Replace the --platform vm_option with --kernel-binaries option.

This new flag value specifies the directory in which the VM should look
up the platform.dill file. A future change will require the VM to load
another kernel binary from disk. This binary will also live in the same
directory that --kernel-binaries specifies. This way, we avoid adding a
different flag for each of the different binaries.

R=asiva@google.com

Review-Url: https://codereview.chromium.org/2933203004 .

runtime/bin/dfe.cc

@@ -5,12 +5,16 @@
 #include "bin/dfe.h"
 #include "bin/dartutils.h"
 #include "bin/error_exit.h"
+#include "bin/file.h"
 
 #include "vm/kernel.h"
 
 namespace dart {
 namespace bin {
 
+const char kPlatformBinaryName[] = "platform.dill";
+
+
 DFE::DFE()
     : frontend_filename_(NULL),
       platform_binary_filename_(NULL),
@@ -19,13 +23,29 @@ DFE::DFE()
 
 DFE::~DFE() {
   frontend_filename_ = NULL;
-  platform_binary_filename_ = NULL;
+
+  if (platform_binary_filename_ != NULL) {
+    delete platform_binary_filename_;
+    platform_binary_filename_ = NULL;
+  }
+
   if (kernel_platform_ != NULL) {
     delete reinterpret_cast<kernel::Program*>(kernel_platform_);
+    kernel_platform_ = NULL;
   }
-  kernel_platform_ = NULL;
 }
 
+
+void DFE::SetKernelBinaries(const char* name) {
+  intptr_t len = snprintf(NULL, 0, "%s%s%s", name, File::PathSeparator(),
+                          kPlatformBinaryName) +
+                 1;
+  platform_binary_filename_ = new char[len];
+  snprintf(platform_binary_filename_, len, "%s%s%s", name,
+           File::PathSeparator(), kPlatformBinaryName);
+}
+
+
 Dart_Handle DFE::ReloadScript(Dart_Isolate isolate, const char* url_string) {
   ASSERT(!Dart_IsServiceIsolate(isolate) && !Dart_IsKernelIsolate(isolate));
   // First check if the URL points to a Kernel IR file in which case we
@@ -85,15 +105,7 @@ void* DFE::CompileAndReadScript(const char* script_uri,
 
 
 void* DFE::ReadPlatform() {
-  const uint8_t* buffer = NULL;
-  intptr_t buffer_length = -1;
-  bool result =
-      TryReadKernelFile(platform_binary_filename_, &buffer, &buffer_length);
-  if (result) {
-    kernel_platform_ = Dart_ReadKernelBinary(buffer, buffer_length);
-    return kernel_platform_;
-  }
-  return NULL;
+  return kernel_platform_ = ReadScript(platform_binary_filename_);
 }
 
 

runtime/bin/dfe.h

@@ -25,9 +25,9 @@ class DFE {
   const char* platform_binary_filename() const {
     return platform_binary_filename_;
   }
-  void set_platform_binary_filename(const char* name) {
-    platform_binary_filename_ = name;
-  }
+
+  void SetKernelBinaries(const char* name);
+
   bool UsePlatformBinary() const { return platform_binary_filename_ != NULL; }
 
   void* kernel_platform() const { return kernel_platform_; }
@@ -66,7 +66,7 @@ class DFE {
                          intptr_t* kernel_ir_size);
 
   const char* frontend_filename_;
-  const char* platform_binary_filename_;
+  char* platform_binary_filename_;
   void* kernel_platform_;
 
   DISALLOW_COPY_AND_ASSIGN(DFE);

runtime/bin/main.cc

@@ -381,13 +381,13 @@ static bool ProcessFrontendOption(const char* filename,
 }
 
 
-static bool ProcessPlatformOption(const char* filename,
-                                  CommandLineOptions* vm_options) {
-  ASSERT(filename != NULL);
-  if (filename[0] == '\0') {
+static bool ProcessKernelBinariesOption(const char* dirname,
+                                        CommandLineOptions* vm_options) {
+  ASSERT(dirname != NULL);
+  if (dirname[0] == '\0') {
     return false;
   }
-  dfe.set_platform_binary_filename(filename);
+  dfe.SetKernelBinaries(dirname);
   return true;
 }
 #endif
@@ -616,7 +616,7 @@ static struct {
     {"--parse_all", ProcessParseAllOption},
 #if !defined(DART_PRECOMPILED_RUNTIME)
     {"--dfe=", ProcessFrontendOption},
-    {"--platform=", ProcessPlatformOption},
+    {"--kernel-binaries=", ProcessKernelBinariesOption},
 #endif
     {"--enable-vm-service", ProcessEnableVmServiceOption},
     {"--disable-service-origin-check", ProcessDisableServiceOriginCheckOption},

tools/testing/dart/compiler_configuration.dart

@@ -198,7 +198,7 @@ class NoneCompilerConfiguration extends CompilerConfiguration {
     List<String> args = [];
     if (useDfe) {
       args.add('--dfe=${buildDir}/gen/kernel-service.dart.snapshot');
-      args.add('--platform=${buildDir}/patched_sdk/platform.dill');
+      args.add('--kernel-binaries=${buildDir}/patched_sdk');
     }
     if (isChecked) {
       args.add('--enable_asserts');
@@ -608,7 +608,7 @@ class PrecompilerCompilerConfiguration extends CompilerConfiguration {
     var args = <String>[];
     if (useDfe) {
       args.add('--dfe=utils/kernel-service/kernel-service.dart');
-      args.add('--platform=${buildDir}/patched_sdk/platform.dill');
+      args.add('--kernel-binaries=${buildDir}/patched_sdk');
     }
     args.add("--snapshot-kind=app-aot");
     if (useBlobs) {