On windows, refer to Dart snapshot directly executable. (#5024)

Author: chinmaygarde

lib/snapshot/snapshot.h

@@ -9,6 +9,6 @@
 extern "C" {
 extern const uint8_t kDartVmSnapshotData[];
 extern const uint8_t kDartVmSnapshotInstructions[];
-extern const uint8_t kDartIsolateCoreSnapshotData[];
-extern const uint8_t kDartIsolateCoreSnapshotInstructions[];
+extern const uint8_t kDartIsolateSnapshotData[];
+extern const uint8_t kDartIsolateSnapshotInstructions[];
 }

runtime/dart_snapshot.cc

@@ -9,6 +9,7 @@
 #include "flutter/fml/native_library.h"
 #include "flutter/fml/paths.h"
 #include "flutter/fml/trace_event.h"
+#include "flutter/lib/snapshot/snapshot.h"
 #include "flutter/runtime/dart_snapshot_buffer.h"
 #include "flutter/runtime/dart_vm.h"
 
@@ -20,8 +21,7 @@ const char* DartSnapshot::kIsolateDataSymbol = "kDartIsolateSnapshotData";
 const char* DartSnapshot::kIsolateInstructionsSymbol =
     "kDartIsolateSnapshotInstructions";
 
-static std::unique_ptr<DartSnapshotBuffer> ResolveVMData(
-    const Settings& settings) {
+std::unique_ptr<DartSnapshotBuffer> ResolveVMData(const Settings& settings) {
   if (settings.aot_snapshot_path.size() > 0) {
     auto path = fml::paths::JoinPaths(
         {settings.aot_snapshot_path, settings.aot_vm_snapshot_data_filename});
@@ -36,7 +36,7 @@ static std::unique_ptr<DartSnapshotBuffer> ResolveVMData(
       loaded_process, DartSnapshot::kVMDataSymbol);
 }
 
-static std::unique_ptr<DartSnapshotBuffer> ResolveVMInstructions(
+std::unique_ptr<DartSnapshotBuffer> ResolveVMInstructions(
     const Settings& settings) {
   if (settings.aot_snapshot_path.size() > 0) {
     auto path = fml::paths::JoinPaths(
@@ -61,7 +61,7 @@ static std::unique_ptr<DartSnapshotBuffer> ResolveVMInstructions(
       loaded_process, DartSnapshot::kVMInstructionsSymbol);
 }
 
-static std::unique_ptr<DartSnapshotBuffer> ResolveIsolateData(
+std::unique_ptr<DartSnapshotBuffer> ResolveIsolateData(
     const Settings& settings) {
   if (settings.aot_snapshot_path.size() > 0) {
     auto path =
@@ -78,7 +78,7 @@ static std::unique_ptr<DartSnapshotBuffer> ResolveIsolateData(
       loaded_process, DartSnapshot::kIsolateDataSymbol);
 }
 
-static std::unique_ptr<DartSnapshotBuffer> ResolveIsolateInstructions(
+std::unique_ptr<DartSnapshotBuffer> ResolveIsolateInstructions(
     const Settings& settings) {
   if (settings.aot_snapshot_path.size() > 0) {
     auto path =
@@ -107,6 +107,12 @@ static std::unique_ptr<DartSnapshotBuffer> ResolveIsolateInstructions(
 fxl::RefPtr<DartSnapshot> DartSnapshot::VMSnapshotFromSettings(
     const Settings& settings) {
   TRACE_EVENT0("flutter", "DartSnapshot::VMSnapshotFromSettings");
+#if OS_WIN
+  return fxl::MakeRefCounted<DartSnapshot>(
+      DartSnapshotBuffer::CreateWithUnmanagedAllocation(kDartVmSnapshotData),
+      DartSnapshotBuffer::CreateWithUnmanagedAllocation(
+          kDartVmSnapshotInstructions));
+#else   // OS_WIN
   auto snapshot =
       fxl::MakeRefCounted<DartSnapshot>(ResolveVMData(settings),         //
                                         ResolveVMInstructions(settings)  //
@@ -115,11 +121,19 @@ fxl::RefPtr<DartSnapshot> DartSnapshot::VMSnapshotFromSettings(
     return snapshot;
   }
   return nullptr;
+#endif  // OS_WIN
 }
 
 fxl::RefPtr<DartSnapshot> DartSnapshot::IsolateSnapshotFromSettings(
     const Settings& settings) {
   TRACE_EVENT0("flutter", "DartSnapshot::IsolateSnapshotFromSettings");
+#if OS_WIN
+  return fxl::MakeRefCounted<DartSnapshot>(
+      DartSnapshotBuffer::CreateWithUnmanagedAllocation(
+          kDartIsolateSnapshotData),
+      DartSnapshotBuffer::CreateWithUnmanagedAllocation(
+          kDartIsolateSnapshotInstructions));
+#else  // OS_WIN
   auto snapshot =
       fxl::MakeRefCounted<DartSnapshot>(ResolveIsolateData(settings),         //
                                         ResolveIsolateInstructions(settings)  //
@@ -128,6 +142,7 @@ fxl::RefPtr<DartSnapshot> DartSnapshot::IsolateSnapshotFromSettings(
     return snapshot;
   }
   return nullptr;
+#endif
 }
 
 DartSnapshot::DartSnapshot(std::unique_ptr<DartSnapshotBuffer> data,

runtime/dart_snapshot_buffer.cc

@@ -51,6 +51,20 @@ class FileSnapshotBuffer final : public DartSnapshotBuffer {
   FXL_DISALLOW_COPY_AND_ASSIGN(FileSnapshotBuffer);
 };
 
+class UnmanagedAllocation final : public DartSnapshotBuffer {
+ public:
+  UnmanagedAllocation(const uint8_t* allocation) : allocation_(allocation) {}
+
+  const uint8_t* GetSnapshotPointer() const override { return allocation_; }
+
+  size_t GetSnapshotSize() const override { return 0; }
+
+ private:
+  const uint8_t* allocation_;
+
+  FXL_DISALLOW_COPY_AND_ASSIGN(UnmanagedAllocation);
+};
+
 std::unique_ptr<DartSnapshotBuffer>
 DartSnapshotBuffer::CreateWithSymbolInLibrary(
     fxl::RefPtr<fml::NativeLibrary> library,
@@ -67,6 +81,14 @@ DartSnapshotBuffer::CreateWithContentsOfFile(const char* file_path,
   return source->GetSnapshotPointer() == nullptr ? nullptr : std::move(source);
 }
 
+std::unique_ptr<DartSnapshotBuffer>
+DartSnapshotBuffer::CreateWithUnmanagedAllocation(const uint8_t* allocation) {
+  if (allocation == nullptr) {
+    return nullptr;
+  }
+  return std::make_unique<UnmanagedAllocation>(allocation);
+}
+
 DartSnapshotBuffer::~DartSnapshotBuffer() = default;
 
 }  // namespace blink

runtime/dart_snapshot_buffer.h

@@ -22,6 +22,9 @@ class DartSnapshotBuffer {
       const char* file_path,
       bool executable);
 
+  static std::unique_ptr<DartSnapshotBuffer> CreateWithUnmanagedAllocation(
+      const uint8_t* allocation);
+
   virtual ~DartSnapshotBuffer();
 
   virtual const uint8_t* GetSnapshotPointer() const = 0;