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Refactor the return-from-function code into popStackAndReturnValueToCaller(). 

Make external function calls slightly less special; now they get a stack frame.

llvm-svn: 9765
This commit is contained in:
Brian Gaeke 2003-11-07 05:22:49 +00:00
parent 34596d7048
commit 65cac90a92
2 changed files with 42 additions and 37 deletions
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78
llvm/lib/ExecutionEngine/Interpreter/Execution.cpp
View File

@ -432,9 +432,38 @@ void Interpreter::exitCalled(GenericValue GV) {
ECStack.clear();
}
/// Pop the last stack frame off of ECStack and then copy the result
/// back into the result variable if we are not returning void. The
/// result variable may be the ExitCode, or the Value of the calling
/// CallInst if there was a previous stack frame. This procedure may
/// invalidate any ECStack iterators you have.
///
void Interpreter::popStackAndReturnValueToCaller (const Type *RetTy,
GenericValue Result) {
// Pop the current stack frame.
ECStack.pop_back();
if (ECStack.empty()) { // Finished main. Put result into exit code...
if (RetTy && RetTy->isIntegral()) { // Nonvoid return type?
ExitCode = Result.IntVal; // Capture the exit code of the program
} else {
ExitCode = 0;
}
} else {
// If we have a previous stack frame, and we have a previous call,
// fill in the return value...
ExecutionContext &CallingSF = ECStack.back();
if (CallingSF.Caller) {
if (CallingSF.Caller->getType() != Type::VoidTy) // Save result...
SetValue(CallingSF.Caller, Result, CallingSF);
CallingSF.Caller = 0; // We returned from the call...
}
}
}
void Interpreter::visitReturnInst(ReturnInst &I) {
ExecutionContext &SF = ECStack.back();
const Type *RetTy = 0;
const Type *RetTy = Type::VoidTy;
GenericValue Result;
// Save away the return value... (if we are not 'ret void')
@ -443,25 +472,7 @@ void Interpreter::visitReturnInst(ReturnInst &I) {
Result = getOperandValue(I.getReturnValue(), SF);
}
// Pop the current stack frame... this invalidates SF
ECStack.pop_back();
if (ECStack.empty()) { // Finished main. Put result into exit code...
if (RetTy && RetTy->isIntegral()) { // Nonvoid return type?
ExitCode = Result.IntVal; // Capture the exit code of the program
} else {
ExitCode = 0;
}
} else {
// If we have a previous stack frame, and we have a previous call,
// fill in the return value...
ExecutionContext &NewSF = ECStack.back();
if (NewSF.Caller) {
if (NewSF.Caller->getType() != Type::VoidTy) // Save result...
SetValue(NewSF.Caller, Result, NewSF);
NewSF.Caller = 0; // We returned from the call...
}
}
popStackAndReturnValueToCaller(RetTy, Result);
}
void Interpreter::visitBranchInst(BranchInst &I) {
@ -796,27 +807,20 @@ void Interpreter::callFunction(Function *F,
assert((ECStack.empty() || ECStack.back().Caller == 0 ||
ECStack.back().Caller->getNumOperands()-1 == ArgVals.size()) &&
"Incorrect number of arguments passed into function call!");
if (F->isExternal()) {
GenericValue Result = callExternalFunction(F, ArgVals);
const Type *RetTy = F->getReturnType();
// Copy the result back into the result variable if we are not returning
// void.
if (RetTy != Type::VoidTy) {
if (!ECStack.empty() && ECStack.back().Caller) {
ExecutionContext &SF = ECStack.back();
SetValue(SF.Caller, Result, SF);
SF.Caller = 0; // We returned from the call...
}
}
return;
}
// Make a new stack frame... and fill it in.
ECStack.push_back(ExecutionContext());
ExecutionContext &StackFrame = ECStack.back();
StackFrame.CurFunction = F;
// Special handling for external functions.
if (F->isExternal()) {
GenericValue Result = callExternalFunction (F, ArgVals);
// Simulate a 'ret' instruction of the appropriate type.
popStackAndReturnValueToCaller (F->getReturnType (), Result);
return;
}
// Get pointers to first LLVM BB & Instruction in function.
StackFrame.CurBB = F->begin();
StackFrame.CurInst = StackFrame.CurBB->begin();

1
llvm/lib/ExecutionEngine/Interpreter/Interpreter.h
View File

@ -157,6 +157,7 @@ private: // Helper functions
GenericValue getOperandValue(Value *V, ExecutionContext &SF);
GenericValue executeCastOperation(Value *SrcVal, const Type *Ty,
ExecutionContext &SF);
void popStackAndReturnValueToCaller(const Type *RetTy, GenericValue Result);
};
#endif