| 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, char *sym, struct parsed_proto *pp) |
| 27 | { |
| 28 | int must_save = 0; |
| 29 | int sarg_ofs = 1; // stack offset to args, in DWORDs |
| 30 | int args_repushed = 0; |
| 31 | int i; |
| 32 | |
| 33 | for (i = 0; i < pp->argc; i++) { |
| 34 | if (pp->arg[i].reg != NULL) |
| 35 | must_save |= is_x86_reg_saved(pp->arg[i].reg); |
| 36 | } |
| 37 | |
| 38 | fprintf(f, ".global _%s\n", sym); |
| 39 | fprintf(f, "_%s:\n", sym); |
| 40 | |
| 41 | if (pp->argc_reg == 0 && !pp->is_stdcall) { |
| 42 | fprintf(f, "\tjmp %s\n\n", sym); |
| 43 | return; |
| 44 | } |
| 45 | |
| 46 | if (pp->argc_stack == 0 && !must_save && !pp->is_stdcall) { |
| 47 | // load arg regs |
| 48 | for (i = 0; i < pp->argc; i++) { |
| 49 | fprintf(f, "\tmovl %d(%%esp), %%%s\n", |
| 50 | (i + sarg_ofs) * 4, pp->arg[i].reg); |
| 51 | } |
| 52 | fprintf(f, "\tjmp %s\n\n", sym); |
| 53 | return; |
| 54 | } |
| 55 | |
| 56 | // save the regs |
| 57 | for (i = 0; i < pp->argc; i++) { |
| 58 | if (pp->arg[i].reg != NULL && is_x86_reg_saved(pp->arg[i].reg)) { |
| 59 | fprintf(f, "\tpushl %%%s\n", pp->arg[i].reg); |
| 60 | sarg_ofs++; |
| 61 | } |
| 62 | } |
| 63 | |
| 64 | // reconstruct arg stack |
| 65 | for (i = pp->argc - 1; i >= 0; i--) { |
| 66 | if (pp->arg[i].reg == NULL) { |
| 67 | fprintf(f, "\tmovl %d(%%esp), %%eax\n", |
| 68 | (i + sarg_ofs) * 4); |
| 69 | fprintf(f, "\tpushl %%eax\n"); |
| 70 | sarg_ofs++; |
| 71 | args_repushed++; |
| 72 | } |
| 73 | } |
| 74 | my_assert(args_repushed, pp->argc_stack); |
| 75 | |
| 76 | // load arg regs |
| 77 | for (i = 0; i < pp->argc; i++) { |
| 78 | if (pp->arg[i].reg != NULL) { |
| 79 | fprintf(f, "\tmovl %d(%%esp), %%%s\n", |
| 80 | (i + sarg_ofs) * 4, pp->arg[i].reg); |
| 81 | } |
| 82 | } |
| 83 | |
| 84 | fprintf(f, "\n\t# %s\n", pp->is_stdcall ? "__stdcall" : "__cdecl"); |
| 85 | fprintf(f, "\tcall %s\n\n", sym); |
| 86 | |
| 87 | if (args_repushed && !pp->is_stdcall) |
| 88 | fprintf(f, "\tadd $%d,%%esp\n", args_repushed * 4); |
| 89 | |
| 90 | // restore regs |
| 91 | for (i = pp->argc - 1; i >= 0; i--) { |
| 92 | if (pp->arg[i].reg != NULL && is_x86_reg_saved(pp->arg[i].reg)) |
| 93 | fprintf(f, "\tpopl %%%s\n", pp->arg[i].reg); |
| 94 | } |
| 95 | |
| 96 | fprintf(f, "\tret\n\n"); |
| 97 | } |
| 98 | |
| 99 | static void out_fromasm_x86(FILE *f, char *sym, struct parsed_proto *pp) |
| 100 | { |
| 101 | int sarg_ofs = 1; // stack offset to args, in DWORDs |
| 102 | int stack_args; |
| 103 | int i; |
| 104 | |
| 105 | fprintf(f, "# %s\n", pp->is_stdcall ? "__stdcall" : "__cdecl"); |
| 106 | fprintf(f, ".global %s\n", sym); |
| 107 | fprintf(f, "%s:\n", sym); |
| 108 | |
| 109 | if (pp->argc_reg == 0 && !pp->is_stdcall) { |
| 110 | fprintf(f, "\tjmp _%s\n\n", sym); |
| 111 | return; |
| 112 | } |
| 113 | |
| 114 | fprintf(f, "\tpushl %%edx\n"); // just in case.. |
| 115 | sarg_ofs++; |
| 116 | |
| 117 | // construct arg stack |
| 118 | stack_args = pp->argc_stack; |
| 119 | for (i = pp->argc - 1; i >= 0; i--) { |
| 120 | if (pp->arg[i].reg == NULL) { |
| 121 | fprintf(f, "\tmovl %d(%%esp), %%edx\n", |
| 122 | (sarg_ofs + stack_args - 1) * 4); |
| 123 | fprintf(f, "\tpushl %%edx\n"); |
| 124 | stack_args--; |
| 125 | } |
| 126 | else { |
| 127 | if (IS(pp->arg[i].reg, "edx")) |
| 128 | // must reload original edx |
| 129 | fprintf(f, "\tmovl %d(%%esp), %%edx\n", |
| 130 | (sarg_ofs - 2) * 4); |
| 131 | |
| 132 | fprintf(f, "\tpushl %%%s\n", pp->arg[i].reg); |
| 133 | } |
| 134 | sarg_ofs++; |
| 135 | } |
| 136 | |
| 137 | // no worries about calling conventions - always __cdecl |
| 138 | fprintf(f, "\n\tcall _%s\n\n", sym); |
| 139 | |
| 140 | if (sarg_ofs > 2) |
| 141 | fprintf(f, "\tadd $%d,%%esp\n", (sarg_ofs - 2) * 4); |
| 142 | |
| 143 | fprintf(f, "\tpopl %%edx\n"); |
| 144 | |
| 145 | if (pp->is_stdcall && pp->argc_stack) |
| 146 | fprintf(f, "\tret $%d\n\n", pp->argc_stack * 4); |
| 147 | else |
| 148 | fprintf(f, "\tret\n\n"); |
| 149 | } |
| 150 | |
| 151 | int main(int argc, char *argv[]) |
| 152 | { |
| 153 | FILE *fout, *fsyms_to, *fsyms_from, *fhdr; |
| 154 | struct parsed_proto pp; |
| 155 | char line[256]; |
| 156 | char sym[256]; |
| 157 | int ret; |
| 158 | |
| 159 | if (argc != 5) { |
| 160 | printf("usage:\n%s <bridge.s> <toasm_symf> <fromasm_symf> <hdrf>\n", |
| 161 | argv[0]); |
| 162 | return 1; |
| 163 | } |
| 164 | |
| 165 | hdrfn = argv[4]; |
| 166 | fhdr = fopen(hdrfn, "r"); |
| 167 | my_assert_not(fhdr, NULL); |
| 168 | |
| 169 | fsyms_from = fopen(argv[3], "r"); |
| 170 | my_assert_not(fsyms_from, NULL); |
| 171 | |
| 172 | fsyms_to = fopen(argv[2], "r"); |
| 173 | my_assert_not(fsyms_to, NULL); |
| 174 | |
| 175 | fout = fopen(argv[1], "w"); |
| 176 | my_assert_not(fout, NULL); |
| 177 | |
| 178 | fprintf(fout, ".text\n\n"); |
| 179 | fprintf(fout, "# to asm\n\n"); |
| 180 | |
| 181 | while (fgets(line, sizeof(line), fsyms_to)) |
| 182 | { |
| 183 | next_word(sym, sizeof(sym), line); |
| 184 | if (sym[0] == 0 || sym[0] == ';' || sym[0] == '#') |
| 185 | continue; |
| 186 | |
| 187 | ret = proto_parse(fhdr, sym, &pp); |
| 188 | if (ret) |
| 189 | goto out; |
| 190 | |
| 191 | out_toasm_x86(fout, sym, &pp); |
| 192 | proto_release(&pp); |
| 193 | } |
| 194 | |
| 195 | fprintf(fout, "# from asm\n\n"); |
| 196 | |
| 197 | while (fgets(line, sizeof(line), fsyms_from)) |
| 198 | { |
| 199 | next_word(sym, sizeof(sym), line); |
| 200 | if (sym[0] == 0 || sym[0] == ';' || sym[0] == '#') |
| 201 | continue; |
| 202 | |
| 203 | ret = proto_parse(fhdr, sym, &pp); |
| 204 | if (ret) |
| 205 | goto out; |
| 206 | |
| 207 | out_fromasm_x86(fout, sym, &pp); |
| 208 | proto_release(&pp); |
| 209 | } |
| 210 | |
| 211 | ret = 0; |
| 212 | out: |
| 213 | fclose(fout); |
| 214 | fclose(fsyms_to); |
| 215 | fclose(fsyms_from); |
| 216 | fclose(fhdr); |
| 217 | if (ret) |
| 218 | remove(argv[1]); |
| 219 | |
| 220 | return ret; |
| 221 | } |