/// <summary>
/// Parses an #undef directive, starting at the character following "undef".
/// Updates this.preprocessorDefinedSymbols and adds a directive object to this.PreprocessorInformation.
/// Leaves this.fragmentIndex pointing to the start of the current line.
/// </summary>
/// <param name="include">True if the definition is part of an included block. If false, the directive is parsed but ignored.</param>
private void ParseUndefine(bool include)
//^ requires this.errorIndex < this.fragmentIndex;
//^ requires this.fragmentIndex > this.startOfCurrentLine;
//^ ensures this.startOfCurrentLine == this.fragmentIndex;
{
if (!this.allowPPDefinitions) {
this.HandleError(Error.PPDefFollowsToken);
this.SkipRestOfDirective();
return;
}
if (!Scanner.IsBlankSpace(this.GetCurrentChar())) {
this.errorIndex = this.fragmentIndex;
this.SkipRestOfDirective();
//^ assume this.fragmentIndex > this.errorIndex;
this.HandleError(Error.ExpectedIdentifier);
return;
}
string s = this.ScanIdentifier();
//^ assert this.startOfCurrentLine <= this.fragmentIndex-s.Length;
if (s == "true" || s == "false") {
//^ assume s.Length > 0;
this.errorIndex = this.fragmentIndex-s.Length;
this.HandleError(Error.ExpectedIdentifier);
this.SkipRestOfDirective();
return;
}
if (include) this.preprocessorDefinedSymbols.Remove(s);
PreprocessorSymbol sym = new PreprocessorSymbol(s, this.GetSourceLocation(this.fragmentIndex-s.Length, s.Length));
ISourceLocation loc = this.GetSourceLocation(this.startOfCurrentLine, this.fragmentIndex-this.startOfCurrentLine);
//^ assume loc.Contains(sym.SourceLocation);
this.preprocessorInformation.directives.Add(new UndefDirective(sym, loc));
this.SkipPastBlanksCommentAndNewLine();
}
internal UndefDirective(PreprocessorSymbol definedSymbol, ISourceLocation sourceLocation)
: base(sourceLocation)
// ^ requires sourceLocation.Contains(definedSymbol.SourceLocation);
{
this.definedSymbol = definedSymbol;
}
internal override Directive MakeShallowCopy(ISourceDocument newDocumentToPreprocess)
//^^ requires newDocumentToPreprocess.IsUpdatedVersionOf(this.SourceLocation.SourceDocument);
{
ISourceLocation sloc = this.SourceLocation;
//^ assume newDocumentToPreprocess.IsUpdatedVersionOf(sloc.SourceDocument); //follows from the precondition
ISourceLocation dsloc = this.DefinedSymbol.SourceLocation;
//^ assume sloc.Contains(dsloc); //follows from the preconditon of the constructor
PreprocessorSymbol newSymbol = new PreprocessorSymbol(this.DefinedSymbol.Name, newDocumentToPreprocess.GetCorrespondingSourceLocation(dsloc));
return new UndefDirective(newSymbol, newDocumentToPreprocess.GetCorrespondingSourceLocation(sloc));
}
/// <summary>
/// Allocates an object that models a preprocessor #define directive.
/// </summary>
/// <param name="definedSymbol">The preprocessor symbol that is defined by this directive.</param>
/// <param name="sourceLocation">The location in the source document where the #define directive appears.</param>
internal DefineDirective(PreprocessorSymbol definedSymbol, ISourceLocation sourceLocation)
: base(sourceLocation)
{
this.definedSymbol = definedSymbol;
}
