VM: Explicitly load function and context before calling a closure.

runtime/vm/flow_graph_compiler.h

 // 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.
 
 #ifndef VM_FLOW_GRAPH_COMPILER_H_
 #define VM_FLOW_GRAPH_COMPILER_H_
 
 #include "vm/allocation.h"
 #include "vm/assembler.h"
 #include "vm/code_descriptors.h"
@@ skipping 398 matching lines @@
                            bool needs_stacktrace);
   void SetNeedsStacktrace(intptr_t try_index);
   void AddCurrentDescriptor(PcDescriptors::Kind kind,
                             intptr_t deopt_id,
                             intptr_t token_pos);
 
   void RecordSafepoint(LocationSummary* locs);
 
   Label* AddDeoptStub(intptr_t deopt_id, ICData::DeoptReasonId reason);
 
-  void AddDeoptIndexAtCall(intptr_t deopt_id, intptr_t token_pos);
+  void AddDeoptIndexAtCall(intptr_t deopt_id,
+                           intptr_t token_pos,
+                           intptr_t stack_adjustment = 0);

[srdjan, 2014/04/30 15:41:58]

Since this is public, please explain briefly what stack_adjustment is used for..

[Florian Schneider, 2014/04/30 16:02:19]

Done. Added comment to the implementation and renamed to input_count: It's the
number of input operands (as opposed to pushed arguments) of the call.
ClosureCallInstr has now 1 input operand (the Function object).

 
   void AddSlowPathCode(SlowPathCode* slow_path);
 
   void FinalizeExceptionHandlers(const Code& code);
   void FinalizePcDescriptors(const Code& code);
   void FinalizeDeoptInfo(const Code& code);
   void FinalizeStackmaps(const Code& code);
   void FinalizeVarDescriptors(const Code& code);
   void FinalizeStaticCallTargetsTable(const Code& code);
 
@@ skipping 33 matching lines @@
   static Address ExternalElementAddressForRegIndex(intptr_t index_scale,
                                                    Register array,
                                                    Register index);
 
   // Returns 'sorted' array in decreasing count order.
   static void SortICDataByCount(const ICData& ic_data,
                                 GrowableArray<CidTarget>* sorted);
 
  private:
   friend class CheckStackOverflowSlowPath;  // For pending_deoptimization_env_.
+  friend class ClosureCallInstr;  // For pending_deoptimization_env_.
 
   void EmitFrameEntry();
 
   void AddStaticCallTarget(const Function& function);
 
   void GenerateDeferredCode();
 
   void EmitInstructionPrologue(Instruction* instr);
   void EmitInstructionEpilogue(Instruction* instr);
 
@@ skipping 122 matching lines @@
   // that should be used when deoptimizing we store it in this variable.
   // In future AddDeoptStub should be moved out of the instruction template.
   Environment* pending_deoptimization_env_;
 
   DISALLOW_COPY_AND_ASSIGN(FlowGraphCompiler);
 };
 
 }  // namespace dart
 
 #endif  // VM_FLOW_GRAPH_COMPILER_H_