[no-wasm] Remove wasm-js

This CL removes wasm-js.cc from compilation if
v8_enable_webassembly=false. In order to do so, an alternative
implementation of {v8::WasmStreaming} has to be provided, because the
public API should stay unchanged. The only path to obtain a
{v8::WasmStreaming} object is via {v8::WasmStreaming::Unpack}, which
will always fail if WebAssembly is not supported. Hence all methods in
{WasmStreamingImpl} are unreachable.

As a drive-by, this CL removes all includes from src/wasm in src/init
(bootstrapper.cc would have been done anyway, and v8.cc is just a few
 changes).

R=jkummerow@chromium.org

Bug: v8:11238
Change-Id: Ic0638eb5cda91ec29c1c07ef400bc670c91630fb
Cq-Include-Trybots: luci.v8.try:v8_linux64_no_wasm_compile_rel
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2737300Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73234}

BUILD.gn

@@ -2993,7 +2993,6 @@ v8_header_set("v8_internal_headers") {
     "src/wasm/wasm-feature-flags.h",
     "src/wasm/wasm-features.h",
     "src/wasm/wasm-import-wrapper-cache.h",
-    "src/wasm/wasm-js.h",
     "src/wasm/wasm-linkage.h",
     "src/wasm/wasm-module-builder.h",
     "src/wasm/wasm-module-sourcemap.h",
@@ -3035,6 +3034,7 @@ v8_header_set("v8_internal_headers") {
       "src/asmjs/asm-types.h",
       "src/debug/debug-wasm-objects-inl.h",
       "src/debug/debug-wasm-objects.h",
+      "src/wasm/wasm-js.h",
     ]
   }
 
@@ -3927,7 +3927,6 @@ v8_source_set("v8_base_without_compiler") {
     "src/wasm/wasm-external-refs.cc",
     "src/wasm/wasm-features.cc",
     "src/wasm/wasm-import-wrapper-cache.cc",
-    "src/wasm/wasm-js.cc",
     "src/wasm/wasm-module-builder.cc",
     "src/wasm/wasm-module-sourcemap.cc",
     "src/wasm/wasm-module.cc",
@@ -3949,6 +3948,7 @@ v8_source_set("v8_base_without_compiler") {
       "src/asmjs/asm-scanner.cc",
       "src/asmjs/asm-types.cc",
       "src/debug/debug-wasm-objects.cc",
+      "src/wasm/wasm-js.cc",
     ]
   }
 

src/api/api.cc

@@ -10119,6 +10119,42 @@ RegisterState& RegisterState::operator=(const RegisterState& other) {
   return *this;
 }
 
+#if !V8_ENABLE_WEBASSEMBLY
+// If WebAssembly is disabled, we still need to provide an implementation of the
+// WasmStreaming API. Since {WasmStreaming::Unpack} will always fail, all
+// methods are unreachable.
+
+class WasmStreaming::WasmStreamingImpl {};
+
+WasmStreaming::WasmStreaming(std::unique_ptr<WasmStreamingImpl>) {
+  UNREACHABLE();
+}
+
+WasmStreaming::~WasmStreaming() = default;
+
+void WasmStreaming::OnBytesReceived(const uint8_t* bytes, size_t size) {
+  UNREACHABLE();
+}
+
+void WasmStreaming::Finish() { UNREACHABLE(); }
+
+void WasmStreaming::Abort(MaybeLocal<Value> exception) { UNREACHABLE(); }
+
+bool WasmStreaming::SetCompiledModuleBytes(const uint8_t* bytes, size_t size) {
+  UNREACHABLE();
+}
+
+void WasmStreaming::SetClient(std::shared_ptr<Client> client) { UNREACHABLE(); }
+
+void WasmStreaming::SetUrl(const char* url, size_t length) { UNREACHABLE(); }
+
+// static
+std::shared_ptr<WasmStreaming> WasmStreaming::Unpack(Isolate* isolate,
+                                                     Local<Value> value) {
+  FATAL("WebAssembly is disabled");
+}
+#endif  // !V8_ENABLE_WEBASSEMBLY
+
 namespace internal {
 
 const size_t HandleScopeImplementer::kEnteredContextsOffset =

src/init/bootstrapper.cc

@@ -63,9 +63,12 @@
 #include "src/objects/swiss-name-dictionary-inl.h"
 #include "src/objects/templates.h"
 #include "src/snapshot/snapshot.h"
-#include "src/wasm/wasm-js.h"
 #include "src/zone/zone-hashmap.h"
 
+#if V8_ENABLE_WEBASSEMBLY
+#include "src/wasm/wasm-js.h"
+#endif  // V8_ENABLE_WEBASSEMBLY
+
 namespace v8 {
 namespace internal {
 
@@ -4945,6 +4948,7 @@ bool Genesis::InstallSpecialObjects(Isolate* isolate,
   Handle<Smi> stack_trace_limit(Smi::FromInt(FLAG_stack_trace_limit), isolate);
   JSObject::AddProperty(isolate, Error, name, stack_trace_limit, NONE);
 
+#if V8_ENABLE_WEBASSEMBLY
   if (FLAG_expose_wasm) {
     // Install the internal data structures into the isolate and expose on
     // the global object.
@@ -4954,6 +4958,7 @@ bool Genesis::InstallSpecialObjects(Isolate* isolate,
     // translated to Wasm to work correctly.
     WasmJs::Install(isolate, false);
   }
+#endif  // V8_ENABLE_WEBASSEMBLY
 
   return true;
 }

src/init/v8.cc

@@ -26,7 +26,10 @@
 #include "src/profiler/heap-profiler.h"
 #include "src/snapshot/snapshot.h"
 #include "src/tracing/tracing-category-observer.h"
+
+#if V8_ENABLE_WEBASSEMBLY
 #include "src/wasm/wasm-engine.h"
+#endif  // V8_ENABLE_WEBASSEMBLY
 
 #if defined(V8_TARGET_OS_WIN) && defined(V8_ENABLE_SYSTEM_INSTRUMENTATION)
 #include "src/diagnostics/system-jit-win.h"
@@ -50,7 +53,9 @@ bool V8::Initialize() {
 }
 
 void V8::TearDown() {
+#if V8_ENABLE_WEBASSEMBLY
   wasm::WasmEngine::GlobalTearDown();
+#endif  // V8_ENABLE_WEBASSEMBLY
 #if defined(USE_SIMULATOR)
   Simulator::GlobalTearDown();
 #endif
@@ -157,7 +162,9 @@ void V8::InitializeOncePerProcessImpl() {
   ElementsAccessor::InitializeOncePerProcess();
   Bootstrapper::InitializeOncePerProcess();
   CallDescriptors::InitializeOncePerProcess();
+#if V8_ENABLE_WEBASSEMBLY
   wasm::WasmEngine::InitializeOncePerProcess();
+#endif  // V8_ENABLE_WEBASSEMBLY
 }
 
 void V8::InitializeOncePerProcess() {