VM: Better handling of OOM errors in the background compiler

runtime/vm/compiler.cc

 // Copyright (c) 2012, 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 "vm/compiler.h"
 
 #include "vm/assembler.h"
 
 #include "vm/ast_printer.h"
 #include "vm/block_scheduler.h"
@@ skipping 1266 matching lines @@
           if (FLAG_trace_compiler) {
             THR_Print("Aborted background compilation: %s\n",
                 function.ToFullyQualifiedCString());
           }
           {
             // If it was a bailout, then disable optimization.
             Error& error = Error::Handle();
             // We got an error during compilation.
             error = thread->sticky_error();
             thread->clear_sticky_error();
-            if (error.IsLanguageError() &&
-                LanguageError::Cast(error).kind() == Report::kBailout) {
+            if ((error.IsLanguageError() &&
+                 LanguageError::Cast(error).kind() == Report::kBailout) ||
+                error.IsUnhandledException()) {
               if (FLAG_trace_compiler) {
                 THR_Print("--> disabling optimizations for '%s'\n",
                           function.ToFullyQualifiedCString());
               }
               function.SetIsOptimizable(false);
             }
           }
           return Error::null();
         }
         // Optimizer bailed out. Disable optimizations and never try again.
@@ skipping 54 matching lines @@
     error = thread->sticky_error();
     thread->clear_sticky_error();
     if (error.raw() == Object::background_compilation_error().raw()) {
       // Exit compilation, retry it later.
       if (FLAG_trace_bailout) {
         THR_Print("Aborted background compilation: %s\n",
             function.ToFullyQualifiedCString());
       }
       return Error::null();
     }
-    // Unoptimized compilation or precompilation may encounter compile-time
-    // errors, but regular optimized compilation should not.
-    ASSERT(!optimized);
     // Do not attempt to optimize functions that can cause errors.
     function.set_is_optimizable(false);
     return error.raw();
   }
   UNREACHABLE();
   return Error::null();
 }
 
 
 RawError* Compiler::CompileFunction(Thread* thread,
@@ skipping 479 matching lines @@
       StackZone stack_zone(thread);
       Zone* zone = stack_zone.GetZone();
       HANDLESCOPE(thread);
       Function& function = Function::Handle(zone);
       { MonitorLocker ml(queue_monitor_);
         function = function_queue()->PeekFunction();
       }
       while (running_ && !function.IsNull() && !isolate_->IsTopLevelParsing()) {
         // Check that we have aggregated and cleared the stats.
         ASSERT(thread->compiler_stats()->IsCleared());
-        const Error& error = Error::Handle(zone,
-            Compiler::CompileOptimizedFunction(thread,
-                                               function,
-                                               Compiler::kNoOSRDeoptId));
-        // TODO(srdjan): We do not expect errors while compiling optimized
-        // code, any errors should have been caught when compiling
-        // unoptimized code. Any issues while optimizing are flagged by
-        // making the result invalid.
-        ASSERT(error.IsNull());
+        Compiler::CompileOptimizedFunction(thread,
+                                           function,
+                                           Compiler::kNoOSRDeoptId);
 #ifndef PRODUCT
         Isolate* isolate = thread->isolate();
         isolate->aggregate_compiler_stats()->Add(*thread->compiler_stats());
         thread->compiler_stats()->Clear();
 #endif  // PRODUCT
 
         QueueElement* qelem = NULL;
         { MonitorLocker ml(queue_monitor_);
           if (function_queue()->IsEmpty()) {
             // We are shutting down, queue was cleared.
@@ skipping 294 matching lines @@
 
 
 bool BackgroundCompiler::IsDisabled() {
   UNREACHABLE();
   return true;
 }
 
 #endif  // DART_PRECOMPILED_RUNTIME
 
 }  // namespace dart