| 1 | /* Scheme interface to architecture. |
| 2 | |
| 3 | Copyright (C) 2014-2017 Free Software Foundation, Inc. |
| 4 | |
| 5 | This file is part of GDB. |
| 6 | |
| 7 | This program 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 of the License, or |
| 10 | (at your option) any later version. |
| 11 | |
| 12 | This program 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 this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 19 | |
| 20 | /* See README file in this directory for implementation notes, coding |
| 21 | conventions, et.al. */ |
| 22 | |
| 23 | #include "defs.h" |
| 24 | #include "arch-utils.h" |
| 25 | #include "disasm.h" |
| 26 | #include "dis-asm.h" |
| 27 | #include "gdbarch.h" |
| 28 | #include "gdbcore.h" /* Why is memory_error here? */ |
| 29 | #include "guile-internal.h" |
| 30 | |
| 31 | static SCM port_keyword; |
| 32 | static SCM offset_keyword; |
| 33 | static SCM size_keyword; |
| 34 | static SCM count_keyword; |
| 35 | |
| 36 | static SCM address_symbol; |
| 37 | static SCM asm_symbol; |
| 38 | static SCM length_symbol; |
| 39 | |
| 40 | class gdbscm_disassembler : public gdb_disassembler |
| 41 | { |
| 42 | public: |
| 43 | gdbscm_disassembler (struct gdbarch *gdbarch, |
| 44 | struct ui_file *stream, |
| 45 | SCM port, ULONGEST offset); |
| 46 | |
| 47 | SCM port; |
| 48 | /* The offset of the address of the first instruction in PORT. */ |
| 49 | ULONGEST offset; |
| 50 | }; |
| 51 | |
| 52 | /* Struct used to pass data from gdbscm_disasm_read_memory to |
| 53 | gdbscm_disasm_read_memory_worker. */ |
| 54 | |
| 55 | struct gdbscm_disasm_read_data |
| 56 | { |
| 57 | bfd_vma memaddr; |
| 58 | bfd_byte *myaddr; |
| 59 | unsigned int length; |
| 60 | gdbscm_disassembler *dinfo; |
| 61 | }; |
| 62 | \f |
| 63 | /* Subroutine of gdbscm_arch_disassemble to simplify it. |
| 64 | Return the result for one instruction. */ |
| 65 | |
| 66 | static SCM |
| 67 | dascm_make_insn (CORE_ADDR pc, const char *assembly, int insn_len) |
| 68 | { |
| 69 | return scm_list_3 (scm_cons (address_symbol, |
| 70 | gdbscm_scm_from_ulongest (pc)), |
| 71 | scm_cons (asm_symbol, |
| 72 | gdbscm_scm_from_c_string (assembly)), |
| 73 | scm_cons (length_symbol, |
| 74 | scm_from_int (insn_len))); |
| 75 | } |
| 76 | |
| 77 | /* Helper function for gdbscm_disasm_read_memory to safely read from a |
| 78 | Scheme port. Called via gdbscm_call_guile. |
| 79 | The result is a statically allocated error message or NULL if success. */ |
| 80 | |
| 81 | static const char * |
| 82 | gdbscm_disasm_read_memory_worker (void *datap) |
| 83 | { |
| 84 | struct gdbscm_disasm_read_data *data |
| 85 | = (struct gdbscm_disasm_read_data *) datap; |
| 86 | gdbscm_disassembler *dinfo = data->dinfo; |
| 87 | SCM seekto, newpos, port = dinfo->port; |
| 88 | size_t bytes_read; |
| 89 | |
| 90 | seekto = gdbscm_scm_from_ulongest (data->memaddr - dinfo->offset); |
| 91 | newpos = scm_seek (port, seekto, scm_from_int (SEEK_SET)); |
| 92 | if (!scm_is_eq (seekto, newpos)) |
| 93 | return "seek error"; |
| 94 | |
| 95 | bytes_read = scm_c_read (port, data->myaddr, data->length); |
| 96 | |
| 97 | if (bytes_read != data->length) |
| 98 | return "short read"; |
| 99 | |
| 100 | /* If we get here the read succeeded. */ |
| 101 | return NULL; |
| 102 | } |
| 103 | |
| 104 | /* disassemble_info.read_memory_func for gdbscm_print_insn_from_port. */ |
| 105 | |
| 106 | static int |
| 107 | gdbscm_disasm_read_memory (bfd_vma memaddr, bfd_byte *myaddr, |
| 108 | unsigned int length, |
| 109 | struct disassemble_info *dinfo) |
| 110 | { |
| 111 | gdbscm_disassembler *self |
| 112 | = static_cast<gdbscm_disassembler *> (dinfo->application_data); |
| 113 | struct gdbscm_disasm_read_data data; |
| 114 | const char *status; |
| 115 | |
| 116 | data.memaddr = memaddr; |
| 117 | data.myaddr = myaddr; |
| 118 | data.length = length; |
| 119 | data.dinfo = self; |
| 120 | |
| 121 | status = gdbscm_with_guile (gdbscm_disasm_read_memory_worker, &data); |
| 122 | |
| 123 | /* TODO: IWBN to distinguish problems reading target memory versus problems |
| 124 | with the port (e.g., EOF). */ |
| 125 | return status != NULL ? -1 : 0; |
| 126 | } |
| 127 | |
| 128 | gdbscm_disassembler::gdbscm_disassembler (struct gdbarch *gdbarch, |
| 129 | struct ui_file *stream, |
| 130 | SCM port_, ULONGEST offset_) |
| 131 | : gdb_disassembler (gdbarch, stream, gdbscm_disasm_read_memory), |
| 132 | port (port_), offset (offset_) |
| 133 | { |
| 134 | } |
| 135 | |
| 136 | /* Subroutine of gdbscm_arch_disassemble to simplify it. |
| 137 | Call gdbarch_print_insn using a port for input. |
| 138 | PORT must be seekable. |
| 139 | OFFSET is the offset in PORT from which addresses begin. |
| 140 | For example, when printing from a bytevector, addresses passed to the |
| 141 | bv seek routines must be in the range [0,size). However, the bytevector |
| 142 | may represent an instruction at address 0x1234. To handle this case pass |
| 143 | 0x1234 for OFFSET. |
| 144 | This is based on gdb_print_insn, see it for details. */ |
| 145 | |
| 146 | static int |
| 147 | gdbscm_print_insn_from_port (struct gdbarch *gdbarch, |
| 148 | SCM port, ULONGEST offset, CORE_ADDR memaddr, |
| 149 | struct ui_file *stream, int *branch_delay_insns) |
| 150 | { |
| 151 | gdbscm_disassembler di (gdbarch, stream, port, offset); |
| 152 | |
| 153 | return di.print_insn (memaddr, branch_delay_insns); |
| 154 | } |
| 155 | |
| 156 | /* (arch-disassemble <gdb:arch> address |
| 157 | [#:port port] [#:offset address] [#:size integer] [#:count integer]) |
| 158 | -> list |
| 159 | |
| 160 | Returns a list of disassembled instructions. |
| 161 | If PORT is provided, read bytes from it. Otherwise read target memory. |
| 162 | If PORT is #f, read target memory. |
| 163 | PORT must be seekable. IWBN to remove this restriction, and a future |
| 164 | release may. For now the restriction is in place because it's not clear |
| 165 | all disassemblers are strictly sequential. |
| 166 | If SIZE is provided, limit the number of bytes read to this amount. |
| 167 | If COUNT is provided, limit the number of instructions to this amount. |
| 168 | |
| 169 | Each instruction in the result is an alist: |
| 170 | (('address . address) ('asm . disassembly) ('length . length)). |
| 171 | We could use a hash table (dictionary) but there aren't that many fields. */ |
| 172 | |
| 173 | static SCM |
| 174 | gdbscm_arch_disassemble (SCM self, SCM start_scm, SCM rest) |
| 175 | { |
| 176 | arch_smob *a_smob |
| 177 | = arscm_get_arch_smob_arg_unsafe (self, SCM_ARG1, FUNC_NAME); |
| 178 | struct gdbarch *gdbarch = arscm_get_gdbarch (a_smob); |
| 179 | const SCM keywords[] = { |
| 180 | port_keyword, offset_keyword, size_keyword, count_keyword, SCM_BOOL_F |
| 181 | }; |
| 182 | int port_arg_pos = -1, offset_arg_pos = -1; |
| 183 | int size_arg_pos = -1, count_arg_pos = -1; |
| 184 | SCM port = SCM_BOOL_F; |
| 185 | ULONGEST offset = 0; |
| 186 | unsigned int count = 1; |
| 187 | unsigned int size; |
| 188 | ULONGEST start_arg; |
| 189 | CORE_ADDR start, end; |
| 190 | CORE_ADDR pc; |
| 191 | unsigned int i; |
| 192 | int using_port; |
| 193 | SCM result; |
| 194 | |
| 195 | gdbscm_parse_function_args (FUNC_NAME, SCM_ARG2, keywords, "U#OUuu", |
| 196 | start_scm, &start_arg, rest, |
| 197 | &port_arg_pos, &port, |
| 198 | &offset_arg_pos, &offset, |
| 199 | &size_arg_pos, &size, |
| 200 | &count_arg_pos, &count); |
| 201 | /* START is first stored in a ULONGEST because we don't have a format char |
| 202 | for CORE_ADDR, and it's not really worth it to have one yet. */ |
| 203 | start = start_arg; |
| 204 | |
| 205 | if (port_arg_pos > 0) |
| 206 | { |
| 207 | SCM_ASSERT_TYPE (gdbscm_is_false (port) |
| 208 | || gdbscm_is_true (scm_input_port_p (port)), |
| 209 | port, port_arg_pos, FUNC_NAME, _("input port")); |
| 210 | } |
| 211 | using_port = gdbscm_is_true (port); |
| 212 | |
| 213 | if (offset_arg_pos > 0 |
| 214 | && (port_arg_pos < 0 |
| 215 | || gdbscm_is_false (port))) |
| 216 | { |
| 217 | gdbscm_out_of_range_error (FUNC_NAME, offset_arg_pos, |
| 218 | gdbscm_scm_from_ulongest (offset), |
| 219 | _("offset provided but port is missing")); |
| 220 | } |
| 221 | |
| 222 | if (size_arg_pos > 0) |
| 223 | { |
| 224 | if (size == 0) |
| 225 | return SCM_EOL; |
| 226 | /* For now be strict about start+size overflowing. If it becomes |
| 227 | a nuisance we can relax things later. */ |
| 228 | if (start + size < start) |
| 229 | { |
| 230 | gdbscm_out_of_range_error (FUNC_NAME, 0, |
| 231 | scm_list_2 (gdbscm_scm_from_ulongest (start), |
| 232 | gdbscm_scm_from_ulongest (size)), |
| 233 | _("start+size overflows")); |
| 234 | } |
| 235 | end = start + size - 1; |
| 236 | } |
| 237 | else |
| 238 | end = ~(CORE_ADDR) 0; |
| 239 | |
| 240 | if (count == 0) |
| 241 | return SCM_EOL; |
| 242 | |
| 243 | result = SCM_EOL; |
| 244 | |
| 245 | for (pc = start, i = 0; pc <= end && i < count; ) |
| 246 | { |
| 247 | int insn_len = 0; |
| 248 | struct ui_file *memfile = mem_fileopen (); |
| 249 | struct cleanup *cleanups = make_cleanup_ui_file_delete (memfile); |
| 250 | |
| 251 | TRY |
| 252 | { |
| 253 | if (using_port) |
| 254 | { |
| 255 | insn_len = gdbscm_print_insn_from_port (gdbarch, port, offset, |
| 256 | pc, memfile, NULL); |
| 257 | } |
| 258 | else |
| 259 | insn_len = gdb_print_insn (gdbarch, pc, memfile, NULL); |
| 260 | } |
| 261 | CATCH (except, RETURN_MASK_ALL) |
| 262 | { |
| 263 | GDBSCM_HANDLE_GDB_EXCEPTION_WITH_CLEANUPS (except, cleanups); |
| 264 | } |
| 265 | END_CATCH |
| 266 | |
| 267 | std::string as = ui_file_as_string (memfile); |
| 268 | |
| 269 | result = scm_cons (dascm_make_insn (pc, as.c_str (), insn_len), |
| 270 | result); |
| 271 | |
| 272 | pc += insn_len; |
| 273 | i++; |
| 274 | do_cleanups (cleanups); |
| 275 | } |
| 276 | |
| 277 | return scm_reverse_x (result, SCM_EOL); |
| 278 | } |
| 279 | \f |
| 280 | /* Initialize the Scheme architecture support. */ |
| 281 | |
| 282 | static const scheme_function disasm_functions[] = |
| 283 | { |
| 284 | { "arch-disassemble", 2, 0, 1, as_a_scm_t_subr (gdbscm_arch_disassemble), |
| 285 | "\ |
| 286 | Return list of disassembled instructions in memory.\n\ |
| 287 | \n\ |
| 288 | Arguments: <gdb:arch> start-address\n\ |
| 289 | [#:port port] [#:offset address]\n\ |
| 290 | [#:size <integer>] [#:count <integer>]\n\ |
| 291 | port: If non-#f, it is an input port to read bytes from.\n\ |
| 292 | offset: Specifies the address offset of the first byte in the port.\n\ |
| 293 | This is useful if the input is from something other than memory\n\ |
| 294 | (e.g., a bytevector) and you want the result to be as if the bytes\n\ |
| 295 | came from that address. The value to pass for start-address is\n\ |
| 296 | then also the desired disassembly address, not the offset in, e.g.,\n\ |
| 297 | the bytevector.\n\ |
| 298 | size: Limit the number of bytes read to this amount.\n\ |
| 299 | count: Limit the number of instructions to this amount.\n\ |
| 300 | \n\ |
| 301 | Returns:\n\ |
| 302 | Each instruction in the result is an alist:\n\ |
| 303 | (('address . address) ('asm . disassembly) ('length . length))." }, |
| 304 | |
| 305 | END_FUNCTIONS |
| 306 | }; |
| 307 | |
| 308 | void |
| 309 | gdbscm_initialize_disasm (void) |
| 310 | { |
| 311 | gdbscm_define_functions (disasm_functions, 1); |
| 312 | |
| 313 | port_keyword = scm_from_latin1_keyword ("port"); |
| 314 | offset_keyword = scm_from_latin1_keyword ("offset"); |
| 315 | size_keyword = scm_from_latin1_keyword ("size"); |
| 316 | count_keyword = scm_from_latin1_keyword ("count"); |
| 317 | |
| 318 | address_symbol = scm_from_latin1_symbol ("address"); |
| 319 | asm_symbol = scm_from_latin1_symbol ("asm"); |
| 320 | length_symbol = scm_from_latin1_symbol ("length"); |
| 321 | } |