// Semantic resolution
protected override Exp ResolveExpAsRight(ISemanticResolver s)
{
// We have a problem. If our arg is a property, then we need to
// transform this x++ --> x = x + 1
// But we can't always transform since we can overload the ++, -- operators.
// So resolve our arg, see if it's a property, and then transform if it is.
// Since we update the Arg, we must resolve it as a left value
Exp.ResolveExpAsLeft(ref this.m_exp, s);
// First check if we have an overload
// Check if we're a property
if (m_exp is PropertyExp)
{
Exp e = null;
int iDelta = IsInc ? 1 : -1;
e = new AssignStmtExp(
m_exp,
new BinaryExp(
m_exp,
new IntExp(iDelta, this.m_filerange),
BinaryExp.BinaryOp.cAdd
)
);
Exp.ResolveExpAsRight(ref e, s);
return e;
}
CalcCLRType(s);
// Ensure type match, unless we have an overload.
s.EnsureAssignable(Arg, typeof(int));
return this;
}
// Do the real work
protected void ParseStatementOrLocal_Helper(out Statement s, out LocalVarDecl v)
{
s = null;
v = null;
// For each statement, we know which type based off the first token.
// Expect for an identifier, in which case it could be a few things.
Token t = m_lexer.PeekNextToken();
#if false
// Skip past any ';' (as empty statements)
while(t.TokenType == Token.Type.cSemi)
{
ConsumeNextToken();
t = m_lexer.PeekNextToken();
}
#endif
if (IsStartOfExp(t))
{
FileRange f = BeginRange();
// This could be either an expression or a type
Exp e = ParseExp();
t = m_lexer.PeekNextToken();
// Case 1 - Var declaration:
// If an identifier follows, then we just read a type and this is
// a var declaration:
// Type id ';'
// Type id '=' exp ';'
if (t.TokenType == Token.Type.cId)
{
TypeSig tSig = this.ConvertExpToType(e);
Identifier id = ReadExpectedIdentifier();
v = new LocalVarDecl(id, tSig);
// Check for optional assignment (if there's an '=' after the name)
Token t3 = m_lexer.PeekNextToken();
if (t3.TokenType == Token.Type.cAssign)
{
ConsumeNextToken(); // '='
Exp eRHS = ParseExp(); // exp
ReadExpectedToken(Token.Type.cSemi); // ';'
SimpleObjExp oleft = new SimpleObjExp(id);
StatementExp se = new AssignStmtExp(oleft, eRHS);
s = new ExpStatement(se);
se.SetLocation(EndRange(f));
} else {
ReadExpectedToken(Token.Type.cSemi); // ';'
}
return;
} // end decl case
// Case 2 - label declaration
else if (t.TokenType == Token.Type.cColon)
{
SimpleObjExp o2 = e as SimpleObjExp;
if (o2 != null)
{
ConsumeNextToken(); // ':'
s = new LabelStatement(o2.Name);
return; // skip reading a ';'
}
ThrowError(new ParserErrorException(Code.cBadLabelDef, t.Location,
"Bad label definition (labels must be a single identifier)"));
} // end case for label decls
// Expect a StatementExp
else if (t.TokenType == Token.Type.cSemi) {
ReadExpectedToken(Token.Type.cSemi);
// Else we must be a StatementExp
StatementExp se = e as StatementExp;
if (se == null)
//this.ThrowError_ExpectedStatementExp(e.Location);
ThrowError(E_ExpectedStatementExp(e.Location));
se.SetLocation(EndRange(f));
s = new ExpStatement(se);
return;
}
ThrowError(E_UnexpectedToken(t));
} // end start of expressions
switch(t.TokenType)
{
// Empty statement
case Token.Type.cSemi:
ConsumeNextToken();
s = new EmptyStatement();
break;
// Return -> 'return' ';'
// | 'return' exp ';'
case Token.Type.cReturn:
{
ConsumeNextToken();
t = m_lexer.PeekNextToken();
Exp e = null;
if (t.TokenType != Token.Type.cSemi)
{
e = ParseExp();
}
ReadExpectedToken(Token.Type.cSemi);
s = new ReturnStatement(e);
}
break;
// Note that the semi colons are included inthe stmt
// IfSmt -> 'if' '(' exp ')' stmt:then
// IfSmt -> 'if' '(' exp ')' stmt:then 'else' stmt:else
case Token.Type.cIf:
{
ConsumeNextToken(); // 'if'
ReadExpectedToken(Token.Type.cLParen);
Exp exp = ParseExp();
ReadExpectedToken(Token.Type.cRParen);
Statement sThen = ParseStatement();
Statement sElse = null;
Token t2 = m_lexer.PeekNextToken();
if (t2.TokenType == Token.Type.cElse)
{
ConsumeNextToken(); // 'else'
sElse = ParseStatement();
}
s = new IfStatement(exp, sThen, sElse);
}
break;
case Token.Type.cSwitch:
s = ParseSwitchStatement();
break;
// Throw an expression
// ThrowStmt -> 'throw' objexp
case Token.Type.cThrow:
{
ConsumeNextToken(); // 'throw'
Exp oe = null;
if (m_lexer.PeekNextToken().TokenType != Token.Type.cSemi)
{
oe = ParseExp();
}
ReadExpectedToken(Token.Type.cSemi);
s = new ThrowStatement(oe);
}
break;
// try-catch-finally
case Token.Type.cTry:
s = ParseTryCatchFinallyStatement();
break;
// while loop
// 'while' '(' exp ')' stmt
case Token.Type.cWhile:
{
ConsumeNextToken(); // 'while'
ReadExpectedToken(Token.Type.cLParen);
Exp e = ParseExp();
ReadExpectedToken(Token.Type.cRParen);
Statement body = ParseStatement();
s = new WhileStatement(e, body);
}
break;
// do loop
// 'do' stmt 'while' '(' exp ')' ';'
case Token.Type.cDo:
{
ConsumeNextToken(); // 'do'
Statement body = ParseStatement();
ReadExpectedToken(Token.Type.cWhile);
ReadExpectedToken(Token.Type.cLParen);
Exp e = ParseExp();
ReadExpectedToken(Token.Type.cRParen);
ReadExpectedToken(Token.Type.cSemi);
s = new DoStatement(e, body);
}
break;
// goto
// 'goto' id:label ';'
case Token.Type.cGoto:
{
ConsumeNextToken(); // 'goto'
Identifier id = ReadExpectedIdentifier(); // id:label
ReadExpectedToken(Token.Type.cSemi); // ';'
s = new GotoStatement(id);
}
break;
// break
// 'break' ';'
case Token.Type.cBreak:
ConsumeNextToken();
ReadExpectedToken(Token.Type.cSemi);
s = new BreakStatement();
break;
// Continue
// 'continue' ';'
case Token.Type.cContinue:
ConsumeNextToken();
ReadExpectedToken(Token.Type.cSemi);
s = new ContinueStatement();
break;
// For-loop
case Token.Type.cFor:
s = ParseForStatement();
break;
// For-each
// -> 'foreach' '(' Type id 'in' exp:collection ')' stmt
case Token.Type.cForEach:
s = ParseForeachStatement();
break;
// BlockStatement - can be nested inside each other
// start with a '{', no terminating semicolon
case Token.Type.cLCurly:
{
s = ParseStatementBlock();
}
break;
default:
ThrowError(E_UnexpectedToken(t)); // unrecognized statement
break;
} // end switch
// Must have come up with something
Debug.Assert(s != null || v != null);
}
// Group 0) assignment (=, +=, etc) & conditional ?:
protected Exp ParseExp_Worker()
{
Exp T = ParseExp1();
Token t = m_lexer.PeekNextToken();
// Assignment
if (t.TokenType == Token.Type.cAssign)
{
ConsumeNextToken();
Exp E = ParseExp();
AssignStmtExp s = new AssignStmtExp(T, E);
return s;
}
// ?: operator --> E ? E : E
if (t.TokenType == Token.Type.cQuestion)
{
ConsumeNextToken();
Exp eTrue = ParseExp();
ReadExpectedToken(Token.Type.cColon);
Exp eFalse = ParseExp();
return new IfExp(T, eTrue, eFalse);
}
else {
// Look for +=,-=,*=,/=,%=
AST.BinaryExp.BinaryOp op = BinaryExp.BinaryOp.cEqu; // set to dummy
switch(t.TokenType)
{
// Arithmetic
case Token.Type.cPlusEqual:
op = BinaryExp.BinaryOp.cAdd;
break;
case Token.Type.cMinusEqual:
op = BinaryExp.BinaryOp.cSub;
break;
case Token.Type.cMulEqual:
op = BinaryExp.BinaryOp.cMul;
break;
case Token.Type.cDivEqual:
op = BinaryExp.BinaryOp.cDiv;
break;
case Token.Type.cModEqual:
op = BinaryExp.BinaryOp.cMod;
break;
// Bitwise
case Token.Type.cBitwiseAndEqual:
op = BinaryExp.BinaryOp.cBitwiseAnd;
break;
case Token.Type.cBitwiseOrEqual:
op = BinaryExp.BinaryOp.cBitwiseOr;
break;
case Token.Type.cBitwiseXorEqual:
op = BinaryExp.BinaryOp.cBitwiseXor;
break;
// Shift
case Token.Type.cShiftLeftEqual:
op = BinaryExp.BinaryOp.cShiftLeft;
break;
case Token.Type.cShiftRightEqual:
op = BinaryExp.BinaryOp.cShiftRight;
break;
}
if (op != BinaryExp.BinaryOp.cEqu)
{
ConsumeNextToken();
Exp E = ParseExp();
//return new OpEqualStmtExp(T, E, op);
// Transform 'a X= b' -> 'a = (a X b)'
// This makes things much more consistent.
AST.AssignStmtExp assign = new AssignStmtExp(
T,
new BinaryExp(
T,
E,
op)
);
return assign;
}
}
Debug.Assert(T != null);
return T;
}
// Resolve
protected override Exp ResolveExpAsRight(ISemanticResolver s)
{
if (m_symbol != null)
return this;
// Resolve the type we're allocating
m_tFullType.ResolveType(s);
Debug.Assert(this.ElemType != null);
// Resolve the initializer list
if (HasInitializerList)
{
// If we specified a length, it'd better match the intializer list length.
if (DimensionExpList != null)
{
Debug.Assert(this.DimensionExpList.Length == 1, "@todo -multidimensional arrays");
Exp e = DimensionExpList[0];
// e must be a compile time constant who's value matches the ArrayInit length
IntExp eInt = e as IntExp;
if (eInt == null)
ThrowError(SymbolError.MustBeCompileTimeConstant(e));
if (eInt.Value != m_ArrayInit.Length)
ThrowError(SymbolError.NewArrayBoundsMismatch(this));
}
m_ArrayInit.Resolve(s, this.ElemType);
// The ability to not specifiy a dimension list is just syntactic sugar.
// So if we still don't have it, we'd better fill it in based of the array-init list.
if (DimensionExpList == null)
{
m_arExpList = new Exp[] { new IntExp(m_ArrayInit.Length, this.Location) };
}
}
Debug.Assert(DimensionExpList != null);
for(int i = 0; i < this.m_arExpList.Length; i++)
{
ResolveExpAsRight(ref m_arExpList[i], s);
}
m_symbol = new ArrayTypeEntry(m_tFullType, s);
CalcCLRType(s);
// Transform an initializer list into an CompoundExpression:
// new T[] { e0, e1, ... en}
// <DeclareTemp(x), x = new T[], x[0]=e0, ... x[n]=en, x>
if (HasInitializerList)
{
DeclareLocalStmtExp declare_x = new DeclareLocalStmtExp(this.ArraySymbol);
LocalExp x = declare_x.GetLocal();
StatementExp [] list = new StatementExp[m_ArrayInit.Length + 2];
list[0] = declare_x;
list[1] = new AssignStmtExp(x, this);
for(int i = 0; i < m_ArrayInit.Length; i++)
list[i + 2] = new AssignStmtExp(
new ArrayAccessExp(
x,
new IntExp(i, null)
),
m_ArrayInit.GetExpAt(i)
);
// Strip the ArrayInitializer off this node.
m_ArrayInit = null;
StatementExp c = new CompoundStmtExp(list, x);
StatementExp.ResolveExpAsRight(ref c, s);
return c;
} // end has Initializer
return this;
}
