[standalone] Automatically decompress gzip'd resources, including sources and script snapshots.

runtime/bin/dfe.cc

 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "bin/dfe.h"
 #include "bin/dartutils.h"
 #include "bin/error_exit.h"
 #include "bin/file.h"
 
 #include "vm/kernel.h"
@@ skipping 125 matching lines @@
                             const uint8_t** kernel_ir,
                             intptr_t* kernel_ir_size) {
   *kernel_ir = NULL;
   *kernel_ir_size = -1;
   void* script_file = DartUtils::OpenFile(script_uri, false);
   if (script_file != NULL) {
     const uint8_t* buffer = NULL;
     DartUtils::ReadFile(&buffer, kernel_ir_size, script_file);
     DartUtils::CloseFile(script_file);
     if (*kernel_ir_size > 0 && buffer != NULL) {
-      // We need a temporary variable because SniffForMagicNumber modifies the
-      // buffer pointer to skip snapshot magic number.
-      const uint8_t* temp = buffer;
-      if (DartUtils::SniffForMagicNumber(&temp, kernel_ir_size) !=
+      if (DartUtils::SniffForMagicNumber(buffer, *kernel_ir_size) !=
           DartUtils::kKernelMagicNumber) {
         free(const_cast<uint8_t*>(buffer));
         *kernel_ir = NULL;
         *kernel_ir_size = -1;
         return false;
       } else {
         // Do not free buffer if this is a kernel file - kernel_file will be
         // backed by the same memory as the buffer and caller will own it.
         // Caller is responsible for freeing the buffer when this function
         // returns true.
         *kernel_ir = buffer;
         return true;
       }
     }
   }
   return false;
 }
 
 }  // namespace bin
 }  // namespace dart