// ParsePreprocessorDirective
//------------------------------------------------------------------------------
bool BFFParser::ParsePreprocessorDirective( BFFIterator & iter )
{
const BFFIterator directiveStart( iter );
// skip directive start token
ASSERT( *iter == BFF_PREPROCESSOR_START );
iter++;
// allow whitepace before directive name
iter.SkipWhiteSpace();
// start of directive name
BFFIterator directiveStartIter( iter );
// find end of directive
while ( iter.IsAtValidDirectiveNameCharacter() )
{
iter++;
}
BFFIterator directiveEndIter( iter );
iter.SkipWhiteSpace();
// determine directive
AStackString< MAX_DIRECTIVE_NAME_LENGTH > directive( directiveStartIter.GetCurrent(), directiveEndIter.GetCurrent() );
if ( directive == "include" )
{
return ParseIncludeDirective( iter );
}
else if ( directive == "once" )
{
FBuild::Get().GetDependencyGraph().SetCurrentFileAsOneUse();
return true;
}
else if ( directive == "define" )
{
return ParseDefineDirective( iter );
}
else if ( directive == "undef" )
{
return ParseUndefDirective( iter );
}
else if ( directive == "if" )
{
return ParseIfDirective( directiveStart, iter );
}
else if ( directive == "endif" )
{
return ParseEndIfDirective( directiveStartIter );
}
else if ( directive == "import" )
{
return ParseImportDirective( directiveStart, iter );
}
// unknown
Error::Error_1030_UnknownDirective( directiveStartIter, directive );
return false;
}
// ParseIfDirective
//------------------------------------------------------------------------------
bool BFFParser::ParseIfDirective( const BFFIterator & directiveStart, BFFIterator & iter )
{
if ( iter.IsAtEnd() )
{
Error::Error_1012_UnexpectedEndOfFile( iter );
return false;
}
bool negate = false;
if ( *iter == '!' )
{
negate = true; // the condition will be inverted
iter++; // skip '!'
iter.SkipWhiteSpace(); // allow whitepace after '!'
if ( iter.IsAtEnd() )
{
Error::Error_1012_UnexpectedEndOfFile( iter );
return false;
}
}
// parse out condition
const BFFIterator conditionStart( iter );
iter.SkipVariableName();
if ( conditionStart.GetCurrent() == iter.GetCurrent() )
{
Error::Error_1007_ExpectedVariable( directiveStart, nullptr );
return false;
}
const BFFIterator conditionEnd( iter );
// Evaluate the condition
bool result;
if ( CheckIfCondition( conditionStart, conditionEnd, result ) == false )
{
return false; // CheckIfCondition will have emitted an error
}
// #ifndef ?
if ( negate )
{
result = !( result );
}
if ( result )
{
++s_IfDepth; // Track that we're inside an if block
return true; // continue parsing like normal
}
// Advance iterator past entire #if block
size_t depth = 1; // handle nested ifs
while ( depth > 0 )
{
// did we hit the end of the file?
if ( iter.IsAtEnd() )
{
(void)directiveStart; // TODO: Show we're looking for matching endif to this
Error::Error_1012_UnexpectedEndOfFile( iter ); // TODO:B better error for this?
return false;
}
// find the next preprocessor directive
iter.SkipWhiteSpace();
if ( *iter == BFF_PREPROCESSOR_START )
{
iter++; // skip #
iter.SkipWhiteSpace(); // allow whitespace between # and directive
const BFFIterator directiveNameStart( iter );
while ( iter.IsAtValidDirectiveNameCharacter() )
{
iter++;
}
const BFFIterator directiveNameEnd( iter );
AStackString<> directiveName( directiveNameStart.GetCurrent(), directiveNameEnd.GetCurrent() );
if ( directiveName == "endif" )
{
--depth;
}
else if ( directiveName == "if" )
{
++depth;
}
// continue to skip rest of line....
}
// skip rest of line
while ( ( iter.IsAtEnd() == false ) &&
( *iter != '\r' ) &&
( *iter != '\n' ) )
{
iter++;
}
}
return true;
}