find-useless-parentheses.sh

#!/bin/bash
found=0

main() {
    if [[ $# -gt 0 ]]
    then
        dotnet trparse -- -l -t ANTLRv4 $@ > o.pt
        if [ -f o.pt ] && [ -s o.pt ]
        then
            compute
        fi
    else
        for i in `find . -name desc.xml | grep -v Generated\*`
        do
            d=`dirname $i`
            pushd $d > /dev/null 2>&1
            if [ ! -z $(find . -maxdepth 1 -name '*.g4' -printf 1 -quit) ]
            then 
                dotnet trparse -- -l -t ANTLRv4 *.g4 > o.pt
                echo Computing useless parentheses in *.g4
                dotnet trparse -- -l -t ANTLRv4 *.g4 > o.pt
                if [ -f o.pt ] && [ -s o.pt ]
                then
                    compute
                fi
            fi
            popd > /dev/null 2>&1
        done
    fi
}

compute() {
    found=0
    cat o.pt | dotnet trquery -- grep '
        (: Find all blocks... :)
        //block[
            (: except not one of these ... :)

            (: do not flag "a ( b | c )* d" or with other operator :)
            not(./parent::ebnf/blockSuffix and ./altList/OR)

            (: do not flag "(a ( b | c )* )?" because it is not the same as the '*?'-operator. :)
            and not(./parent::ebnf/blockSuffix/ebnfSuffix/QUESTION and ./altList[count(./*) = 1]/alternative[count(./*) = 1]/element[count(./*) = 1]/ebnf[./block and ./blockSuffix/ebnfSuffix/*])

            (: do not flag blocks that contain a lot of elements like "(a b c)*" :)
            and not(./parent::ebnf/blockSuffix and count(./altList/alternative/element) > 1)

            (: do not flag if there are alts *and* it is preceed or followed by an element,
               e.g., "a (b | c d)" or "(a | b) c". :)
            and not(./altList/OR and ../../following-sibling::element)
            and not(./altList/OR and ../../preceding-sibling::element)

            (: do not flag "a ( v += b )* c" or with other operator :)
            and not(
		(
			(count(./altList/alternative/element/labeledElement/ASSIGN) > 0)
			or
			(count(./altList/alternative/element/labeledElement/PLUS_ASSIGN) > 0)
		)
		and (count(./parent::ebnf/blockSuffix) > 0)
	    )

            and not(
		(
			(count(./parent::labeledElement/ASSIGN) > 0)
			or
			(count(./parent::labeledElement/PLUS_ASSIGN) > 0)
		)
	    )
            ]' | dotnet trcaret -- -H > up-output.txt
    cat o.pt | dotnet trquery -- grep '
        (: Find all blocks... :)
        //lexerBlock[
            (: except not one of these ... :)
            not(./parent::lexerElement/ebnfSuffix and ./lexerAltList/OR) and
            not(./parent::lexerElement/ebnfSuffix and count(./lexerAltList/lexerAlt/lexerElements/lexerElement) > 1) and
            not(./lexerAltList/OR and ../following-sibling::lexerElement) and
            not(./lexerAltList/OR and ../preceding-sibling::lexerElement) and
(:          not(./parent::lexerElement/ebnfSuffix and ./lexerAltList/lexerAlt/lexerElements/lexerElement/lexerAtom/characterRange) and :)
            not(count(./lexerAltList/lexerAlt) > 1 and ../../../lexerCommands) and
            not(./parent::labeledLexerElement/(ASSIGN or PLUS_ASSIGN))
            ]' | dotnet trcaret -- -H >> up-output.txt
    cat o.pt | dotnet trquery -- grep '
        (: Find all blockSets... :)
        //blockSet[
            (: except not one of these ... :)
            not(./OR)
            ]' | dotnet trcaret -- -H >> up-output.txt
    if [ -s up-output.txt ]
    then
        echo Found useless parentheses in grammars...  1>&2
        found=1
        cat up-output.txt 1>&2
    fi
    rm -f up-output.txt
    rm -f o.pt
}

main $@
exit $found