feat: store local name in debug mode binary

src/compiler.ts

@@ -1016,13 +1016,14 @@ export class Compiler extends DiagnosticEmitter {
       let numLocals = locals.length;
       let varTypes = new Array<TypeRef>(numLocals);
       for (let i = 0; i < numLocals; ++i) varTypes[i] = locals[i].type.toRef();
-      module.addFunction(
+      const funcRef = module.addFunction(
         startFunction.internalName,
         startSignature.paramRefs,
         startSignature.resultRefs,
         varTypes,
         module.flatten(startFunctionBody)
       );
+      startFunction.finalize(module, funcRef);
       previousBody.push(
         module.call(startFunction.internalName, null, TypeRef.None)
       );
@@ -10295,7 +10296,6 @@ export class Compiler extends DiagnosticEmitter {
 }
 
 // helpers
-
 function mangleImportName(
   element: Element,
   declaration: DeclarationStatement

src/module.ts

@@ -1913,6 +1913,10 @@ export class Module {
     return ret;
   }
 
+  setLocalName(funcRef: FunctionRef, index: u32, name: string): void {
+    binaryen._BinaryenFunctionSetLocalName(funcRef, index, this.allocStringCached(name));
+  }
+
   getFunction(
     name: string
   ): FunctionRef {

src/program.ts

@@ -3773,6 +3773,22 @@ export class Function extends TypedElement {
         );
       }
     }
+    if (this.program.options.debugInfo) {
+      let localNameMap = new Set<string>();
+      let localsByIndex = this.localsByIndex;
+      for (let i = 0, k = localsByIndex.length; i < k; i++) {
+        let localName = localsByIndex[i].name;
+        if (localNameMap.has(localName)) {
+          let repeat = 0;
+          while (localNameMap.has(`${localName}_${repeat}`)) {
+            repeat++;
+          }
+          localName = `${localName}_${repeat}`;
+        }
+        localNameMap.add(localName);
+        module.setLocalName(ref, i, localName);
+      }
+    }
   }
 }
 

tests/compiler/NonNullable.debug.wat

@@ -25,44 +25,44 @@
  (elem $0 (i32.const 1))
  (export "memory" (memory $0))
  (start $~start)
- (func $~lib/string/String#get:length (param $0 i32) (result i32)
-  local.get $0
+ (func $~lib/string/String#get:length (param $this i32) (result i32)
+  local.get $this
   i32.const 20
   i32.sub
   i32.load offset=16
   i32.const 1
   i32.shr_u
  )
- (func $~lib/util/string/compareImpl (param $0 i32) (param $1 i32) (param $2 i32) (param $3 i32) (param $4 i32) (result i32)
-  (local $5 i32)
-  (local $6 i32)
-  (local $7 i32)
-  (local $8 i32)
-  (local $9 i32)
-  local.get $0
-  local.get $1
+ (func $~lib/util/string/compareImpl (param $str1 i32) (param $index1 i32) (param $str2 i32) (param $index2 i32) (param $len i32) (result i32)
+  (local $ptr1 i32)
+  (local $ptr2 i32)
+  (local $var$7 i32)
+  (local $a i32)
+  (local $b i32)
+  local.get $str1
+  local.get $index1
   i32.const 1
   i32.shl
   i32.add
-  local.set $5
-  local.get $2
-  local.get $3
+  local.set $ptr1
+  local.get $str2
+  local.get $index2
   i32.const 1
   i32.shl
   i32.add
-  local.set $6
+  local.set $ptr2
   i32.const 0
   i32.const 2
   i32.lt_s
   drop
-  local.get $4
+  local.get $len
   i32.const 4
   i32.ge_u
   if (result i32)
-   local.get $5
+   local.get $ptr1
    i32.const 7
    i32.and
-   local.get $6
+   local.get $ptr2
    i32.const 7
    i32.and
    i32.or
@@ -73,124 +73,124 @@
   if
    block $do-break|0
     loop $do-loop|0
-     local.get $5
+     local.get $ptr1
      i64.load
-     local.get $6
+     local.get $ptr2
      i64.load
      i64.ne
      if
       br $do-break|0
      end
-     local.get $5
+     local.get $ptr1
      i32.const 8
      i32.add
-     local.set $5
-     local.get $6
+     local.set $ptr1
+     local.get $ptr2
      i32.const 8
      i32.add
-     local.set $6
-     local.get $4
+     local.set $ptr2
+     local.get $len
      i32.const 4
      i32.sub
-     local.set $4
-     local.get $4
+     local.set $len
+     local.get $len
      i32.const 4
      i32.ge_u
      br_if $do-loop|0
     end
    end
   end
   loop $while-continue|1
-   local.get $4
-   local.tee $7
+   local.get $len
+   local.tee $var$7
    i32.const 1
    i32.sub
-   local.set $4
-   local.get $7
-   local.set $7
-   local.get $7
+   local.set $len
+   local.get $var$7
+   local.set $var$7
+   local.get $var$7
    if
-    local.get $5
+    local.get $ptr1
     i32.load16_u
-    local.set $8
-    local.get $6
+    local.set $a
+    local.get $ptr2
     i32.load16_u
-    local.set $9
-    local.get $8
-    local.get $9
+    local.set $b
+    local.get $a
+    local.get $b
     i32.ne
     if
-     local.get $8
-     local.get $9
+     local.get $a
+     local.get $b
      i32.sub
      return
     end
-    local.get $5
+    local.get $ptr1
     i32.const 2
     i32.add
-    local.set $5
-    local.get $6
+    local.set $ptr1
+    local.get $ptr2
     i32.const 2
     i32.add
-    local.set $6
+    local.set $ptr2
     br $while-continue|1
    end
   end
   i32.const 0
  )
- (func $~lib/string/String.__eq (param $0 i32) (param $1 i32) (result i32)
-  (local $2 i32)
-  local.get $0
-  local.get $1
+ (func $~lib/string/String.__eq (param $left i32) (param $right i32) (result i32)
+  (local $leftLength i32)
+  local.get $left
+  local.get $right
   i32.eq
   if
    i32.const 1
    return
   end
-  local.get $0
+  local.get $left
   i32.const 0
   i32.eq
   if (result i32)
    i32.const 1
   else
-   local.get $1
+   local.get $right
    i32.const 0
    i32.eq
   end
   if
    i32.const 0
    return
   end
-  local.get $0
+  local.get $left
   call $~lib/string/String#get:length
-  local.set $2
-  local.get $2
-  local.get $1
+  local.set $leftLength
+  local.get $leftLength
+  local.get $right
   call $~lib/string/String#get:length
   i32.ne
   if
    i32.const 0
    return
   end
-  local.get $0
+  local.get $left
   i32.const 0
-  local.get $1
+  local.get $right
   i32.const 0
-  local.get $2
+  local.get $leftLength
   call $~lib/util/string/compareImpl
   i32.eqz
  )
- (func $~lib/string/String.__ne (param $0 i32) (param $1 i32) (result i32)
-  local.get $0
-  local.get $1
+ (func $~lib/string/String.__ne (param $left i32) (param $right i32) (result i32)
+  local.get $left
+  local.get $right
   call $~lib/string/String.__eq
   i32.eqz
  )
- (func $NonNullable/assertNonNull<~lib/string/String> (param $0 i32)
+ (func $NonNullable/assertNonNull<~lib/string/String> (param $t i32)
   i32.const 0
   i32.eqz
   drop
-  local.get $0
+  local.get $t
   i32.const 0
   call $~lib/string/String.__ne
   i32.eqz
@@ -203,12 +203,12 @@
    unreachable
   end
  )
- (func $NonNullable/safetyCheck<~lib/string/String|null> (param $0 i32)
-  local.get $0
+ (func $NonNullable/safetyCheck<~lib/string/String|null> (param $t i32)
+  local.get $t
   i32.const 0
   call $~lib/string/String.__ne
   if
-   local.get $0
+   local.get $t
    call $NonNullable/assertNonNull<~lib/string/String>
   end
  )