_t scope_count;
 155   seh_scope_elem *scopes;
 156 } seh_context;
 157
 158 typedef enum seh_kind {
 159   seh_kind_unknown = 0,
 160   seh_kind_mips = 1,  /* Used for MIPS and x86 pdata generation.  */
 161   seh_kind_arm = 2,   /* Used for ARM, PPC, SH3, and SH4 pdata (PDATA_EH) generation.  */
 162   seh_kind_x64 = 3    /* Used for IA64 and x64 pdata/xdata generation.  */
 163 } seh_kind;
 164
 165 /* Forward declarations.  */
 166 static void obj_coff_seh_stack_alloc (int);
 167 static void obj_coff_seh_setframe (int);
 168 static void obj_coff_seh_endprologue (int);
 169 static void obj_coff_seh_save  (int);
 170 static void obj_coff_seh_push  (int);
 171 static void obj_coff_seh_endproc  (int);
 172 static void obj_coff_seh_eh (int);
 173 static void obj_coff_seh_32 (int);
 174 static void obj_coff_seh_proc  (int);
 175 static void obj_coff_seh_handler (int);
 176 static void obj_coff_seh_scope (int);
 177 static int seh_read_offset (const char *, bfd_vma *);
 178 static int seh_x64_read_reg (const char *, int, int *);
 179 static void seh_x64_make_prologue_element (int, int, bfd_vma);
 180 static void make_function_entry_pdata (seh_context *c);
 181
 182 #define UNDSEC (asection *) &bfd_und_section
 183
 184 /* Check if x64 UNW_... macros are already defined.  */
 185 #ifndef PEX64_FLAG_NHANDLER
 186 /* We can't include here coff/pe.h header. So we have to copy macros
 187    from coff/pe.h here.  */
 188 #define PEX64_UNWCODE_CODE(VAL) ((VAL) & 0xf)
 189 #define PEX64_UNWCODE_INFO(VAL) (((VAL) >> 4) & 0xf)
 190
 191 /* The unwind info.  */
 192 #define UNW_FLAG_NHANDLER     0
 193 #define UNW_FLAG_EHANDLER     1
 194 #define UNW_FLAG_UHANDLER     2
 195 #define UNW_FLAG_FHANDLER     3
 196 #define UNW_FLAG_CHAININFO    4
 197
 198 #define UNW_FLAG_MASK         0x1f
 199
 200 /* The unwind codes.  */
 201 #define UWOP_PUSH_NONVOL      0
 202 #define UWOP_ALLOC_LARGE      1
 203 #define UWOP_ALLOC_SMALL      2
 204 #define UWOP_SET_FPREG        3
 205 #define UWOP_SAVE_NONVOL      4
 206 #define UWOP_SAVE_NONVOL_FAR  5
 207 #define UWOP_SAVE_XMM         6
 208 #define UWOP_SAVE_XMM_FAR     7
 209 #define UWOP_SAVE_XMM128      8
 210 #define UWOP_SAVE_XMM128_FAR  9
 211 #define UWOP_PUSH_MACHFRAME   10
 212
 213 #define PEX64_UWI_VERSION(VAL)  ((VAL) & 7)
 214 #define PEX64_UWI_FLAGS(VAL)    (((VAL) >> 3) & 0x1f)
 215 #define PEX64_UWI_FRAMEREG(VAL) ((VAL) & 0xf)
 216 #define PEX64_UWI_FRAMEOFF(VAL) (((VAL) >> 4) & 0xf)
 217 #define PEX64_UWI_SIZEOF_UWCODE_ARRAY(VAL) \
 218   ((((VAL) + 1) & ~1) * 2)
 219
 220 #define PEX64_OFFSET_TO_UNWIND_CODE 0x4
 221
 222 #define PEX64_OFFSET_TO_HANDLER_RVA (COUNTOFUNWINDCODES) \
 223   (PEX64_OFFSET_TO_UNWIND_CODE + \
 224    PEX64_UWI_SIZEOF_UWCODE_ARRAY(COUNTOFUNWINDCODES))
 225
 226 #define PEX64_OFFSET_TO_SCOPE_COUNT(COUNTOFUNWINDCODES) \
 227   (PEX64_OFFSET_TO_HANDLER_RVA(COUNTOFUNWINDCODES) + 4)
 228
 229 #define PEX64_SCOPE_ENTRY(COUNTOFUNWINDCODES, IDX) \
 230   (PEX64_OFFSET_TO_SCOPE_COUNT(COUNTOFUNWINDCODES) + \
 231    PEX64_SCOPE_ENTRY_SIZE * (IDX))
 232
 233 #endif
 234