Warnings options (The GNU Algol 68 Compiler)

### 1.4 Warnings options ¶

Warnings are diagnostic messages that report constructions that are not inherently erroneous but that are risky or suggest there is likely to be a bug in the program. Unless `-Werror` is specified, they do not prevent compilation of the program.

`-Wvoiding` ¶

  Warn on non-void units being voided due to a strong context.

`-Wscope`

  Warn when a potential name scope violation is found.

`-Whidden-declarations=level`

  Warn when a declaration hides another declaration in a larger reach. This includes operators that hide firmly related operators defined in larger reach.

  `-Whidden-declarations=none`

    At this level no warning is issued for any hidden declaration on an outer scope.

  `-Whidden-declarations=prelude`

    At this level, warnings are issued for hidden declarations defined in the standard prelude. This is the default warning level of `-Whidden-declarations`.

  `-Whidden-declarations=all`

    At this level, warnings are issued for any and all hidden declarations.

`-Wextensions` ¶

  Warn when a non-portable Algol 68 construct is used, like GNU extensions to Algol 68.