happy-frontend: check in generated code

This drastically simplifies the bootstrapping mechanism.
If you have `happy` pre-installed, you can run:

  packages/frontend/bootstrap.sh

to regenerate Parser.hs and AttrGrammar/Parser.hs

ChangeLog.md

@@ -12,8 +12,7 @@ The main focus of this release was modularizing Happy.
   - `happy-grammar`
   - `happy-tabular`
 
-* Partially revert the new bootstrapping system of 1.21.0 to mitigate
-  build issues.
+* Revert the new bootstrapping system of 1.21.0 to mitigate build issues.
 
 ## 1.21.0
 

Makefile

@@ -34,12 +34,8 @@ sdist-test-only ::
 	echo "packages: ." > "${SDIST_DIR}/happy-$(HAPPY_VER)/cabal.project"
 	echo "tests: True" >> "${SDIST_DIR}/happy-$(HAPPY_VER)/cabal.project"
 	cd "${SDIST_DIR}/happy-$(HAPPY_VER)/" \
-		&& cabal v2-build all --flag -bootstrap \
-		&& cabal v2-install --flag -bootstrap --installdir="./bootstrap-root" \
-		&& cabal v2-test all -j --flag -bootstrap \
-		&& export PATH=./bootstrap-root:$$PATH \
-		&& cabal v2-build all --flag +bootstrap \
-		&& cabal v2-test all -j --flag +bootstrap
+		&& cabal v2-build all \
+		&& cabal v2-test all -j
 	@echo ""
 	@echo "Success! ${SDIST_DIR}/happy-$(HAPPY_VER).tar.gz is ready for distribution!"
 	@echo ""

doc/contributing.rst

@@ -30,34 +30,24 @@ Repo Layout
 Build Instructions
 ------------------
 
-Happy is normal Cabal-packaged Haskell executable, except for the fact that a
-pre-built Happy is *required* to build the full version of Happy, which is the default.
-
-- If you *do* have an existing Happy executable on the PATH or in the default
-  installation location (`~/.cabal/bin` for example), do regular
-
-  ::
+Happy is mostly a normal Cabal-packaged Haskell executable::
 
     $ cabal build
 
-  like with any other project.
-
-- If you do *not* have an existing Happy executable, instead do
-
-  ::
+The only wrinkle is that developing Happy's own parser (i.e. the frontend
+component that parses ``.y`` files) requires an existing Happy executable on
+the PATH.
 
-    $ cabal build -f -bootstrap
+Do *not* modify these files by hand::
 
-- If you install that minimial, non-bootstrapped happy
+    packages/frontend/src/Happy/Frontend/Parser.hs
+    packages/frontend/src/Happy/Frontend/AttrGrammar/Parser.hs
 
-  ::
+Instead, edit these files::
 
-    $ cabal install -f -bootstrap
+    packages/frontend/boot-src/Parser.ly
+    packages/frontend/boot-src/AttrGrammarParser.ly
 
-  you can then build normally (with the bootstrap flag enabled).
+and regenerate the ``.hs``-files with::
 
-*We're sorry the bootstrap process is a bit tedious right now; we hope to
-improve it in the future. The ideal fix would be to make cabal-installer's
-cycle detector to be less pessimistic, per
-`<https://github.com/haskell/cabal/issues/7189>`_, so that the build tool dependency
-can be properly expressed and everything works automatically.*
+    $ packages/frontend/bootstrap.sh

packages/frontend/src/Happy/Frontend/AttrGrammar/Parser.ly → packages/frontend/boot-src/AttrGrammarParser.ly

@@ -8,7 +8,7 @@ or a conditional statement.
 > {-# OPTIONS_GHC -w #-}
 > module Happy.Frontend.AttrGrammar.Parser (agParser) where
 > import Happy.Frontend.ParseMonad.Class
-> import Happy.Frontend.ParseMonad.Bootstrapped
+> import Happy.Frontend.ParseMonad
 > import Happy.Frontend.AttrGrammar
 > }
 

packages/frontend/src/Happy/Frontend/Parser/Bootstrapped.ly → packages/frontend/boot-src/Parser.ly

@@ -8,9 +8,9 @@ The parser.
 
 > {
 > {-# OPTIONS_GHC -w #-}
-> module Happy.Frontend.Parser.Bootstrapped (ourParser) where
+> module Happy.Frontend.Parser (ourParser) where
 > import Happy.Frontend.ParseMonad.Class
-> import Happy.Frontend.ParseMonad.Bootstrapped
+> import Happy.Frontend.ParseMonad
 > import Happy.Frontend.AbsSyn
 > import Happy.Frontend.Lexer
 > }

packages/frontend/bootstrap.sh

@@ -0,0 +1,5 @@
+#!/usr/bin/env sh
+
+BASEDIR=$(dirname "$0")
+happy -agc "$BASEDIR/boot-src/Parser.ly" -o "$BASEDIR/src/Happy/Frontend/Parser.hs"
+happy -agc "$BASEDIR/boot-src/AttrGrammarParser.ly" -o "$BASEDIR/src/Happy/Frontend/AttrGrammar/Parser.hs"

packages/frontend/happy-frontend.cabal

@@ -38,13 +38,6 @@ tested-with:
         GHC == 7.4.2
         GHC == 7.0.4
 
-flag bootstrap
-  description:
-    Optimize the implementation of happy using a pre-built happy,
-    and add support for attribute grammars.
-  manual: True
-  default: True
-
 library
   hs-source-dirs:      src
   exposed-modules:     Happy.Frontend,
@@ -70,21 +63,6 @@ library
         Happy.Frontend.Parser
         Happy.Frontend.Lexer
         Happy.Frontend.ParamRules
-
-
-  if flag(bootstrap)
-    -- TODO put this back when Cabal can use it's qualified goals to better
-    -- understand bootstrapping, see
-    -- https://github.com/haskell/cabal/issues/7189
-    --build-tools: happy
-    cpp-options: -DHAPPY_BOOTSTRAP
-    other-modules:
-      Happy.Frontend.ParseMonad.Bootstrapped
-      Happy.Frontend.Parser.Bootstrapped
-      Happy.Frontend.AttrGrammar
-      Happy.Frontend.AttrGrammar.Parser
-      Happy.Frontend.AttrGrammar.Mangler
-  else
-    other-modules:
-      Happy.Frontend.ParseMonad.Oracle
-      Happy.Frontend.Parser.Oracle
+        Happy.Frontend.AttrGrammar
+        Happy.Frontend.AttrGrammar.Parser
+        Happy.Frontend.AttrGrammar.Mangler

packages/frontend/src/Happy/Frontend.hs

@@ -1,5 +1,5 @@
 module Happy.Frontend where
-  
+
 import Happy.Frontend.AbsSyn
 import Happy.Frontend.Parser
 import Happy.Frontend.ParseMonad.Class
@@ -30,11 +30,3 @@ deLitify = deLit where
     deLit2 ('\n':r)     = '\n' : deLit r
     deLit2 (_:r)        = deLit2 r
     deLit2 []           = []
-
--- Iff happy is built with bootstrapping, attribute grammars are supported
-supportsParsingAttributeGrammars :: Bool
-#ifdef HAPPY_BOOTSTRAP
-supportsParsingAttributeGrammars = True
-#else
-supportsParsingAttributeGrammars = False
-#endif