AVRO-4331: [csharp] Fix unreachable code in generated Get()/Put() - #3937
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AVRO-4331: [csharp] Fix unreachable code in generated Get()/Put()#3937GBNikola wants to merge 1 commit into
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avrogen built the Get()/Put() switch body via CodeSnippetExpression, which CodeDom wraps in a CodeExpressionStatement and always suffixes with a ";". Since every switch arm returns or throws, that trailing ";" is unreachable. Roslyn stays quiet about it, but IDE analyzers with fuller flow analysis (ReSharper/Rider) flag it, forcing consumers to suppress CS0162 for all avrogen output. Use CodeSnippetStatement instead, which emits the block verbatim with no appended semicolon.
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What is the purpose of the change
Fixes AVRO-4331. Generated
Get(int fieldPos)/Put(int fieldPos, object)build theirswitch body via
CodeSnippetExpression, whichCodeDomwraps in aCodeExpressionStatementand always suffixes with a;when emitting C#. Since everyswitch arm returns or throws, that trailing
;is an unreachable empty statement.Roslyn/
dotnet buildnever flags it, but IDE analyzers with fuller flow analysis(ReSharper/Rider) do, forcing consumers to add per-file suppressions for all avrogen
output.
This swaps
CodeSnippetExpressionforCodeSnippetStatement, which emits the switchblock verbatim with no appended semicolon. Both types live in
System.CodeDomand areavailable on every target framework the C# SDK already supports
(
netstandard2.0/netstandard2.1for the library,net6.0-net8.0for tests), sothere's no compatibility impact.
Verifying this change
This change added tests and can be verified as follows:
RecordGetAndPutSwitchesShouldNotEmitUnreachableStatementinCodeGenTest.cs,which generates a record and asserts the generated
Get/Putswitch has no stray;after its closing brace. Fails without the fix, passes with it.
Documentation