[Go] excess imports are generated

neomantra commented 3 years ago

When generating Go imports, the current implementation uses a single TreeSet to track the import names.

Golang is strict in imports and complains if an import is not used.

With some schema, excess imports are created and compilation fails.

Here's an example:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<sbe:messageSchema xmlns:sbe="http://fixprotocol.io/2016/sbe"
    package="issue847"
    id="1"
    version="0"
    semanticVersion="1.0"
    description="test case 847 20210511"
    byteOrder="littleEndian">
    <types>
        <composite name="Comp1" description="C1">
            <type name="lmn"  primitiveType="uint16"/>
            <type name="wxy" primitiveType="uint16"/>
        </composite>
        <composite name="messageHeader" description="MH">
            <type name="blockLength" primitiveType="uint16"/>
            <type name="templateId"  primitiveType="uint16"/>
            <type name="schemaId"    primitiveType="uint16"/>
            <type name="version"     primitiveType="uint16"/>
            <ref  name="c1"          type="Comp1"/>
        </composite>
    </types>
    <sbe:message name="barmsg" id="4">
        <field name="header" id="1" type="messageHeader"/>
    </sbe:message>
</sbe:messageSchema>

Which fails with the following error:

./Comp2.go:6:2: imported and not used: "fmt"
./Comp2.go:8:2: imported and not used: "math"

billsegall commented 3 years ago

Where is Comp2.go being generated from this schema? Are there perhaps old files left behind?

neomantra commented 3 years ago

Sorry, I had late-night pasted the wrong XML snippet when I was composing that.

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<sbe:messageSchema xmlns:sbe="http://fixprotocol.io/2016/sbe"
    package="issue848"
    id="1"
    version="0"
    semanticVersion="1.0"
    description="test case 848 20210511"
    byteOrder="littleEndian">
    <types>
        <composite name="Comp1" description="C1">
            <type name="lmn"  primitiveType="uint16"/>
            <type name="wxy" primitiveType="uint16"/>
        </composite>
        <composite name="messageHeader" description="MH">
            <type name="blockLength" primitiveType="uint16"/>
            <type name="templateId"  primitiveType="uint16"/>
            <type name="schemaId"    primitiveType="uint16"/>
            <type name="version"     primitiveType="uint16"/>
            <ref  name="c1"          type="Comp1"/>
        </composite>
        <composite name="Comp2" description="C2">
            <ref  name="c1"          type="Comp1"/>
        </composite>
    </types>
    <sbe:message name="barmsg" id="4">
        <field name="header" id="1" type="messageHeader"/>
        <field name="c2"     id="2" type="Comp2"/>
    </sbe:message>
</sbe:messageSchema>

Test case file in my PR: https://github.com/real-logic/simple-binary-encoding/blob/f236400955bd2e436f40c40b1f51db8f965e7082/sbe-tool/src/test/resources/issue847.xml

real-logic / simple-binary-encoding

[Go] excess imports are generated #848