Implement new stacktrace and deoptimization stress testing flags:

runtime/vm/intermediate_language_arm.cc

 // Copyright (c) 2013, 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_ARM.
 #if defined(TARGET_ARCH_ARM)
 
 #include "vm/intermediate_language.h"
 
 #include "vm/dart_entry.h"
@@ skipping 2555 matching lines @@
   return summary;
 }
 
 
 class CheckStackOverflowSlowPath : public SlowPathCode {
  public:
   explicit CheckStackOverflowSlowPath(CheckStackOverflowInstr* instruction)
       : instruction_(instruction) { }
 
   virtual void EmitNativeCode(FlowGraphCompiler* compiler) {
+    if (FLAG_use_osr) {
+      uword flags_address = Isolate::Current()->stack_overflow_flags_address();
+      Register value = instruction_->locs()->temp(0).reg();
+      __ Comment("CheckStackOverflowSlowPathOsr");
+      __ Bind(osr_entry_label());
+      __ LoadImmediate(IP, flags_address);
+      __ LoadImmediate(value, Isolate::kOsrRequest);
+      __ str(value, Address(IP));
+    }
     __ Comment("CheckStackOverflowSlowPath");
     __ Bind(entry_label());
     compiler->SaveLiveRegisters(instruction_->locs());
     // pending_deoptimization_env_ is needed to generate a runtime call that
     // may throw an exception.
     ASSERT(compiler->pending_deoptimization_env_ == NULL);
     Environment* env = compiler->SlowPathEnvironmentFor(instruction_);
     compiler->pending_deoptimization_env_ = env;
     compiler->GenerateRuntimeCall(instruction_->token_pos(),
                                   instruction_->deopt_id(),
                                   kStackOverflowRuntimeEntry,
                                   0,
                                   instruction_->locs());
 
     if (FLAG_use_osr && !compiler->is_optimizing() && instruction_->in_loop()) {
       // In unoptimized code, record loop stack checks as possible OSR entries.
       compiler->AddCurrentDescriptor(PcDescriptors::kOsrEntry,
                                      instruction_->deopt_id(),
                                      0);  // No token position.
     }
     compiler->pending_deoptimization_env_ = NULL;
     compiler->RestoreLiveRegisters(instruction_->locs());
     __ b(exit_label());
   }
 
+  Label* osr_entry_label() {
+    ASSERT(FLAG_use_osr);
+    return &osr_entry_label_;
+  }
+
  private:
   CheckStackOverflowInstr* instruction_;
+  Label osr_entry_label_;
 };
 
 
 void CheckStackOverflowInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   CheckStackOverflowSlowPath* slow_path = new CheckStackOverflowSlowPath(this);
   compiler->AddSlowPathCode(slow_path);
 
   __ LoadImmediate(IP, Isolate::Current()->stack_limit_address());
   __ ldr(IP, Address(IP));
   __ cmp(SP, ShifterOperand(IP));
   __ b(slow_path->entry_label(), LS);
   if (compiler->CanOSRFunction() && in_loop()) {
     Register temp = locs()->temp(0).reg();
     // In unoptimized code check the usage counter to trigger OSR at loop
     // stack checks.  Use progressively higher thresholds for more deeply
     // nested loops to attempt to hit outer loops with OSR when possible.
     __ LoadObject(temp, compiler->parsed_function().function());
     intptr_t threshold =
         FLAG_optimization_counter_threshold * (loop_depth() + 1);
     __ ldr(temp, FieldAddress(temp, Function::usage_counter_offset()));
     __ CompareImmediate(temp, threshold);
-    __ b(slow_path->entry_label(), GE);
+    __ b(slow_path->osr_entry_label(), GE);
+  }
+  if (compiler->ForceSlowPathForStackOverflow()) {
+    __ b(slow_path->entry_label());
   }
   __ Bind(slow_path->exit_label());
 }
 
 
 static void EmitSmiShiftLeft(FlowGraphCompiler* compiler,
                              BinarySmiOpInstr* shift_left) {
   const bool is_truncating = shift_left->is_truncating();
   const LocationSummary& locs = *shift_left->locs();
   Register left = locs.in(0).reg();
@@ skipping 3227 matching lines @@
   compiler->GenerateCall(token_pos(),
                          &label,
                          PcDescriptors::kOther,
                          locs());
   __ Drop(ArgumentCount());  // Discard arguments.
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM