1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
|
/*
* Copyright (c) 2020, the SerenityOS developers.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#pragma once
#include "AST.h"
#include <AK/Function.h>
#include <AK/RefPtr.h>
#include <AK/String.h>
#include <AK/StringBuilder.h>
#include <AK/Vector.h>
class Parser {
public:
Parser(StringView input)
: m_input(move(input))
{
}
RefPtr<AST::Node> parse();
private:
RefPtr<AST::Node> parse_toplevel();
RefPtr<AST::Node> parse_sequence();
RefPtr<AST::Node> parse_and_logical_sequence();
RefPtr<AST::Node> parse_or_logical_sequence();
RefPtr<AST::Node> parse_variable_decls();
RefPtr<AST::Node> parse_pipe_sequence();
RefPtr<AST::Node> parse_command();
RefPtr<AST::Node> parse_control_structure();
RefPtr<AST::Node> parse_for_loop();
RefPtr<AST::Node> parse_redirection();
RefPtr<AST::Node> parse_list_expression();
RefPtr<AST::Node> parse_expression();
RefPtr<AST::Node> parse_string_composite();
RefPtr<AST::Node> parse_string();
RefPtr<AST::Node> parse_doublequoted_string_inner();
RefPtr<AST::Node> parse_variable();
RefPtr<AST::Node> parse_evaluate();
RefPtr<AST::Node> parse_comment();
RefPtr<AST::Node> parse_bareword();
RefPtr<AST::Node> parse_glob();
template<typename A, typename... Args>
NonnullRefPtr<A> create(Args... args);
bool at_end() const { return m_input.length() <= m_offset; }
char peek();
char consume();
void putback();
bool expect(char);
bool expect(const StringView&);
StringView consume_while(Function<bool(char)>);
struct ScopedOffset {
ScopedOffset(Vector<size_t>& offsets, size_t offset)
: offsets(offsets)
, offset(offset)
{
offsets.append(offset);
}
~ScopedOffset()
{
auto last = offsets.take_last();
ASSERT(last == offset);
}
Vector<size_t>& offsets;
size_t offset;
};
OwnPtr<ScopedOffset> push_start();
StringView m_input;
size_t m_offset { 0 };
Vector<size_t> m_rule_start_offsets;
};
#if 0
constexpr auto the_grammar = R"(
toplevel :: sequence?
sequence :: variable_decls? or_logical_sequence terminator sequence
| variable_decls? or_logical_sequence '&' sequence
| variable_decls? control_structure terminator sequence
| variable_decls? or_logical_sequence
| variable_decls? terminator sequence
or_logical_sequence :: and_logical_sequence '|' '|' and_logical_sequence
| and_logical_sequence
and_logical_sequence :: pipe_sequence '&' '&' and_logical_sequence
| pipe_sequence
terminator :: ';'
| '\n'
variable_decls :: identifier '=' expression (' '+ variable_decls)? ' '*
| identifier '=' '(' pipe_sequence ')' (' '+ variable_decls)? ' '*
pipe_sequence :: command '|' pipe_sequence
| command
control_structure :: for_loop
for_loop :: 'for' ws+ (identifier ' '+ 'in' ws*)? expression ws+ '{' toplevel '}'
command :: redirection command
| list_expression command?
redirection :: number? '>'{1,2} ' '* string_composite
| number? '<' ' '* string_composite
| number? '>' '&' number
| number? '>' '&' '-'
list_expression :: ' '* expression (' '+ list_expression)?
expression :: evaluate expression?
| string_composite expression?
| comment expession?
| '(' list_expression ')' expression?
evaluate :: '$' '(' pipe_sequence ')'
| '$' expression {eval / dynamic resolve}
string_composite :: string string_composite?
| variable string_composite?
| bareword string_composite?
| glob string_composite?
string :: '"' dquoted_string_inner '"'
| "'" [^']* "'"
dquoted_string_inner :: '\' . dquoted_string_inner? {concat}
| variable dquoted_string_inner? {compose}
| . dquoted_string_inner?
| '\' 'x' digit digit dquoted_string_inner?
| '\' [abefrn] dquoted_string_inner?
variable :: '$' identifier
| '$' '$'
| '$' '?'
| '$' '*'
| '$' '#'
| ...
comment :: '#' [^\n]*
bareword :: [^"'*$&#|()[\]{} ?;<>] bareword?
| '\' [^"'*$&#|()[\]{} ?;<>] bareword?
bareword_with_tilde_expansion :: '~' bareword?
glob :: [*?] bareword?
| bareword [*?]
)";
#endif
|
