Properly propagate existing conditionals in flows (AssemblyScript#844)

Author: dcodeIO

src/flow.ts

@@ -521,6 +521,7 @@ export class Flow {
 
   /** Inherits categorical flags as conditional flags from the specified flow (e.g. then without else). */
   inheritConditional(other: Flow): void {
+    this.set(other.flags & FlowFlags.ANY_CONDITIONAL);
     if (other.is(FlowFlags.RETURNS)) {
       this.set(FlowFlags.CONDITIONALLY_RETURNS);
     }
@@ -539,6 +540,7 @@ export class Flow {
     var localFlags = other.localFlags;
     for (let i = 0, k = localFlags.length; i < k; ++i) {
       let flags = localFlags[i];
+      this.setLocalFlag(i, flags & LocalFlags.ANY_CONDITIONAL);
       if (flags & LocalFlags.RETAINED) this.setLocalFlag(i, LocalFlags.CONDITIONALLY_RETAINED);
       if (flags & LocalFlags.READFROM) this.setLocalFlag(i, LocalFlags.CONDITIONALLY_READFROM);
       if (flags & LocalFlags.WRITTENTO) this.setLocalFlag(i, LocalFlags.CONDITIONALLY_WRITTENTO);

tests/compiler/continue.json

@@ -0,0 +1,5 @@
+{
+  "asc_flags": [
+    "--runtime none"
+  ]
+}

tests/compiler/continue.optimized.wat

@@ -0,0 +1,36 @@
+(module
+ (type $FUNCSIG$vi (func (param i32)))
+ (type $FUNCSIG$v (func))
+ (memory $0 0)
+ (export "memory" (memory $0))
+ (export "testInherit" (func $continue/testInherit))
+ (func $continue/testInherit (; 0 ;) (type $FUNCSIG$vi) (param $0 i32)
+  (local $1 i32)
+  block $break|0
+   loop $loop|0
+    local.get $1
+    i32.const 10
+    i32.ge_s
+    br_if $break|0
+    block $continue|0
+     local.get $0
+     i32.const 0
+     local.get $1
+     i32.const 5
+     i32.eq
+     select
+     br_if $continue|0
+    end
+    local.get $1
+    i32.const 1
+    i32.add
+    local.set $1
+    br $loop|0
+   end
+   unreachable
+  end
+ )
+ (func $null (; 1 ;) (type $FUNCSIG$v)
+  nop
+ )
+)

tests/compiler/continue.ts

@@ -0,0 +1,12 @@
+// see https://github.com/AssemblyScript/assemblyscript/issues/813
+export function testInherit(b: bool): void {
+  for (let i = 0; i < 10; i++) {
+    if (b) {
+      if (i == 5) {
+        continue;
+      }
+      // inheritConditional
+    }
+    // yielding a continue block
+  }
+}

tests/compiler/continue.untouched.wat

@@ -0,0 +1,42 @@
+(module
+ (type $FUNCSIG$vi (func (param i32)))
+ (type $FUNCSIG$v (func))
+ (memory $0 0)
+ (table $0 1 funcref)
+ (elem (i32.const 0) $null)
+ (export "memory" (memory $0))
+ (export "testInherit" (func $continue/testInherit))
+ (func $continue/testInherit (; 0 ;) (type $FUNCSIG$vi) (param $0 i32)
+  (local $1 i32)
+  block $break|0
+   i32.const 0
+   local.set $1
+   loop $loop|0
+    local.get $1
+    i32.const 10
+    i32.lt_s
+    i32.eqz
+    br_if $break|0
+    block $continue|0
+     local.get $0
+     if
+      local.get $1
+      i32.const 5
+      i32.eq
+      if
+       br $continue|0
+      end
+     end
+    end
+    local.get $1
+    i32.const 1
+    i32.add
+    local.set $1
+    br $loop|0
+   end
+   unreachable
+  end
+ )
+ (func $null (; 1 ;) (type $FUNCSIG$v)
+ )
+)