factor 'tcRnModuleTcRnM' out of 'tcRnModule' and export it

'tcRnModuleTcRnM' builds the TcRnM monad computation that is the bulk of
'tcRnModule'

This commit makes it simpler for courageous Core plugins to invoke the
typechecker. In particular, they no longer need to copy-and-paste what is now
the body of 'tcRnModuleTcRnM'. The key change is that the 'tcRnModuleTcRnM'
computation can be run with (a hypothetical) 'initTcFromCoreM' instead of
'initTc'.

1 files changed, 22 insertions, 12 deletions

diff --git a/compiler/typecheck/TcRnDriver.lhs b/compiler/typecheck/TcRnDriver.lhs
index b5bf4a7169..1f0da6b3cf 100644
--- a/compiler/typecheck/TcRnDriver.lhs
+++ b/compiler/typecheck/TcRnDriver.lhs
@@ -16,7 +16,7 @@ module TcRnDriver (
 #endif
         tcRnLookupName,
         tcRnGetInfo,
-        tcRnModule,
+        tcRnModule, tcRnModuleTcRnM,
         tcTopSrcDecls,
         tcRnExtCore
     ) where
@@ -118,19 +118,12 @@ tcRnModule :: HscEnv
            -> IO (Messages, Maybe TcGblEnv)
 
 tcRnModule hsc_env hsc_src save_rn_syntax
-   HsParsedModule {
-      hpm_module =
-         (L loc (HsModule maybe_mod export_ies
-                          import_decls local_decls mod_deprec
-                          maybe_doc_hdr)),
-      hpm_src_files =
-         src_files
-   }
+   parsedModule@HsParsedModule {hpm_module=L loc this_module}
  = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
 
    let { this_pkg = thisPackage (hsc_dflags hsc_env) ;
-         (this_mod, prel_imp_loc)
-            = case maybe_mod of
+         pair@(this_mod,_)
+            = case hsmodName this_module of
                 Nothing -- 'module M where' is omitted
                     ->  (mAIN, srcLocSpan (srcSpanStart loc))
 
@@ -138,6 +131,23 @@ tcRnModule hsc_env hsc_src save_rn_syntax
                     -> (mkModule this_pkg mod, mod_loc) } ;
 
    initTc hsc_env hsc_src save_rn_syntax this_mod $
+     tcRnModuleTcRnM hsc_env hsc_src parsedModule pair }
+
+tcRnModuleTcRnM :: HscEnv
+                -> HscSource
+                -> HsParsedModule
+                -> (Module, SrcSpan)
+                -> TcRn TcGblEnv
+tcRnModuleTcRnM hsc_env hsc_src
+   (HsParsedModule {
+      hpm_module =
+         (L loc (HsModule maybe_mod export_ies
+                          import_decls local_decls mod_deprec
+                          maybe_doc_hdr)),
+      hpm_src_files =
+         src_files
+   })
+   (this_mod, prel_imp_loc) =
    setSrcSpan loc $
    do {         -- Deal with imports; first add implicit prelude
         implicit_prelude <- xoptM Opt_ImplicitPrelude;
@@ -210,7 +220,7 @@ tcRnModule hsc_env hsc_src save_rn_syntax
                 -- Dump output and return
         tcDump tcg_env ;
         return tcg_env
-    }}}}
+    }}}
 
 
 implicitPreludeWarn :: SDoc