[kernel] Free memory for kernel data.

runtime/vm/dart_api_impl.cc

Index: runtime/vm/dart_api_impl.cc
diff --git a/runtime/vm/dart_api_impl.cc b/runtime/vm/dart_api_impl.cc
index ea47c97744ba30ba1cd2fe184bc1970070ee1c31..31c7dcdd184e9294f36a819423a5172a429bc961 100644
--- a/runtime/vm/dart_api_impl.cc
+++ b/runtime/vm/dart_api_impl.cc
@@ -5054,11 +5054,15 @@ static void CompileSource(Thread* thread,
 static Dart_Handle LoadKernelProgram(Thread* T,
                                      const String& url,
                                      void* kernel) {
-  // NOTE: Now the VM owns the [kernel_program] memory!  Currently we do not
-  // free it because (similar to the token stream) it will be used to repeatedly
-  // run the `kernel::FlowGraphBuilder()`.
-  kernel::KernelReader reader(reinterpret_cast<kernel::Program*>(kernel));
+  // NOTE: Now the VM owns the [kernel_program] memory!
+  // We will promptly delete it when done.
+  kernel::Program* program = reinterpret_cast<kernel::Program*>(kernel);
+  kernel::KernelReader reader(program);
   const Object& tmp = reader.ReadProgram();
+  delete program;
+  program = NULL;

[Kevin Millikin (Google), 2017/08/14 06:20:50]

program = NULL and kernel = NULL don't seem necessary.

If you were worried that this function might grow a lot more code that used
program after it was deleted, you could put it in its own scope.  (But I
wouldn't worry too much about that.)

[jensj, 2017/08/14 08:38:12]

Done.

+  kernel = NULL;
+
   if (tmp.IsError()) {
     return Api::NewHandle(T, tmp.raw());
   }
@@ -5236,12 +5240,15 @@ DART_EXPORT Dart_Handle Dart_LoadKernel(void* kernel_program) {
   CHECK_CALLBACK_STATE(T);
   CHECK_COMPILATION_ALLOWED(I);
 
-  // NOTE: Now the VM owns the [kernel_program] memory!  Currently we do not
-  // free it because (similar to the token stream) it will be used to repeatedly
-  // run the `kernel::FlowGraphBuilder()`.
-  kernel::KernelReader reader(
-      reinterpret_cast<kernel::Program*>(kernel_program));
+  // NOTE: Now the VM owns the [kernel_program] memory!
+  // We will promptly delete it when done.
+  kernel::Program* program = reinterpret_cast<kernel::Program*>(kernel_program);
+  kernel::KernelReader reader(program);
   const Object& tmp = reader.ReadProgram();
+  delete program;
+  program = NULL;

[Kevin Millikin (Google), 2017/08/14 06:20:50]

Likewise, here I don't think setting them to NULL is really needed.

[jensj, 2017/08/14 08:38:12]

Done.

+  kernel_program = NULL;
+
   if (tmp.IsError()) {
     return Api::NewHandle(T, tmp.raw());
   }