dotnet/roslyn

SyntaxGenerator removes DisabledTextTrivia even with "KeepDirectives" is specified

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#21,122 opened on Jul 25, 2017

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Area-IDEBughelp wanted

Description

Consider the following code:

#if SomethingNotSet
    this is disabled code
#endif

    SomeCode();

If you use SyntaxGenerator to remove the "SomeCode();" statement and you specify that you want to keep leading directives, you get the following:

#if SomethingNotSet
#endif

This seems pretty broken. Keeping directives is so that the directives will not be touched and the code will retain its meaning. Here though we remove the DisabledText breaking the intent.

Contributor guide

Tech stack
csharp
Domain
tooling
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
4
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
half day
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
C# preprocessor directivesRoslyn SyntaxGeneratorTrivia handling
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
25
Research direction
Investigate the SyntaxGenerator class to understand how disabled text trivia is handled when KeepDirectives option is used. The issue provides a minimal repro: removing a statement with leading directives causes disabled text to be stripped. Look at the methods related to directive trivia in SyntaxGenerator, and consider adding logic to preserve DisabledTextTrivia when KeepDirectives is specified.
SyntaxGenerator removes DisabledTextTrivia even with "KeepDirectives" is specified · dotnet/roslyn#21122 | Good First Issue