Merge remote-tracking branch 'osa1/port_16449_ghc_8_8' into wip/ghc-8.8-merges

6 files changed, 25 insertions, 1 deletions

diff --git a/compiler/prelude/PrelRules.hs b/compiler/prelude/PrelRules.hs
index 7111c7b07a..b0ad91db99 100644
--- a/compiler/prelude/PrelRules.hs
+++ b/compiler/prelude/PrelRules.hs
@@ -467,13 +467,16 @@ shiftRule :: (DynFlags -> Integer -> Int -> Integer) -> RuleM CoreExpr
 -- Used for shift primops
 --    ISllOp, ISraOp, ISrlOp :: Word# -> Int# -> Word#
 --    SllOp, SrlOp           :: Word# -> Int# -> Word#
--- See Note [Guarding against silly shifts]
 shiftRule shift_op
   = do { dflags <- getDynFlags
        ; [e1, Lit (LitNumber LitNumInt shift_len _)] <- getArgs
        ; case e1 of
            _ | shift_len == 0
              -> return e1
+             -- See Note [Guarding against silly shifts]
+             | shift_len < 0 || shift_len > wordSizeInBits dflags
+             -> return $ mkRuntimeErrorApp rUNTIME_ERROR_ID wordPrimTy
+                           ("Bad shift length " ++ show shift_len)
 
            -- Do the shift at type Integer, but shift length is Int
            Lit (LitNumber nt x t)
diff --git a/testsuite/tests/codeGen/should_compile/T16449_1.hs b/testsuite/tests/codeGen/should_compile/T16449_1.hs
new file mode 100644
index 0000000000..b1ec71efef
--- /dev/null
+++ b/testsuite/tests/codeGen/should_compile/T16449_1.hs
@@ -0,0 +1,8 @@
+module T16449_1 where
+
+import Data.Bits (setBit)
+
+f :: Int
+f = foldl setter 0 $ zip [0..] [()]
+  where
+    setter v (ix, _) = setBit v ix
diff --git a/testsuite/tests/codeGen/should_compile/all.T b/testsuite/tests/codeGen/should_compile/all.T
index 7217d93e30..7a9229533d 100644
--- a/testsuite/tests/codeGen/should_compile/all.T
+++ b/testsuite/tests/codeGen/should_compile/all.T
@@ -52,3 +52,5 @@ test('T15723',
   [ unless(have_profiling(), skip),
     unless(have_dynamic(), skip),
   ], run_command, ['$MAKE -s --no-print-directory T15723'])
+
+test('T16449_1', normal, compile, [''])
diff --git a/testsuite/tests/codeGen/should_run/T16449_2.hs b/testsuite/tests/codeGen/should_run/T16449_2.hs
new file mode 100644
index 0000000000..3424d43e25
--- /dev/null
+++ b/testsuite/tests/codeGen/should_run/T16449_2.hs
@@ -0,0 +1,9 @@
+{-# LANGUAGE MagicHash #-}
+
+module Main where
+
+import GHC.Prim
+import GHC.Int
+
+-- Shift should be larger than the word size (e.g. 64 on 64-bit) for this test.
+main = print (I# (uncheckedIShiftL# 1# 1000#))
diff --git a/testsuite/tests/codeGen/should_run/T16449_2.stderr b/testsuite/tests/codeGen/should_run/T16449_2.stderr
new file mode 100644
index 0000000000..869a5b0f91
--- /dev/null
+++ b/testsuite/tests/codeGen/should_run/T16449_2.stderr
@@ -0,0 +1 @@
+T16449_2: Bad shift length 1000
diff --git a/testsuite/tests/codeGen/should_run/all.T b/testsuite/tests/codeGen/should_run/all.T
index 7f976b8107..ade88df6ab 100644
--- a/testsuite/tests/codeGen/should_run/all.T
+++ b/testsuite/tests/codeGen/should_run/all.T
@@ -192,3 +192,4 @@ test('T15892',
         # happen, so -G1 -A32k:
         extra_run_opts('+RTS -G1 -A32k -RTS') ],
      compile_and_run, ['-O'])
+test('T16449_2', exit_code(1), compile_and_run, [''])