Fix memory count for string operations (#1924)

* Closes #1919

runtime/src/juvix/object/print.c

@@ -207,6 +207,7 @@ size_t print_to_buf(char *buf, size_t n, word_t x) {
     return k;
 }
 
+// The returned pointer should be freed with `free_strbuf`
 char *print(word_t x) {
     // TODO: replace this with malloc when we have it for all APIs
     char *buf = palloc(1);

src/Juvix/Compiler/Asm/Transformation/Prealloc.hs

@@ -38,6 +38,14 @@ computeCodePrealloc tab code = prealloc <$> foldS sig code (0, [])
       TailCall {} -> return (0, cmd : prealloc acc)
       CallClosures {} -> return (0, cmd : prealloc acc)
       TailCallClosures {} -> return (0, cmd : prealloc acc)
+      Binop StrConcat -> do
+        opts <- ask
+        let size = opts ^. optLimits . limitsMaxStringSize
+        return (k + size, cmd : c)
+      ValShow -> do
+        opts <- ask
+        let size = opts ^. optLimits . limitsMaxStringSize
+        return (k + size, cmd : c)
       _ -> return (k, cmd : c)
       where
         cmd = Instr instr
@@ -108,6 +116,14 @@ checkCodePrealloc tab code = do
         opts <- ask
         let size = opts ^. optLimits . limitsMaxClosureSize
         return $ \k -> cont (k - size)
+      Binop StrConcat -> do
+        opts <- ask
+        let size = opts ^. optLimits . limitsMaxStringSize
+        return $ \k -> cont (k - size)
+      ValShow -> do
+        opts <- ask
+        let size = opts ^. optLimits . limitsMaxStringSize
+        return $ \k -> cont (k - size)
       _ -> return id
 
     goBranch :: CmdBranch -> (Int -> Int) -> (Int -> Int) -> (Int -> Int) -> Sem r (Int -> Int)

src/Juvix/Compiler/Backend.hs

@@ -12,6 +12,7 @@ data Limits = Limits
     _limitsMaxLocalVars :: Int,
     _limitsMaxClosureSize :: Int,
     _limitsClosureHeadSize :: Int,
+    _limitsMaxStringSize :: Int,
     _limitsMaxStackDelta :: Int,
     _limitsMaxFunctionAlloc :: Int,
     _limitsDispatchStackSize :: Int,
@@ -32,6 +33,7 @@ getLimits tgt debug = case tgt of
         _limitsMaxLocalVars = 2048,
         _limitsMaxClosureSize = 253 + 3,
         _limitsClosureHeadSize = if debug then 3 else 2,
+        _limitsMaxStringSize = 255 + 1,
         _limitsMaxStackDelta = 16368,
         _limitsMaxFunctionAlloc = 16368,
         _limitsDispatchStackSize = 4,
@@ -45,6 +47,7 @@ getLimits tgt debug = case tgt of
         _limitsMaxLocalVars = 1024,
         _limitsMaxClosureSize = 253 + 3,
         _limitsClosureHeadSize = if debug then 3 else 2,
+        _limitsMaxStringSize = 255 + 1,
         _limitsMaxStackDelta = 8184,
         _limitsMaxFunctionAlloc = 8184,
         _limitsDispatchStackSize = 4,

test/Asm/Compile/Base.hs

@@ -26,6 +26,10 @@ asmCompileAssertion' tab mainFile expectedFile stdinText step = do
             Runtime.clangAssertion cFile expectedFile stdinText step
         )
   where
+    -- TODO: In the future, the target supplied here might need to correspond to
+    -- the actual target, and C code will then need to be re-generated for each
+    -- target separately. Now this works only because those limits that
+    -- Prealloc.hs uses are the same for the Native64 and Wasm32 targets.
     asmOpts :: Options
     asmOpts = makeOptions Backend.TargetCNative64 True