| 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 int is_x86_reg_saved(const char *reg) |
| 14 | { |
| 15 | static const char *nosave_regs[] = { "eax", "edx", "ecx" }; |
| 16 | int nosave = 0; |
| 17 | int r; |
| 18 | |
| 19 | for (r = 0; r < ARRAY_SIZE(nosave_regs); r++) |
| 20 | if (strcmp(reg, nosave_regs[r]) == 0) |
| 21 | nosave = 1; |
| 22 | |
| 23 | return !nosave; |
| 24 | } |
| 25 | |
| 26 | static void out_toasm_x86(FILE *f, const char *sym_in, |
| 27 | const char *sym_out, const struct parsed_proto *pp) |
| 28 | { |
| 29 | int must_save = 0; |
| 30 | int sarg_ofs = 1; // stack offset to args, in DWORDs |
| 31 | int args_repushed = 0; |
| 32 | int argc_repush; |
| 33 | int i; |
| 34 | |
| 35 | argc_repush = pp->argc; |
| 36 | if (pp->is_vararg) |
| 37 | argc_repush = ARRAY_SIZE(pp->arg); // hopefully enough? |
| 38 | |
| 39 | for (i = 0; i < pp->argc; i++) { |
| 40 | if (pp->arg[i].reg != NULL) |
| 41 | must_save |= is_x86_reg_saved(pp->arg[i].reg); |
| 42 | } |
| 43 | |
| 44 | fprintf(f, ".global _%s\n", sym_in); |
| 45 | fprintf(f, "_%s:\n", sym_in); |
| 46 | |
| 47 | if (pp->argc_reg == 0) { |
| 48 | fprintf(f, "\tjmp %s\n\n", sym_out); |
| 49 | return; |
| 50 | } |
| 51 | |
| 52 | if (pp->argc_stack == 0 && !must_save && !pp->is_stdcall |
| 53 | && !pp->is_vararg) |
| 54 | { |
| 55 | // load arg regs |
| 56 | for (i = 0; i < pp->argc; i++) { |
| 57 | fprintf(f, "\tmovl %d(%%esp), %%%s\n", |
| 58 | (i + sarg_ofs) * 4, pp->arg[i].reg); |
| 59 | } |
| 60 | fprintf(f, "\tjmp %s\n\n", sym_out); |
| 61 | return; |
| 62 | } |
| 63 | |
| 64 | // save the regs |
| 65 | for (i = 0; i < pp->argc; i++) { |
| 66 | if (pp->arg[i].reg != NULL && is_x86_reg_saved(pp->arg[i].reg)) { |
| 67 | fprintf(f, "\tpushl %%%s\n", pp->arg[i].reg); |
| 68 | sarg_ofs++; |
| 69 | } |
| 70 | } |
| 71 | |
| 72 | // reconstruct arg stack |
| 73 | for (i = argc_repush - 1; i >= 0; i--) { |
| 74 | if (pp->arg[i].reg == NULL) { |
| 75 | fprintf(f, "\tmovl %d(%%esp), %%eax\n", |
| 76 | (i + sarg_ofs) * 4); |
| 77 | fprintf(f, "\tpushl %%eax\n"); |
| 78 | sarg_ofs++; |
| 79 | args_repushed++; |
| 80 | } |
| 81 | } |
| 82 | // my_assert(args_repushed, pp->argc_stack); |
| 83 | |
| 84 | // load arg regs |
| 85 | for (i = 0; i < pp->argc; i++) { |
| 86 | if (pp->arg[i].reg != NULL) { |
| 87 | fprintf(f, "\tmovl %d(%%esp), %%%s\n", |
| 88 | (i + sarg_ofs) * 4, pp->arg[i].reg); |
| 89 | } |
| 90 | } |
| 91 | |
| 92 | fprintf(f, "\n\t# %s\n", pp->is_stdcall ? "__stdcall" : "__cdecl"); |
| 93 | fprintf(f, "\tcall %s\n\n", sym_out); |
| 94 | |
| 95 | if (args_repushed && !pp->is_stdcall) |
| 96 | fprintf(f, "\tadd $%d,%%esp\n", args_repushed * 4); |
| 97 | |
| 98 | // restore regs |
| 99 | for (i = pp->argc - 1; i >= 0; i--) { |
| 100 | if (pp->arg[i].reg != NULL && is_x86_reg_saved(pp->arg[i].reg)) |
| 101 | fprintf(f, "\tpopl %%%s\n", pp->arg[i].reg); |
| 102 | } |
| 103 | |
| 104 | fprintf(f, "\tret\n\n"); |
| 105 | } |
| 106 | |
| 107 | static void out_fromasm_x86(FILE *f, const char *sym, |
| 108 | const struct parsed_proto *pp) |
| 109 | { |
| 110 | int sarg_ofs = 1; // stack offset to args, in DWORDs |
| 111 | int saved_regs = 0; |
| 112 | int argc_repush; |
| 113 | int stack_args; |
| 114 | int ret64; |
| 115 | int i; |
| 116 | |
| 117 | argc_repush = pp->argc; |
| 118 | stack_args = pp->argc_stack; |
| 119 | if (pp->is_vararg) { |
| 120 | argc_repush = ARRAY_SIZE(pp->arg); // hopefully enough? |
| 121 | stack_args = argc_repush - pp->argc_reg; |
| 122 | } |
| 123 | |
| 124 | ret64 = strstr(pp->ret_type.name, "int64") != NULL; |
| 125 | |
| 126 | fprintf(f, "# %s", pp->is_stdcall ? "__stdcall" : "__cdecl"); |
| 127 | if (ret64) |
| 128 | fprintf(f, " ret64"); |
| 129 | fprintf(f, "\n.global %s\n", sym); |
| 130 | fprintf(f, "%s:\n", sym); |
| 131 | |
| 132 | if (pp->argc_reg == 0) { |
| 133 | //fprintf(f, "\tjmp _%s\n\n", sym); |
| 134 | fprintf(f, "\tjmp _%s", sym); |
| 135 | if (pp->is_stdcall && pp->argc > 0) |
| 136 | fprintf(f, "@%d", pp->argc * 4); |
| 137 | fprintf(f, "\n\n"); |
| 138 | return; |
| 139 | } |
| 140 | |
| 141 | // at least sc sub_47B150 needs edx to be preserved |
| 142 | // int64 returns use edx:eax - no edx save |
| 143 | // we use ecx also as scratch |
| 144 | fprintf(f, "\tpushl %%ecx\n"); |
| 145 | saved_regs++; |
| 146 | sarg_ofs++; |
| 147 | if (!ret64) { |
| 148 | fprintf(f, "\tpushl %%edx\n"); |
| 149 | saved_regs++; |
| 150 | sarg_ofs++; |
| 151 | } |
| 152 | |
| 153 | // construct arg stack |
| 154 | for (i = argc_repush - 1; i >= 0; i--) { |
| 155 | if (pp->arg[i].reg == NULL) { |
| 156 | fprintf(f, "\tmovl %d(%%esp), %%ecx\n", |
| 157 | (sarg_ofs + stack_args - 1) * 4); |
| 158 | fprintf(f, "\tpushl %%ecx\n"); |
| 159 | stack_args--; |
| 160 | } |
| 161 | else { |
| 162 | if (IS(pp->arg[i].reg, "ecx")) |
| 163 | // must reload original ecx |
| 164 | fprintf(f, "\tmovl %d(%%esp), %%ecx\n", |
| 165 | (sarg_ofs - 2) * 4); |
| 166 | |
| 167 | fprintf(f, "\tpushl %%%s\n", pp->arg[i].reg); |
| 168 | } |
| 169 | sarg_ofs++; |
| 170 | } |
| 171 | |
| 172 | // no worries about calling conventions - always __cdecl |
| 173 | fprintf(f, "\n\tcall _%s\n\n", sym); |
| 174 | |
| 175 | if (sarg_ofs > saved_regs + 1) |
| 176 | fprintf(f, "\tadd $%d,%%esp\n", |
| 177 | (sarg_ofs - (saved_regs + 1)) * 4); |
| 178 | |
| 179 | if (!ret64) |
| 180 | fprintf(f, "\tpopl %%edx\n"); |
| 181 | fprintf(f, "\tpopl %%ecx\n"); |
| 182 | |
| 183 | if (pp->is_stdcall && pp->argc_stack) |
| 184 | fprintf(f, "\tret $%d\n\n", pp->argc_stack * 4); |
| 185 | else |
| 186 | fprintf(f, "\tret\n\n"); |
| 187 | } |
| 188 | |
| 189 | int main(int argc, char *argv[]) |
| 190 | { |
| 191 | FILE *fout, *fsyms_to, *fsyms_from, *fhdr; |
| 192 | const struct parsed_proto *pp; |
| 193 | char line[256]; |
| 194 | char sym_noat[256]; |
| 195 | char sym[256]; |
| 196 | char *p; |
| 197 | int ret = 1; |
| 198 | |
| 199 | if (argc != 5) { |
| 200 | printf("usage:\n%s <bridge.s> <toasm_symf> <fromasm_symf> <hdrf>\n", |
| 201 | argv[0]); |
| 202 | return 1; |
| 203 | } |
| 204 | |
| 205 | hdrfn = argv[4]; |
| 206 | fhdr = fopen(hdrfn, "r"); |
| 207 | my_assert_not(fhdr, NULL); |
| 208 | |
| 209 | fsyms_from = fopen(argv[3], "r"); |
| 210 | my_assert_not(fsyms_from, NULL); |
| 211 | |
| 212 | fsyms_to = fopen(argv[2], "r"); |
| 213 | my_assert_not(fsyms_to, NULL); |
| 214 | |
| 215 | fout = fopen(argv[1], "w"); |
| 216 | my_assert_not(fout, NULL); |
| 217 | |
| 218 | fprintf(fout, ".text\n\n"); |
| 219 | fprintf(fout, "# to asm\n\n"); |
| 220 | |
| 221 | while (fgets(line, sizeof(line), fsyms_to)) |
| 222 | { |
| 223 | next_word(sym, sizeof(sym), line); |
| 224 | if (sym[0] == 0 || sym[0] == ';' || sym[0] == '#') |
| 225 | continue; |
| 226 | |
| 227 | // IDA asm doesn't do '@' notation.. |
| 228 | strcpy(sym_noat, sym); |
| 229 | p = strchr(sym_noat, '@'); |
| 230 | if (p != NULL) |
| 231 | *p = 0; |
| 232 | |
| 233 | pp = proto_parse(fhdr, sym_noat, 0); |
| 234 | if (pp == NULL) |
| 235 | goto out; |
| 236 | |
| 237 | out_toasm_x86(fout, sym, sym_noat, pp); |
| 238 | } |
| 239 | |
| 240 | fprintf(fout, "# from asm\n\n"); |
| 241 | |
| 242 | while (fgets(line, sizeof(line), fsyms_from)) |
| 243 | { |
| 244 | next_word(sym, sizeof(sym), line); |
| 245 | if (sym[0] == 0 || sym[0] == ';' || sym[0] == '#') |
| 246 | continue; |
| 247 | |
| 248 | pp = proto_parse(fhdr, sym, 0); |
| 249 | if (pp == NULL) |
| 250 | goto out; |
| 251 | |
| 252 | out_fromasm_x86(fout, sym, pp); |
| 253 | } |
| 254 | |
| 255 | ret = 0; |
| 256 | out: |
| 257 | fclose(fout); |
| 258 | fclose(fsyms_to); |
| 259 | fclose(fsyms_from); |
| 260 | fclose(fhdr); |
| 261 | if (ret) |
| 262 | remove(argv[1]); |
| 263 | |
| 264 | return ret; |
| 265 | } |