Prevent GHC from silently dying when preprocessor is not found

The Windows preprocessor code calls `runInteractiveProcess` but does
not check if an exception is thrown.
`runInteractiveProcess` calls `CreateProcess` which when given a format
the system loader does not know about
will throw an exception. This is what makes #9399 fail.

Ultimately we should not use any `CreateProcess` based calls but
instead `ShellExecuteEx` as  this would allow
us to run applications that the shell knows about instead of just the
loader. More details on #365.

This patch removes `PhaseFailed` and throws `ProgramError` instead.
`PhaseFailed` was largely unneeded since it never gave
very useful information aside from the `errorcode` which was almost
always `1`. `IOErrors` have also been eliminated and `GhcExceptions`
thrown in their place wherever possible.

Updates haddock submodule.

Test Plan:
`./validate` to make sure anything didn't break and
`make TESTS="T365"` to test that an error is now properly thrown

Reviewers: austin, thomie, bgamari

Reviewed By: thomie, bgamari

Subscribers: #ghc_windows_task_force

Differential Revision: https://phabricator.haskell.org/D1256

GHC Trac Issues: #365

1 files changed, 0 insertions, 1 deletions

diff --git a/ghc/InteractiveUI.hs b/ghc/InteractiveUI.hs
index 2dcedb0b0b..80c1483863 100644
--- a/ghc/InteractiveUI.hs
+++ b/ghc/InteractiveUI.hs
@@ -3214,7 +3214,6 @@ showException se =
            -- omit the location for CmdLineError:
            Just (CmdLineError s)    -> putException s
            -- ditto:
-           Just ph@(PhaseFailed {}) -> putException (showGhcException ph "")
            Just other_ghc_ex        -> putException (show other_ghc_ex)
            Nothing                  ->
                case fromException se of