Fix error handling in the lua-continuations backend

Author: minoki

lib/lunarml/mlinit-continuations.lua

@@ -461,13 +461,12 @@ end
 --END
 
 -- Delimited continuations
---BEGIN _handle _withSubCont _pushSubCont _run: table pcall getmetatable error table_unpack
+--BEGIN _handle _withSubCont _pushSubCont _run: table table_move pcall getmetatable error table_unpack
 local _handle, _withSubCont, _pushSubCont, _run
 do
   local ipairs = ipairs
   local table_insert = table.insert
   local table_remove = table.remove
-  local table_move = table.move
   local coroutine = coroutine
   local coroutine_create = coroutine.create
   local coroutine_yield = coroutine.yield
@@ -489,9 +488,6 @@ do
       success, result = pcall(f)
       _depth = olddepth
     end
-    if not success and getmetatable(result) ~= _exn_meta then
-      result = _Error(result)
-    end
     return success, result
   end
   function _pushPrompt(tag, f)

src/codegen-lua.sml

@@ -2779,11 +2779,13 @@ struct
           val resultOrError = e
           val functionExp = L.FunctionExp (vector [], vector
             (doStat (ctx, env', NONE, body)))
+          val pcallId =
+            if #hasDelimitedContinuations ctx then L.PredefinedId "_handle"
+            else L.PredefinedId "pcall"
         in
           [ L.LocalStat
               ( [(status, L.CONST), (resultOrError, L.CONST)]
-              , [L.CallExp
-                   (L.VarExp (L.PredefinedId "pcall"), vector [functionExp])]
+              , [L.CallExp (L.VarExp pcallId, vector [functionExp])]
               )
           , L.IfStat
               ( L.UnaryExp (L.NOT, L.VarExp (L.UserDefinedId status))

test/Makefile

@@ -83,6 +83,15 @@ should_run += should_run/xorshift64.sml
 else ifeq ($(VARIANT), lua-continuations)
 should_run += should_run/xorshift64.sml
 endif
+ifeq ($(VARIANT), luajit)
+should_run += should_run/deephandle.sml
+else ifeq ($(VARIANT), lua-continuations)
+should_run += should_run/deephandle.sml
+else ifeq ($(VARIANT), nodejs)
+should_run += should_run/deephandle.sml
+else ifeq ($(VARIANT), nodejs-cps)
+should_run += should_run/deephandle.sml
+endif
 should_compile += $(addprefix should_compile/,\
   signature_sharing1.sml \
   signature_sharing2.sml \

test/should_run/deephandle.sml

@@ -0,0 +1,6 @@
+fun f i =
+  if i = 0 then
+    raise Fail "Hello!"
+  else
+    f (i - 1) handle e => raise e;
+f 500 handle Fail s => print (s ^ "\n");

test/should_run/deephandle.stdout

@@ -0,0 +1 @@
+Hello!