Fable support

Author: ncave

fcs/build.fsx

@@ -31,7 +31,7 @@ let dotnetExePath =
     if File.Exists(pathToCli) then
         pathToCli
     else
-        DotNetCli.InstallDotNetSDK "2.2.105"
+        DotNetCli.InstallDotNetSDK "2.2.108"
 
 let runDotnet workingDir args =
     let result =
@@ -90,6 +90,10 @@ Target "BuildVersion" (fun _ ->
     Shell.Exec("appveyor", sprintf "UpdateBuild -Version \"%s\"" buildVersion) |> ignore
 )
 
+Target "BuildTools" (fun _ ->
+    runDotnet __SOURCE_DIRECTORY__ "build ../src/buildtools/buildtools.proj -v n -c Proto"
+)
+
 Target "Build" (fun _ ->
     runDotnet __SOURCE_DIRECTORY__ "build ../src/buildtools/buildtools.proj -v n -c Proto"
     let fslexPath = __SOURCE_DIRECTORY__ + "/../artifacts/bin/fslex/Proto/netcoreapp2.1/fslex.dll"
@@ -110,6 +114,30 @@ Target "NuGet" (fun _ ->
     runDotnet __SOURCE_DIRECTORY__ "pack FSharp.Compiler.Service.sln -v n -c Release"
 )
 
+Target "CodeGen.Fable" (fun _ ->
+    let outDir = __SOURCE_DIRECTORY__ + "/fcs-fable/codegen/"
+
+    // build FCS codegen
+    let fslexPath = __SOURCE_DIRECTORY__ + "/../artifacts/bin/fslex/Proto/netcoreapp2.1/fslex.dll"
+    let fsyaccPath = __SOURCE_DIRECTORY__ + "/../artifacts/bin/fsyacc/Proto/netcoreapp2.1/fsyacc.dll"
+    runDotnet outDir (sprintf "build -v n /p:FsLexPath=%s /p:FsYaccPath=%s" fslexPath fsyaccPath)
+
+    // run FCS fssrgen (without .resx output, inlining it instead)
+    runDotnet outDir "run -- ../../../src/fsharp/FSComp.txt FSComp.fs"
+    runDotnet outDir "run -- ../../../src/fsharp/fsi/FSIstrings.txt FSIstrings.fs"
+
+    // Fable-specific (comment the #line directive as it is not supported)
+    ["lex.fs"; "pplex.fs"; "illex.fs"; "ilpars.fs"; "pars.fs"; "pppars.fs"]
+    |> Seq.map (fun fileName -> outDir + fileName)
+    |> RegexReplaceInFilesWithEncoding @"(?<!/)# (?=\d)" "//# " Text.Encoding.UTF8
+
+    // // prevent stack overflows on large files (make lexer rules inline)
+    // let pattern = @"(?<=and )(?!inline )([a-zA-Z]+ )+ *lexbuf "
+    // ["lex.fs"; "pplex.fs"; "illex.fs"]
+    // |> Seq.map (fun fileName -> outDir + fileName)
+    // |> RegexReplaceInFilesWithEncoding pattern @"inline $0" Text.Encoding.UTF8
+)
+
 Target "GenerateDocsEn" (fun _ ->
     executeFSIWithArgs "docsrc/tools" "generate.fsx" [] [] |> ignore
 )
@@ -137,6 +165,10 @@ Target "Release" DoNothing
 Target "GenerateDocs" DoNothing
 Target "TestAndNuGet" DoNothing
 
+"Clean"
+  ==> "BuildTools"
+  ==> "CodeGen.Fable"
+
 "Start"
   =?> ("BuildVersion", isAppVeyorBuild)
   ==> "Restore"

fcs/fcs-fable/.gitignore

@@ -0,0 +1,3 @@
+# Codegen
+codegen/*.fs
+codegen/*.fsi