ci: add a stronger test for cross bindists

This commit adds a simple GHC API program that parses and reprints the
original hello world program used for basic testing of cross bindists.
Before there's full cross-compilation support in the test suite
driver, this provides better coverage than the original test.

2 files changed, 47 insertions, 3 deletions

diff --git a/.gitlab/ci.sh b/.gitlab/ci.sh
index 1200e883e4..217440bbaf 100755
--- a/.gitlab/ci.sh
+++ b/.gitlab/ci.sh
@@ -580,9 +580,8 @@ function test_hadrian() {
       local instdir="$TOP/_build/install"
       local test_compiler="$instdir/bin/${cross_prefix}ghc$exe"
       install_bindist _build/bindist/ghc-*/ "$instdir"
-      echo 'main = putStrLn "hello world"' > hello.hs
-      echo "hello world" > expected
-      run "$test_compiler" hello.hs
+      echo 'main = putStrLn "hello world"' > expected
+      run "$test_compiler" -package ghc "$TOP/.gitlab/hello.hs" -o hello
       $CROSS_EMULATOR ./hello > actual
       run diff expected actual
     else
diff --git a/.gitlab/hello.hs b/.gitlab/hello.hs
new file mode 100644
index 0000000000..2837cac62d
--- /dev/null
+++ b/.gitlab/hello.hs
@@ -0,0 +1,45 @@
+{-# OPTIONS_GHC -Wno-missing-fields #-}
+
+import GHC hiding (parseModule)
+import GHC.Data.StringBuffer
+import GHC.Driver.Config.Parser
+import GHC.Parser
+import GHC.Parser.Lexer
+import GHC.Platform
+import GHC.Plugins
+import GHC.Settings
+import GHC.Settings.Config
+
+fakeSettings :: Settings
+fakeSettings =
+  Settings
+    { sGhcNameVersion =
+        GhcNameVersion
+          { ghcNameVersion_programName =
+              "ghc",
+            ghcNameVersion_projectVersion =
+              cProjectVersion
+          },
+      sFileSettings =
+        FileSettings {},
+      sToolSettings = ToolSettings {},
+      sTargetPlatform =
+        genericPlatform,
+      sPlatformMisc = PlatformMisc {}
+    }
+
+fakeDynFlags :: DynFlags
+fakeDynFlags = defaultDynFlags fakeSettings
+
+parse :: DynFlags -> String -> IO (Located (HsModule GhcPs))
+parse dflags src = do
+  let buf = stringToStringBuffer src
+  let loc = mkRealSrcLoc (mkFastString "Main.hs") 1 1
+  case unP parseModule (initParserState (initParserOpts dflags) buf loc) of
+    PFailed _ -> fail "parseModule failed"
+    POk _ rdr_module -> pure rdr_module
+
+main :: IO ()
+main = do
+  m <- parse fakeDynFlags "main = putStrLn \"hello world\""
+  putStrLn $ showSDoc fakeDynFlags $ ppr m