Home | History | Annotate | Download | only in hlsl 
      1 //
      2 // Copyright (C) 2016 Google, Inc.
      3 //
      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
      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 //
     18 //    Neither the name of Google, Inc., nor the names of its
     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,
     27 // INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
     28 // BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     29 // LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
     30 // CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31 // LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
     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 
     40 void HlslTokenStream::pushPreToken(const HlslToken& tok)
     41 {
     42     assert(preTokenStackSize < tokenBufferSize);
     43     preTokenStack[preTokenStackSize++] = tok;
     44 }
     45 
     46 HlslToken HlslTokenStream::popPreToken()
     47 {
     48     assert(preTokenStackSize > 0);
     49 
     50     return preTokenStack[--preTokenStackSize];
     51 }
     52 
     53 void HlslTokenStream::pushTokenBuffer(const HlslToken& tok)
     54 {
     55     tokenBuffer[tokenBufferPos] = tok;
     56     tokenBufferPos = (tokenBufferPos+1) % tokenBufferSize;
     57 }
     58 
     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 //
     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
     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.
    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 
    119 void HlslTokenStream::recedeToken()
    120 {
    121     pushPreToken(token);
    122     token = popTokenBuffer();
    123 }
    124 
    125 // Return the current token class.
    126 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.
    133 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.
    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