| 1 | #include <stdio.h> |
| 2 | #include <stdlib.h> |
| 3 | #include <string.h> |
| 4 | |
| 5 | #include "my_assert.h" |
| 6 | #include "my_str.h" |
| 7 | |
| 8 | #define ARRAY_SIZE(x) (sizeof(x) / sizeof(x[0])) |
| 9 | #define IS(w, y) !strcmp(w, y) |
| 10 | |
| 11 | #include "protoparse.h" |
| 12 | |
| 13 | static const char *c_save_regs[] = { "ebx", "esi", "edi", "ebp" }; |
| 14 | |
| 15 | static int is_x86_reg_saved(const char *reg) |
| 16 | { |
| 17 | static const char *nosave_regs[] = { "eax", "edx", "ecx" }; |
| 18 | int nosave = 0; |
| 19 | int r; |
| 20 | |
| 21 | for (r = 0; r < ARRAY_SIZE(nosave_regs); r++) |
| 22 | if (strcmp(reg, nosave_regs[r]) == 0) |
| 23 | nosave = 1; |
| 24 | |
| 25 | return !nosave; |
| 26 | } |
| 27 | |
| 28 | // output decorated name |
| 29 | static const char *pp_to_name(const struct parsed_proto *pp) |
| 30 | { |
| 31 | static char buf[256]; |
| 32 | char atval[16]; |
| 33 | |
| 34 | if (!pp->is_fastcall && pp->argc_reg != 0) { |
| 35 | // can only be handled by __cdecl C func |
| 36 | snprintf(buf, sizeof(buf), "_%s", pp->name); |
| 37 | return buf; |
| 38 | } |
| 39 | |
| 40 | atval[0] = 0; |
| 41 | if (pp->is_stdcall) { |
| 42 | snprintf(atval, sizeof(atval), "@%d", |
| 43 | pp->argc * 4); |
| 44 | } |
| 45 | snprintf(buf, sizeof(buf), "%s%s%s", |
| 46 | pp->is_fastcall ? "@" : "_", |
| 47 | pp->name, atval); |
| 48 | |
| 49 | return buf; |
| 50 | } |
| 51 | |
| 52 | static void out_toasm_x86(FILE *f, const char *sym_out, |
| 53 | const struct parsed_proto *pp) |
| 54 | { |
| 55 | int must_save = 0; |
| 56 | int sarg_ofs = 1; // stack offset to args, in DWORDs |
| 57 | int args_repushed = 0; |
| 58 | int argc_repush; |
| 59 | const char *name; |
| 60 | int i; |
| 61 | |
| 62 | argc_repush = pp->argc; |
| 63 | if (pp->is_vararg) |
| 64 | argc_repush = ARRAY_SIZE(pp->arg); // hopefully enough? |
| 65 | |
| 66 | for (i = 0; i < pp->argc; i++) { |
| 67 | if (pp->arg[i].reg != NULL) |
| 68 | must_save |= is_x86_reg_saved(pp->arg[i].reg); |
| 69 | } |
| 70 | |
| 71 | name = pp_to_name(pp); |
| 72 | fprintf(f, ".global %s\n", name); |
| 73 | fprintf(f, "%s:\n", name); |
| 74 | |
| 75 | if (pp->argc_reg == 0 || pp->is_fastcall) { |
| 76 | fprintf(f, "\t# %s\n", |
| 77 | pp->is_fastcall ? "__fastcall" : |
| 78 | (pp->is_stdcall ? "__stdcall" : "__cdecl")); |
| 79 | fprintf(f, "\tjmp %s\n\n", sym_out); |
| 80 | return; |
| 81 | } |
| 82 | |
| 83 | if (pp->argc_stack == 0 && !must_save && !pp->is_stdcall |
| 84 | && !pp->is_vararg && !pp->has_retreg) |
| 85 | { |
| 86 | // load arg regs |
| 87 | for (i = 0; i < pp->argc; i++) { |
| 88 | fprintf(f, "\tmovl %d(%%esp), %%%s\n", |
| 89 | (i + sarg_ofs) * 4, pp->arg[i].reg); |
| 90 | } |
| 91 | fprintf(f, "\tjmp %s\n\n", sym_out); |
| 92 | return; |
| 93 | } |
| 94 | |
| 95 | // asm_stack_args | saved_regs | ra | args_from_c |
| 96 | |
| 97 | // save the regs |
| 98 | // because we don't always know what we are calling, |
| 99 | // be safe and save everything that has to be saved in __cdecl |
| 100 | for (i = 0; i < ARRAY_SIZE(c_save_regs); i++) { |
| 101 | fprintf(f, "\tpushl %%%s\n", c_save_regs[i]); |
| 102 | sarg_ofs++; |
| 103 | } |
| 104 | |
| 105 | // reconstruct arg stack for asm |
| 106 | for (i = argc_repush - 1; i >= 0; i--) { |
| 107 | if (pp->arg[i].reg == NULL) { |
| 108 | fprintf(f, "\tmovl %d(%%esp), %%eax\n", |
| 109 | (i + sarg_ofs) * 4); |
| 110 | fprintf(f, "\tpushl %%eax\n"); |
| 111 | sarg_ofs++; |
| 112 | args_repushed++; |
| 113 | } |
| 114 | } |
| 115 | |
| 116 | // load arg regs |
| 117 | for (i = 0; i < pp->argc; i++) { |
| 118 | if (pp->arg[i].reg != NULL) { |
| 119 | fprintf(f, "\tmovl %d(%%esp), %%%s\n", |
| 120 | (i + sarg_ofs) * 4, pp->arg[i].reg); |
| 121 | if (pp->arg[i].type.is_retreg) |
| 122 | fprintf(f, "\tmovl (%%%s), %%%s\n", |
| 123 | pp->arg[i].reg, pp->arg[i].reg); |
| 124 | } |
| 125 | } |
| 126 | |
| 127 | fprintf(f, "\n\t# %s\n", pp->is_stdcall ? "__stdcall" : "__cdecl"); |
| 128 | fprintf(f, "\tcall %s\n\n", sym_out); |
| 129 | |
| 130 | if (args_repushed && !pp->is_stdcall) { |
| 131 | fprintf(f, "\tadd $%d,%%esp\n", args_repushed * 4); |
| 132 | sarg_ofs -= args_repushed; |
| 133 | } |
| 134 | |
| 135 | // update the retreg regs |
| 136 | if (pp->has_retreg) { |
| 137 | for (i = 0; i < pp->argc; i++) { |
| 138 | if (pp->arg[i].type.is_retreg) { |
| 139 | fprintf(f, "\tmovl %d(%%esp), %%ecx\n" |
| 140 | "\tmovl %%%s, (%%ecx)\n", |
| 141 | (i + sarg_ofs) * 4, pp->arg[i].reg); |
| 142 | } |
| 143 | } |
| 144 | } |
| 145 | |
| 146 | // restore regs |
| 147 | for (i = ARRAY_SIZE(c_save_regs) - 1; i >= 0; i--) |
| 148 | fprintf(f, "\tpopl %%%s\n", c_save_regs[i]); |
| 149 | |
| 150 | fprintf(f, "\tret\n\n"); |
| 151 | } |
| 152 | |
| 153 | static void out_fromasm_x86(FILE *f, const char *sym, |
| 154 | const struct parsed_proto *pp) |
| 155 | { |
| 156 | int reg_ofs[ARRAY_SIZE(pp->arg)]; |
| 157 | int sarg_ofs = 1; // stack offset to args, in DWORDs |
| 158 | int saved_regs = 0; |
| 159 | int ecx_ofs = -1; |
| 160 | int edx_ofs = -1; |
| 161 | int c_is_stdcall; |
| 162 | int argc_repush; |
| 163 | int stack_args; |
| 164 | int ret64; |
| 165 | int i; |
| 166 | |
| 167 | argc_repush = pp->argc; |
| 168 | stack_args = pp->argc_stack; |
| 169 | if (pp->is_vararg) { |
| 170 | argc_repush = ARRAY_SIZE(pp->arg); // hopefully enough? |
| 171 | stack_args = argc_repush - pp->argc_reg; |
| 172 | } |
| 173 | |
| 174 | ret64 = strstr(pp->ret_type.name, "int64") != NULL; |
| 175 | |
| 176 | fprintf(f, "# %s", |
| 177 | pp->is_fastcall ? "__fastcall" : |
| 178 | (pp->is_stdcall ? "__stdcall" : "__cdecl")); |
| 179 | if (ret64) |
| 180 | fprintf(f, " ret64"); |
| 181 | fprintf(f, "\n.global %s\n", sym); |
| 182 | fprintf(f, "%s:\n", sym); |
| 183 | |
| 184 | if ((pp->argc_reg == 0 || pp->is_fastcall) |
| 185 | && !IS(pp->name, "storm_491")) // wants edx save :( |
| 186 | { |
| 187 | fprintf(f, "\tjmp %s\n\n", pp_to_name(pp)); |
| 188 | return; |
| 189 | } |
| 190 | |
| 191 | c_is_stdcall = (pp->argc_reg == 0 && pp->is_stdcall); |
| 192 | |
| 193 | // at least sc sub_47B150 needs edx to be preserved |
| 194 | // int64 returns use edx:eax - no edx save |
| 195 | // we use ecx also as scratch |
| 196 | fprintf(f, "\tpushl %%ecx\n"); |
| 197 | saved_regs++; |
| 198 | sarg_ofs++; |
| 199 | ecx_ofs = sarg_ofs; |
| 200 | if (!ret64) { |
| 201 | fprintf(f, "\tpushl %%edx\n"); |
| 202 | saved_regs++; |
| 203 | sarg_ofs++; |
| 204 | edx_ofs = sarg_ofs; |
| 205 | } |
| 206 | |
| 207 | // need space for retreg args |
| 208 | if (pp->has_retreg) { |
| 209 | for (i = 0; i < pp->argc; i++) { |
| 210 | if (!pp->arg[i].type.is_retreg) |
| 211 | continue; |
| 212 | if (IS(pp->arg[i].reg, "ecx") && ecx_ofs >= 0) { |
| 213 | reg_ofs[i] = ecx_ofs; |
| 214 | continue; |
| 215 | } |
| 216 | if (IS(pp->arg[i].reg, "edx") && edx_ofs >= 0) { |
| 217 | reg_ofs[i] = edx_ofs; |
| 218 | continue; |
| 219 | } |
| 220 | fprintf(f, "\tpushl %%%s\n", pp->arg[i].reg); |
| 221 | saved_regs++; |
| 222 | sarg_ofs++; |
| 223 | reg_ofs[i] = sarg_ofs; |
| 224 | } |
| 225 | } |
| 226 | |
| 227 | // construct arg stack |
| 228 | for (i = argc_repush - 1; i >= 0; i--) { |
| 229 | if (pp->arg[i].reg == NULL) { |
| 230 | fprintf(f, "\tmovl %d(%%esp), %%ecx\n", |
| 231 | (sarg_ofs + stack_args - 1) * 4); |
| 232 | fprintf(f, "\tpushl %%ecx\n"); |
| 233 | stack_args--; |
| 234 | } |
| 235 | else { |
| 236 | const char *reg = pp->arg[i].reg; |
| 237 | if (pp->arg[i].type.is_retreg) { |
| 238 | reg = "ecx"; |
| 239 | fprintf(f, "\tlea %d(%%esp), %%ecx\n", |
| 240 | (sarg_ofs - reg_ofs[i]) * 4); |
| 241 | } |
| 242 | else if (IS(reg, "ecx")) |
| 243 | // must reload original ecx |
| 244 | fprintf(f, "\tmovl %d(%%esp), %%ecx\n", |
| 245 | (sarg_ofs - 2) * 4); |
| 246 | |
| 247 | fprintf(f, "\tpushl %%%s\n", reg); |
| 248 | } |
| 249 | sarg_ofs++; |
| 250 | } |
| 251 | |
| 252 | fprintf(f, "\n\tcall %s\n\n", pp_to_name(pp)); |
| 253 | |
| 254 | if (!c_is_stdcall && sarg_ofs > saved_regs + 1) |
| 255 | fprintf(f, "\tadd $%d,%%esp\n", |
| 256 | (sarg_ofs - (saved_regs + 1)) * 4); |
| 257 | |
| 258 | // pop retregs |
| 259 | if (pp->has_retreg) { |
| 260 | for (i = pp->argc - 1; i >= 0; i--) { |
| 261 | if (!pp->arg[i].type.is_retreg) |
| 262 | continue; |
| 263 | if (IS(pp->arg[i].reg, "ecx") && ecx_ofs >= 0) { |
| 264 | continue; |
| 265 | } |
| 266 | if (IS(pp->arg[i].reg, "edx") && edx_ofs >= 0) { |
| 267 | continue; |
| 268 | } |
| 269 | fprintf(f, "\tpopl %%%s\n", pp->arg[i].reg); |
| 270 | } |
| 271 | } |
| 272 | |
| 273 | if (!ret64) |
| 274 | fprintf(f, "\tpopl %%edx\n"); |
| 275 | fprintf(f, "\tpopl %%ecx\n"); |
| 276 | |
| 277 | if (pp->is_stdcall && pp->argc_stack) |
| 278 | fprintf(f, "\tret $%d\n\n", pp->argc_stack * 4); |
| 279 | else |
| 280 | fprintf(f, "\tret\n\n"); |
| 281 | } |
| 282 | |
| 283 | int main(int argc, char *argv[]) |
| 284 | { |
| 285 | FILE *fout, *fsyms_to, *fsyms_from, *fhdr; |
| 286 | const struct parsed_proto *pp; |
| 287 | char line[256]; |
| 288 | char sym_noat[256]; |
| 289 | char sym[256]; |
| 290 | char *p; |
| 291 | int ret = 1; |
| 292 | |
| 293 | if (argc != 5) { |
| 294 | printf("usage:\n%s <bridge.s> <toasm_symf> <fromasm_symf> <hdrf>\n", |
| 295 | argv[0]); |
| 296 | return 1; |
| 297 | } |
| 298 | |
| 299 | hdrfn = argv[4]; |
| 300 | fhdr = fopen(hdrfn, "r"); |
| 301 | my_assert_not(fhdr, NULL); |
| 302 | |
| 303 | fsyms_from = fopen(argv[3], "r"); |
| 304 | my_assert_not(fsyms_from, NULL); |
| 305 | |
| 306 | fsyms_to = fopen(argv[2], "r"); |
| 307 | my_assert_not(fsyms_to, NULL); |
| 308 | |
| 309 | fout = fopen(argv[1], "w"); |
| 310 | my_assert_not(fout, NULL); |
| 311 | |
| 312 | fprintf(fout, ".text\n\n"); |
| 313 | fprintf(fout, "# to asm\n\n"); |
| 314 | |
| 315 | while (fgets(line, sizeof(line), fsyms_to)) |
| 316 | { |
| 317 | next_word(sym, sizeof(sym), line); |
| 318 | if (sym[0] == 0 || sym[0] == ';' || sym[0] == '#') |
| 319 | continue; |
| 320 | |
| 321 | // IDA asm doesn't do '@' notation.. |
| 322 | strcpy(sym_noat, sym); |
| 323 | p = strchr(sym_noat, '@'); |
| 324 | if (p != NULL) |
| 325 | *p = 0; |
| 326 | |
| 327 | pp = proto_parse(fhdr, sym_noat, 0); |
| 328 | if (pp == NULL) |
| 329 | goto out; |
| 330 | |
| 331 | out_toasm_x86(fout, sym_noat, pp); |
| 332 | } |
| 333 | |
| 334 | fprintf(fout, "# from asm\n\n"); |
| 335 | |
| 336 | while (fgets(line, sizeof(line), fsyms_from)) |
| 337 | { |
| 338 | next_word(sym, sizeof(sym), line); |
| 339 | if (sym[0] == 0 || sym[0] == ';' || sym[0] == '#') |
| 340 | continue; |
| 341 | |
| 342 | pp = proto_parse(fhdr, sym, 0); |
| 343 | if (pp == NULL) |
| 344 | goto out; |
| 345 | |
| 346 | out_fromasm_x86(fout, sym, pp); |
| 347 | } |
| 348 | |
| 349 | ret = 0; |
| 350 | out: |
| 351 | fclose(fout); |
| 352 | fclose(fsyms_to); |
| 353 | fclose(fsyms_from); |
| 354 | fclose(fhdr); |
| 355 | if (ret) |
| 356 | remove(argv[1]); |
| 357 | |
| 358 | return ret; |
| 359 | } |