src/preprocessor.cxx

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1 /*
2 * botc source code
3 * Copyright (C) 2012 Santeri `Dusk` Piippo
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions are met:
8 *
9 * 1. Redistributions of source code must retain the above copyright notice,
10 * this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright notice,
12 * this list of conditions and the following disclaimer in the documentation
13 * and/or other materials provided with the distribution.
14 * 3. Neither the name of the developer nor the names of its contributors may
15 * be used to endorse or promote products derived from this software without
16 * specific prior written permission.
17 * 4. Redistributions in any form must be accompanied by information on how to
18 * obtain complete source code for the software and any accompanying
19 * software that uses the software. The source code must either be included
20 * in the distribution or be available for no more than the cost of
21 * distribution plus a nominal fee, and must be freely redistributable
22 * under reasonable conditions. For an executable file, complete source
23 * code means the source code for all modules it contains. It does not
24 * include source code for modules or files that typically accompany the
25 * major components of the operating system on which the executable file
26 * runs.
27 *
28 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
29 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
31 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
32 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
33 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
34 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
35 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
36 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
37 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
38 * POSSIBILITY OF SUCH DAMAGE.
39 */
40
41 #define __PARSER_CXX__
42
43 #include <stdio.h>
44 #include <stdlib.h>
45 #include "common.h"
46 #include "str.h"
47 #include "scriptreader.h"
48
49 /* Since the preprocessor is *called* from ReadChar and I don't want
50 * to worry about recursive preprocessing, the preprocessor uses its
51 * own bare-bones variant of the function for file reading.
52 */
53 char ScriptReader::PPReadChar () {
54 char c;
55 if (!fread (&c, sizeof (char), 1, fp[fc]))
56 return 0;
57 curchar[fc]++;
58 return c;
59 }
60
61 void ScriptReader::PPMustChar (char c) {
62 char d = PPReadChar ();
63 if (c != d)
64 ParserError ("expected `%c`, got `%d`", c, d);
65 }
66
67 // ============================================================================
68 // Reads a word until whitespace
69 str ScriptReader::PPReadWord (char &term) {
70 str word;
71 while (1) {
72 char c = PPReadChar();
73 if (feof (fp[fc]) || (IsCharWhitespace (c) && word.len ())) {
74 term = c;
75 break;
76 }
77 word += c;
78 }
79 return word;
80 }
81
82 // ============================================================================
83 // Preprocess any directives found in the script file
84 void ScriptReader::PreprocessDirectives () {
85 size_t spos = ftell (fp[fc]);
86 if (!DoDirectivePreprocessing ())
87 fseek (fp[fc], spos, SEEK_SET);
88 }
89
90 /* ============================================================================
91 * Returns true if the pre-processing was successful, false if not.
92 * If pre-processing was successful, the file pointer remains where
93 * it was, if not, it's pushed back to where it was before preprocessing
94 * took place and is parsed normally.
95 */
96 bool ScriptReader::DoDirectivePreprocessing () {
97 char trash;
98 // Directives start with a pound sign
99 if (PPReadChar() != '#')
100 return false;
101
102 // Read characters until next whitespace to
103 // build the name of the directive
104 str directive = PPReadWord (trash);
105
106 // Now check the directive name against known names
107 if (directive == "include") {
108 // #include-directive
109 char terminator;
110 str file = PPReadWord (terminator);
111
112 if (!file.len())
113 ParserError ("expected file name for #include, got nothing instead");
114 OpenFile (file);
115 return true;
116 } else if (directive == "neurosphere") {
117 // #neurosphere - activates neurosphere compatibility, aka stuff
118 // that is still WIP and what main zandronum does not yet support.
119 // Most end users should never need this.
120 g_Neurosphere = true;
121 return true;
122 }
123
124 ParserError ("unknown directive `#%s`!", directive.chars());
125 return false;
126 }

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