//
// Copyright (C) 2002-2005 3Dlabs Inc. Ltd.
// Copyright (C) 2013 LunarG, Inc.
//
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//
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// modification, are permitted provided that the following conditions
// are met:
//
// Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//
// 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.
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// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
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// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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//
#ifndef _GLSLANG_SCAN_INCLUDED_
#define _GLSLANG_SCAN_INCLUDED_
#include "Versions.h"
namespace glslang {
// Use a global end-of-input character, so no translation is needed across
// layers of encapsulation. Characters are all 8 bit, and positive, so there is
// no aliasing of character 255 onto -1, for example.
const int EndOfInput = -1;
//
// A character scanner that seamlessly, on read-only strings, reads across an
// array of strings without assuming null termination.
//
class TInputScanner {
public:
TInputScanner(int n, const char* const s[], size_t L[], const char* const* names = nullptr,
int b = 0, int f = 0, bool single = false) :
numSources(n),
// up to this point, common usage is "char*", but now we need positive 8-bit characters
sources(reinterpret_cast<const unsigned char* const *>(s)),
lengths(L), currentSource(0), currentChar(0), stringBias(b), finale(f), singleLogical(single),
endOfFileReached(false)
{
loc = new TSourceLoc[numSources];
for (int i = 0; i < numSources; ++i) {
loc[i].init(i - stringBias);
}
if (names != nullptr) {
for (int i = 0; i < numSources; ++i)
loc[i].name = names[i] != nullptr ? NewPoolTString(names[i]) : nullptr;
}
loc[currentSource].line = 1;
logicalSourceLoc.init(1);
logicalSourceLoc.name = loc[0].name;
}
virtual ~TInputScanner()
{
delete [] loc;
}
// retrieve the next character and advance one character
int get()
{
int ret = peek();
if (ret == EndOfInput)
return ret;
++loc[currentSource].column;
++logicalSourceLoc.column;
if (ret == '\n') {
++loc[currentSource].line;
++logicalSourceLoc.line;
logicalSourceLoc.column = 0;
loc[currentSource].column = 0;
}
advance();
return ret;
}
// retrieve the next character, no advance
int peek()
{
if (currentSource >= numSources) {
endOfFileReached = true;
return EndOfInput;
}
// Make sure we do not read off the end of a string.
// N.B. Sources can have a length of 0.
int sourceToRead = currentSource;
size_t charToRead = currentChar;
while(charToRead >= lengths[sourceToRead]) {
charToRead = 0;
sourceToRead += 1;
if (sourceToRead >= numSources) {
return EndOfInput;
}
}
// Here, we care about making negative valued characters positive
return sources[sourceToRead][charToRead];
}
// go back one character
void unget()
{
// Do not roll back once we've reached the end of the file.
if (endOfFileReached)
return;
if (currentChar > 0) {
--currentChar;
--loc[currentSource].column;
--logicalSourceLoc.column;
if (loc[currentSource].column < 0) {
// We've moved back past a new line. Find the
// previous newline (or start of the file) to compute
// the column count on the now current line.
size_t chIndex = currentChar;
while (chIndex > 0) {
if (sources[currentSource][chIndex] == '\n') {
break;
}
--chIndex;
}
logicalSourceLoc.column = (int)(currentChar - chIndex);
loc[currentSource].column = (int)(currentChar - chIndex);
}
} else {
do {
--currentSource;
} while (currentSource > 0 && lengths[currentSource] == 0);
if (lengths[currentSource] == 0) {
// set to 0 if we've backed up to the start of an empty string
currentChar = 0;
} else
currentChar = lengths[currentSource] - 1;
}
if (peek() == '\n') {
--loc[currentSource].line;
--logicalSourceLoc.line;
}
}
// for #line override
void setLine(int newLine)
{
logicalSourceLoc.line = newLine;
loc[getLastValidSourceIndex()].line = newLine;
}
// for #line override in filename based parsing
void setFile(const char* filename)
{
TString* fn_tstr = NewPoolTString(filename);
logicalSourceLoc.name = fn_tstr;
loc[getLastValidSourceIndex()].name = fn_tstr;
}
void setFile(const char* filename, int i)
{
TString* fn_tstr = NewPoolTString(filename);
if (i == getLastValidSourceIndex()) {
logicalSourceLoc.name = fn_tstr;
}
loc[i].name = fn_tstr;
}
void setString(int newString)
{
logicalSourceLoc.string = newString;
loc[getLastValidSourceIndex()].string = newString;
logicalSourceLoc.name = nullptr;
loc[getLastValidSourceIndex()].name = nullptr;
}
// for #include content indentation
void setColumn(int col)
{
logicalSourceLoc.column = col;
loc[getLastValidSourceIndex()].column = col;
}
void setEndOfInput()
{
endOfFileReached = true;
currentSource = numSources;
}
bool atEndOfInput() const { return endOfFileReached; }
const TSourceLoc& getSourceLoc() const
{
if (singleLogical) {
return logicalSourceLoc;
} else {
return loc[std::max(0, std::min(currentSource, numSources - finale - 1))];
}
}
// Returns the index (starting from 0) of the most recent valid source string we are reading from.
int getLastValidSourceIndex() const { return std::min(currentSource, numSources - 1); }
void consumeWhiteSpace(bool& foundNonSpaceTab);
bool consumeComment();
void consumeWhitespaceComment(bool& foundNonSpaceTab);
bool scanVersion(int& version, EProfile& profile, bool& notFirstToken);
protected:
// advance one character
void advance()
{
++currentChar;
if (currentChar >= lengths[currentSource]) {
++currentSource;
if (currentSource < numSources) {
loc[currentSource].string = loc[currentSource - 1].string + 1;
loc[currentSource].line = 1;
loc[currentSource].column = 0;
}
while (currentSource < numSources && lengths[currentSource] == 0) {
++currentSource;
if (currentSource < numSources) {
loc[currentSource].string = loc[currentSource - 1].string + 1;
loc[currentSource].line = 1;
loc[currentSource].column = 0;
}
}
currentChar = 0;
}
}
int numSources; // number of strings in source
const unsigned char* const *sources; // array of strings; must be converted to positive values on use, to avoid aliasing with -1 as EndOfInput
const size_t *lengths; // length of each string
int currentSource;
size_t currentChar;
// This is for reporting what string/line an error occurred on, and can be overridden by #line.
// It remembers the last state of each source string as it is left for the next one, so unget()
// can restore that state.
TSourceLoc* loc; // an array
int stringBias; // the first string that is the user's string number 0
int finale; // number of internal strings after user's last string
TSourceLoc logicalSourceLoc;
bool singleLogical; // treats the strings as a single logical string.
// locations will be reported from the first string.
// Set to true once peek() returns EndOfFile, so that we won't roll back
// once we've reached EndOfFile.
bool endOfFileReached;
};
} // end namespace glslang
#endif // _GLSLANG_SCAN_INCLUDED_