1 /*
2 * Copyright (c) 2024, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 #pragma once
27 #include <vector>
28 #include <cstring>
29 #include <iostream>
30 #include <iomanip>
31 #include <stack>
32
33 struct Cursor {
34 private:
35 std::stack<const char *> where;
36 public:
37 char *ptr;
38 Cursor(char *ptr): ptr(ptr) {
39 }
40 virtual ~Cursor() {
41 }
42 void in(const char * location){
43 where.push(location);
44 }
45 void out(){
46 where.pop();
47 }
48 private:
49 Cursor *skipWhiteSpace() {
50 while (*ptr == ' ' || *ptr == '\n' || *ptr == '\t') {
51 step(1);
52 }
53 return this;
54 }
55
56
57 Cursor *skipIdentifier() {
58 while (peekAlpha() || peekDigit()) {
59 step(1);
60 }
61 return this;
62 }
63 public:
64 void step(int count) {
65 while (count--) {
66 ptr++;
67 }
68 }
69
70 bool peekAlpha() {
71 skipWhiteSpace();
72 return (::isalpha(*ptr));
73 }
74
75 bool peekDigit() {
76 skipWhiteSpace();
77 return (::isdigit(*ptr));
78 }
79
80 bool is(char ch) {
81 skipWhiteSpace();
82 if (*ptr == ch) {
83 step(1);
84 return true;
85 }
86 return false;
87 }
88 bool isColon() {
89 return is(':');
90 }
91
92 bool expect(char ch, const char *context, int line ) {
93 if (is(ch)){
94 return true;
95 }
96 if (!where.empty()){
97 std::cerr << where.top() << " ";
98 }
99 std::cerr << "@" << line << ": parse error expecting '" << ch << "' "<< context <<" looking at " << ptr << std::endl;
100 exit(1);
101 return false;
102 }
103 bool expect(char ch, int line ) {
104 return expect(ch, "", line);
105 }
106 bool expectDigit(const char *context, int line ) {
107 if (::isdigit(*ptr)){
108 return true;
109 }
110 if (!where.empty()){
111 std::cerr << where.top() << " ";
112 }
113 std::cerr << "@" << line << ": parse error expecting digit "<< context <<" looking at " << ptr << std::endl;
114 exit(1);
115 return false;
116 }
117 bool expectAlpha(const char *context, int line ) {
118 if (::isalpha(*ptr)){
119 return true;
120 }
121 if (!where.empty()){
122 std::cerr << where.top() << " ";
123 }
124 std::cerr << "@" << line << ": parse error expecting alpha "<< context <<" looking at " << ptr << std::endl;
125 exit(1);
126 return false;
127 }
128 bool isEither(char ch1, char ch2, char*actual) {
129 skipWhiteSpace();
130 if (*ptr == ch1 || *ptr == ch2) {
131 step(1);
132 *actual = *ptr;
133 return true;
134 }
135 return false;
136 }
137 void expectEither(char ch1, char ch2, char*actual, int line) {
138 skipWhiteSpace();
139 if (*ptr == ch1 || *ptr == ch2) {
140 step(1);
141 *actual = *ptr;
142 return;
143 }
144 if (!where.empty()){
145 std::cerr << where.top() << " ";
146 }
147 std::cerr << "@" << line << ": parse error expecting '" << ch1 << "' or '"<<ch2<< "' looking at " << ptr << std::endl;
148 exit(1);
149
150 }
151 /*bool is(char *str) {
152 skipWhiteSpace();
153 int count = 0;
154 char *safePtr = ptr;
155 while (*str && *ptr && *str == *ptr) {
156 ptr++;
157 str++;
158 count++;
159 }
160 if (count > 0 && *str == '\0') {
161 step(count);
162 return true;
163 }
164 ptr = safePtr;
165 return false;
166 }*/
167
168 int getInt() {
169 int value = *ptr - '0';
170 step(1);
171 if (peekDigit()) {
172 return value * 10 + getInt();
173 }
174 return value;
175 }
176
177 long getLong() {
178 long value = *ptr - '0';
179 step(1);
180 if (peekDigit()) {
181 return value * 10 + getLong();
182 }
183 return value;
184 }
185
186 char *getIdentifier() {
187 char *identifierStart = ptr;
188 skipIdentifier();
189 size_t len = ptr - identifierStart;
190 char *identifier = new char[len + 1];
191 std::memcpy(identifier, identifierStart, len);
192 identifier[len] = '\0';
193 return identifier;
194 }
195
196 void error(std::ostream &ostream, const char *file, int line, const char *str) {
197 ostream << file << ":" << "@" << line << ": parse error " << str << " looking at " << ptr << std::endl;
198 exit(1);
199 }
200
201 };
202 ;