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Commit b159bd58 by John Kessenich
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Merge pull request #38 from google/preprocessing-line-number

Preprocessing line number handling
parents 62aa5bdf 79f6451b
Showing with 90 additions and 51 deletions
glslang/MachineIndependent/ShaderLang.cpp
......@@ -599,6 +599,67 @@ bool ProcessDeferred(
return success;
}
// Responsible for keeping track of the most recent source string and line in
// the preprocessor and outputting newlines appropriately if the source string
// or line changes.
class SourceLineSynchronizer {
public:
SourceLineSynchronizer(const std::function<int()>& lastSourceIndex,
std::stringstream* output)
: getLastSourceIndex(lastSourceIndex), output(output) {}
SourceLineSynchronizer(const SourceLineSynchronizer&) = delete;
SourceLineSynchronizer& operator=(const SourceLineSynchronizer&) = delete;
// Sets the internally tracked source string index to that of the most
// recently read token. If we switched to a new source string, returns
// true and inserts a newline. Otherwise, returns false and outputs nothing.
bool syncToMostRecentString() {
if (getLastSourceIndex() != lastSource) {
// After switching to a new source string, we need to reset lastLine
// because line number resets every time a new source string is
// used. We also need to output a newline to separate the output
// from the previous source string (if there is one).
if (lastSource != -1 || lastLine != 0)
*output << std::endl;
lastSource = getLastSourceIndex();
lastLine = -1;
return true;
}
return false;
}
// Calls syncToMostRecentString() and then sets the internally tracked line
// number to tokenLine. If we switched to a new line, returns true and inserts
// newlines appropriately. Otherwise, returns false and outputs nothing.
bool syncToLine(int tokenLine) {
syncToMostRecentString();
const bool newLineStarted = lastLine < tokenLine;
for (; lastLine < tokenLine; ++lastLine) {
if (lastLine > 0) *output << std::endl;
}
return newLineStarted;
}
// Sets the internally tracked line number to newLineNum.
void setLineNum(int newLineNum) { lastLine = newLineNum; }
private:
// A function for getting the index of the last valid source string we've
// read tokens from.
const std::function<int()> getLastSourceIndex;
// output stream for newlines.
std::stringstream* output;
// lastSource is the source string index (starting from 0) of the last token
// processed. It is tracked in order for newlines to be inserted when a new
// source string starts. -1 means we haven't started processing any source
// string.
int lastSource = -1;
// lastLine is the line number (starting from 1) of the last token processed.
// It is tracked in order for newlines to be inserted when a token appears
// on a new line. 0 means we haven't started processing any line in the
// current source string.
int lastLine = 0;
};
// DoPreprocessing is a valid ProcessingContext template argument,
// which only performs the preprocessing step of compilation.
......@@ -615,99 +676,77 @@ struct DoPreprocessing {
static const std::string noSpaceBeforeTokens = ",";
glslang::TPpToken token;
std::stringstream outputStream;
int lastLine = -1; // lastLine is the line number of the last token
// processed. It is tracked in order for new-lines to be inserted when
// a token appears on a new line.
int lastToken = -1;
parseContext.setScanner(&input);
ppContext.setInput(input, versionWillBeError);
// Inserts newlines and incremnets lastLine until
// lastLine >= line.
auto adjustLine = [&lastLine, &outputStream](int line) {
int tokenLine = line - 1;
while(lastLine < tokenLine) {
if (lastLine >= 0) {
outputStream << std::endl;
}
++lastLine;
}
};
std::stringstream outputStream;
SourceLineSynchronizer lineSync(
std::bind(&TInputScanner::getLastValidSourceIndex, &input), &outputStream);
parseContext.setExtensionCallback([&adjustLine, &outputStream](
parseContext.setExtensionCallback([&lineSync, &outputStream](
int line, const char* extension, const char* behavior) {
adjustLine(line);
lineSync.syncToLine(line);
outputStream << "#extension " << extension << " : " << behavior;
});
parseContext.setLineCallback([&adjustLine, &lastLine, &outputStream, &parseContext](
int curLineNo, int newLineNo, bool hasSource, int sourceNum) {
parseContext.setLineCallback([&lineSync, &outputStream, &parseContext](
int curLineNum, int newLineNum, bool hasSource, int sourceNum) {
// SourceNum is the number of the source-string that is being parsed.
adjustLine(curLineNo);
outputStream << "#line " << newLineNo;
lineSync.syncToLine(curLineNum);
outputStream << "#line " << newLineNum;
if (hasSource) {
outputStream << " " << sourceNum;
}
if (parseContext.lineDirectiveShouldSetNextLine()) {
// newLineNo is the new line number for the line following the #line
// newLineNum is the new line number for the line following the #line
// directive. So the new line number for the current line is
newLineNo -= 1;
newLineNum -= 1;
}
outputStream << std::endl;
// Line number starts from 1. And we are at the next line of the #line
// directive now. So lastLine (from 0) should be (newLineNo - 1) + 1.
lastLine = newLineNo;
// And we are at the next line of the #line directive now.
lineSync.setLineNum(newLineNum + 1);
});
parseContext.setVersionCallback(
[&adjustLine, &outputStream](int line, int version, const char* str) {
adjustLine(line);
[&lineSync, &outputStream](int line, int version, const char* str) {
lineSync.syncToLine(line);
outputStream << "#version " << version;
if (str) {
outputStream << " " << str;
}
});
parseContext.setPragmaCallback([&adjustLine, &outputStream](
parseContext.setPragmaCallback([&lineSync, &outputStream](
int line, const glslang::TVector<glslang::TString>& ops) {
adjustLine(line);
lineSync.syncToLine(line);
outputStream << "#pragma ";
for(size_t i = 0; i < ops.size(); ++i) {
outputStream << ops[i];
}
});
parseContext.setErrorCallback([&adjustLine, &outputStream](
parseContext.setErrorCallback([&lineSync, &outputStream](
int line, const char* errorMessage) {
adjustLine(line);
lineSync.syncToLine(line);
outputStream << "#error " << errorMessage;
});
int lastToken = EOF; // lastToken records the last token processed.
while (const char* tok = ppContext.tokenize(&token)) {
int tokenLine = token.loc.line - 1; // start at 0;
bool newLine = false;
while (lastLine < tokenLine) {
if (lastLine > -1) {
outputStream << std::endl;
newLine = true;
}
++lastLine;
if (lastLine == tokenLine) {
// Don't emit whitespace onto empty lines.
// Copy any whitespace characters at the start of a line
// from the input to the output.
for(int i = 0; i < token.loc.column - 1; ++i) {
outputStream << " ";
}
}
bool isNewString = lineSync.syncToMostRecentString();
bool isNewLine = lineSync.syncToLine(token.loc.line);
if (isNewLine) {
// Don't emit whitespace onto empty lines.
// Copy any whitespace characters at the start of a line
// from the input to the output.
outputStream << std::string(token.loc.column - 1, ' ');
}
// Output a space in between tokens, but not at the start of a line,
// and also not around special tokens. This helps with readability
// and consistency.
if (!newLine &&
lastToken != -1 &&
if (!isNewString && !isNewLine && lastToken != -1 &&
(unNeededSpaceTokens.find((char)token.token) == std::string::npos) &&
(unNeededSpaceTokens.find((char)lastToken) == std::string::npos) &&
(noSpaceBeforeTokens.find((char)token.token) == std::string::npos)) {
......
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