Unify retains in String#split (#1006)

Author: MaxGraey

std/assembly/string.ts

@@ -453,19 +453,21 @@ import { idof } from "./builtins";
       if (!length) return changetype<Array<String>>(__allocArray(0, alignof<String>(), idof<Array<String>>()));  // retains
       // split by chars
       length = min<isize>(length, <isize>limit);
-      let result = __allocArray(length, alignof<String>(), idof<Array<String>>());
-      let resultStart = changetype<ArrayBufferView>(result).dataStart;
+      let result = changetype<Array<String>>(__allocArray(length, alignof<String>(), idof<Array<String>>())); // retains
+      // @ts-ignore: cast
+      let resultStart = result.dataStart as usize;
       for (let i: isize = 0; i < length; ++i) {
         let charStr = __alloc(2, idof<String>());
         store<u16>(charStr, load<u16>(changetype<usize>(this) + (<usize>i << 1)));
         store<usize>(resultStart + (<usize>i << alignof<usize>()), charStr); // result[i] = charStr
         if (isManaged<String>()) __retain(charStr);
       }
-      return changetype<Array<String>>(result); // retains
+      return result;
     } else if (!length) {
-      let result = __allocArray(1, alignof<String>(), idof<Array<String>>());
-      store<usize>(changetype<ArrayBufferView>(result).dataStart, changetype<usize>("")); // static ""
-      return changetype<Array<String>>(result); // retains
+      let result = changetype<Array<String>>(__allocArray(1, alignof<String>(), idof<Array<String>>())); // retains
+      // @ts-ignore: cast
+      store<usize>(result.dataStart as usize, changetype<usize>("")); // static ""
+      return result;
     }
     var result = changetype<Array<String>>(__allocArray(0, alignof<String>(), idof<Array<String>>())); // retains
     var end = 0, start = 0, i = 0;
@@ -478,12 +480,12 @@ import { idof } from "./builtins";
       } else {
         result.push(changetype<String>(""));
       }
-      if (++i == limit) return changetype<Array<String>>(result); // retains
+      if (++i == limit) return result;
       start = end + sepLen;
     }
     if (!start) { // also means: loop above didn't do anything
       result.push(this);
-      return changetype<Array<String>>(result); // retains
+      return result;
     }
     var len = length - start;
     if (len > 0) {
@@ -493,8 +495,7 @@ import { idof } from "./builtins";
     } else {
       result.push(changetype<String>("")); // static ""
     }
-    return changetype<Array<String>>(result); // retains
-    // releases result
+    return result;
   }
 
   toLowerCase(): String {

tests/compiler/std/string-encoding.optimized.wat

@@ -2722,7 +2722,7 @@
    if
     i32.const 0
     i32.const 544
-    i32.const 695
+    i32.const 696
     i32.const 8
     call $~lib/builtins/abort
     unreachable
@@ -2745,7 +2745,7 @@
    if
     i32.const 0
     i32.const 544
-    i32.const 699
+    i32.const 700
     i32.const 8
     call $~lib/builtins/abort
     unreachable
@@ -3062,7 +3062,7 @@
   if
    i32.const 0
    i32.const 544
-   i32.const 713
+   i32.const 714
    i32.const 6
    call $~lib/builtins/abort
    unreachable

tests/compiler/std/string-encoding.untouched.wat

@@ -4453,7 +4453,7 @@
    if
     i32.const 0
     i32.const 544
-    i32.const 695
+    i32.const 696
     i32.const 8
     call $~lib/builtins/abort
     unreachable
@@ -4477,7 +4477,7 @@
    if
     i32.const 0
     i32.const 544
-    i32.const 699
+    i32.const 700
     i32.const 8
     call $~lib/builtins/abort
     unreachable
@@ -4833,7 +4833,7 @@
   if
    i32.const 0
    i32.const 544
-   i32.const 713
+   i32.const 714
    i32.const 6
    call $~lib/builtins/abort
    unreachable

tests/compiler/std/string.optimized.wat

@@ -6022,12 +6022,12 @@
     if
      i32.const 1
      call $~lib/rt/__allocArray
+     call $~lib/rt/pure/__retain
      local.tee $0
      i32.load offset=4
      i32.const 496
      i32.store
      local.get $0
-     call $~lib/rt/pure/__retain
      return
     end
    else
@@ -6042,6 +6042,7 @@
     select
     local.tee $3
     call $~lib/rt/__allocArray
+    call $~lib/rt/pure/__retain
     local.tee $4
     i32.load offset=4
     local.set $5
@@ -6081,7 +6082,6 @@
      end
     end
     local.get $4
-    call $~lib/rt/pure/__retain
     return
    end
    i32.const 0

tests/compiler/std/string.untouched.wat

@@ -9056,6 +9056,7 @@
    i32.const 4
    i32.const 0
    call $~lib/rt/__allocArray
+   call $~lib/rt/pure/__retain
    local.set $4
    local.get $4
    i32.load offset=4
@@ -9100,7 +9101,6 @@
     unreachable
    end
    local.get $4
-   call $~lib/rt/pure/__retain
    local.set $7
    local.get $1
    call $~lib/rt/pure/__release
@@ -9115,13 +9115,13 @@
     i32.const 4
     i32.const 0
     call $~lib/rt/__allocArray
+    call $~lib/rt/pure/__retain
     local.set $3
     local.get $3
     i32.load offset=4
     i32.const 496
     i32.store
     local.get $3
-    call $~lib/rt/pure/__retain
     local.set $4
     local.get $1
     call $~lib/rt/pure/__release