comparison: src/preprocessor.cxx
src/preprocessor.cxx
- changeset 73
- 1ee9b312dc18
- parent 72
- 03e4d9db3fd9
- child 74
- 007fbadfa7f9
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| 72:03e4d9db3fd9 | 73:1ee9b312dc18 |
|---|---|
| 1 #include <stdio.h> | |
| 2 #include <stdlib.h> | |
| 3 #include "main.h" | |
| 4 #include "str.h" | |
| 5 #include "scriptreader.h" | |
| 6 | |
| 7 /* Since the preprocessor is *called* from ReadChar and I don't want | |
| 8 * to worry about recursive preprocessing, the preprocessor uses its | |
| 9 * own bare-bones variant of the function for file reading. | |
| 10 */ | |
| 11 char ScriptReader::PPReadChar () { | |
| 12 char c; | |
| 13 if (!fread (&c, sizeof (char), 1, fp[fc])) | |
| 14 return 0; | |
| 15 curchar[fc]++; | |
| 16 return c; | |
| 17 } | |
| 18 | |
| 19 void ScriptReader::PPMustChar (char c) { | |
| 20 char d = PPReadChar (); | |
| 21 if (c != d) | |
| 22 ParserError ("expected `%c`, got `%d`", c, d); | |
| 23 } | |
| 24 | |
| 25 // ============================================================================ | |
| 26 // Reads a word until whitespace | |
| 27 string ScriptReader::PPReadWord (char &term) { | |
| 28 string word; | |
| 29 while (1) { | |
| 30 char c = PPReadChar(); | |
| 31 if (feof (fp[fc]) || (isspace (c) && word.len ())) { | |
| 32 term = c; | |
| 33 break; | |
| 34 } | |
| 35 word += c; | |
| 36 } | |
| 37 return word; | |
| 38 } | |
| 39 | |
| 40 // ============================================================================ | |
| 41 // Preprocess any directives found in the script file | |
| 42 void ScriptReader::PreprocessDirectives () { | |
| 43 size_t spos = ftell (fp[fc]); | |
| 44 if (!DoDirectivePreprocessing ()) | |
| 45 fseek (fp[fc], spos, SEEK_SET); | |
| 46 } | |
| 47 | |
| 48 /* ============================================================================ | |
| 49 * Returns true if the pre-processing was successful, false if not. | |
| 50 * If pre-processing was successful, the file pointer remains where | |
| 51 * it was, if not, it's pushed back to where it was before preprocessing | |
| 52 * took place and is parsed normally. | |
| 53 */ | |
| 54 bool ScriptReader::DoDirectivePreprocessing () { | |
| 55 char trash; | |
| 56 // Directives start with a pound sign | |
| 57 if (PPReadChar() != '#') | |
| 58 return false; | |
| 59 | |
| 60 // Read characters until next whitespace to | |
| 61 // build the name of the directive | |
| 62 string directive = PPReadWord (trash); | |
| 63 | |
| 64 // Now check the directive name against known names | |
| 65 if (directive == "include") { | |
| 66 // #include-directive | |
| 67 char terminator; | |
| 68 string file = PPReadWord (terminator); | |
| 69 | |
| 70 if (!file.len()) | |
| 71 ParserError ("expected file name for #include, got nothing instead"); | |
| 72 OpenFile (file); | |
| 73 return true; | |
| 74 } else if (directive == "neurosphere") { | |
| 75 // #neurosphere - activates neurosphere compatibility, aka stuff | |
| 76 // that is still WIP and what main zandronum does not yet support. | |
| 77 // Most end users should never need this. | |
| 78 g_Neurosphere = true; | |
| 79 return true; | |
| 80 } | |
| 81 | |
| 82 ParserError ("unknown directive `#%s`!", directive.chars()); | |
| 83 return false; | |
| 84 } |
