[wasm] Fix bounds check for zero initial memory.

src/assembler.h

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // All Rights Reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 // - Redistributions of source code must retain the above copyright notice,
 // this list of conditions and the following disclaimer.
 //
@@ skipping 375 matching lines @@
   enum Mode {
     // Please note the order is important (see IsCodeTarget, IsGCRelocMode).
     CODE_TARGET,  // Code target which is not any of the above.
     CODE_TARGET_WITH_ID,
     DEBUGGER_STATEMENT,  // Code target for the debugger statement.
     EMBEDDED_OBJECT,
     // To relocate pointers into the wasm memory embedded in wasm code
     WASM_MEMORY_REFERENCE,
     WASM_GLOBAL_REFERENCE,
     WASM_MEMORY_SIZE_REFERENCE,
+    WASM_MEMTYPE_SIZE_REFERENCE,
     CELL,
 
     // Everything after runtime_entry (inclusive) is not GC'ed.
     RUNTIME_ENTRY,
     COMMENT,
 
     // Additional code inserted for debug break slot.
     DEBUG_BREAK_SLOT_AT_POSITION,
     DEBUG_BREAK_SLOT_AT_RETURN,
     DEBUG_BREAK_SLOT_AT_CALL,
@@ skipping 24 matching lines @@
     // Pseudo-types
     NUMBER_OF_MODES,
     NONE32,             // never recorded 32-bit value
     NONE64,             // never recorded 64-bit value
     CODE_AGE_SEQUENCE,  // Not stored in RelocInfo array, used explictly by
                         // code aging.
 
     FIRST_REAL_RELOC_MODE = CODE_TARGET,
     LAST_REAL_RELOC_MODE = VENEER_POOL,
     LAST_CODE_ENUM = DEBUGGER_STATEMENT,
-    LAST_GCED_ENUM = WASM_MEMORY_SIZE_REFERENCE,
+    LAST_GCED_ENUM = WASM_MEMTYPE_SIZE_REFERENCE,
     FIRST_SHAREABLE_RELOC_MODE = CELL,
   };
 
   STATIC_ASSERT(NUMBER_OF_MODES <= kBitsPerInt);
 
   explicit RelocInfo(Isolate* isolate) : isolate_(isolate) {
     DCHECK_NOT_NULL(isolate);
   }
 
   RelocInfo(Isolate* isolate, byte* pc, Mode rmode, intptr_t data, Code* host)
@@ skipping 72 matching lines @@
   }
   static inline bool IsGeneratorContinuation(Mode mode) {
     return mode == GENERATOR_CONTINUATION;
   }
   static inline bool IsWasmMemoryReference(Mode mode) {
     return mode == WASM_MEMORY_REFERENCE;
   }
   static inline bool IsWasmMemorySizeReference(Mode mode) {
     return mode == WASM_MEMORY_SIZE_REFERENCE;
   }
+  static inline bool IsWasmMemtypeSizeReference(Mode mode) {
+    return mode == WASM_MEMTYPE_SIZE_REFERENCE;
+  }
   static inline bool IsWasmGlobalReference(Mode mode) {
     return mode == WASM_GLOBAL_REFERENCE;
   }
+  static inline bool IsWasmReference(Mode mode) {
+    return mode == WASM_MEMORY_REFERENCE ||
+           mode == WASM_MEMORY_SIZE_REFERENCE ||
+           mode == WASM_MEMTYPE_SIZE_REFERENCE || mode == WASM_GLOBAL_REFERENCE;
+  }
+  static inline bool IsWasmSizeReference(Mode mode) {
+    return mode == WASM_MEMORY_SIZE_REFERENCE ||
+           mode == WASM_MEMTYPE_SIZE_REFERENCE;
+  }
   static inline int ModeMask(Mode mode) { return 1 << mode; }
 
   // Accessors
   Isolate* isolate() const { return isolate_; }
   byte* pc() const { return pc_; }
   void set_pc(byte* pc) { pc_ = pc; }
   Mode rmode() const {  return rmode_; }
   intptr_t data() const { return data_; }
   Code* host() const { return host_; }
   void set_host(Code* host) { host_ = host; }
 
   // Apply a relocation by delta bytes. When the code object is moved, PC
   // relative addresses have to be updated as well as absolute addresses
   // inside the code (internal references).
   // Do not forget to flush the icache afterwards!
   INLINE(void apply(intptr_t delta));
 
   // Is the pointer this relocation info refers to coded like a plain pointer
   // or is it strange in some way (e.g. relative or patched into a series of
   // instructions).
   bool IsCodedSpecially();
 
   // If true, the pointer this relocation info refers to is an entry in the
   // constant pool, otherwise the pointer is embedded in the instruction stream.
   bool IsInConstantPool();
 
   Address wasm_memory_reference();
   Address wasm_global_reference();
   uint32_t wasm_memory_size_reference();
+  uint8_t wasm_memtype_size_reference();
   void update_wasm_memory_reference(
       Address old_base, Address new_base, uint32_t old_size, uint32_t new_size,
       ICacheFlushMode icache_flush_mode = FLUSH_ICACHE_IF_NEEDED);
   void update_wasm_global_reference(
       Address old_base, Address new_base,
       ICacheFlushMode icache_flush_mode = FLUSH_ICACHE_IF_NEEDED);
   void set_target_address(
       Address target,
       WriteBarrierMode write_barrier_mode = UPDATE_WRITE_BARRIER,
       ICacheFlushMode icache_flush_mode = FLUSH_ICACHE_IF_NEEDED);
@@ skipping 706 matching lines @@
     std::vector<ConstantPoolEntry> shared_entries;
   };
 
   Label emitted_label_;  // Records pc_offset of emitted pool
   PerTypeEntryInfo info_[ConstantPoolEntry::NUMBER_OF_TYPES];
 };
 
 }  // namespace internal
 }  // namespace v8
 #endif  // V8_ASSEMBLER_H_