Semantic Analysis - Crafting a Compiler - page 380

class NodeVisitor
procedure ( n )

foreach c ∈ n . getChildren() do call c . accept( this )

visit C hildren

end

end

class SemanticsVisitor extends NodeVisitor
/ This extends the class definition of Figure 9.26 /

procedure visit (Calling cn )

40

call visit C hildren ( cn )

cn . calledMethod ← null

methodSet ← get M ethods ( cn )

actualArgsType ← get A rg T ypes ( cn . args )

foreach de f ∈ methodSet do
if not

applicable ( get A rgs ( de f . signature ) , actualArgsType )

then methodSet ← methodSet −{ de f }

if size ( methodSet ) = 0

then call error (” No method matches this call ”)

return
else

if 1

then methodSet ← filter

size ( methodSet ) >

D efs ( methodSet )

if size ( methodSet ) > 1

then call error (” More than one method matches this call ”)

else

Let m be the singleton member of methodSet
cn . calledMethod ← m
if cn . quali f ier

null and cn . quali f ier superNode and m . accessMode static

then call error (” Method called must be static ”)

else

if in E xpression C ontext ( cn ) and m . returnType = void

then call error (” Call must return a value ”)

end

end

Figure 9.34: Semantic Analysis Visitors (Part 4)