VM: [Kernel] Implement CatchBlockEntryInstr::should_restore_closure_context on all platforms.

runtime/vm/intermediate_language_arm64.cc

 // Copyright (c) 2014, 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/globals.h"  // Needed here to get TARGET_ARCH_ARM64.
 #if defined(TARGET_ARCH_ARM64)
 
 #include "vm/intermediate_language.h"
 
 #include "vm/compiler.h"
@@ skipping 2599 matching lines @@
     compiler->parallel_move_resolver()->EmitNativeCode(parallel_move());
   }
 
   // Restore SP from FP as we are coming from a throw and the code for
   // popping arguments has not been run.
   const intptr_t fp_sp_dist =
       (kFirstLocalSlotFromFp + 1 - compiler->StackSize()) * kWordSize;
   ASSERT(fp_sp_dist <= 0);
   __ AddImmediate(SP, FP, fp_sp_dist);
 
-  // Restore stack and initialize the two exception variables:
-  // exception and stack trace variables.
-  __ StoreToOffset(kExceptionObjectReg, FP,
-                   exception_var().index() * kWordSize);
-  __ StoreToOffset(kStackTraceObjectReg, FP,
-                   stacktrace_var().index() * kWordSize);
+  // Auxiliary variables introduced by the try catch can be captured if we are
+  // inside a function with yield/resume points. In this case we first need
+  // to restore the context to match the context at entry into the closure.
+  if (should_restore_closure_context()) {
+    const ParsedFunction& parsed_function = compiler->parsed_function();
+    ASSERT(parsed_function.function().IsClosureFunction());
+    LocalScope* scope = parsed_function.node_sequence()->scope();
+
+    LocalVariable* closure_parameter = scope->VariableAt(0);
+    ASSERT(!closure_parameter->is_captured());
+    __ LoadFromOffset(CTX, FP, closure_parameter->index() * kWordSize);
+    __ LoadFieldFromOffset(CTX, CTX, Closure::context_offset());
+
+    const intptr_t context_index =
+        parsed_function.current_context_var()->index();
+    __ StoreToOffset(CTX, FP, context_index * kWordSize);
+  }
+
+  // Initialize exception and stack trace variables.
+  if (exception_var().is_captured()) {
+    ASSERT(stacktrace_var().is_captured());
+    __ StoreIntoObjectOffset(CTX,
+                             Context::variable_offset(exception_var().index()),
+                             kExceptionObjectReg);
+    __ StoreIntoObjectOffset(CTX,
+                             Context::variable_offset(stacktrace_var().index()),
+                             kStackTraceObjectReg);
+  } else {
+    // Restore stack and initialize the two exception variables:
+    // exception and stack trace variables.
+    __ StoreToOffset(kExceptionObjectReg, FP,
+                     exception_var().index() * kWordSize);
+    __ StoreToOffset(kStackTraceObjectReg, FP,
+                     stacktrace_var().index() * kWordSize);
+  }
 }
 
 
 LocationSummary* CheckStackOverflowInstr::MakeLocationSummary(Zone* zone,
                                                               bool opt) const {
   const intptr_t kNumInputs = 0;
   const intptr_t kNumTemps = 1;
   LocationSummary* summary = new (zone) LocationSummary(
       zone, kNumInputs, kNumTemps, LocationSummary::kCallOnSlowPath);
   summary->set_temp(0, Location::RequiresRegister());
@@ skipping 3414 matching lines @@
   compiler->GenerateRuntimeCall(TokenPosition::kNoSource, deopt_id(),
                                 kGrowRegExpStackRuntimeEntry, 1, locs());
   __ Drop(1);
   __ Pop(result);
 }
 
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM64