Charles Stoner

@mokshinpv, thanks for reporting this issue. Currently, the repro project fails with: ``` error NU1101: Unable to find package Antlr4. ```

Thanks @mokshinpv, I was able to build successfully after all. Are you seeing the compile performance issue when building with `msbuild.exe` or `dotnet build`? Were additional analyzers included after upgrading?...

With the simplified repro from @jjonescz, it looks like 46% of the time is in `RoutePatternAnalyzer.AnalyzeToken()`.

@JamesNK, it looks like [`HasLanguageComment`](https://github.com/dotnet/aspnetcore/blob/main/src/Framework/AspNetCoreAnalyzers/src/Analyzers/RouteEmbeddedLanguage/Infrastructure/RouteStringSyntaxDetector.cs#L142C25-L142C43) may be walking up the parent chain for each token in the string concatenation.

If `HasLanguageComment()` is called for each token, for an expression that is a concatenation of N strings, this could be O(N^2).

It looks like CSharpRegexDiagnosticAnalyzer has similar perf. In an expression `new Regex("a" + "b" + ...)` with a concatenation of N strings, the analyzer perf appears to be O(N^2). cc...

> foreach (var argAndParam in argsAndParamsAll) Do we need to consider only ref-to-ref-struct parameters here when the method returns a ref-to-ref-struct? --- In reply to: [1343737470](https://github.com/dotnet/roslyn/pull/65857#issuecomment-1343737470) [](http://example.com/codeflow?ancestors=1343737470) --- Refers to:...

> Assert.Equal("Base..ctor(System.Int32 X, System.Int32 Y)", model.GetSymbolInfo(baseWithargs).Symbol.ToTestDisplayString()); Is this testing a different `GetSymbolInfo()` overload to the line above? (It looks like both test `GetSymbolInfo(SyntaxNode, CancellationToken)`.) --- In reply to: [1347324742](https://github.com/dotnet/roslyn/pull/65899#issuecomment-1347324742) [](http://example.com/codeflow?ancestors=1347324742)...

> case "System.Runtime.CompilerServices.IsExternalInit": Are these `"IsExternalInit"` cases hit? --- In reply to: [1347534571](https://github.com/dotnet/roslyn/pull/65899#issuecomment-1347534571) [](http://example.com/codeflow?ancestors=1347534571) --- Refers to: src/Compilers/CSharp/Test/Semantic/Semantics/PrimaryConstructorTests.cs:4781 in 47bf749. [](commit_id = 47bf749773b240a4f1873c5097655b4b13e6ebab, deletion_comment = False)

> Diagnostic(ErrorCode.WRN_BadXMLRef, "I1").WithArguments("I1").WithLocation(3, 49), Is this warning expected? Is the `cref` not valid? --- In reply to: [1347537920](https://github.com/dotnet/roslyn/pull/65899#issuecomment-1347537920) [](http://example.com/codeflow?ancestors=1347537920) --- Refers to: src/Compilers/CSharp/Test/Semantic/Semantics/PrimaryConstructorTests.cs:5362 in 47bf749. [](commit_id = 47bf749773b240a4f1873c5097655b4b13e6ebab, deletion_comment =...