[wasm] All strings are length-prefixed and inline

src/wasm/decoder.h

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_WASM_DECODER_H_
 #define V8_WASM_DECODER_H_
 
 #include "src/base/smart-pointers.h"
 #include "src/flags.h"
 #include "src/signature.h"
@@ skipping 207 matching lines @@
         b = *pc_++;
         TRACE("%02x ", b);
         result = result | ((b & 0x7F) << shift);
         if ((b & 0x80) == 0) break;
         shift += 7;
       }
 
       *length = static_cast<int>(pc_ - pos);
       if (pc_ == end && (b & 0x80)) {
         error(pc_ - 1, "varint too large");
+      } else if (*length == 0) {
+        error(pc_, "varint of length 0");
       } else {
         TRACE("= %u\n", result);
       }
       return result;
     }
     return traceOffEnd<uint32_t>();
   }
 
   // Consume {size} bytes and send them to the bit bucket, advancing {pc_}.
   void consume_bytes(int size) {
@@ skipping 157 matching lines @@
     return result;
   }
 };
 
 #undef TRACE
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_WASM_DECODER_H_