Harden isolate initialization

In the case of a corrupted snapshot we fall back to initializing the isolate
from scratch. Howver, we don't ship the full SetupIsolateDelegate. This causes
spurious failures during later initialization.

This CL mostly turns the DCHECKs in SetupIsolateDelegate into hard CHECKs making
it easier to spot these kind of failures.


Bug: chromium:767846
Cq-Include-Trybots: master.tryserver.chromium.linux:linux_chromium_rel_ng
Change-Id: Ibe8a5beece27433439b1b09412f6110be703ff86
Reviewed-on: https://chromium-review.googlesource.com/779189Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49533}

src/api.cc

@@ -8609,6 +8609,9 @@ Isolate* IsolateNewImpl(internal::Isolate* isolate,
   // TODO(jochen): Once we got rid of Isolate::Current(), we can remove this.
   Isolate::Scope isolate_scope(v8_isolate);
   if (params.entry_hook || !i::Snapshot::Initialize(isolate)) {
+    // If snapshot data was provided and we failed to deserialize it must
+    // have been corrupted.
+    CHECK_NULL(isolate->snapshot_blob());
     base::ElapsedTimer timer;
     if (i::FLAG_profile_deserialization) timer.Start();
     isolate->Init(nullptr);

src/setup-isolate-deserialize.cc

@@ -13,7 +13,7 @@ namespace v8 {
 namespace internal {
 
 void SetupIsolateDelegate::SetupBuiltins(Isolate* isolate) {
-  DCHECK(!create_heap_objects_);
+  CHECK(!create_heap_objects_);
   // No actual work to be done; builtins will be deserialized from the snapshot.
 }
 
@@ -27,11 +27,11 @@ void SetupIsolateDelegate::SetupInterpreter(
        << std::endl;
   }
 #endif
-  DCHECK(interpreter->IsDispatchTableInitialized());
+  CHECK(interpreter->IsDispatchTableInitialized());
 }
 
 bool SetupIsolateDelegate::SetupHeap(Heap* heap) {
-  DCHECK(!create_heap_objects_);
+  CHECK(!create_heap_objects_);
   // No actual work to be done; heap will be deserialized from the snapshot.
   return true;
 }

src/setup-isolate-full.cc

@@ -17,7 +17,7 @@ void SetupIsolateDelegate::SetupBuiltins(Isolate* isolate) {
   if (create_heap_objects_) {
     SetupBuiltinsInternal(isolate);
   } else {
-    DCHECK(isolate->snapshot_available());
+    CHECK(isolate->snapshot_available());
   }
 }
 
@@ -26,7 +26,7 @@ void SetupIsolateDelegate::SetupInterpreter(
   if (create_heap_objects_) {
     interpreter::SetupInterpreter::InstallBytecodeHandlers(interpreter);
   } else {
-    DCHECK(interpreter->IsDispatchTableInitialized());
+    CHECK(interpreter->IsDispatchTableInitialized());
   }
 }
 
@@ -34,7 +34,7 @@ bool SetupIsolateDelegate::SetupHeap(Heap* heap) {
   if (create_heap_objects_) {
     return SetupHeapInternal(heap);
   } else {
-    DCHECK(heap->isolate()->snapshot_available());
+    CHECK(heap->isolate()->snapshot_available());
     return true;
   }
 }