1 //
2 // Copyright (C) 2016 Google, Inc.
3 //
4 // All rights reserved.
5 //
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7 // modification, are permitted provided that the following conditions
8 // are met:
9 //
10 // Redistributions of source code must retain the above copyright
11 // notice, this list of conditions and the following disclaimer.
12 //
13 // Redistributions in binary form must reproduce the above
14 // copyright notice, this list of conditions and the following
15 // disclaimer in the documentation and/or other materials provided
16 // with the distribution.
17 //
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19 // contributors may be used to endorse or promote products derived
20 // from this software without specific prior written permission.
21 //
22 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
23 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
24 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
25 // FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
26 // COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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28 // BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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32 // ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
33 // POSSIBILITY OF SUCH DAMAGE.
34 //
35
36 #include "hlslTokenStream.h"
37
38 namespace glslang {
39
pushPreToken(const HlslToken & tok)40 void HlslTokenStream::pushPreToken(const HlslToken& tok)
41 {
42 assert(preTokenStackSize < tokenBufferSize);
43 preTokenStack[preTokenStackSize++] = tok;
44 }
45
popPreToken()46 HlslToken HlslTokenStream::popPreToken()
47 {
48 assert(preTokenStackSize > 0);
49
50 return preTokenStack[--preTokenStackSize];
51 }
52
pushTokenBuffer(const HlslToken & tok)53 void HlslTokenStream::pushTokenBuffer(const HlslToken& tok)
54 {
55 tokenBuffer[tokenBufferPos] = tok;
56 tokenBufferPos = (tokenBufferPos+1) % tokenBufferSize;
57 }
58
popTokenBuffer()59 HlslToken HlslTokenStream::popTokenBuffer()
60 {
61 // Back up
62 tokenBufferPos = (tokenBufferPos+tokenBufferSize-1) % tokenBufferSize;
63
64 return tokenBuffer[tokenBufferPos];
65 }
66
67 //
68 // Make a new source of tokens, not from the source, but from an
69 // already pre-processed token stream.
70 //
71 // This interrupts current token processing which must be restored
72 // later. Some simplifying assumptions are made (and asserted).
73 //
pushTokenStream(const TVector<HlslToken> * tokens)74 void HlslTokenStream::pushTokenStream(const TVector<HlslToken>* tokens)
75 {
76 // not yet setup to interrupt a stream that has been receded
77 // and not yet reconsumed
78 assert(preTokenStackSize == 0);
79
80 // save current state
81 currentTokenStack.push_back(token);
82
83 // set up new token stream
84 tokenStreamStack.push_back(tokens);
85
86 // start position at first token:
87 token = (*tokens)[0];
88 tokenPosition.push_back(0);
89 }
90
91 // Undo pushTokenStream(), see above
popTokenStream()92 void HlslTokenStream::popTokenStream()
93 {
94 tokenStreamStack.pop_back();
95 tokenPosition.pop_back();
96 token = currentTokenStack.back();
97 currentTokenStack.pop_back();
98 }
99
100 // Load 'token' with the next token in the stream of tokens.
advanceToken()101 void HlslTokenStream::advanceToken()
102 {
103 pushTokenBuffer(token);
104 if (preTokenStackSize > 0)
105 token = popPreToken();
106 else {
107 if (tokenStreamStack.size() == 0)
108 scanner.tokenize(token);
109 else {
110 ++tokenPosition.back();
111 if (tokenPosition.back() >= (int)tokenStreamStack.back()->size())
112 token.tokenClass = EHTokNone;
113 else
114 token = (*tokenStreamStack.back())[tokenPosition.back()];
115 }
116 }
117 }
118
recedeToken()119 void HlslTokenStream::recedeToken()
120 {
121 pushPreToken(token);
122 token = popTokenBuffer();
123 }
124
125 // Return the current token class.
peek() const126 EHlslTokenClass HlslTokenStream::peek() const
127 {
128 return token.tokenClass;
129 }
130
131 // Return true, without advancing to the next token, if the current token is
132 // the expected (passed in) token class.
peekTokenClass(EHlslTokenClass tokenClass) const133 bool HlslTokenStream::peekTokenClass(EHlslTokenClass tokenClass) const
134 {
135 return peek() == tokenClass;
136 }
137
138 // Return true and advance to the next token if the current token is the
139 // expected (passed in) token class.
acceptTokenClass(EHlslTokenClass tokenClass)140 bool HlslTokenStream::acceptTokenClass(EHlslTokenClass tokenClass)
141 {
142 if (peekTokenClass(tokenClass)) {
143 advanceToken();
144 return true;
145 }
146
147 return false;
148 }
149
150 } // end namespace glslang
151