Symbol Tables and Declaration Processing - Crafting a Compiler - page 331

procedure visit (ArrayReferencing ar )

call visit C hildren ( ar )

if ar . arrayName . type = errorType
then ar . type ← errorType
else

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if ar . arrayName . kind arrayTypeDescriptor
then
call

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error ( ar . arrayName , ” is not an array ”)

ar . type ← errorType

else
ar . type ← ar . arrayName . type . elementType

if ar . indexExpr . type errorType and ar . indexExpr . type integer
then

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call error (” Index expression is not an integer :” , ar . indexExpr )

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end

Figure 8.37: Type checking array references

procedure visit (StructReferencing sr )

call sr . ob jectName . accept( this )

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if sr . ob jectName . type = errorType
then sr . type ← errorType
else

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if sr . ob jectName . type structTypeDescriptor
then
call

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error ( sr . ob jectName , ” does not name a struct . ”)

sr . type ← errorType

else

st ← sr . ob jectName . type . fields
attributeRe f ← st . retrieveSymbol( fieldName . name )
if attributeRe f =

79

null

then
call

error ( fieldName . name , ” is not a f ield o f ” , sr . ob jectName . )

sr . type ← errorType

else sr . type ← attributeRe f . f ieldType

end

Figure 8.38: Type checking structure references