gas/config/obj-coff-seh.h

   1 /* seh pdata/xdata coff object file format
   2    Copyright (C) 2009-2021 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, exception-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   .seh_code
  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_code", obj_coff_seh_code, 0}, \
  78         {"seh_handlerdata", obj_coff_seh_handlerdata, 0},
  79
  80 /* Type definitions.  */
  81
  82 typedef struct seh_prologue_element
  83 {
  84   int code;
  85   int info;
  86   offsetT off;
  87   symbolS *pc_addr;
  88 } seh_prologue_element;
  89
  90 typedef struct seh_context
  91 {
  92   struct seh_context *next;
  93
  94   /* Initial code-segment.  */
  95   segT code_seg;
  96   /* Function name.  */
  97   char *func_name;
  98   /* BeginAddress.  */
  99   symbolS *start_addr;
 100   /* EndAddress.  */
 101   symbolS *end_addr;
 102   /* Unwind data.  */
 103   symbolS *xdata_addr;
 104   /* PrologueEnd.  */
 105   symbolS *endprologue_addr;
 106   /* ExceptionHandler.  */
 107   expressionS handler;
 108   /* ExceptionHandlerData. (arm, mips)  */
 109   expressionS handler_data;
 110
 111   /* ARM .seh_eh directive seen.  */
 112   int handler_written;
 113
 114   /* WinCE specific data.  */
 115   int use_instruction_32;
 116   /* Was record already processed.  */
 117   int done;
 118
 119   /* x64 flags for the xdata header.  */
 120   int handler_flags;
 121   int subsection;
 122
 123   /* x64 framereg and frame offset information.  */
 124   int framereg;
 125   int frameoff;
 126
 127   /* Information about x64 specific unwind data fields.  */
 128   int elems_count;
 129   int elems_max;
 130   seh_prologue_element *elems;
 131 } seh_context;
 132
 133 typedef enum seh_kind {
 134   seh_kind_unknown = 0,
 135   seh_kind_mips = 1,  /* Used for MIPS and x86 pdata generation.  */
 136   seh_kind_arm = 2,   /* Used for ARM, PPC, SH3, and SH4 pdata (PDATA_EH) generation.  */
 137   seh_kind_x64 = 3    /* Used for IA64 and x64 pdata/xdata generation.  */
 138 } seh_kind;
 139
 140 /* Forward declarations.  */
 141 static void obj_coff_seh_stackalloc (int);
 142 static void obj_coff_seh_setframe (int);
 143 static void obj_coff_seh_endprologue (int);
 144 static void obj_coff_seh_save (int);
 145 static void obj_coff_seh_pushreg (int);
 146 static void obj_coff_seh_pushframe (int);
 147 static void obj_coff_seh_endproc  (int);
 148 static void obj_coff_seh_eh (int);
 149 static void obj_coff_seh_32 (int);
 150 static void obj_coff_seh_proc  (int);
 151 static void obj_coff_seh_handler (int);
 152 static void obj_coff_seh_handlerdata (int);
 153 static void obj_coff_seh_code (int);
 154
 155 #define UNDSEC bfd_und_section_ptr
 156
 157 /* Check if x64 UNW_... macros are already defined.  */
 158 #ifndef PEX64_FLAG_NHANDLER
 159 /* We can't include here coff/pe.h header. So we have to copy macros
 160    from coff/pe.h here.  */
 161 #define PEX64_UNWCODE_CODE(VAL) ((VAL) & 0xf)
 162 #define PEX64_UNWCODE_INFO(VAL) (((VAL) >> 4) & 0xf)
 163
 164 /* The unwind info.  */
 165 #define UNW_FLAG_NHANDLER     0
 166 #define UNW_FLAG_EHANDLER     1
 167 #define UNW_FLAG_UHANDLER     2
 168 #define UNW_FLAG_FHANDLER     3
 169 #define UNW_FLAG_CHAININFO    4
 170
 171 #define UNW_FLAG_MASK         0x1f
 172
 173 /* The unwind codes.  */
 174 #define UWOP_PUSH_NONVOL      0
 175 #define UWOP_ALLOC_LARGE      1
 176 #define UWOP_ALLOC_SMALL      2
 177 #define UWOP_SET_FPREG        3
 178 #define UWOP_SAVE_NONVOL      4
 179 #define UWOP_SAVE_NONVOL_FAR  5
 180 #define UWOP_SAVE_XMM         6
 181 #define UWOP_SAVE_XMM_FAR     7
 182 #define UWOP_SAVE_XMM128      8
 183 #define UWOP_SAVE_XMM128_FAR  9
 184 #define UWOP_PUSH_MACHFRAME   10
 185
 186 #define PEX64_UWI_VERSION(VAL)  ((VAL) & 7)
 187 #define PEX64_UWI_FLAGS(VAL)    (((VAL) >> 3) & 0x1f)
 188 #define PEX64_UWI_FRAMEREG(VAL) ((VAL) & 0xf)
 189 #define PEX64_UWI_FRAMEOFF(VAL) (((VAL) >> 4) & 0xf)
 190 #define PEX64_UWI_SIZEOF_UWCODE_ARRAY(VAL) \
 191   ((((VAL) + 1) & ~1) * 2)
 192
 193 #define PEX64_OFFSET_TO_UNWIND_CODE 0x4
 194
 195 #define PEX64_OFFSET_TO_HANDLER_RVA (COUNTOFUNWINDCODES) \
 196   (PEX64_OFFSET_TO_UNWIND_CODE + \
 197    PEX64_UWI_SIZEOF_UWCODE_ARRAY(COUNTOFUNWINDCODES))
 198
 199 #define PEX64_OFFSET_TO_SCOPE_COUNT(COUNTOFUNWINDCODES) \
 200   (PEX64_OFFSET_TO_HANDLER_RVA(COUNTOFUNWINDCODES) + 4)
 201
 202 #define PEX64_SCOPE_ENTRY(COUNTOFUNWINDCODES, IDX) \
 203   (PEX64_OFFSET_TO_SCOPE_COUNT(COUNTOFUNWINDCODES) + \
 204    PEX64_SCOPE_ENTRY_SIZE * (IDX))
 205
 206 #endif