• Ömer Sinan Ağacan's avatar
    Mention which -Werror promoted a warning to an error · 4befb415
    Ömer Sinan Ağacan authored
    Previously -Werror or -Werror=flag printed warnings as usual and then
    printed
    these two lines:
    
        <no location info>: error:
        Failing due to -Werror.
    
    This is not ideal: first, it's not clear which flag made one of the
    warnings an
    error. Second, warning messages are not modified in any way, so there's
    no way
    to know which warnings caused this error.
    
    With this patch we (1) promote warning messages to error messages if a
    relevant
    -Werror is enabled (2) mention which -Werror is used during this
    promotion.
    
    Previously:
    
        [1 of 1] Compiling Main             ( test.hs, test.o )
    
        test.hs:9:10: warning: [-Wincomplete-patterns]
            Pattern match(es) are non-exhaustive
            In a case alternative: Patterns not matched: (C2 _)
          |
        9 | sInt s = case s of
          |          ^^^^^^^^^...
    
        test.hs:12:14: warning: [-Wmissing-fields]
            • Fields of ‘Rec’ not initialised: f2
            • In the first argument of ‘print’, namely ‘Rec {f1 =
    1}’
              In the expression: print Rec {f1 = 1}
              In an equation for ‘main’: main = print Rec {f1 = 1}
           |
        12 | main = print Rec{ f1 = 1 }
           |              ^^^^^^^^^^^^^
    
        <no location info>: error:
        Failing due to -Werror.
    
    Now:
    
        [1 of 1] Compiling Main             ( test.hs, test.o )
    
        test.hs:9:10: error: [-Wincomplete-patterns,
    -Werror=incomplete-patterns]
            Pattern match(es) are non-exhaustive
            In a case alternative: Patterns not matched: (C2 _)
          |
        9 | sInt s = case s of
          |          ^^^^^^^^^...
    
        test.hs:12:14: error: [-Wmissing-fields, -Werror=missing-fields]
            • Fields of ‘Rec’ not initialised: f2
            • In the first argument of ‘print’, namely ‘Rec {f1 =
    1}’
              In the expression: print Rec {f1 = 1}
              In an equation for ‘main’: main = print Rec {f1 = 1}
           |
        12 | main = print Rec{ f1 = 1 }
           |              ^^^^^^^^^^^^^
    
    Test Plan: - Update old tests, add new tests if there aren't any
    relevant tests
    
    Reviewers: austin, bgamari
    
    Reviewed By: bgamari
    
    Subscribers: rwbarton, thomie
    
    Differential Revision: https://phabricator.haskell.org/D3709
    4befb415
DynFlags.hs 220 KB