Merge pull request #120 from hvr/pr/simple-alex

Make bootstrapping even easier by avoiding custom Setup.hs

Author: simonmar

.gitignore

@@ -3,6 +3,7 @@
 *~
 *.o
 *.info
+/.ghc.environment.*
 /AlexTemplate-debug.bak
 /AlexTemplate-ghc-debug.bak
 /AlexTemplate-ghc.bak
@@ -32,6 +33,7 @@
 /AlexWrapper-posn
 /AlexWrapper-posn-bytestring
 /AlexWrapper-strict-bytestring
+/data/
 /dist
 /dist-newstyle
 /doc/alex.1

.travis.yml

@@ -1,25 +1,28 @@
 # language: haskell
 
 env:
+# - GHCVER=7.0.4
+ - GHCVER=7.4.2
+ - GHCVER=7.6.3
  - GHCVER=7.8.4
  - GHCVER=7.10.3
- - GHCVER=8.0.1
+ - GHCVER=8.0.2
+ - GHCVER=8.2.2
+ - GHCVER=8.4.1
 
 before_install:
  - sudo add-apt-repository -y ppa:hvr/ghc
  - sudo apt-get update
- - sudo apt-get install alex-3.1.7 happy-1.19.5 cabal-install-1.24 ghc-$GHCVER
- - export PATH=/opt/cabal/bin:/opt/ghc/$GHCVER/bin:/opt/alex/3.1.7/bin:/opt/happy/1.19.5/bin:$PATH
+ - sudo apt-get install alex-3.1.7 happy-1.19.5 cabal-install-head ghc-$GHCVER
+ - export PATH=/opt/cabal/head/bin:/opt/ghc/$GHCVER/bin:/opt/alex/3.1.7/bin:/opt/happy/1.19.5/bin:$PATH
 
 install:
- - cabal-1.24 update
- - cabal-1.24 install --only-dependencies --enable-tests
+ - cabal update
 
 script:
  - make sdist
  - cd dist
  - tar xvzf alex-*.tar.gz
  - cd alex-*/
- - cabal-1.24 configure --enable-tests
- - cabal-1.24 build
- - cabal-1.24 test
+ - "echo 'packages: .' > cabal.project"
+ - cabal new-test --enable-tests

Makefile

@@ -13,6 +13,7 @@ sdist ::
 	$(ALEX) $(ALEX_OPTS) src/Scan.x -o src/Scan.hs
 	mv src/Parser.y src/Parser.y.boot
 	mv src/Scan.x src/Scan.x.boot
+	cabal new-run gen-alex-sdist
 	cabal sdist
 	git checkout .
 	git clean -f

README.md

@@ -5,15 +5,9 @@
 Alex is a Lex-like tool for generating Haskell scanners.  For complete
 documentation, see the doc directory.
 
-   http://www.haskell.org/alex/
+- <https://www.haskell.org/alex/>
 
-   http://hackage.haskell.org/package/alex
-
-Alex is built using Cabal.  First install GHC and cabal-install, then:
-
-    $ cabal configure
-    $ cabal build
-    $ cabal install
+- <https://hackage.haskell.org/package/alex>
 
 Alex version 2.0 has changed fairly considerably since version 1.x,
 and the syntax is almost completely different.  For a detailed list of
@@ -29,6 +23,63 @@ The source code in the 'src' and 'examples' directories is intended
 for a Haskell 98 compiler with hierarchical modules.  It should work
 with GHC >= 5.04.
 
+## Build Instructions
+
+If you just want to *use* Alex, you can download or install (via
+`cabal install alex`) an
+[Alex release from Hackage](https://hackage.haskell.org/package/alex); also note that
+distributions such as the
+[Haskell Platform](https://www.haskell.org/platform/) and other package
+manager-based distributions provide packages for Alex. Moreover,
+recent versions of `cabal` will automatically install the required
+version of `alex` based on
+[`build-tools`/`build-tool-depends` declarations](http://cabal.readthedocs.io/en/latest/developing-packages.html#pkg-field-build-tool-depends).
+
+Read on if you want to build Alex directly from Git.
+
+Alex is built using GHC & Cabal; so first install
+[GHC](https://www.haskell.org/ghc) and
+[`cabal-install-2.0`](https://www.haskell.org/cabal) (or later).
+
+Since Alex itself is implemented in terms of an Alex scanner,
+bootstrapping Alex is a bit tricky:
+
+You need to have the build-tools `alex` and `happy` manually
+installed; either via your system package manager distribution, the
+Haskell Platform, or e.g. via (run this outside the Git repository!):
+
+    $ cabal install alex happy
+
+which installs them into `${HOME}/.cabal/bin` by default (make sure
+they're in your `$PATH` for the next steps!).
+
+### Variant A
+
+First you need to generate the pre-processed templates via
+
+    $ cabal new-run gen-alex-sdist
+
+(otherwise `cabal install` will complain about
+"`data/AlexTemplate: copyFile: does not exist (No such file or directory)`")
+
+And then you can install `alex` simply by invoking
+
+    $ cabal install
+    
+from inside the Git folder.
+
+### Variant B
+
+Alternatively, you can use the `Makefile` which automates the steps of
+producing a self-contained pre-bootstrapped source distribution with
+pre-generated lexer/scanners (and which also performs the `cabal
+new-run gen-alex-sdist` pre-preprocessing step):
+
+    $ make sdist
+    $ cabal install dist/alex-*.tar.gz
+
+## Contributing & Reporting Issues
+
 Please report any bugs or comments at  https://github.com/simonmar/alex/issues
 
 Share and enjoy,

Setup.hs

@@ -0,0 +1,2 @@
+import Distribution.Simple
+main = defaultMain

Setup.lhs

@@ -1,3 +1,4 @@
+cabal-version: >= 1.8
 name: alex
 version: 3.2.3
 -- don't forget updating changelog.md!
@@ -18,8 +19,26 @@ description:
   lex or flex for C/C++.
 
 category: Development
-cabal-version: >= 1.8
-build-type: Custom
+build-type: Simple
+
+data-dir: data/
+
+data-files:
+        AlexTemplate
+        AlexTemplate-ghc
+        AlexTemplate-ghc-nopred
+        AlexTemplate-ghc-debug
+        AlexTemplate-debug
+        AlexWrapper-basic
+        AlexWrapper-basic-bytestring
+        AlexWrapper-strict-bytestring
+        AlexWrapper-posn
+        AlexWrapper-posn-bytestring
+        AlexWrapper-monad
+        AlexWrapper-monad-bytestring
+        AlexWrapper-monadUserState
+        AlexWrapper-monadUserState-bytestring
+        AlexWrapper-gscan
 
 extra-source-files:
         CHANGELOG.md
@@ -50,7 +69,7 @@ extra-source-files:
         src/Parser.y.boot
         src/Scan.x.boot
         src/ghc_hooks.c
-         templates/GenericTemplate.hs
+        templates/GenericTemplate.hs
         templates/wrappers.hs
         tests/Makefile
         tests/simple.x
@@ -126,4 +145,7 @@ executable alex
 test-suite tests
   type: exitcode-stdio-1.0
   main-is: test.hs
+  -- This line is important as it ensures that the local `exe:alex` component declared above is built before the test-suite component is invoked, as well as making sure that `alex` is made available on $PATH and `$alex_datadir` is set accordingly before invoking `test.hs`
+  build-tools: alex
+
   build-depends: base, process

alex.cabal

@@ -0,0 +1,6 @@
+
+packages:
+  ./
+  ./gen-alex-sdist/
+
+

cabal.project

@@ -0,0 +1,74 @@
+module Main (main) where
+
+import           Control.Monad
+import           Language.Preprocessor.Cpphs
+import           System.Directory
+import           System.FilePath
+
+main :: IO ()
+main = do
+  sequence_ ([ cpp_template "GenericTemplate.hs" dst opts | (dst,opts) <- templates ] ++
+             [ cpp_template "wrappers.hs"        dst opts | (dst,opts) <- wrappers ])
+
+  putStrLn ""
+  putStrLn "-- fragment for alex.cabal file"
+  putStrLn "data-dir: data/"
+  putStrLn ""
+  putStrLn "data-files:"
+  forM_ all_template_files $ \fn -> putStrLn ("        " ++ fn)
+  putStrLn "-- end of fragment"
+  putStrLn ""
+  putStrLn "You can invoke `cabal sdist` now"
+
+cpp_template :: FilePath -> FilePath -> [String] -> IO ()
+cpp_template src0 dst0 defs = do
+    ex <- doesFileExist src
+    unless ex $
+      fail ("file " ++ show src ++ " not found; are you in the right directory?")
+
+    putStrLn ("generating " ++ show dst ++ "  (from " ++ show src ++ ")...")
+    createDirectoryIfMissing False "data"
+    srcdat <- readFile src
+    outdat <- runCpphs cppflags src =<< readFile src
+    writeFile dst outdat
+
+    return ()
+  where
+    src = "templates" </> src0
+    dst = "data"      </> dst0
+
+    cppflags = defaultCpphsOptions
+      { defines = [(d,"1") | d <- defs ]
+      , boolopts = defaultBoolOptions
+                   { hashline  = False
+                   , locations = True
+                   , ansi      = False
+                   , macros    = True
+                   }
+      }
+
+all_template_files :: [FilePath]
+all_template_files = map fst (templates ++ wrappers)
+
+templates :: [(FilePath,[String])]
+templates = [
+  ("AlexTemplate",           []),
+  ("AlexTemplate-ghc",       ["ALEX_GHC"]),
+  ("AlexTemplate-ghc-nopred",["ALEX_GHC", "ALEX_NOPRED"]),
+  ("AlexTemplate-ghc-debug", ["ALEX_GHC","ALEX_DEBUG"]),
+  ("AlexTemplate-debug",     ["ALEX_DEBUG"])
+ ]
+
+wrappers :: [(FilePath,[String])]
+wrappers = [
+  ("AlexWrapper-basic",                     ["ALEX_BASIC"]),
+  ("AlexWrapper-basic-bytestring",          ["ALEX_BASIC_BYTESTRING"]),
+  ("AlexWrapper-strict-bytestring",         ["ALEX_STRICT_BYTESTRING"]),
+  ("AlexWrapper-posn",                      ["ALEX_POSN"]),
+  ("AlexWrapper-posn-bytestring",           ["ALEX_POSN_BYTESTRING"]),
+  ("AlexWrapper-monad",                     ["ALEX_MONAD"]),
+  ("AlexWrapper-monad-bytestring",          ["ALEX_MONAD_BYTESTRING"]),
+  ("AlexWrapper-monadUserState",            ["ALEX_MONAD", "ALEX_MONAD_USER_STATE"]),
+  ("AlexWrapper-monadUserState-bytestring", ["ALEX_MONAD_BYTESTRING", "ALEX_MONAD_USER_STATE"]),
+  ("AlexWrapper-gscan",                     ["ALEX_GSCAN"])
+ ]

gen-alex-sdist/Main.hs

@@ -0,0 +1,2 @@
+import Distribution.Simple
+main = defaultMain