From ef100642340de82787aaebb316118b25e2769fe8 Mon Sep 17 00:00:00 2001
From: dcode <dcode@dcode.io>
Date: Wed, 3 Feb 2021 23:55:12 +0100
Subject: [PATCH 1/3] Properly handle semantically anonymous functions

---
 src/compiler.ts                               |  57 +++++---
 tests/compiler/function-call.optimized.wat    |   4 +-
 tests/compiler/function-call.untouched.wat    |   4 +-
 .../function-expression.optimized.wat         |  79 +++++++----
 tests/compiler/function-expression.ts         |  11 ++
 .../function-expression.untouched.wat         | 131 +++++++++++++-----
 6 files changed, 203 insertions(+), 83 deletions(-)

diff --git a/src/compiler.ts b/src/compiler.ts
index ce51af29c3..a7f1dde511 100644
--- a/src/compiler.ts
+++ b/src/compiler.ts
@@ -3429,7 +3429,7 @@ export class Compiler extends DiagnosticEmitter {
         break;
       }
       case NodeKind.FUNCTION: {
-        expr = this.compileFunctionExpression(<FunctionExpression>expression, contextualType.signatureReference, constraints);
+        expr = this.compileFunctionExpression(<FunctionExpression>expression, contextualType, constraints);
         break;
       }
       case NodeKind.IDENTIFIER:
@@ -7311,26 +7311,30 @@ export class Compiler extends DiagnosticEmitter {
 
   private compileFunctionExpression(
     expression: FunctionExpression,
-    contextualSignature: Signature | null,
+    contextualType: Type,
     constraints: Constraints
   ): ExpressionRef {
     var declaration = expression.declaration.clone(); // generic contexts can have multiple
     assert(!declaration.typeParameters); // function expression cannot be generic
     var flow = this.currentFlow;
     var actualFunction = flow.actualFunction;
+    var isNamed = declaration.name.text.length > 0;
+    var isSemanticallyAnonymous = !isNamed || contextualType != Type.void;
     var prototype = new FunctionPrototype(
-      declaration.name.text.length
-        ? declaration.name.text
-        : "anonymous|" + (actualFunction.nextAnonymousId++).toString(),
+      isSemanticallyAnonymous
+        ? (isNamed ? declaration.name.text + "|" : "anonymous|") + (actualFunction.nextAnonymousId++).toString()
+        : declaration.name.text,
       actualFunction,
       declaration,
       DecoratorFlags.NONE
     );
     var instance: Function | null;
     var contextualTypeArguments = uniqueMap(flow.contextualTypeArguments);
+    var module = this.module;
 
     // compile according to context. this differs from a normal function in that omitted parameter
     // and return types can be inferred and omitted arguments can be replaced with dummies.
+    var contextualSignature = contextualType.signatureReference;
     if (contextualSignature) {
       let signatureNode = prototype.functionTypeNode;
       let parameterNodes = signatureNode.parameters;
@@ -7344,7 +7348,7 @@ export class Compiler extends DiagnosticEmitter {
           DiagnosticCode.Expected_0_arguments_but_got_1,
           expression.range, numParameters.toString(), numPresentParameters.toString()
         );
-        return this.module.unreachable();
+        return module.unreachable();
       }
 
       // check non-omitted parameter types
@@ -7356,13 +7360,13 @@ export class Compiler extends DiagnosticEmitter {
             actualFunction.parent,
             contextualTypeArguments
           );
-          if (!resolvedType) return this.module.unreachable();
+          if (!resolvedType) return module.unreachable();
           if (!parameterTypes[i].isStrictlyAssignableTo(resolvedType)) {
             this.error(
               DiagnosticCode.Type_0_is_not_assignable_to_type_1,
               parameterNode.range, parameterTypes[i].toString(), resolvedType.toString()
             );
-            return this.module.unreachable();
+            return module.unreachable();
           }
         }
         // any unused parameters are inherited but ignored
@@ -7376,7 +7380,7 @@ export class Compiler extends DiagnosticEmitter {
           actualFunction.parent,
           contextualTypeArguments
         );
-        if (!resolvedType) return this.module.unreachable();
+        if (!resolvedType) return module.unreachable();
         if (
           returnType == Type.void
             ? resolvedType != Type.void
@@ -7386,7 +7390,7 @@ export class Compiler extends DiagnosticEmitter {
             DiagnosticCode.Type_0_is_not_assignable_to_type_1,
             signatureNode.returnType.range, resolvedType.toString(), returnType.toString()
           );
-          return this.module.unreachable();
+          return module.unreachable();
         }
       }
 
@@ -7399,20 +7403,20 @@ export class Compiler extends DiagnosticEmitter {
             DiagnosticCode._this_cannot_be_referenced_in_current_location,
             thisTypeNode.range
           );
-          return this.module.unreachable();
+          return module.unreachable();
         }
         let resolvedType = this.resolver.resolveType(
           thisTypeNode,
           actualFunction.parent,
           contextualTypeArguments
         );
-        if (!resolvedType) return this.module.unreachable();
+        if (!resolvedType) return module.unreachable();
         if (!thisType.isStrictlyAssignableTo(resolvedType)) {
           this.error(
             DiagnosticCode.Type_0_is_not_assignable_to_type_1,
             thisTypeNode.range, thisType.toString(), resolvedType.toString()
           );
-          return this.module.unreachable();
+          return module.unreachable();
         }
       }
 
@@ -7428,7 +7432,7 @@ export class Compiler extends DiagnosticEmitter {
       instance.flow.outer = flow;
       let worked = this.compileFunction(instance);
       this.currentType = contextualSignature.type;
-      if (!worked) return this.module.unreachable();
+      if (!worked) return module.unreachable();
 
     // otherwise compile like a normal function
     } else {
@@ -7437,13 +7441,30 @@ export class Compiler extends DiagnosticEmitter {
       instance.flow.outer = flow;
       let worked = this.compileFunction(instance);
       this.currentType = instance.signature.type;
-      if (!worked) return this.module.unreachable();
+      if (!worked) return module.unreachable();
     }
 
     var offset = this.ensureRuntimeFunction(instance); // reports
-    return this.options.isWasm64
-      ? this.module.i64(i64_low(offset), i64_high(offset))
-      : this.module.i32(i64_low(offset));
+    var expr = this.options.isWasm64
+      ? module.i64(i64_low(offset), i64_high(offset))
+      : module.i32(i64_low(offset));
+
+    // add a local referring to the function if applicable
+    if (!isSemanticallyAnonymous) {
+      let fname = instance.name;
+      if (flow.lookupLocal(fname)) {
+        this.error(
+          DiagnosticCode.Duplicate_identifier_0,
+          declaration.name.range, fname
+        );
+      } else {
+        let ftype = instance.type;
+        let local = flow.addScopedLocal(instance.name, ftype);
+        expr = module.local_tee(local.index, expr, ftype.isManaged);
+      }
+    }
+    
+    return expr;
   }
 
   /** Makes sure the enclosing source file of the specified expression has been compiled. */
diff --git a/tests/compiler/function-call.optimized.wat b/tests/compiler/function-call.optimized.wat
index 4d1a3f6d86..a6c5a04fdc 100644
--- a/tests/compiler/function-call.optimized.wat
+++ b/tests/compiler/function-call.optimized.wat
@@ -41,7 +41,7 @@
  (data (i32.const 1760) "\t\00\00\00 \00\00\00\00\00\00\00 ")
  (data (i32.const 1812) " ")
  (table $0 9 funcref)
- (elem (i32.const 1) $start:function-call~anonymous|0 $start:function-call~anonymous|0 $start:function-call~anonymous|2 $start:function-call~anonymous|2 $start:function-call~fn2 $function-call/Foo#fnVoid $start:function-call~fn2 $function-call/Foo#fnRet)
+ (elem (i32.const 1) $start:function-call~anonymous|0 $start:function-call~anonymous|0 $start:function-call~anonymous|2 $start:function-call~anonymous|2 $start:function-call~fn2|4 $function-call/Foo#fnVoid $start:function-call~fn2|4 $function-call/Foo#fnRet)
  (global $~lib/rt/itcms/total (mut i32) (i32.const 0))
  (global $~lib/rt/itcms/threshold (mut i32) (i32.const 1024))
  (global $~lib/rt/itcms/state (mut i32) (i32.const 0))
@@ -64,7 +64,7 @@
   local.get $1
   i32.add
  )
- (func $start:function-call~fn2 (param $0 i32) (result i32)
+ (func $start:function-call~fn2|4 (param $0 i32) (result i32)
   local.get $0
  )
  (func $~lib/rt/itcms/initLazy (param $0 i32) (result i32)
diff --git a/tests/compiler/function-call.untouched.wat b/tests/compiler/function-call.untouched.wat
index 2808a52435..6e8a33cf4b 100644
--- a/tests/compiler/function-call.untouched.wat
+++ b/tests/compiler/function-call.untouched.wat
@@ -29,7 +29,7 @@
  (data (i32.const 700) "\1c\00\00\00\00\00\00\00\00\00\00\00\08\00\00\00\08\00\00\00\08\00\00\00\00\00\00\00\00\00\00\00")
  (data (i32.const 736) "\t\00\00\00 \00\00\00\00\00\00\00 \00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00 \00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00")
  (table $0 9 funcref)
- (elem (i32.const 1) $start:function-call~anonymous|0 $start:function-call~anonymous|1 $start:function-call~anonymous|2 $start:function-call~anonymous|3 $start:function-call~fn2 $function-call/Foo#fnVoid $function-call/Foo#fnThis $function-call/Foo#fnRet)
+ (elem (i32.const 1) $start:function-call~anonymous|0 $start:function-call~anonymous|1 $start:function-call~anonymous|2 $start:function-call~anonymous|3 $start:function-call~fn2|4 $function-call/Foo#fnVoid $function-call/Foo#fnThis $function-call/Foo#fnRet)
  (global $function-call/fnVoid (mut i32) (i32.const 32))
  (global $~argumentsLength (mut i32) (i32.const 0))
  (global $function-call/faVoid (mut i32) (i32.const 64))
@@ -71,7 +71,7 @@
   local.get $1
   i32.add
  )
- (func $start:function-call~fn2 (param $0 i32) (result i32)
+ (func $start:function-call~fn2|4 (param $0 i32) (result i32)
   local.get $0
  )
  (func $~lib/rt/itcms/Object#set:nextWithColor (param $0 i32) (param $1 i32)
diff --git a/tests/compiler/function-expression.optimized.wat b/tests/compiler/function-expression.optimized.wat
index 130350508e..7b7c6f6c09 100644
--- a/tests/compiler/function-expression.optimized.wat
+++ b/tests/compiler/function-expression.optimized.wat
@@ -7,6 +7,7 @@
  (type $i32_=>_none (func (param i32)))
  (type $i32_i32_i32_=>_none (func (param i32 i32 i32)))
  (type $i32_i32_i32_i32_=>_none (func (param i32 i32 i32 i32)))
+ (type $i64_=>_i64 (func (param i64) (result i64)))
  (import "env" "abort" (func $~lib/builtins/abort (param i32 i32 i32 i32)))
  (memory $0 1)
  (data (i32.const 1036) "\1c")
@@ -55,9 +56,13 @@
  (data (i32.const 1992) "\03\00\00\00\08\00\00\00\10")
  (data (i32.const 2012) "\1c")
  (data (i32.const 2024) "\07\00\00\00\08\00\00\00\11")
- (data (i32.const 2048) "\t\00\00\00 \00\00\00\00\00\00\00 ")
- (table $0 18 funcref)
- (elem (i32.const 1) $start:function-expression~anonymous|0 $start:function-expression~anonymous|0 $start:function-expression~someName $start:function-expression~anonymous|2 $start:function-expression~anonymous|3 $start:function-expression~anonymous|4 $start:function-expression~anonymous|5 $start:function-expression~anonymous|3 $start:function-expression~anonymous|4 $start:function-expression~anonymous|5 $start:function-expression~anonymous|2 $function-expression/testGlobal~anonymous|0~anonymous|0 $function-expression/testGlobal~anonymous|0 $function-expression/testGlobal~anonymous|0~anonymous|0 $function-expression/testLocal~anonymous|0 $function-expression/testGlobal~anonymous|0~anonymous|0 $function-expression/testField~anonymous|0)
+ (data (i32.const 2044) "\1c")
+ (data (i32.const 2056) "\03\00\00\00\08\00\00\00\12")
+ (data (i32.const 2076) "\1c")
+ (data (i32.const 2088) "\t\00\00\00\08\00\00\00\13")
+ (data (i32.const 2112) "\n\00\00\00 \00\00\00\00\00\00\00 ")
+ (table $0 20 funcref)
+ (elem (i32.const 1) $start:function-expression~anonymous|0 $start:function-expression~anonymous|0 $start:function-expression~someName|2 $start:function-expression~anonymous|3 $start:function-expression~anonymous|4 $start:function-expression~anonymous|5 $start:function-expression~anonymous|6 $start:function-expression~anonymous|4 $start:function-expression~anonymous|5 $start:function-expression~anonymous|6 $start:function-expression~anonymous|3 $function-expression/testGlobal~anonymous|0~anonymous|0 $function-expression/testGlobal~anonymous|0 $function-expression/testGlobal~anonymous|0~anonymous|0 $function-expression/testLocal~anonymous|0 $function-expression/testGlobal~anonymous|0~anonymous|0 $function-expression/testField~anonymous|0 $start:function-expression~anonymous|0 $function-expression/semanticallyAnonymous~fnDecl|0)
  (global $~lib/rt/itcms/total (mut i32) (i32.const 0))
  (global $~lib/rt/itcms/threshold (mut i32) (i32.const 1024))
  (global $~lib/rt/itcms/state (mut i32) (i32.const 0))
@@ -68,27 +73,28 @@
  (global $~lib/rt/itcms/white (mut i32) (i32.const 0))
  (global $~lib/rt/itcms/fromSpace (mut i32) (i32.const 0))
  (global $~lib/rt/tlsf/ROOT (mut i32) (i32.const 0))
- (global $~lib/memory/__stack_pointer (mut i32) (i32.const 18508))
+ (global $~lib/memory/__stack_pointer (mut i32) (i32.const 18580))
+ (export "semanticallyAnonymous" (func $function-expression/semanticallyAnonymous))
  (export "memory" (memory $0))
  (start $~start)
  (func $start:function-expression~anonymous|0 (param $0 i32) (result i32)
   local.get $0
  )
- (func $start:function-expression~someName
+ (func $start:function-expression~someName|2
   nop
  )
- (func $start:function-expression~anonymous|2 (result i32)
+ (func $start:function-expression~anonymous|3 (result i32)
   i32.const 1
  )
- (func $start:function-expression~anonymous|3 (param $0 i32) (param $1 i32) (result i32)
+ (func $start:function-expression~anonymous|4 (param $0 i32) (param $1 i32) (result i32)
   local.get $0
   local.get $1
   i32.add
  )
- (func $start:function-expression~anonymous|4 (param $0 i32) (param $1 i32) (result i32)
+ (func $start:function-expression~anonymous|5 (param $0 i32) (param $1 i32) (result i32)
   local.get $0
  )
- (func $start:function-expression~anonymous|5 (param $0 i32) (param $1 i32) (result i32)
+ (func $start:function-expression~anonymous|6 (param $0 i32) (param $1 i32) (result i32)
   i32.const 42
  )
  (func $function-expression/testGlobal~anonymous|0~anonymous|0 (param $0 i32) (result i32)
@@ -222,7 +228,7 @@
    if
     i32.const 0
     local.get $0
-    i32.const 18508
+    i32.const 18580
     i32.lt_u
     local.get $0
     i32.load offset=8
@@ -268,7 +274,7 @@
    i32.const 1
   else
    local.get $1
-   i32.const 2048
+   i32.const 2112
    i32.load
    i32.gt_u
    if
@@ -282,7 +288,7 @@
    local.get $1
    i32.const 3
    i32.shl
-   i32.const 2052
+   i32.const 2116
    i32.add
    i32.load
    i32.const 32
@@ -887,10 +893,10 @@
   if
    unreachable
   end
-  i32.const 18512
+  i32.const 18592
   i32.const 0
   i32.store
-  i32.const 20080
+  i32.const 20160
   i32.const 0
   i32.store
   loop $for-loop|0
@@ -901,7 +907,7 @@
     local.get $1
     i32.const 2
     i32.shl
-    i32.const 18512
+    i32.const 18592
     i32.add
     i32.const 0
     i32.store offset=4
@@ -919,7 +925,7 @@
       i32.add
       i32.const 2
       i32.shl
-      i32.const 18512
+      i32.const 18592
       i32.add
       i32.const 0
       i32.store offset=96
@@ -937,13 +943,13 @@
     br $for-loop|0
    end
   end
-  i32.const 18512
-  i32.const 20084
+  i32.const 18592
+  i32.const 20164
   memory.size
   i32.const 16
   i32.shl
   call $~lib/rt/tlsf/addMemory
-  i32.const 18512
+  i32.const 18592
   global.set $~lib/rt/tlsf/ROOT
  )
  (func $~lib/rt/itcms/step (result i32)
@@ -1022,7 +1028,7 @@
       local.set $0
       loop $while-continue|0
        local.get $0
-       i32.const 18508
+       i32.const 18580
        i32.lt_u
        if
         local.get $0
@@ -1112,7 +1118,7 @@
       unreachable
      end
      local.get $0
-     i32.const 18508
+     i32.const 18580
      i32.lt_u
      if
       local.get $0
@@ -1135,7 +1141,7 @@
       i32.const 4
       i32.add
       local.tee $1
-      i32.const 18508
+      i32.const 18580
       i32.ge_u
       if
        global.get $~lib/rt/tlsf/ROOT
@@ -1494,6 +1500,26 @@
   i32.store8 offset=1
   local.get $0
  )
+ (func $function-expression/semanticallyAnonymous~fnDecl|0 (param $0 i64) (result i64)
+  local.get $0
+ )
+ (func $function-expression/semanticallyAnonymous
+  global.get $~lib/memory/__stack_pointer
+  i32.const 4
+  i32.sub
+  global.set $~lib/memory/__stack_pointer
+  call $~stack_check
+  global.get $~lib/memory/__stack_pointer
+  i32.const 0
+  i32.store
+  global.get $~lib/memory/__stack_pointer
+  i32.const 2064
+  i32.store
+  global.get $~lib/memory/__stack_pointer
+  i32.const 4
+  i32.add
+  global.set $~lib/memory/__stack_pointer
+ )
  (func $~lib/rt/__visit_members (param $0 i32)
   block $folding-inner1
    block $folding-inner0
@@ -1504,7 +1530,7 @@
        i32.const 8
        i32.sub
        i32.load
-       br_table $~lib/arraybuffer/ArrayBuffer $~lib/string/String $folding-inner0 $folding-inner1 $folding-inner1 $folding-inner1 $folding-inner1 $folding-inner1 $folding-inner0 $invalid
+       br_table $~lib/arraybuffer/ArrayBuffer $~lib/string/String $folding-inner0 $folding-inner1 $folding-inner1 $folding-inner1 $folding-inner1 $folding-inner1 $folding-inner0 $folding-inner1 $invalid
       end
       return
      end
@@ -1530,11 +1556,11 @@
  )
  (func $~stack_check
   global.get $~lib/memory/__stack_pointer
-  i32.const 2124
+  i32.const 2196
   i32.lt_s
   if
-   i32.const 18528
-   i32.const 18576
+   i32.const 18608
+   i32.const 18656
    i32.const 1
    i32.const 1
    call $~lib/builtins/abort
@@ -1881,6 +1907,7 @@
   i32.const 12
   i32.add
   global.set $~lib/memory/__stack_pointer
+  call $function-expression/semanticallyAnonymous
   global.get $~lib/memory/__stack_pointer
   i32.const 4
   i32.add
diff --git a/tests/compiler/function-expression.ts b/tests/compiler/function-expression.ts
index 8fe0fdbf2e..b69ec8ca86 100644
--- a/tests/compiler/function-expression.ts
+++ b/tests/compiler/function-expression.ts
@@ -82,3 +82,14 @@ function testField(): void {
   assert(fieldInst.fieldFunc()(1) == 25);
 }
 testField();
+
+export function semanticallyAnonymous(): void {
+  function fnDecl(val: i32): i32 {
+    return val;
+  }
+  const exprDecl = function fnDecl(val: i64): i64 { // must not shadow
+    return val;
+  };
+  assert(fnDecl != exprDecl);
+}
+semanticallyAnonymous();
diff --git a/tests/compiler/function-expression.untouched.wat b/tests/compiler/function-expression.untouched.wat
index 610152ae02..6b01cab120 100644
--- a/tests/compiler/function-expression.untouched.wat
+++ b/tests/compiler/function-expression.untouched.wat
@@ -8,6 +8,7 @@
  (type $i32_i32_i32_=>_none (func (param i32 i32 i32)))
  (type $i32_i32_i32_i32_=>_none (func (param i32 i32 i32 i32)))
  (type $i32_i32_i32_=>_i32 (func (param i32 i32 i32) (result i32)))
+ (type $i64_=>_i64 (func (param i64) (result i64)))
  (import "env" "abort" (func $~lib/builtins/abort (param i32 i32 i32 i32)))
  (memory $0 1)
  (data (i32.const 12) "\1c\00\00\00\00\00\00\00\00\00\00\00\03\00\00\00\08\00\00\00\01\00\00\00\00\00\00\00\00\00\00\00")
@@ -36,9 +37,11 @@
  (data (i32.const 892) "<\00\00\00\00\00\00\00\00\00\00\00\01\00\00\00\1e\00\00\00~\00l\00i\00b\00/\00r\00t\00/\00t\00l\00s\00f\00.\00t\00s\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00")
  (data (i32.const 956) "\1c\00\00\00\00\00\00\00\00\00\00\00\03\00\00\00\08\00\00\00\10\00\00\00\00\00\00\00\00\00\00\00")
  (data (i32.const 988) "\1c\00\00\00\00\00\00\00\00\00\00\00\07\00\00\00\08\00\00\00\11\00\00\00\00\00\00\00\00\00\00\00")
- (data (i32.const 1024) "\t\00\00\00 \00\00\00\00\00\00\00 \00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00")
- (table $0 18 funcref)
- (elem (i32.const 1) $start:function-expression~anonymous|0 $start:function-expression~anonymous|1 $start:function-expression~someName $start:function-expression~anonymous|2 $start:function-expression~anonymous|3 $start:function-expression~anonymous|4 $start:function-expression~anonymous|5 $function-expression/testOmittedReturn1~anonymous|0 $function-expression/testOmittedReturn2~anonymous|0 $function-expression/testOmittedReturn3~anonymous|0 $function-expression/testNullable~anonymous|0 $function-expression/testGlobal~anonymous|0~anonymous|0 $function-expression/testGlobal~anonymous|0 $function-expression/testLocal~anonymous|0~anonymous|0 $function-expression/testLocal~anonymous|0 $function-expression/testField~anonymous|0~anonymous|0 $function-expression/testField~anonymous|0)
+ (data (i32.const 1020) "\1c\00\00\00\00\00\00\00\00\00\00\00\03\00\00\00\08\00\00\00\12\00\00\00\00\00\00\00\00\00\00\00")
+ (data (i32.const 1052) "\1c\00\00\00\00\00\00\00\00\00\00\00\t\00\00\00\08\00\00\00\13\00\00\00\00\00\00\00\00\00\00\00")
+ (data (i32.const 1088) "\n\00\00\00 \00\00\00\00\00\00\00 \00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00")
+ (table $0 20 funcref)
+ (elem (i32.const 1) $start:function-expression~anonymous|0 $start:function-expression~anonymous|1 $start:function-expression~someName|2 $start:function-expression~anonymous|3 $start:function-expression~anonymous|4 $start:function-expression~anonymous|5 $start:function-expression~anonymous|6 $function-expression/testOmittedReturn1~anonymous|0 $function-expression/testOmittedReturn2~anonymous|0 $function-expression/testOmittedReturn3~anonymous|0 $function-expression/testNullable~anonymous|0 $function-expression/testGlobal~anonymous|0~anonymous|0 $function-expression/testGlobal~anonymous|0 $function-expression/testLocal~anonymous|0~anonymous|0 $function-expression/testLocal~anonymous|0 $function-expression/testField~anonymous|0~anonymous|0 $function-expression/testField~anonymous|0 $function-expression/semanticallyAnonymous~fnDecl $function-expression/semanticallyAnonymous~fnDecl|0)
  (global $function-expression/f1 (mut i32) (i32.const 32))
  (global $~argumentsLength (mut i32) (i32.const 0))
  (global $function-expression/f2 (mut i32) (i32.const 128))
@@ -57,10 +60,11 @@
  (global $~lib/rt/tlsf/ROOT (mut i32) (i32.const 0))
  (global $~lib/ASC_LOW_MEMORY_LIMIT i32 (i32.const 0))
  (global $~lib/ASC_SHRINK_LEVEL i32 (i32.const 0))
- (global $~lib/rt/__rtti_base i32 (i32.const 1024))
- (global $~lib/memory/__data_end i32 (i32.const 1100))
- (global $~lib/memory/__stack_pointer (mut i32) (i32.const 17484))
- (global $~lib/memory/__heap_base i32 (i32.const 17484))
+ (global $~lib/rt/__rtti_base i32 (i32.const 1088))
+ (global $~lib/memory/__data_end i32 (i32.const 1172))
+ (global $~lib/memory/__stack_pointer (mut i32) (i32.const 17556))
+ (global $~lib/memory/__heap_base i32 (i32.const 17556))
+ (export "semanticallyAnonymous" (func $function-expression/semanticallyAnonymous))
  (export "memory" (memory $0))
  (start $~start)
  (func $start:function-expression~anonymous|0 (param $0 i32) (result i32)
@@ -69,13 +73,13 @@
  (func $start:function-expression~anonymous|1 (param $0 i32) (result i32)
   local.get $0
  )
- (func $start:function-expression~someName
+ (func $start:function-expression~someName|2
   nop
  )
- (func $start:function-expression~anonymous|2 (result i32)
+ (func $start:function-expression~anonymous|3 (result i32)
   i32.const 1
  )
- (func $start:function-expression~anonymous|3 (param $0 i32) (param $1 i32) (result i32)
+ (func $start:function-expression~anonymous|4 (param $0 i32) (param $1 i32) (result i32)
   local.get $0
   local.get $1
   i32.add
@@ -89,10 +93,10 @@
   i32.load
   call_indirect (type $i32_i32_=>_i32)
  )
- (func $start:function-expression~anonymous|4 (param $0 i32) (param $1 i32) (result i32)
+ (func $start:function-expression~anonymous|5 (param $0 i32) (param $1 i32) (result i32)
   local.get $0
  )
- (func $start:function-expression~anonymous|5 (param $0 i32) (param $1 i32) (result i32)
+ (func $start:function-expression~anonymous|6 (param $0 i32) (param $1 i32) (result i32)
   i32.const 42
  )
  (func $function-expression/testOmittedReturn1~anonymous|0 (param $0 i32) (param $1 i32) (result i32)
@@ -2621,6 +2625,45 @@
   local.get $0
   i32.add
  )
+ (func $function-expression/semanticallyAnonymous~fnDecl (param $0 i32) (result i32)
+  local.get $0
+ )
+ (func $function-expression/semanticallyAnonymous~fnDecl|0 (param $0 i64) (result i64)
+  local.get $0
+ )
+ (func $function-expression/semanticallyAnonymous
+  (local $0 i32)
+  global.get $~lib/memory/__stack_pointer
+  i32.const 4
+  i32.sub
+  global.set $~lib/memory/__stack_pointer
+  call $~stack_check
+  global.get $~lib/memory/__stack_pointer
+  i32.const 0
+  i32.store
+  global.get $~lib/memory/__stack_pointer
+  i32.const 1040
+  local.tee $0
+  i32.store
+  local.get $0
+  drop
+  local.get $0
+  i32.const 1072
+  i32.ne
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 64
+   i32.const 93
+   i32.const 3
+   call $~lib/builtins/abort
+   unreachable
+  end
+  global.get $~lib/memory/__stack_pointer
+  i32.const 4
+  i32.add
+  global.set $~lib/memory/__stack_pointer
+ )
  (func $~lib/rt/__visit_globals (param $0 i32)
   (local $1 i32)
   i32.const 768
@@ -2707,60 +2750,77 @@
    call $~lib/rt/itcms/__visit
   end
  )
+ (func $~lib/function/Function<%28i64%29=>i64>#__visit (param $0 i32) (param $1 i32)
+  local.get $0
+  i32.load offset=4
+  local.get $1
+  call $~lib/rt/itcms/__visit
+ )
+ (func $~lib/function/Function<%28i64%29=>i64>~visit (param $0 i32) (param $1 i32)
+  local.get $0
+  local.get $1
+  call $~lib/function/Function<%28i64%29=>i64>#__visit
+ )
  (func $~lib/rt/__visit_members (param $0 i32) (param $1 i32)
   block $invalid
-   block $function-expression/FieldClass
-    block $~lib/function/Function<%28%29=>%28i32%29=>i32>
-     block $~lib/function/Function<%28i32%2Ci32%29=>i32>
-      block $~lib/function/Function<%28%29=>i32>
-       block $~lib/function/Function<%28%29=>void>
-        block $~lib/function/Function<%28i32%29=>i32>
-         block $~lib/arraybuffer/ArrayBufferView
-          block $~lib/string/String
-           block $~lib/arraybuffer/ArrayBuffer
-            local.get $0
-            i32.const 8
-            i32.sub
-            i32.load
-            br_table $~lib/arraybuffer/ArrayBuffer $~lib/string/String $~lib/arraybuffer/ArrayBufferView $~lib/function/Function<%28i32%29=>i32> $~lib/function/Function<%28%29=>void> $~lib/function/Function<%28%29=>i32> $~lib/function/Function<%28i32%2Ci32%29=>i32> $~lib/function/Function<%28%29=>%28i32%29=>i32> $function-expression/FieldClass $invalid
+   block $~lib/function/Function<%28i64%29=>i64>
+    block $function-expression/FieldClass
+     block $~lib/function/Function<%28%29=>%28i32%29=>i32>
+      block $~lib/function/Function<%28i32%2Ci32%29=>i32>
+       block $~lib/function/Function<%28%29=>i32>
+        block $~lib/function/Function<%28%29=>void>
+         block $~lib/function/Function<%28i32%29=>i32>
+          block $~lib/arraybuffer/ArrayBufferView
+           block $~lib/string/String
+            block $~lib/arraybuffer/ArrayBuffer
+             local.get $0
+             i32.const 8
+             i32.sub
+             i32.load
+             br_table $~lib/arraybuffer/ArrayBuffer $~lib/string/String $~lib/arraybuffer/ArrayBufferView $~lib/function/Function<%28i32%29=>i32> $~lib/function/Function<%28%29=>void> $~lib/function/Function<%28%29=>i32> $~lib/function/Function<%28i32%2Ci32%29=>i32> $~lib/function/Function<%28%29=>%28i32%29=>i32> $function-expression/FieldClass $~lib/function/Function<%28i64%29=>i64> $invalid
+            end
+            return
            end
            return
           end
+          local.get $0
+          local.get $1
+          call $~lib/arraybuffer/ArrayBufferView~visit
           return
          end
          local.get $0
          local.get $1
-         call $~lib/arraybuffer/ArrayBufferView~visit
+         call $~lib/function/Function<%28i32%29=>i32>~visit
          return
         end
         local.get $0
         local.get $1
-        call $~lib/function/Function<%28i32%29=>i32>~visit
+        call $~lib/function/Function<%28%29=>void>~visit
         return
        end
        local.get $0
        local.get $1
-       call $~lib/function/Function<%28%29=>void>~visit
+       call $~lib/function/Function<%28%29=>i32>~visit
        return
       end
       local.get $0
       local.get $1
-      call $~lib/function/Function<%28%29=>i32>~visit
+      call $~lib/function/Function<%28i32%2Ci32%29=>i32>~visit
       return
      end
      local.get $0
      local.get $1
-     call $~lib/function/Function<%28i32%2Ci32%29=>i32>~visit
+     call $~lib/function/Function<%28%29=>%28i32%29=>i32>~visit
      return
     end
     local.get $0
     local.get $1
-    call $~lib/function/Function<%28%29=>%28i32%29=>i32>~visit
+    call $function-expression/FieldClass~visit
     return
    end
    local.get $0
    local.get $1
-   call $function-expression/FieldClass~visit
+   call $~lib/function/Function<%28i64%29=>i64>~visit
    return
   end
   unreachable
@@ -2773,8 +2833,8 @@
   global.get $~lib/memory/__data_end
   i32.lt_s
   if
-   i32.const 17504
-   i32.const 17552
+   i32.const 17584
+   i32.const 17632
    i32.const 1
    i32.const 1
    call $~lib/builtins/abort
@@ -3036,6 +3096,7 @@
   call $~lib/rt/itcms/initLazy
   global.set $~lib/rt/itcms/fromSpace
   call $function-expression/testField
+  call $function-expression/semanticallyAnonymous
   global.get $~lib/memory/__stack_pointer
   i32.const 4
   i32.add

From cb0337b2f9e4b9bf0989263e8ef88dc2a8ef9fb7 Mon Sep 17 00:00:00 2001
From: dcode <dcode@dcode.io>
Date: Thu, 4 Feb 2021 00:04:27 +0100
Subject: [PATCH 2/3] make the local constant

---
 src/compiler.ts | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/compiler.ts b/src/compiler.ts
index a7f1dde511..a8d3adeb2b 100644
--- a/src/compiler.ts
+++ b/src/compiler.ts
@@ -7449,7 +7449,7 @@ export class Compiler extends DiagnosticEmitter {
       ? module.i64(i64_low(offset), i64_high(offset))
       : module.i32(i64_low(offset));
 
-    // add a local referring to the function if applicable
+    // add a constant local referring to the function if applicable
     if (!isSemanticallyAnonymous) {
       let fname = instance.name;
       if (flow.lookupLocal(fname)) {
@@ -7460,6 +7460,7 @@ export class Compiler extends DiagnosticEmitter {
       } else {
         let ftype = instance.type;
         let local = flow.addScopedLocal(instance.name, ftype);
+        flow.setLocalFlag(local.index, LocalFlags.CONSTANT);
         expr = module.local_tee(local.index, expr, ftype.isManaged);
       }
     }

From 2d64b4d4d416e5d9fda2451a1cd3672c4f67ef22 Mon Sep 17 00:00:00 2001
From: dcode <dcode@dcode.io>
Date: Thu, 4 Feb 2021 00:13:41 +0100
Subject: [PATCH 3/3] allow shadowing, diagnose related declaration

---
 src/compiler.ts | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/src/compiler.ts b/src/compiler.ts
index a8d3adeb2b..d7364db52f 100644
--- a/src/compiler.ts
+++ b/src/compiler.ts
@@ -7452,11 +7452,21 @@ export class Compiler extends DiagnosticEmitter {
     // add a constant local referring to the function if applicable
     if (!isSemanticallyAnonymous) {
       let fname = instance.name;
-      if (flow.lookupLocal(fname)) {
-        this.error(
-          DiagnosticCode.Duplicate_identifier_0,
-          declaration.name.range, fname
-        );
+      let existingLocal = flow.getScopedLocal(fname);
+      if (existingLocal) {
+        if (!existingLocal.declaration.range.source.isNative) {
+          this.errorRelated(
+            DiagnosticCode.Duplicate_identifier_0,
+            declaration.name.range,
+            existingLocal.declaration.name.range,
+            fname
+          );
+        } else { // scoped locals are shared temps that don't track declarations
+          this.error(
+            DiagnosticCode.Duplicate_identifier_0,
+            declaration.name.range, fname
+          );
+        }
       } else {
         let ftype = instance.type;
         let local = flow.addScopedLocal(instance.name, ftype);