func checkInstr(instr ssa.Instruction, blockDomTree *analysis.DominatorTree) error {
thisBlockNode := blockDomTree.NodeForBlock(instr.Block())
if _, ok := instr.(*ssa.Phi); !ok {
for _, op := range ssa.GetOperands(instr) {
if opInstr, ok := op.(ssa.Instruction); ok {
opInstrBlock := opInstr.Block()
if thisBlockNode.DominatedBy(blockDomTree.NodeForBlock(opInstrBlock), true) {
continue
} else if opInstrBlock == instr.Block() {
if opInstrBlock.InstrIndex(opInstr) < opInstrBlock.InstrIndex(instr) {
continue
}
}
return &InstrError{
Instr: instr,
Message: "Instruction is not dominated by operand `" + ssa.ValueString(op) + "`",
}
}
}
}
switch i := instr.(type) {
case *ssa.BinOp:
return checkBinOp(i)
case *ssa.Load:
return checkLoad(i)
case *ssa.Call:
return checkCall(i)
case *ssa.Alloc:
return checkAlloc(i)
case *ssa.Store:
return checkStore(i)
case *ssa.Convert:
return checkConvert(i)
case *ssa.ICmp:
return checkICmp(i)
case *ssa.CondBr:
return checkCondBr(i)
case *ssa.Br:
return checkBr(i)
case *ssa.Phi:
return checkPhi(i, blockDomTree)
case *ssa.Ret:
return checkRet(i)
case *ssa.GEP:
return checkGEP(i)
case *ssa.Unreachable:
// do nothing
default:
panic("unim")
}
return nil
}
func checkPhi(instr *ssa.Phi, dom *analysis.DominatorTree) error {
if err := errIfNonFirstClassType(instr.Type(), instr); err != nil {
return err
}
incomingBlockMap := make(map[*ssa.Block]bool, instr.NumIncoming())
for _, pred := range dom.BlockCFG().NodeForBlock(instr.Block()).Prev() {
incomingBlockMap[pred.Block()] = false
}
for i := 0; i < instr.NumIncoming(); i++ {
val, block := instr.GetIncoming(i)
if seen, exists := incomingBlockMap[block]; !exists {
return &InstrError{
Instr: instr,
Message: "Impossible incoming block `" + block.Name() + "`",
}
} else if seen {
return &InstrError{
Instr: instr,
Message: "Duplicate incoming block `" + block.Name() + "`",
}
}
if err := errIfMismatchedTypes(instr.Type(), val.Type(), instr); err != nil {
return err
}
incomingBlockMap[block] = true
if valInstr, ok := val.(ssa.Instruction); ok {
// for an incoming value to be valid, the incoming block must be dominated by the block the value comes from
if !dom.NodeForBlock(block).DominatedBy(dom.NodeForBlock(valInstr.Block()), false) {
return &InstrError{
Instr: instr,
Message: fmt.Sprintf("Value `%s` must dominate block `%s`", val.Name(), block.Name()),
}
}
}
}
for block, seen := range incomingBlockMap {
if !seen {
return &InstrError{
Instr: instr,
Message: "Missing incoming block `" + block.Name() + "`",
}
}
}
return nil
}