private AssignStat AssignStat() { string first = "id"; this.SkipErrors(first); var lookaheadToken = this.TokenStream.Peek(); string lookahead = lookaheadToken.AToCCFormat(); if (first.HasToken(lookahead)) { this.ApplyDerivation("assignStat -> variable '=' expr"); var assignStatement = new AssignStat(lookaheadToken.SourceLocation); var variable = Variable(); Match("="); var expr = Expr(); assignStatement.Variable = variable; assignStatement.ExpressionValue = expr; return(assignStatement); } return(null); }
public override void Visit(AssignStat assignStat) { if (assignStat.ExpressionValue is Node expression) { if (assignStat.Variable.SemanticalType != expression.SemanticalType) { ErrorManager.Add($"Could not convert {expression.SemanticalType} to a {assignStat.Variable.SemanticalType}.", assignStat.Location); } assignStat.SemanticalType = expression.SemanticalType; } else { ErrorManager.Add($"Could not establish an expression value.", assignStat.Location); } }
} // NT_Stat private static void NT_IncDecAssignOrCallStat(out Stat s) { int spix = 0; Symbol sy = null; Expr lhs = null, e = null; SrcPos sp = null; s = null; for (;;) { switch (Syn.Interpret()) { case 0: return; case 1: Lex.GETidentAttr(out spix); break; case 2: // SEM sy = SymTab.SymbolOf(spix, Symbol.Kind.varKind, Symbol.Kind.parKind, Symbol.Kind.funcKind); break; case 3: // SEM s = new IncStat(sp, new VarOperand(sy)); break; case 4: // SEM s = new DecStat(sp, new VarOperand(sy)); break; case 5: // SEM lhs = new VarOperand(sy); break; case 6: // SEM sp = new SrcPos(); break; case 7: NT_Expr(out e); break; case 8: // SEM lhs = new ArrIdxOperator(sp, new VarOperand(sy), e); break; case 9: // SEM sp = new SrcPos(); break; case 10: NT_Expr(out e); break; case 11: // SEM s = new AssignStat(sp, lhs, e); break; case 12: // SEM sp = new SrcPos(); break; case 13: NT_ActParList(out e); break; case 14: // SEM s = new CallStat(sp, sy, e); break; } // switch } // for } // NT_IncDecAssignOrCallStat
} // NT_ConstDecl private static void NT_Init(out Stat s, ref Symbol sy) { int fact = 1, number = 0; s = null; for (;;) { switch (Syn.Interpret()) { case 0: return; case 1: // SEM if (sy.type != Type.boolType) { SemErr("invalid type"); } sy.val = 0; break; case 2: // SEM if (sy.type != Type.boolType) { SemErr("invalid type"); } sy.val = 1; break; case 3: // SEM fact = -1; break; case 4: Lex.GETnumberAttr(out number); break; case 5: // SEM if (sy.type.IsPtrType()) { if (number != 0) { SemErr("invalid value"); } } else if (sy.type.kind != Type.Kind.intKind) { SemErr("invalid type"); } sy.val = fact * number; break; case 6: // SEM if (sy.kind == Symbol.Kind.varKind && loopLevel > 0) { s = new AssignStat(new SrcPos(), new VarOperand(sy), new LitOperand(sy.type, sy.val)); } break; } // switch } // for } // NT_Init
private static void CgAssignStat(FuncInfo fi, AssignStat node) { var exps = RemoveTailNil(node.ExpList); var nExps = exps.Count; var nVars = node.VarList.Count; var tRegs = new int[nVars]; var kRegs = new int[nVars]; var vRegs = new int[nVars]; var oldRegs = fi.UsedRegs; for (var i = 0; i < node.VarList.Count; i++) { var exp = node.VarList[i]; if (exp is TableAccessExp tableAccessExp) { tRegs[i] = fi.AllocReg(); CgExp(fi, tableAccessExp.PrefixExp, tRegs[i], 1); kRegs[i] = fi.AllocReg(); CgExp(fi, tableAccessExp.KeyExp, kRegs[i], 1); } else if (exp is NameExp nameExp) { var name = nameExp.Name; if (fi.SlotOfLocVar(name) < 0 && fi.IndexOfUpval(name) < 0) { kRegs[i] = -1; fi.IndexOfConstant(name, out var constIdx); if (constIdx > 0xff) { kRegs[i] = fi.AllocReg(); } } } } for (var i = 0; i < nVars; i++) { vRegs[i] = fi.UsedRegs + i; } if (nExps >= nVars) { for (var i = 0; i < exps.Count; i++) { var exp = exps[i]; var a = fi.AllocReg(); if (i >= nVars && i == nExps - 1 && IsVarargOrFuncCall(exp)) { CgExp(fi, exp, a, 0); } else { CgExp(fi, exp, a, 1); } } } else { var multRet = false; for (var i = 0; i < exps.Count; i++) { var exp = exps[i]; var a = fi.AllocReg(); if (i == nExps - 1 && IsVarargOrFuncCall(exp)) { multRet = true; var n = nVars - nExps + 1; CgExp(fi, exp, a, n); fi.AllocRegs(n - 1); } else { CgExp(fi, exp, a, 1); } } if (!multRet) { var n = nVars - nExps; var a = fi.AllocRegs(n); fi.EmitLoadNil(a, n); } } for (var i = 0; i < node.VarList.Count; i++) { var exp = node.VarList[i]; if (exp is NameExp nameExp) { var varName = nameExp.Name; var a = fi.SlotOfLocVar(varName); if (a >= 0) { fi.EmitMove(a, vRegs[i]); } else { var b = fi.IndexOfUpval(varName); if (b >= 0) { fi.EmitSetUpval(vRegs[i], b); } else { a = fi.SlotOfLocVar("_ENV"); if (a >= 0) { if (kRegs[i] < 0) { fi.IndexOfConstant(varName, out var constIdx); b = 0x100 + constIdx; fi.EmitSetTable(a, b, vRegs[i]); } else { fi.EmitSetTable(a, kRegs[i], vRegs[i]); } } else { a = fi.IndexOfUpval("_ENV"); if (kRegs[i] < 0) { fi.IndexOfConstant(varName, out var idx); b = 0x100 + idx; fi.EmitSetTabUp(a, b, vRegs[i]); } else { fi.EmitSetTable(a, kRegs[i], vRegs[i]); } } } } } else { fi.EmitSetTable(tRegs[i], kRegs[i], vRegs[i]); } } fi.UsedRegs = oldRegs; }
} // DumpSymTab // === generate source text from symbol table and AST === public static void WriteStat(Stat stat) { switch (stat.kind) { case Stat.Kind.emptyStatKind: genMcpp.WriteLine(Indent() + ";"); break; case Stat.Kind.blockStatKind: BlockStat b_s = (BlockStat)stat; genMcpp.WriteLine(Indent() + "{"); IncIndent(); WriteStatList(b_s.statList); DecIndent(); genMcpp.WriteLine(Indent() + "}"); break; case Stat.Kind.incStatKind: IncStat i_s = (IncStat)stat; genMcpp.WriteLine(Indent() + i_s.vo.sy + "++;"); break; case Stat.Kind.decStatKind: DecStat d_s = (DecStat)stat; genMcpp.WriteLine(Indent() + d_s.vo.sy + "--;"); break; case Stat.Kind.assignStatKind: AssignStat a_s = (AssignStat)stat; genMcpp.WriteLine(Indent() + a_s.lhs + " = " + a_s.rhs + ";"); break; case Stat.Kind.callStatKind: CallStat c_s = (CallStat)stat; genMcpp.WriteLine(Indent() + c_s.func + "(" + c_s.apl + ");"); break; case Stat.Kind.ifStatKind: IfStat if_s = (IfStat)stat; genMcpp.WriteLine(Indent() + "if (" + if_s.cond + ")"); IncIndent(); WriteStatList(if_s.thenStat); DecIndent(); if (if_s.elseStat != null) { genMcpp.WriteLine(Indent() + "else "); IncIndent(); WriteStatList(if_s.elseStat); DecIndent(); } // if break; case Stat.Kind.whileStatKind: WhileStat w_s = (WhileStat)stat; genMcpp.WriteLine(Indent() + "while (" + w_s.cond + ")"); IncIndent(); WriteStatList(w_s.body); DecIndent(); break; case Stat.Kind.breakStatKind: genMcpp.WriteLine(Indent() + "break;"); break; case Stat.Kind.inputStatKind: InputStat in_s = (InputStat)stat; genMcpp.WriteLine(Indent() + "cin >> " + in_s.vo.sy + ";"); break; case Stat.Kind.outputStatKind: OutputStat out_s = (OutputStat)stat; genMcpp.Write(Indent() + "cout"); foreach (Object o in out_s.values) { genMcpp.Write(" << "); if (o is Expr) { genMcpp.Write(o); } else if (o is String) { String s = o as String; if (s == "\n") { genMcpp.Write("endl"); } else { genMcpp.Write('"' + s + '"'); } } else { throw new Exception("invalid value"); } } // foreach genMcpp.WriteLine(";"); break; case Stat.Kind.deleteStatKind: DeleteStat del_s = (DeleteStat)stat; genMcpp.WriteLine(Indent() + "delete[] " + NameList.NameOf(del_s.vo.sy.spix) + ";"); break; case Stat.Kind.returnStatKind: ReturnStat r_s = (ReturnStat)stat; genMcpp.Write(Indent() + "return"); if (r_s.e != null) { genMcpp.Write(" " + r_s.e); } genMcpp.WriteLine(";"); break; default: throw new Exception("invalid statement kind"); } // switch } // WriteStatList
public virtual void Visit(AssignStat assignStat) { }
public override void Visit(AssignStat assignStat) { this.LoadAndStore(assignStat.ExpressionValue, assignStat.Variable, assignStat.ExpressionValue.NodeMemorySize, $"{assignStat}"); }