[commit: ghc] master: Improve suggestion for misspelled flag including '=' (fixes #11789) (181688a)

[git at git.haskell.org]

Repository : ssh://git@git.haskell.org/ghc

On branch  : master
Link       : http://ghc.haskell.org/trac/ghc/changeset/181688abae5c0b32237a5bd783dfc9667641cce2/ghc

>---------------------------------------------------------------

commit 181688abae5c0b32237a5bd783dfc9667641cce2
Author: Daishi Nakajima <nakaji.dayo at gmail.com>
Date:   Wed Jan 18 16:23:55 2017 -0500

    Improve suggestion for misspelled flag including '=' (fixes #11789)
    
    Test Plan:
    Added 2 test cases, verified that  ghc can suggest in the following
    cases:
    
      - for misspelled flag containing '=', ghc suggests flags that doesn't
        contain '='
      - for misspelled flag containing '=', ghc suggests flags that
        contains '='
    
    Reviewers: austin, dfeuer, bgamari
    
    Reviewed By: dfeuer, bgamari
    
    Subscribers: dfeuer, mpickering, thomie
    
    Differential Revision: https://phabricator.haskell.org/D2978
    
    GHC Trac Issues: #11789


>---------------------------------------------------------------

181688abae5c0b32237a5bd783dfc9667641cce2
 ghc/Main.hs                                       | 11 ++++++++++-
 testsuite/tests/driver/should_fail/T11789a.hs     |  1 +
 testsuite/tests/driver/should_fail/T11789a.stderr |  5 +++++
 testsuite/tests/driver/should_fail/T11789b.hs     |  1 +
 testsuite/tests/driver/should_fail/T11789b.stderr |  7 +++++++
 testsuite/tests/driver/should_fail/all.T          |  3 +++
 6 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/ghc/Main.hs b/ghc/Main.hs
index 83d5238..a650d35 100644
--- a/ghc/Main.hs
+++ b/ghc/Main.hs
@@ -915,9 +915,18 @@ unknownFlagsErr fs = throwGhcException $ UsageError $ concatMap oneError fs
   where
     oneError f =
         "unrecognised flag: " ++ f ++ "\n" ++
-        (case fuzzyMatch f (nub allNonDeprecatedFlags) of
+        (case match f (nubSort allNonDeprecatedFlags) of
             [] -> ""
             suggs -> "did you mean one of:\n" ++ unlines (map ("  " ++) suggs))
+    -- fixes #11789
+    -- If the flag contains '=',
+    -- this uses both the whole and the left side of '=' for comparing.
+    match f allFlags
+        | elem '=' f =
+              let (flagsWithEq, flagsWithoutEq) = partition (elem '=') allFlags
+                  fName = takeWhile (/= '=') f
+              in (fuzzyMatch f flagsWithEq) ++ (fuzzyMatch fName flagsWithoutEq)
+        | otherwise = fuzzyMatch f allFlags
 
 {- Note [-Bsymbolic and hooks]
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
diff --git a/testsuite/tests/driver/should_fail/T11789a.hs b/testsuite/tests/driver/should_fail/T11789a.hs
new file mode 100644
index 0000000..78595d6
--- /dev/null
+++ b/testsuite/tests/driver/should_fail/T11789a.hs
@@ -0,0 +1 @@
+module MisspelledFlagA where
diff --git a/testsuite/tests/driver/should_fail/T11789a.stderr b/testsuite/tests/driver/should_fail/T11789a.stderr
new file mode 100644
index 0000000..3e2b780
--- /dev/null
+++ b/testsuite/tests/driver/should_fail/T11789a.stderr
@@ -0,0 +1,5 @@
+ghc: unrecognised flag: -fppr-cols=1000
+did you mean one of:
+  -dppr-cols
+
+Usage: For basic information, try the `--help' option.
diff --git a/testsuite/tests/driver/should_fail/T11789b.hs b/testsuite/tests/driver/should_fail/T11789b.hs
new file mode 100644
index 0000000..87ac7b8
--- /dev/null
+++ b/testsuite/tests/driver/should_fail/T11789b.hs
@@ -0,0 +1 @@
+module MisspelledFlagB where
diff --git a/testsuite/tests/driver/should_fail/T11789b.stderr b/testsuite/tests/driver/should_fail/T11789b.stderr
new file mode 100644
index 0000000..4c4e0c6
--- /dev/null
+++ b/testsuite/tests/driver/should_fail/T11789b.stderr
@@ -0,0 +1,7 @@
+ghc: unrecognised flag: -rtsopts=somw
+did you mean one of:
+  -rtsopts=some
+  -rtsopts=none
+  -rtsopts
+
+Usage: For basic information, try the `--help' option.
diff --git a/testsuite/tests/driver/should_fail/all.T b/testsuite/tests/driver/should_fail/all.T
index 3d0708b..22c8375 100644
--- a/testsuite/tests/driver/should_fail/all.T
+++ b/testsuite/tests/driver/should_fail/all.T
@@ -2,3 +2,6 @@
 test('T10895', normal, multimod_compile_fail, ['T10895.hs', '-v0 -o dummy'])
 
 test('T12752', expect_fail, compile, ['-Wcpp-undef -Werror'])
+
+test('T11789a', normal, compile_fail, ['-fppr-cols=1000'])
+test('T11789b', normal, compile_fail, ['-rtsopts=somw'])