driver: Add test for #12983

This test has worked since 8.10.2 at least but was recently broken and
is now working again after this patch.

Closes #12983

9 files changed, 145 insertions, 0 deletions

diff --git a/testsuite/tests/driver/T12983/Makefile b/testsuite/tests/driver/T12983/Makefile
new file mode 100644
index 0000000000..e15b2fb7da
--- /dev/null
+++ b/testsuite/tests/driver/T12983/Makefile
@@ -0,0 +1,8 @@
+TOP=../../..
+include $(TOP)/mk/boilerplate.mk
+include $(TOP)/mk/test.mk
+
+# This makefile rule only exists because TEST_HC is set in boilerplate.mk
+# and otherwise the TEST_HC variable wouldn't be set in the context of the bash script
+T12983:
+	TEST_HC="$(TEST_HC)" ./build.sh
diff --git a/testsuite/tests/driver/T12983/T12983.stdout b/testsuite/tests/driver/T12983/T12983.stdout
new file mode 100644
index 0000000000..321e702d27
--- /dev/null
+++ b/testsuite/tests/driver/T12983/T12983.stdout
@@ -0,0 +1,41 @@
+
+Preparing everyting with --make ...
+
+[1 of 3] Compiling Hospital
+[2 of 3] Compiling Types
+[3 of 3] Compiling Main
+Linking src/MetaHandler ...
+Done with preparations with --make
+
+Building with --make
+
+[1 of 4] Compiling ShortText
+[2 of 4] Compiling Hospital [Source file changed]
+[4 of 4] Compiling Main [Hospital[TH] changed]
+Linking src/MetaHandler ...
+
+Preparing everything ...
+src/Hospital.hs
+src/Types.hs
+src/MetaHandler.hs
+Done with preparations
+Building file-by-file, with -fforce-recomp
+
+src/ShortText.hs
+src/Hospital.hs
+-fforce-recomp src/Types.hs
+src/MetaHandler.hs
+
+Preparing everything ...
+src/Hospital.hs
+src/Types.hs
+src/MetaHandler.hs
+Done with preparations
+
+Building file-by-file
+
+src/ShortText.hs
+src/Hospital.hs
+src/Types.hs
+compilation IS NOT required
+src/MetaHandler.hs
diff --git a/testsuite/tests/driver/T12983/all.T b/testsuite/tests/driver/T12983/all.T
new file mode 100644
index 0000000000..f5a4f4d519
--- /dev/null
+++ b/testsuite/tests/driver/T12983/all.T
@@ -0,0 +1,3 @@
+# Test for #12983, a recompilation bug with Template Haskell
+test('T12983', [req_th, unless(have_dynamic(), skip), extra_files(['build.sh', 'src'])], makefile_test, [])
+
diff --git a/testsuite/tests/driver/T12983/build.sh b/testsuite/tests/driver/T12983/build.sh
new file mode 100755
index 0000000000..9026802e08
--- /dev/null
+++ b/testsuite/tests/driver/T12983/build.sh
@@ -0,0 +1,57 @@
+#!/usr/bin/env bash
+
+GHC="${TEST_HC}"
+
+flags="${TEST_HC_OPTS} -O0 -fhide-source-paths -isrc -ibuild -dynamic-too -outputdir build -package template-haskell"
+
+function compile()
+{
+    echo $@
+    "$GHC" -c $flags $@ || exit 1
+}
+
+function setup()
+{
+    echo
+    echo "Preparing everything ..."
+    rm -rf build
+    mkdir -p build
+    cp src/Old_Hospital.hs src/Hospital.hs
+    compile src/Hospital.hs
+    compile src/Types.hs
+    compile src/MetaHandler.hs
+    echo "Done with preparations"
+}
+
+echo
+echo "Preparing everyting with --make ..."
+echo
+rm -rf build
+mkdir -p build
+cp src/Old_Hospital.hs src/Hospital.hs
+"$GHC" --make $flags src/MetaHandler.hs
+echo "Done with preparations with --make"
+echo
+echo "Building with --make"
+echo
+cp src/New_Hospital.hs src/Hospital.hs
+"$GHC" --make $flags src/MetaHandler.hs
+
+setup
+echo "Building file-by-file, with -fforce-recomp"
+echo
+cp src/New_Hospital.hs src/Hospital.hs
+compile src/ShortText.hs
+compile src/Hospital.hs
+compile -fforce-recomp src/Types.hs
+compile src/MetaHandler.hs
+
+setup
+echo
+echo "Building file-by-file"
+echo
+cp src/New_Hospital.hs src/Hospital.hs
+compile src/ShortText.hs
+compile src/Hospital.hs
+compile src/Types.hs
+compile src/MetaHandler.hs
diff --git a/testsuite/tests/driver/T12983/src/MetaHandler.hs b/testsuite/tests/driver/T12983/src/MetaHandler.hs
new file mode 100644
index 0000000000..87b48db36c
--- /dev/null
+++ b/testsuite/tests/driver/T12983/src/MetaHandler.hs
@@ -0,0 +1,10 @@
+{-# LANGUAGE TemplateHaskell #-}
+module Main where
+
+import qualified Types
+
+-- splices in "string :: String"
+$(Types.genCode)
+
+main :: IO ()
+main = putStrLn string
diff --git a/testsuite/tests/driver/T12983/src/New_Hospital.hs b/testsuite/tests/driver/T12983/src/New_Hospital.hs
new file mode 100644
index 0000000000..2cbd21401c
--- /dev/null
+++ b/testsuite/tests/driver/T12983/src/New_Hospital.hs
@@ -0,0 +1,6 @@
+module Hospital where
+
+import ShortText
+
+foo :: Int -> String
+foo i = toString (ShortText (show i))
diff --git a/testsuite/tests/driver/T12983/src/Old_Hospital.hs b/testsuite/tests/driver/T12983/src/Old_Hospital.hs
new file mode 100644
index 0000000000..4a0819ea58
--- /dev/null
+++ b/testsuite/tests/driver/T12983/src/Old_Hospital.hs
@@ -0,0 +1,4 @@
+module Hospital where
+
+foo :: Int -> String
+foo i = show i
diff --git a/testsuite/tests/driver/T12983/src/ShortText.hs b/testsuite/tests/driver/T12983/src/ShortText.hs
new file mode 100644
index 0000000000..88ca2cf6bc
--- /dev/null
+++ b/testsuite/tests/driver/T12983/src/ShortText.hs
@@ -0,0 +1,6 @@
+module ShortText where
+
+data ShortText = ShortText String
+
+toString :: ShortText -> String
+toString (ShortText s) = s
diff --git a/testsuite/tests/driver/T12983/src/Types.hs b/testsuite/tests/driver/T12983/src/Types.hs
new file mode 100644
index 0000000000..20602dfd85
--- /dev/null
+++ b/testsuite/tests/driver/T12983/src/Types.hs
@@ -0,0 +1,10 @@
+{-# LANGUAGE TemplateHaskell #-}
+module Types where
+
+import qualified Hospital
+import Language.Haskell.TH
+
+genCode :: Q [Dec]
+genCode =
+    let s = Hospital.foo 5
+    in [d|string = s|]