build: generate more treeshaking friendly code

packages/runtime-core/src/componentRenderUtils.ts

@@ -60,12 +60,13 @@ export function renderComponentRoot(
   } = instance
 
   let result
+  let fallthroughAttrs
   const prev = setCurrentRenderingInstance(instance)
   if (__DEV__) {
     accessedAttrs = false
   }
+
   try {
-    let fallthroughAttrs
     if (vnode.shapeFlag & ShapeFlags.STATEFUL_COMPONENT) {
       // withProxy is a proxy with a different `has` trap only for
       // runtime-compiled render functions using `with` block.
@@ -110,6 +111,11 @@ export function renderComponentRoot(
         ? attrs
         : getFunctionalFallthrough(attrs)
     }
+  } catch (err) {
+    blockStack.length = 0
+    handleError(err, instance, ErrorCodes.RENDER_FUNCTION)
+    result = createVNode(Comment)
+  }
 
   // attr merging
   // in dev mode, comments are preserved, and it's possible for a template
@@ -227,11 +233,6 @@ export function renderComponentRoot(
   } else {
     result = root
   }
-  } catch (err) {
-    blockStack.length = 0
-    handleError(err, instance, ErrorCodes.RENDER_FUNCTION)
-    result = createVNode(Comment)
-  }
 
   setCurrentRenderingInstance(prev)
   return result

packages/runtime-core/src/scheduler.ts

@@ -1,5 +1,5 @@
 import { ErrorCodes, callWithErrorHandling } from './errorHandling'
-import { isArray } from '@vue/shared'
+import { isArray, NOOP } from '@vue/shared'
 import { ComponentInternalInstance, getComponentName } from './component'
 import { warn } from './warning'
 
@@ -128,10 +128,7 @@ function queueCb(
   if (!isArray(cb)) {
     if (
       !activeQueue ||
-      !activeQueue.includes(
-        cb,
-        cb.allowRecurse ? index + 1 : index
-      )
+      !activeQueue.includes(cb, cb.allowRecurse ? index + 1 : index)
     ) {
       pendingQueue.push(cb)
     }
@@ -241,11 +238,20 @@ function flushJobs(seen?: CountMap) {
   //    its update can be skipped.
   queue.sort((a, b) => getId(a) - getId(b))
 
+  // conditional usage of checkRecursiveUpdate must be determined out of
+  // try ... catch block since Rollup by default de-optimizes treeshaking
+  // inside try-catch. This can leave all warning code unshaked. Although
+  // they would get eventually shaken by a minifier like terser, some minifiers
+  // would fail to do that (e.g. https://github.com/evanw/esbuild/issues/1610)
+  const check = __DEV__
+    ? (job: SchedulerJob) => checkRecursiveUpdates(seen!, job)
+    : NOOP
+
   try {
     for (flushIndex = 0; flushIndex < queue.length; flushIndex++) {
       const job = queue[flushIndex]
       if (job && job.active !== false) {
-        if (__DEV__ && checkRecursiveUpdates(seen!, job)) {
+        if (__DEV__ && check(job)) {
           continue
         }
         // console.log(`running:`, job.id)