/* Performs semantic analysis on the program. Returns null if any of the phases
* fails. If a fatal error is encountered in one phase, analysis will not continue,
* but internal recovery is attempted within each phase of analysis.
*
* The phases are:
* 1. Building a symbol table. This checks that there are no name clashes in
* type declarations or cyclic dependencies. Cyclic dependencies are treated
* as fatal errors and will lead to type and reference checks not being run.
* If name clashes are found, the compiler will not even proceed to check
* cyclic dependencies. This is also treated as a fatal error.
* 2. Semantic checks. This phase checks first the validity of name references
* and then performs type checks on all expressions. References to possibly
* uninitialized variables are also detected.
*
* All errors are logged in the error log.
*/
private bool ConstructSymbolTableAndCheckProgram(Program abstractSyntaxTree)
{
var symbolTableSuccess = new SymbolTableBuilder(abstractSyntaxTree, _errorLog).BuildSymbolTable();
bool semanticCheckSuccess = true;
if (symbolTableSuccess != SymbolTableBuilder.ExitCode.FatalError)
{
semanticCheckSuccess = new SemanticsChecker(abstractSyntaxTree, _errorLog).RunCheck();
}
return (symbolTableSuccess == SymbolTableBuilder.ExitCode.Success) && semanticCheckSuccess;
}
public TypeChecker(SemanticsChecker parent)
{
_parent = parent;
_returnTypes = new Stack<IType>();
_checkOK = true;
}
