Bundle ghcversion.h and hpp with damlc. (#8278)

* Bundle hpp with damlc.

This PR eliminates the red squiggly lines you get when opening up the
standard library in daml studio (e.g. after a Go To Definitien).

(When CPP is used, Go To Definition is still pointing to the wrong place,
because the line numbers are messed up. But it's better than having a
million error messages.)

We could also remove --cpp flag in a separate PR, though that may be
considered a breaking change.

changelog_begin
changelog_end

* cleanup locateRunfiles jank

* Revert "cleanup locateRunfiles jank"

This reverts commit 82552003ae.

compiler/damlc/BUILD.bazel

@@ -23,6 +23,7 @@ da_haskell_binary(
         "@static_asset_d3plus//:js/d3plus.min.js",
         ghc_pkg,
         "//compiler/damlc:ghcversion",
+        "//compiler/damlc:hpp",
         "//compiler/damlc/pkg-db",
         "//compiler/damlc/stable-packages",
         "//compiler/repl-service/server:repl_service_jar",
@@ -46,7 +47,18 @@ genrule(
         echo > $(OUTS)
     """,
     tools = [],
-    visibility = ["__pkg__"],
+    visibility = ["//visibility:public"],
+)
+
+genrule(
+    name = "hpp",
+    srcs = ["@stackage-exe//hpp"],
+    outs = ["hpp"],
+    cmd = """
+        cp $(location @stackage-exe//hpp) $(OUTS)
+    """,
+    tools = [],
+    visibility = ["//visibility:public"],
 )
 
 # damlc without runfiles. We use that to build the daml-prim and daml-stdlib
@@ -63,6 +75,7 @@ da_haskell_binary(
     ] if is_windows else [],
     data = [
         "//compiler/damlc:ghcversion",
+        "//compiler/damlc:hpp",
         "//compiler/damlc/stable-packages",
     ],
     hackage_deps = [
@@ -81,6 +94,8 @@ package_app(
     resources = [
         ":daml-base-anchors.json",
         ":ghc-pkg-dist",
+        "//compiler/damlc:ghcversion",
+        "//compiler/damlc:hpp",
         "//compiler/damlc/daml-ide-core:dlint.yaml",
         "//compiler/damlc/pkg-db",
         "//compiler/damlc/stable-packages",
@@ -220,12 +235,10 @@ genrule(
             --output=$(OUTS) \
             --package-name=daml-prim \
             --format=Json \
-            --cpp $(location @stackage-exe//hpp) \
             $(locations //compiler/damlc/daml-prim-src)
     """,
     tools = [
         "//compiler/damlc",
-        "@stackage-exe//hpp",
     ],
     visibility = ["//visibility:public"],
 )
@@ -239,12 +252,10 @@ genrule(
             --output=$(OUTS) \
             --package-name=daml-stdlib \
             --format=Json \
-            --cpp $(location @stackage-exe//hpp) \
             $(locations //compiler/damlc/daml-stdlib-src)
     """,
     tools = [
         "//compiler/damlc",
-        "@stackage-exe//hpp",
     ],
     visibility = ["//visibility:public"],
 )

compiler/damlc/daml-opts/daml-opts/DA/Daml/Options.hs

@@ -23,6 +23,7 @@ module DA.Daml.Options
     , dataDependableExtensions
     ) where
 
+import Control.Applicative ((<|>))
 import Control.Exception
 import Control.Exception.Safe (handleIO)
 import Control.Concurrent.Extra
@@ -353,8 +354,8 @@ wOptsUnset =
 
 newtype GhcVersionHeader = GhcVersionHeader FilePath
 
-adjustDynFlags :: Options -> GhcVersionHeader -> FilePath -> DynFlags -> DynFlags
-adjustDynFlags options@Options{..} (GhcVersionHeader versionHeader) tmpDir dflags
+adjustDynFlags :: Options -> GhcVersionHeader -> FilePath -> Maybe FilePath -> DynFlags -> DynFlags
+adjustDynFlags options@Options{..} (GhcVersionHeader versionHeader) tmpDir defaultCppPath dflags
   =
   -- Generally, the lexer's "haddock mode" is disabled (`Haddock
   -- False` is the default option. In this case, we run the lexer in
@@ -387,7 +388,7 @@ adjustDynFlags options@Options{..} (GhcVersionHeader versionHeader) tmpDir dflag
   where
     apply f xs d = foldl' f d xs
     alterSettings f d = d { settings = f (settings d) }
-    addCppFlags = case optCppPath of
+    addCppFlags = case optCppPath <|> defaultCppPath of
         Nothing -> id
         Just cppPath -> alterSettings $ \s -> s
             { sPgm_P = (cppPath, [])
@@ -430,7 +431,21 @@ setImports :: [FilePath] -> DynFlags -> DynFlags
 setImports paths dflags = dflags { importPaths = paths }
 
 locateGhcVersionHeader :: IO GhcVersionHeader
-locateGhcVersionHeader = GhcVersionHeader <$> locateRunfiles (mainWorkspace </> "compiler" </> "damlc" </> "ghcversion.h")
+locateGhcVersionHeader = GhcVersionHeader <$> do
+    resourcesDir <- locateRunfiles (mainWorkspace </> "compiler" </> "damlc" </> "ghcversion.h")
+    isDirectory <- doesDirectoryExist resourcesDir
+    let path | isDirectory = resourcesDir </> "ghcversion.h"
+             | otherwise = resourcesDir
+    pure path
+
+locateCppPath :: IO (Maybe FilePath)
+locateCppPath = do
+    resourcesDir <- locateRunfiles (mainWorkspace </> "compiler" </> "damlc" </> "hpp")
+    isDirectory <- doesDirectoryExist resourcesDir
+    let path | isDirectory = resourcesDir </> "hpp"
+             | otherwise = resourcesDir
+    exists <- doesFileExist path
+    pure (guard exists >> Just path)
 
 -- | Configures the @DynFlags@ for this session to DAML-1.2
 --  compilation:
@@ -443,7 +458,8 @@ setupDamlGHC :: GhcMonad m => Maybe NormalizedFilePath -> Options -> m ()
 setupDamlGHC mbProjectRoot options@Options{..} = do
   tmpDir <- liftIO getTemporaryDirectory
   versionHeader <- liftIO locateGhcVersionHeader
-  modifyDynFlags $ adjustDynFlags options versionHeader tmpDir
+  defaultCppPath <- liftIO locateCppPath
+  modifyDynFlags $ adjustDynFlags options versionHeader tmpDir defaultCppPath
 
   unless (null optGhcCustomOpts) $ do
     damlDFlags <- getSessionDynFlags

triggers/daml/BUILD.bazel

@@ -40,7 +40,6 @@ dependencies:
 build-options: {build_options}
 EOF
           $(location //compiler/damlc) build --project-root $$TMP_DIR \
-              --cpp $$PWD/$(location @stackage-exe//hpp) \
               -o $$PWD/$@
           rm -rf $$TMP_DIR
         """.format(
@@ -54,7 +53,6 @@ EOF
         ),
         tools = [
             "//compiler/damlc",
-            "@stackage-exe//hpp",
         ],
         visibility = ["//visibility:public"],
     )
@@ -96,7 +94,6 @@ dependencies:
   - daml-script.dar
 EOF
         DAMLC=$$PWD/$(location //compiler/damlc)
-        TOOLCPP=$$PWD/$(location @stackage-exe//hpp)
         JSON=$$PWD/$(location :daml-trigger.json)
         cd $$TMP_DIR
         $$DAMLC init
@@ -104,7 +101,6 @@ EOF
             --combine \
             --output=$$JSON \
             --format=Json \
-            --cpp $$TOOLCPP \
             --package-name=daml-trigger \
             $$TMP_DIR/daml/Daml/Trigger.daml \
             $$TMP_DIR/daml/Daml/Trigger/Assert.daml \
@@ -116,7 +112,6 @@ EOF
     ),
     tools = [
         "//compiler/damlc",
-        "@stackage-exe//hpp",
     ],
     visibility = ["//visibility:public"],
 )