1 /* Copyright 2002, 2020 Rene Rivera.
2 ** Distributed under the Boost Software License, Version 1.0.
3 ** (See accompanying file LICENSE_1_0.txt or http://www.boost.org/LICENSE_1_0.txt)
4 */
5
6 #include <cstdio>
7 #include <string>
8 #include <algorithm>
9 #include <cctype>
10 #include <set>
11 #include <cstring>
12
13 /*
14 # yyacc - yacc wrapper
15 #
16 # Allows tokens to be written as `literal` and then automatically
17 # substituted with #defined tokens.
18 #
19 # Usage:
20 # yyacc file.y filetab.h file.yy
21 #
22 # inputs:
23 # file.yy yacc grammar with ` literals
24 #
25 # outputs:
26 # file.y yacc grammar
27 # filetab.h array of string <-> token mappings
28 #
29 # 3-13-93
30 # Documented and p moved in sed command (for some reason,
31 # s/x/y/p doesn't work).
32 # 10-12-93
33 # Take basename as second argument.
34 # 12-31-96
35 # reversed order of args to be compatible with GenFile rule
36 # 11-20-2002
37 # Reimplemented as a C program for portability. (Rene Rivera)
38 # 05-xx-2020
39 # Reimplement yet again, in C++. (Rene Rivera)
40 */
41
42 static const std::string usage[] = {
43 "yyacc <grammar output.y> <token table output.h> <grammar source.yy>"
44 };
45
print_usage()46 void print_usage()
47 {
48 for (auto u: usage)
49 {
50 std::printf("%s\n", u.c_str());
51 }
52 }
53
tokenize_string(std::string s)54 std::string tokenize_string(std::string s)
55 {
56 std::string result = s;
57 if (s == ":") result = "_colon";
58 else if (s == "!") result = "_bang";
59 else if (s == "!=") result = "_bang_equals";
60 else if (s == "&&") result = "_amperamper";
61 else if (s == "&") result = "_amper";
62 else if (s == "+") result = "_plus";
63 else if (s == "+=") result = "_plus_equals";
64 else if (s == "||") result = "_barbar";
65 else if (s == "|") result = "_bar";
66 else if (s == ";") result = "_semic";
67 else if (s == "-") result = "_minus";
68 else if (s == "<") result = "_langle";
69 else if (s == "<=") result = "_langle_equals";
70 else if (s == ">") result = "_rangle";
71 else if (s == ">=") result = "_rangle_equals";
72 else if (s == ".") result = "_period";
73 else if (s == "?") result = "_question";
74 else if (s == "?=") result = "_question_equals";
75 else if (s == "=") result = "_equals";
76 else if (s == ",") result = "_comma";
77 else if (s == "[") result = "_lbracket";
78 else if (s == "]") result = "_rbracket";
79 else if (s == "{") result = "_lbrace";
80 else if (s == "}") result = "_rbrace";
81 else if (s == "(") result = "_lparen";
82 else if (s == ")") result = "_rparen";
83
84 std::transform(
85 result.begin(), result.end(), result.begin(),
86 [](unsigned char c){ return std::toupper(c); });
87 return result+"_t";
88 }
89
90 struct literal
91 {
92 std::string string;
93 std::string token;
94
operator <literal95 bool operator<(const literal & x) const
96 {
97 return this->string < x.string;
98 }
99 };
100
main(int argc,char ** argv)101 int main(int argc, char ** argv)
102 {
103 int result = 0;
104 if (argc != 4)
105 {
106 print_usage();
107 result = 1;
108 }
109 else
110 {
111 FILE * token_output_f = 0;
112 FILE * grammar_output_f = 0;
113 FILE * grammar_source_f = 0;
114
115 grammar_source_f = fopen(argv[3],"r");
116 if (grammar_source_f == 0) { result = 1; }
117 if (result == 0)
118 {
119 std::set<literal> literals;
120 char l[2048];
121 while (1)
122 {
123 if (fgets(l,2048,grammar_source_f) != 0)
124 {
125 char * c = l;
126 while (1)
127 {
128 char * c1 = std::strchr(c,'`');
129 if (c1 != 0)
130 {
131 char * c2 = std::strchr(c1+1,'`');
132 if (c2 != 0)
133 {
134 auto l = std::string(c1+1,c2-c1-1);
135 literals.insert({ l, tokenize_string(l) });
136 c = c2+1;
137 }
138 else
139 break;
140 }
141 else
142 break;
143 }
144 }
145 else
146 {
147 break;
148 }
149 }
150 token_output_f = std::fopen(argv[2],"w");
151 if (token_output_f != 0)
152 {
153 for (const literal & l: literals)
154 {
155 std::fprintf(token_output_f," { \"%s\", %s },\n",l.string.c_str(), l.token.c_str());
156 }
157 std::fclose(token_output_f);
158 }
159 else
160 result = 1;
161 if (result == 0)
162 {
163 grammar_output_f = std::fopen(argv[1],"w");
164 if (grammar_output_f != 0)
165 {
166 for (const literal & l: literals)
167 {
168 fprintf(grammar_output_f,"%%token %s\n",l.token.c_str());
169 }
170 rewind(grammar_source_f);
171 while (1)
172 {
173 if (fgets(l,2048,grammar_source_f) != 0)
174 {
175 char * c = l;
176 while (1)
177 {
178 char * c1 = strchr(c,'`');
179 if (c1 != 0)
180 {
181 char * c2 = strchr(c1+1,'`');
182 if (c2 != 0)
183 {
184 auto replacement = literals.find({std::string(c1+1,c2-c1-1), ""});
185 *c1 = 0;
186 std::fprintf(grammar_output_f,"%s%s",c,replacement->token.c_str());
187 c = c2+1;
188 }
189 else
190 {
191 std::fprintf(grammar_output_f,"%s",c);
192 break;
193 }
194 }
195 else
196 {
197 std::fprintf(grammar_output_f,"%s",c);
198 break;
199 }
200 }
201 }
202 else
203 {
204 break;
205 }
206 }
207 std::fclose(grammar_output_f);
208 }
209 else
210 result = 1;
211 }
212 }
213 if (result != 0)
214 {
215 perror("yyacc");
216 }
217 }
218 return result;
219 }
220