internal IOperand CompileForm([NotNull] IRoutineBuilder rb, [NotNull] ZilForm form, bool wantResult,
IVariable resultStorage)
{
using (DiagnosticContext.Push(form.SourceLine))
{
var unwrapped = form.Unwrap(Context);
if (!ReferenceEquals(unwrapped, form))
{
switch (unwrapped)
{
case ZilForm newForm:
form = newForm;
break;
default:
return(wantResult ? CompileAsOperand(rb, unwrapped, form.SourceLine, resultStorage) : null);
}
}
if (!(form.First is ZilAtom head))
{
Context.HandleError(new CompilerError(form, CompilerMessages.FORM_Must_Start_With_An_Atom));
return(wantResult ? Game.Zero : null);
}
// built-in statements handled by ZBuiltins
var zversion = Context.ZEnvironment.ZVersion;
Debug.Assert(form.Rest != null);
var argCount = form.Rest.Count();
if (wantResult)
{
// prefer the value version, then value+predicate, predicate, void
if (ZBuiltins.IsBuiltinValueCall(head.Text, zversion, argCount))
{
return(ZBuiltins.CompileValueCall(head.Text, this, rb, form, resultStorage));
}
if (ZBuiltins.IsBuiltinValuePredCall(head.Text, zversion, argCount))
{
var label1 = rb.DefineLabel();
resultStorage = resultStorage ?? rb.Stack;
ZBuiltins.CompileValuePredCall(head.Text, this, rb, form, resultStorage, label1, true);
rb.MarkLabel(label1);
return(resultStorage);
}
if (ZBuiltins.IsBuiltinPredCall(head.Text, zversion, argCount))
{
var label1 = rb.DefineLabel();
var label2 = rb.DefineLabel();
resultStorage = resultStorage ?? rb.Stack;
ZBuiltins.CompilePredCall(head.Text, this, rb, form, label1, true);
rb.EmitStore(resultStorage, Game.Zero);
rb.Branch(label2);
rb.MarkLabel(label1);
rb.EmitStore(resultStorage, Game.One);
rb.MarkLabel(label2);
return(resultStorage);
}
if (ZBuiltins.IsBuiltinVoidCall(head.Text, zversion, argCount))
{
ZBuiltins.CompileVoidCall(head.Text, this, rb, form);
return(Game.One);
}
}
else
{
// prefer the void version, then predicate, value, value+predicate
// (predicate saves a cleanup instruction)
if (ZBuiltins.IsBuiltinVoidCall(head.Text, zversion, argCount))
{
ZBuiltins.CompileVoidCall(head.Text, this, rb, form);
return(null);
}
if (ZBuiltins.IsBuiltinPredCall(head.Text, zversion, argCount))
{
var dummy = rb.DefineLabel();
ZBuiltins.CompilePredCall(head.Text, this, rb, form, dummy, true);
rb.MarkLabel(dummy);
return(null);
}
if (ZBuiltins.IsBuiltinValueCall(head.Text, zversion, argCount))
{
if (ZBuiltins.CompileValueCall(head.Text, this, rb, form, null) == rb.Stack)
{
rb.EmitPopStack();
}
return(null);
}
if (ZBuiltins.IsBuiltinValuePredCall(head.Text, zversion, argCount))
{
var label1 = rb.DefineLabel();
ZBuiltins.CompileValuePredCall(head.Text, this, rb, form, rb.Stack, label1, true);
rb.MarkLabel(label1);
rb.EmitPopStack();
return(null);
}
}
// routine calls
var obj = Context.GetZVal(Context.ZEnvironment.InternGlobalName(head));
while (obj is ZilConstant cnst)
{
obj = cnst.Value;
}
switch (obj)
{
case ZilRoutine rtn:
// check argument count
var args = form.Skip(1).ToArray();
if (args.Length < rtn.ArgSpec.MinArgCount ||
rtn.ArgSpec.MaxArgCount != null && args.Length > rtn.ArgSpec.MaxArgCount)
{
Context.HandleError(CompilerError.WrongArgCount(
rtn.Name?.ToString() ?? "<unnamed routine>",
new ArgCountRange(rtn.ArgSpec.MinArgCount, rtn.ArgSpec.MaxArgCount)));
return(wantResult ? Game.Zero : null);
}
// compile routine call
resultStorage = wantResult ? (resultStorage ?? rb.Stack) : null;
using (var argOperands = CompileOperands(rb, form.SourceLine, args))
{
rb.EmitCall(Routines[head], argOperands.AsArray(), resultStorage);
}
return(resultStorage);
case ZilFalse _:
// this always returns 0. we can eliminate the call if none of the arguments have side effects.
var argsWithSideEffects = form.Skip(1).Where(HasSideEffects).ToArray();
if (argsWithSideEffects.Length <= 0)
{
return(Game.Zero);
}
resultStorage = wantResult ? (resultStorage ?? rb.Stack) : null;
using (var argOperands = CompileOperands(rb, form.SourceLine, argsWithSideEffects))
{
var operands = argOperands.AsArray();
if (operands.Any(o => o == rb.Stack))
{
rb.EmitCall(Game.Zero, operands.Where(o => o == rb.Stack).ToArray(), resultStorage);
}
}
return(resultStorage);
default:
// unrecognized
if (!ZBuiltins.IsNearMatchBuiltin(head.Text, zversion, argCount, out var error))
{
error = new CompilerError(CompilerMessages.Unrecognized_0_1, "routine or instruction", head);
}
Context.HandleError(error);
return(wantResult ? Game.Zero : null);
}
}
}
internal void CompileCondition([NotNull] IRoutineBuilder rb, [NotNull] ZilObject expr, [NotNull] ISourceLine src,
[NotNull] ILabel label, bool polarity)
{
expr = expr.Unwrap(Context);
var type = expr.StdTypeAtom;
// ReSharper disable once SwitchStatementMissingSomeCases
switch (type)
{
case StdAtom.FALSE:
if (polarity == false)
{
rb.Branch(label);
}
return;
case StdAtom.ATOM:
var atom = (ZilAtom)expr;
if (atom.StdAtom != StdAtom.T && atom.StdAtom != StdAtom.ELSE)
{
// could be a missing , or . before variable name
var warning = new CompilerError(src, CompilerMessages.Bare_Atom_0_Treated_As_True_Here, expr);
if (Locals.ContainsKey(atom) || Globals.ContainsKey(atom))
{
warning = warning.Combine(new CompilerError(src, CompilerMessages.Did_You_Mean_The_Variable));
}
Context.HandleError(warning);
}
if (polarity)
{
rb.Branch(label);
}
return;
case StdAtom.FIX:
bool nonzero = ((ZilFix)expr).Value != 0;
if (polarity == nonzero)
{
rb.Branch(label);
}
return;
case StdAtom.FORM:
// handled below
break;
default:
Context.HandleError(new CompilerError(expr.SourceLine ?? src, CompilerMessages.Expressions_Of_This_Type_Cannot_Be_Compiled));
return;
}
// it's a FORM
var form = (ZilForm)expr;
if (!(form.First is ZilAtom head))
{
Context.HandleError(new CompilerError(form, CompilerMessages.FORM_Must_Start_With_An_Atom));
return;
}
// check for standard built-ins
// prefer the predicate version, then value, value+predicate, void
// (value+predicate is hard to clean up)
var zversion = Context.ZEnvironment.ZVersion;
var argCount = form.Count() - 1;
if (ZBuiltins.IsBuiltinPredCall(head.Text, zversion, argCount))
{
ZBuiltins.CompilePredCall(head.Text, this, rb, form, label, polarity);
return;
}
if (ZBuiltins.IsBuiltinValueCall(head.Text, zversion, argCount))
{
var result = ZBuiltins.CompileValueCall(head.Text, this, rb, form, rb.Stack);
BranchIfNonZero(result);
return;
}
if (ZBuiltins.IsBuiltinValuePredCall(head.Text, zversion, argCount))
{
if (rb.CleanStack)
{
/* wasting the branch and checking the result with ZERO? is more efficient
* than using the branch and having to clean the result off the stack */
var noBranch = rb.DefineLabel();
ZBuiltins.CompileValuePredCall(head.Text, this, rb, form, rb.Stack, noBranch, true);
rb.MarkLabel(noBranch);
rb.BranchIfZero(rb.Stack, label, !polarity);
}
else
{
ZBuiltins.CompileValuePredCall(head.Text, this, rb, form, rb.Stack, label, polarity);
}
return;
}
if (ZBuiltins.IsBuiltinVoidCall(head.Text, zversion, argCount))
{
ZBuiltins.CompileVoidCall(head.Text, this, rb, form);
// void calls return true
if (polarity)
{
rb.Branch(label);
}
return;
}
// special cases
var op1 = CompileAsOperand(rb, form, form.SourceLine);
BranchIfNonZero(op1);
void BranchIfNonZero(IOperand operand)
{
if (operand is INumericOperand numericResult)
{
if (numericResult.Value != 0 == polarity)
{
rb.Branch(label);
}
}
else
{
rb.BranchIfZero(operand, label, !polarity);
}
}
}
internal IOperand CompileAsOperandWithBranch([NotNull] IRoutineBuilder rb, [NotNull] ZilObject expr,
[CanBeNull] IVariable resultStorage,
[NotNull] ILabel label, bool polarity, [CanBeNull][InstantHandle] Func <IVariable> tempVarProvider = null)
{
expr = expr.Unwrap(Context);
IOperand result = resultStorage;
switch (expr)
{
case ZilFalse _:
if (resultStorage == null)
{
result = Game.Zero;
}
else
{
rb.EmitStore(resultStorage, Game.Zero);
}
if (polarity == false)
{
rb.Branch(label);
}
return(result);
case ZilFix fix:
if (resultStorage == null)
{
result = Game.MakeOperand(fix.Value);
}
else
{
rb.EmitStore(resultStorage, Game.MakeOperand(fix.Value));
}
bool nonzero = fix.Value != 0;
if (polarity == nonzero)
{
rb.Branch(label);
}
return(result);
case ZilForm form:
if (!(form.First is ZilAtom head))
{
Context.HandleError(new CompilerError(form, CompilerMessages.FORM_Must_Start_With_An_Atom));
return(Game.Zero);
}
// check for standard built-ins
// prefer the value+predicate version, then value, predicate, void
var zversion = Context.ZEnvironment.ZVersion;
var argCount = form.Count() - 1;
if (ZBuiltins.IsBuiltinValuePredCall(head.Text, zversion, argCount))
{
if (resultStorage == null)
{
Debug.Assert(tempVarProvider != null);
resultStorage = tempVarProvider();
}
ZBuiltins.CompileValuePredCall(head.Text, this, rb, form, resultStorage, label, polarity);
return(resultStorage);
}
if (ZBuiltins.IsBuiltinValueCall(head.Text, zversion, argCount))
{
result = ZBuiltins.CompileValueCall(head.Text, this, rb, form, resultStorage);
if (resultStorage != null && resultStorage != result)
{
rb.EmitStore(resultStorage, result);
result = resultStorage;
}
else if (resultStorage == null && result == rb.Stack)
{
Debug.Assert(tempVarProvider != null);
resultStorage = tempVarProvider();
rb.EmitStore(resultStorage, result);
result = resultStorage;
}
rb.BranchIfZero(result, label, !polarity);
return(result);
}
if (ZBuiltins.IsBuiltinPredCall(head.Text, zversion, argCount))
{
if (resultStorage == null)
{
Debug.Assert(tempVarProvider != null);
resultStorage = tempVarProvider();
}
var label1 = rb.DefineLabel();
var label2 = rb.DefineLabel();
ZBuiltins.CompilePredCall(head.Text, this, rb, form, label1, true);
rb.EmitStore(resultStorage, Game.Zero);
rb.Branch(polarity ? label2 : label);
rb.MarkLabel(label1);
rb.EmitStore(resultStorage, Game.One);
if (polarity)
{
rb.Branch(label);
}
rb.MarkLabel(label2);
return(resultStorage);
}
if (ZBuiltins.IsBuiltinVoidCall(head.Text, zversion, argCount))
{
ZBuiltins.CompileVoidCall(head.Text, this, rb, form);
// void calls return true
if (resultStorage == null)
{
result = Game.One;
}
else
{
rb.EmitStore(resultStorage, Game.One);
}
if (polarity)
{
rb.Branch(label);
}
return(result);
}
// for anything more complicated, treat it as a value
result = CompileAsOperand(rb, form, form.SourceLine, resultStorage);
if (resultStorage != null && resultStorage != result)
{
rb.EmitStore(resultStorage, result);
result = resultStorage;
}
else if (resultStorage == null && result == rb.Stack)
{
Debug.Assert(tempVarProvider != null);
resultStorage = tempVarProvider();
rb.EmitStore(resultStorage, result);
result = resultStorage;
}
rb.BranchIfZero(result, label, !polarity);
return(result);
default:
var constValue = CompileConstant(expr);
if (constValue == null)
{
Context.HandleError(new CompilerError(expr, CompilerMessages.Expressions_Of_This_Type_Cannot_Be_Compiled));
return(Game.Zero);
}
else
{
if (resultStorage == null)
{
result = constValue;
}
else
{
rb.EmitStore(resultStorage, constValue);
}
if (polarity)
{
rb.Branch(label);
}
}
return(result);
}
}