Abstract

The compiler is pretty lax about command-line options whose values it does not use and just ignores many of them. It should report errors instead.

Over time we've started adding checks against this (e.g. #9075, #9364) they they're still very incomplete.

Motivation

Not getting an error when an option is invalid makes it harder for the user to realize that. It's especially problematic with options that seem to make sense together:

• --pretty-json sounds like it would affect --standard-json but it only works with --combined-json (#11583.)
• --bin should be supported in the assembler mode but currently isn't (#3870).

Specification

• There are several input modes (compiler, linker, assembler, standard JSON) and many options are not valid in one of these modes. The invalid ones should produce an error.
  • Take a look at tests for input modes in CommandLineParser. Basically, all options do not result in a change in CommandLineOptions in a specific mode should be invalid in that mode.
• Options that have equivalents and Standard JSON should be errors when --standard-json is used. For example:
  • Model checker settings.
  • Remappings.
  • --color/--no-color - Standard JSON output is not colorized and even when it will be (#11507), this option should not affect it.
  • --libraries.
  • --error-codes.
• Please also check options whose values are not ignored by CommandLineParser but are still not used by CommandLineInterface.

Backwards Compatibility

This does not introduce any backwards-incompatible changes to the language itself but any command-line tools relying on the current behavior of options being ignored will be affected.