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annotate src/parse.c @ 37:538e15927776
Added symbol handling to expression subsystem; adpated instruction handlers to the new scheme; misc fixes
| author | lost |
|---|---|
| date | Sat, 03 Jan 2009 04:20:49 +0000 |
| parents | 99e3b3310bac |
| children | 9bd584bb6296 |
| rev | line source |
|---|---|
| 36 | 1 /* |
| 2 parse.c | |
| 3 Copyright © 2008 William Astle | |
| 4 | |
| 5 This file is part of LWASM. | |
| 6 | |
| 7 LWASM is free software: you can redistribute it and/or modify it under the | |
| 8 terms of the GNU General Public License as published by the Free Software | |
| 9 Foundation, either version 3 of the License, or (at your option) any later | |
| 10 version. | |
| 11 | |
| 12 This program is distributed in the hope that it will be useful, but WITHOUT | |
| 13 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
| 14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
| 15 more details. | |
| 16 | |
| 17 You should have received a copy of the GNU General Public License along with | |
| 18 this program. If not, see <http://www.gnu.org/licenses/>. | |
| 19 */ | |
| 20 | |
| 21 /* | |
| 22 Contains the general parser | |
| 23 */ | |
| 24 | |
| 25 #define __parse_c_seen__ | |
| 26 | |
| 27 #include <ctype.h> | |
| 28 #include <string.h> | |
| 29 | |
| 30 #include "lwasm.h" | |
| 31 #include "instab.h" | |
| 32 #include "util.h" | |
| 33 | |
| 34 // parse a line and despatch to the appropriate handlers for opcodes | |
| 35 int lwasm_parse_line(asmstate_t *as, lwasm_line_t *l) | |
| 36 { | |
| 37 char *p, *p2; | |
| 38 char *opc; | |
| 39 int opnum; | |
|
37
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40 char *sym; |
| 36 | 41 |
| 42 p = l -> text; | |
| 43 | |
| 44 if (!*p) | |
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45 { |
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46 as -> context += 1; |
| 36 | 47 return 0; |
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48 } |
| 36 | 49 |
| 50 if (!isspace(*p) && *p != '*' && *p != ';') | |
| 51 { | |
| 52 // we have a symbol specified here | |
| 53 // parse it and define | |
| 54 // need to handle local symbols here... | |
|
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55 for (p2 = p; *p2 && !isspace(*p2); p2++) |
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56 /* do nothing */ ; |
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57 |
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58 sym = lwasm_alloc((p2 - p) + 1); |
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59 sym[p2 - p] = '\0'; |
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60 memcpy(sym, p, p2 - p); |
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61 |
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62 l -> sym = sym; |
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63 // have a symbol; now determine if it is valid and register it |
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64 // at the current address of the line |
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65 if (lwasm_register_symbol(as, l, sym, as -> addr) < 0) |
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66 l -> sym = NULL; |
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67 } |
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68 else |
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69 { |
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70 while (*p && isspace(*p)) |
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71 (*p)++; |
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72 if (!*p) |
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73 { |
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74 as -> context += 1; |
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75 return 0; |
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76 } |
| 36 | 77 } |
| 78 | |
| 79 // skip white space | |
| 80 while (*p && isspace(*p)) | |
| 81 p++; | |
| 82 | |
| 83 // if comment or end of line, return | |
| 84 if (!*p || *p == '*' || *p == ';') | |
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85 { |
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86 lwasm_free(l -> sym); |
| 36 | 87 return 0; |
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88 } |
| 36 | 89 |
| 90 // parse the opcode | |
| 91 for (p2 = p; *p2 && !isspace(*p2); p2++) | |
| 92 /* do nothing */ ; | |
| 93 | |
| 94 opc = lwasm_alloc((p2 - p) + 1); | |
| 95 memcpy(opc, p, p2 - p); | |
| 96 opc[p2 - p] = '\0'; | |
| 97 | |
| 98 // skip intervening whitespace if present | |
| 99 while (*p2 && isspace(*p2)) | |
| 100 p2++; | |
| 101 | |
| 102 // check for macro (pass 1) | |
| 103 | |
| 104 // look up instruction in insn table | |
| 105 for (opnum = 0; instab[opnum].opcode; opnum++) | |
| 106 { | |
| 107 if (!strcasecmp(instab[opnum].opcode, opc)) | |
| 108 break; | |
| 109 } | |
| 110 | |
| 111 if (!(instab[opnum].opcode) || !(instab[opnum].fn)) | |
| 112 { | |
| 113 // invalid operation code, throw error | |
| 114 register_error(as, l, 1, "Invalid operation code '%s'", opc); | |
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115 lwasm_free(l -> sym); |
| 36 | 116 lwasm_free(opc); |
| 117 return -1; | |
| 118 } | |
| 119 | |
| 120 // dispatch handler | |
| 121 (instab[opnum].fn)(as, l, &p2, opnum); | |
| 122 | |
| 123 lwasm_free(opc); | |
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124 lwasm_free(sym); |
| 36 | 125 } |