protected IEnumerable <Opcode> BuildBoilerplateLoader()
{
List <Opcode> boilerplate = new List <Opcode>();
InternalPath path = new BuiltInPath();
// First label of the load/runner will be called "@LR00", which is important because that's
// what we hardcode all the compiler-built VisitRunStatement's to call out to:
labelCounter = 0;
labelFormat = "@LR{0:D2}";
boilerplate.Add(new OpcodePushScope(-999, 0)
{
Label = nextLabel, SourcePath = path
});
// High level kerboscript function calls flip the argument orders for us, but
// low level kRISC does not so the parameters have to be read in stack order:
// store parameter 2 in a local name:
boilerplate.Add(new OpcodeStoreLocal("$runonce")
{
Label = nextLabel, SourcePath = path
});
// store parameter 1 in a local name:
boilerplate.Add(new OpcodeStoreLocal("$filename")
{
Label = nextLabel, SourcePath = path
});
// Unconditionally call load() no matter what. load() will abort and return
// early if the program was already compiled, and tell us that on the stack:
boilerplate.Add(new OpcodePush(new kOS.Safe.Execution.KOSArgMarkerType())
{
Label = nextLabel, SourcePath = path
});
boilerplate.Add(new OpcodePush("$filename")
{
Label = nextLabel, SourcePath = path
});
boilerplate.Add(new OpcodeEval()
{
Label = nextLabel, SourcePath = path
});
boilerplate.Add(new OpcodePush(true)
{
Label = nextLabel, SourcePath = path
}); // the flag that tells load() to abort early if it's already loaded:
boilerplate.Add(new OpcodePush(null)
{
Label = nextLabel, SourcePath = path
});
boilerplate.Add(new OpcodeCall("load()")
{
Label = nextLabel, SourcePath = path
});
// Stack now has the 2 return values of load():
// Topmost value is a boolean flag for whether or not the program was already loaded.
// Second-from-top value is the entry point into the program.
// If load() didn't claim the program was already loaded, or if we aren't operating
// in "once" mode, then jump to the part where we call the loaded program, else
// fall through to a dummy do-nothing return for the "run once, but it already ran" case:
Opcode branchFromOne = new OpcodeBranchIfFalse()
{
Label = nextLabel, SourcePath = path
};
boilerplate.Add(branchFromOne);
boilerplate.Add(new OpcodePush("$runonce")
{
Label = nextLabel, SourcePath = path
});
Opcode branchFromTwo = new OpcodeBranchIfFalse()
{
Label = nextLabel, SourcePath = path
};
boilerplate.Add(branchFromTwo);
boilerplate.Add(new OpcodePop()
{
Label = nextLabel, SourcePath = path
}); // onsume the entry point that load() returned. We won't be calling it.
boilerplate.Add(new OpcodePush(0)
{
Label = nextLabel, SourcePath = path
}); // ---+-- The dummy do-nothing return.
boilerplate.Add(new OpcodeReturn(1)
{
Label = nextLabel, SourcePath = path
}); // ---'
// Actually call the Program from its entry Point, which is now the thing left on top
// of the stack from the second return value of load():
Opcode branchTo = new OpcodeStoreLocal("$entrypoint")
{
Label = nextLabel, SourcePath = path
};
boilerplate.Add(branchTo);
boilerplate.Add(new OpcodeCall("$entrypoint")
{
Label = nextLabel, SourcePath = path
});
boilerplate.Add(new OpcodePop()
{
Label = nextLabel, SourcePath = path
});
boilerplate.Add(new OpcodePush(0)
{
Label = nextLabel, SourcePath = path
});
boilerplate.Add(new OpcodeReturn(1)
{
Label = nextLabel, SourcePath = path
});
branchFromOne.DestinationLabel = branchTo.Label;
branchFromTwo.DestinationLabel = branchTo.Label;
return(boilerplate);
}
protected IEnumerable <Opcode> BuildBoilerplateLoader()
{
List <Opcode> boilerplate = new List <Opcode>();
InternalPath path = new BuiltInPath();
// First label of the load/runner will be called "@LR00", which is important because that's
// what we hardcode all the compiler-built VisitRunStatement's to call out to:
labelCounter = 0;
labelFormat = "@LR{0:D2}";
boilerplate.Add(new OpcodePushScope(-999, 0)
{
Label = nextLabel, SourcePath = path
});
// High level kerboscript function calls flip the argument orders for us, but
// low level kRISC does not so the parameters have to be read in stack order:
// store parameter 2 in a local name:
boilerplate.Add(new OpcodeStoreLocal("$runonce")
{
Label = nextLabel, SourcePath = path
});
// store parameter 1 in a local name:
boilerplate.Add(new OpcodeStoreLocal("$filename")
{
Label = nextLabel, SourcePath = path
});
// Unconditionally call load() no matter what. load() will abort and return
// early if the program was already compiled, and tell us that on the stack:
boilerplate.Add(new OpcodePush(new kOS.Safe.Execution.KOSArgMarkerType())
{
Label = nextLabel, SourcePath = path
});
boilerplate.Add(new OpcodePush("$filename")
{
Label = nextLabel, SourcePath = path
});
boilerplate.Add(new OpcodeEval()
{
Label = nextLabel, SourcePath = path
});
boilerplate.Add(new OpcodePush(true)
{
Label = nextLabel, SourcePath = path
}); // the flag that tells load() to abort early if it's already loaded:
boilerplate.Add(new OpcodePush(null)
{
Label = nextLabel, SourcePath = path
});
boilerplate.Add(new OpcodeCall("load()")
{
Label = nextLabel, SourcePath = path
});
// Stack now has the 2 return values of load():
// Topmost value is a boolean flag for whether or not the program was already loaded.
// Second-from-top value is the entry point into the program.
// If load() didn't claim the program was already loaded, or if we aren't operating
// in "once" mode, then jump to the part where we call the loaded program, else
// fall through to a dummy do-nothing return for the "run once, but it already ran" case:
Opcode branchFromOne = new OpcodeBranchIfFalse()
{
Label = nextLabel, SourcePath = path
};
boilerplate.Add(branchFromOne);
boilerplate.Add(new OpcodePush("$runonce")
{
Label = nextLabel, SourcePath = path
});
Opcode branchFromTwo = new OpcodeBranchIfFalse()
{
Label = nextLabel, SourcePath = path
};
boilerplate.Add(branchFromTwo);
// If we fall through to this opcode (the br.false above doesn't jump), we are
// in the "program already ran, so skip running it" clause of a RUN ONCE.
// In that case the stack will still have the jump address returned by load(),
// and also all the args that were meant to be passed to the program (which is not
// getting run.) In that case, we need to pop the stack of everything above the
// next KOSArgMarker to emulate what a call would have done to the stack had it run.
Opcode loopStart = new OpcodePop()
{
Label = nextLabel, SourcePath = path
};
boilerplate.Add(loopStart);
boilerplate.Add(new OpcodeTestArgBottom()
{
Label = nextLabel, SourcePath = path
});
Opcode branchThatExitsLoop = new OpcodeBranchIfTrue()
{
Label = nextLabel, SourcePath = path
};
boilerplate.Add(branchThatExitsLoop);
boilerplate.Add(new OpcodeBranchJump()
{
Label = nextLabel, SourcePath = path, DestinationLabel = loopStart.Label
});
Opcode afterLoop = new OpcodePop()
{
Label = nextLabel, SourcePath = path
}; // Pop the KOSArgMarker that was under the args
boilerplate.Add(afterLoop);
branchThatExitsLoop.DestinationLabel = afterLoop.Label;
boilerplate.Add(new OpcodePush(0)
{
Label = nextLabel, SourcePath = path
}); // ---+-- The dummy do-nothing return.
boilerplate.Add(new OpcodeReturn(1)
{
Label = nextLabel, SourcePath = path
}); // ---'
// Actually call the Program from its entry Point, which is now the thing left on top
// of the stack from the second return value of load():
Opcode branchTo = new OpcodeStoreLocal("$entrypoint")
{
Label = nextLabel, SourcePath = path
};
boilerplate.Add(branchTo);
boilerplate.Add(new OpcodeCall("$entrypoint")
{
Label = nextLabel, SourcePath = path
});
boilerplate.Add(new OpcodePop()
{
Label = nextLabel, SourcePath = path
});
boilerplate.Add(new OpcodePush(0)
{
Label = nextLabel, SourcePath = path
});
boilerplate.Add(new OpcodeReturn(1)
{
Label = nextLabel, SourcePath = path
});
branchFromOne.DestinationLabel = branchTo.Label;
branchFromTwo.DestinationLabel = branchTo.Label;
return(boilerplate);
}
