Ditch static flags

This patch converts the 4 lasting static flags (read from the command
line and unsafely stored in immutable global variables) into dynamic
flags. Most use cases have been converted into reading them from a DynFlags.

In cases for which we don't have easy access to a DynFlags, we read from
'unsafeGlobalDynFlags' that is set at the beginning of each 'runGhc'.
It's not perfect (not thread-safe) but it is still better as we can
set/unset these 4 flags before each run when using GHC API.

Updates haddock submodule.

Rebased and finished by: bgamari

Test Plan: validate

Reviewers: goldfire, erikd, hvr, austin, simonmar, bgamari

Reviewed By: simonmar

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D2839

GHC Trac Issues: #8440

1 files changed, 31 insertions, 4 deletions

diff --git a/compiler/main/DynFlags.hs b/compiler/main/DynFlags.hs
index 682480b44f..d7a5f1f92c 100644
--- a/compiler/main/DynFlags.hs
+++ b/compiler/main/DynFlags.hs
@@ -28,6 +28,7 @@ module DynFlags (
         ProfAuto(..),
         glasgowExtsFlags,
         warningGroups, warningHierarchies,
+        hasPprDebug, hasNoDebugOutput, hasNoStateHack, hasNoOptCoercion,
         dopt, dopt_set, dopt_unset,
         gopt, gopt_set, gopt_unset, setGeneralFlag', unSetGeneralFlag',
         wopt, wopt_set, wopt_unset,
@@ -381,7 +382,8 @@ data DumpFlag
    | Opt_D_verbose_core2core
    | Opt_D_dump_debug
    | Opt_D_dump_json
-
+   | Opt_D_ppr_debug
+   | Opt_D_no_debug_output
    deriving (Eq, Show, Enum)
 
 -- | Enumerates the simple on-or-off dynamic flags
@@ -561,6 +563,9 @@ data GeneralFlag
    -- safe haskell flags
    | Opt_DistrustAllPackages
    | Opt_PackageTrust
+
+   | Opt_G_NoStateHack
+   | Opt_G_NoOptCoercion
    deriving (Eq, Show, Enum)
 
 -- | Used when outputting warnings: if a reason is given, it is
@@ -1889,6 +1894,19 @@ languageExtensions (Just Haskell2010)
        LangExt.DoAndIfThenElse,
        LangExt.RelaxedPolyRec]
 
+hasPprDebug :: DynFlags -> Bool
+hasPprDebug = dopt Opt_D_ppr_debug
+
+hasNoDebugOutput :: DynFlags -> Bool
+hasNoDebugOutput = dopt Opt_D_no_debug_output
+
+hasNoStateHack :: DynFlags -> Bool
+hasNoStateHack = gopt Opt_G_NoStateHack
+
+hasNoOptCoercion :: DynFlags -> Bool
+hasNoOptCoercion = gopt Opt_G_NoOptCoercion
+
+
 -- | Test whether a 'DumpFlag' is set
 dopt :: DumpFlag -> DynFlags -> Bool
 dopt f dflags = (fromEnum f `IntSet.member` dumpFlags dflags)
@@ -2736,6 +2754,10 @@ dynamic_flags_deps = [
         (NoArg (unSetGeneralFlag Opt_AutoLinkPackages))
   , make_ord_flag defGhcFlag "no-hs-main"
         (NoArg (setGeneralFlag Opt_NoHsMain))
+  , make_ord_flag defGhcFlag "fno-state-hack"
+        (NoArg (setGeneralFlag Opt_G_NoStateHack))
+  , make_ord_flag defGhcFlag "fno-opt-coercion"
+        (NoArg (setGeneralFlag Opt_G_NoOptCoercion))
   , make_ord_flag defGhcFlag "with-rtsopts"
         (HasArg setRtsOpts)
   , make_ord_flag defGhcFlag "rtsopts"
@@ -2979,10 +3001,14 @@ dynamic_flags_deps = [
         (NoArg (setGeneralFlag Opt_D_faststring_stats))
   , make_ord_flag defGhcFlag "dno-llvm-mangler"
         (NoArg (setGeneralFlag Opt_NoLlvmMangler)) -- hidden flag
-  , make_ord_flag defGhcFlag "ddump-debug"        (setDumpFlag Opt_D_dump_debug)
-
+  , make_ord_flag defGhcFlag "ddump-debug"
+        (setDumpFlag Opt_D_dump_debug)
   , make_ord_flag defGhcFlag "ddump-json"
         (noArg (flip dopt_set Opt_D_dump_json . setJsonLogAction ) )
+  , make_ord_flag defGhcFlag "dppr-debug"
+        (setDumpFlag Opt_D_ppr_debug)
+  , make_ord_flag defGhcFlag "dno-debug-output"
+        (setDumpFlag Opt_D_no_debug_output)
 
         ------ Machine dependent (-m<blah>) stuff ---------------------------
 
@@ -4435,7 +4461,8 @@ setDumpFlag' dump_flag
           -- on during recompilation checking, so in those cases we
           -- don't want to turn it off.
           want_recomp = dump_flag `notElem` [Opt_D_dump_if_trace,
-                                             Opt_D_dump_hi_diffs]
+                                             Opt_D_dump_hi_diffs,
+                                             Opt_D_no_debug_output]
 
 forceRecompile :: DynP ()
 -- Whenver we -ddump, force recompilation (by switching off the