private SimanticsBlock FindSwitchBlockStart(SimanticsBlock end)
{
while (end.Parent != null)
{
if (end.BlockType == SimanticsBlockType.Switch)
{
return(end);
}
end = end.Parent;
}
return(null);
}
private void OutputBlock(SimanticsBlock block, CSTranslationClass cls)
{
for (int i = 0; i < block.IBody.Count - 1; i++)
{
var inst = block.IBody[i];
var body = cls.Instructions[inst.Index];
switch (body.ReturnType)
{
case PrimitiveReturnType.SimanticsTrue:
case PrimitiveReturnType.SimanticsTrueFalse: //truefalse result discarded, same destination
WriteLines(body.Body, true); break;
case PrimitiveReturnType.NativeStatementTrue:
case PrimitiveReturnType.NativeStatementTrueFalse: //truefalse result discarded, same destination
WriteLines(body.Body, false); break;
case PrimitiveReturnType.NativeExpressionTrueFalse:
//we have a problem... the expression needs to evaluate, but we don't do anything with the result.
//put it in the boolean temp and ignore it.
if (body.Body.Count == 1)
{
WriteLine($"_bResult = {body.Body.First()};");
}
else
{
WriteLines(body.Body, true);
}
break;
case PrimitiveReturnType.SimanticsSubroutine:
//a subroutine that yields but doesn't branch.
default:
throw new Exception("Non-statement in the middle of a sequence (detected areas with no branching)?");
}
}
var lastInst = block.IBody[block.IBody.Count - 1];
var lastBody = cls.Instructions[lastInst.Index];
LastInstruction = block.LastInstructionIndex;
string caseConst = null;
if (block.BlockType == SimanticsBlockType.Switch ||
block.BlockType == SimanticsBlockType.SwitchCase ||
block.BlockType == SimanticsBlockType.SwitchLast)
{
caseConst = CSScopeMemory.GetConstant(Context, block.SwitchOperand.RhsOwner, block.SwitchOperand.RhsData);
}
switch (block.BlockType)
{
case SimanticsBlockType.InstructionSequence:
case SimanticsBlockType.IfElse:
//just set the instruction based on the value and return back to the while loop
if (lastBody.ReturnType == PrimitiveReturnType.SimanticsSubroutine || lastInst.Yields)
{
UpdateInstruction();
if (lastBody.Body.Count > 1)
{
WriteLines(lastBody.Body, false);
WriteLine($"return _sResult;");
}
else
{
WriteLine($"return {lastBody.Body.First()};");
}
break;
}
switch (lastBody.ReturnType)
{
case PrimitiveReturnType.NativeStatementTrueFalse:
if (lastInst.Instruction.TruePointer == lastInst.Instruction.FalsePointer)
{
goto case PrimitiveReturnType.NativeStatementTrue;
}
WriteLines(lastBody.Body, false);
WriteLine("if (_bResult) ");
OutputBinaryBranch(lastInst.Instruction, cls);
break;
case PrimitiveReturnType.NativeExpressionTrueFalse:
if (lastInst.Instruction.TruePointer == lastInst.Instruction.FalsePointer)
{
WriteLine($"_bResult = {lastBody.Body.First()}; //true and false do the same thing");
OutputReturnBlockOrJump(lastInst.Instruction.TruePointer, cls);
}
else
{
WriteLine($"if ({lastBody.Body.First()}) ");
OutputBinaryBranch(lastInst.Instruction, cls);
}
break;
case PrimitiveReturnType.SimanticsTrueFalse:
if (lastInst.Instruction.TruePointer == lastInst.Instruction.FalsePointer)
{
goto case PrimitiveReturnType.SimanticsTrue;
}
WriteLine($"if ({lastBody.Body.First()} == VMPrimitiveExitCode.GOTO_TRUE) ");
OutputBinaryBranch(lastInst.Instruction, cls);
break;
case PrimitiveReturnType.SimanticsStatement:
if (lastInst.Instruction.TruePointer == lastInst.Instruction.FalsePointer)
{
WriteLines(lastBody.Body, false);
OutputReturnBlockOrJump(lastInst.Instruction.TruePointer, cls);
}
else
{
WriteLines(lastBody.Body, false);
WriteLine($"if (_sResult == VMPrimitiveExitCode.GOTO_TRUE) ");
OutputBinaryBranch(lastInst.Instruction, cls);
}
break;
case PrimitiveReturnType.NativeStatementTrue:
WriteLines(lastBody.Body, false);
OutputReturnBlockOrJump(lastInst.Instruction.TruePointer, cls);
break;
case PrimitiveReturnType.SimanticsTrue:
WriteLines(lastBody.Body, true);
OutputReturnBlockOrJump(lastInst.Instruction.TruePointer, cls);
break;
}
if (block.Parent == cls.Structure.RootBlock && cls.HasGlobalSwitch)
{
WriteLine("break;");
}
break;
case SimanticsBlockType.Switch:
string switchLhs = CSScopeMemory.GetExpression(Context, block.SwitchOperand.LhsOwner, block.SwitchOperand.LhsData, true);
WriteLine($"switch ({switchLhs}) ");
WriteLine("{");
IndentLevel++;
WriteLine($"case {caseConst}:");
IndentLevel++;
var set = new HashSet <string> {
caseConst
};
cls.SwitchPreviousCases[block] = set;
OutputReturnBlockOrJump(lastInst.Instruction.TruePointer, cls);
WriteLine($"break;");
IndentLevel--;
OutputReturnBlockOrJump(lastInst.Instruction.FalsePointer, cls);
break;
case SimanticsBlockType.SwitchCase:
var cset = cls.SwitchPreviousCases[FindSwitchBlockStart(block)];
if (cset.Contains(caseConst))
{
WriteLine($"// case {caseConst} duplicated! skipped block at {lastInst.Instruction.FalsePointer}");
}
else
{
cset.Add(caseConst);
WriteLine($"case {caseConst}:");
IndentLevel++;
OutputReturnBlockOrJump(lastInst.Instruction.TruePointer, cls);
WriteLine($"break;");
IndentLevel--;
}
OutputReturnBlockOrJump(lastInst.Instruction.FalsePointer, cls);
break;
case SimanticsBlockType.SwitchLast:
var lset = cls.SwitchPreviousCases[FindSwitchBlockStart(block)];
if (lset.Contains(caseConst))
{
WriteLine($"// case {caseConst} duplicated! skipped block at {lastInst.Instruction.FalsePointer}");
}
else
{
lset.Add(caseConst);
WriteLine($"case {caseConst}:");
IndentLevel++;
OutputReturnBlockOrJump(lastInst.Instruction.TruePointer, cls);
WriteLine($"break;");
IndentLevel--;
}
WriteLine($"default:");
IndentLevel++;
OutputReturnBlockOrJump(lastInst.Instruction.FalsePointer, cls);
WriteLine($"break;");
IndentLevel--;
IndentLevel--;
WriteLine("}");
if (FindSwitchBlockStart(block).Parent == cls.Structure.RootBlock && cls.HasGlobalSwitch)
{
WriteLine("break;");
}
break;
default:
throw new Exception($"Block type {block.BlockType.ToString()} not yet implemented.");
}
//our last instruction
}
