ILSpy

9645 Commits

54 Branches

94 Tags

91 MiB

Branch: fix/lambda-parameter-syntax

Commit Graph

Author	SHA1	Message	Date
Siegfried Pammer	4af44a1d60	Emit params and default values on lambda parameter lists C# 12 allows both on the explicitly typed parameter list of a lambda, and nowhere else: an anonymous method cannot declare either, and neither can a lambda whose parameter list is about to be dropped. Guarded by a setting so the output stays valid for earlier language versions. Only what the anonymous function's own metadata declares is written. A lambda may state a default the delegate does not have, a different one, or none where the delegate has one, and reflection over the lambda's method reports what the lambda declared - so filling either in from the delegate's Invoke would make the recompiled assembly describe itself differently from the original. Call sites are unaffected either way, because they bind against the delegate, which still declares both. Roslyn writes ParamArrayAttribute on the anonymous function's own method only from version 5 on; before that it stands on the delegate type alone, where it is not the lambda's to restate, so the fixture guards those cases on ROSLYN5. The correctness test reads the metadata back through reflection, which is the only place the difference is observable. Assisted-by: Claude:claude-opus-5[1m]:Claude Code	2 weeks ago

Author

SHA1

Message

Date

Siegfried Pammer

4af44a1d60

Emit params and default values on lambda parameter lists

C# 12 allows both on the explicitly typed parameter list of a lambda, and
nowhere else: an anonymous method cannot declare either, and neither can a
lambda whose parameter list is about to be dropped. Guarded by a setting so
the output stays valid for earlier language versions.

Only what the anonymous function's own metadata declares is written. A lambda
may state a default the delegate does not have, a different one, or none where
the delegate has one, and reflection over the lambda's method reports what the
lambda declared - so filling either in from the delegate's Invoke would make
the recompiled assembly describe itself differently from the original. Call
sites are unaffected either way, because they bind against the delegate, which
still declares both.

Roslyn writes ParamArrayAttribute on the anonymous function's own method only
from version 5 on; before that it stands on the delegate type alone, where it
is not the lambda's to restate, so the fixture guards those cases on ROSLYN5.
The correctness test reads the metadata back through reflection, which is the
only place the difference is observable.

Assisted-by: Claude:claude-opus-5[1m]:Claude Code

2 weeks ago

1 Commits (fix/lambda-parameter-syntax)