PPC: Debugger: use debug break slots to break at function exit.

src/ppc/full-codegen-ppc.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #if V8_TARGET_ARCH_PPC
 
 #include "src/code-factory.h"
 #include "src/code-stubs.h"
@@ skipping 473 matching lines @@
     EmitProfilingCounterDecrement(weight);
     Label ok;
     __ cmpi(r6, Operand::Zero());
     __ bge(&ok);
     __ push(r3);
     __ Call(isolate()->builtins()->InterruptCheck(), RelocInfo::CODE_TARGET);
     __ pop(r3);
     EmitProfilingCounterReset();
     __ bind(&ok);
 
-#ifdef DEBUG
-    // Add a label for checking the size of the code used for returning.
-    Label check_exit_codesize;
-    __ bind(&check_exit_codesize);
-#endif
     // Make sure that the constant pool is not emitted inside of the return
     // sequence.
     {
       Assembler::BlockTrampolinePoolScope block_trampoline_pool(masm_);
       int32_t arg_count = info_->scope()->num_parameters() + 1;
       int32_t sp_delta = arg_count * kPointerSize;
       SetReturnPosition(function());
-      __ RecordJSReturn();
       int no_frame_start = __ LeaveFrame(StackFrame::JAVA_SCRIPT, sp_delta);
-#if V8_TARGET_ARCH_PPC64
-      // With 64bit we may need nop() instructions to ensure we have
-      // enough space to SetDebugBreakAtReturn()
-      if (is_int16(sp_delta)) {
-        if (!FLAG_enable_embedded_constant_pool) masm_->nop();
-        masm_->nop();
-      }
-#endif
       __ blr();
       info_->AddNoFrameRange(no_frame_start, masm_->pc_offset());
     }
-
-#ifdef DEBUG
-    // Check that the size of the code used for returning is large enough
-    // for the debugger's requirements.
-    DCHECK(Assembler::kJSReturnSequenceInstructions <=
-           masm_->InstructionsGeneratedSince(&check_exit_codesize));
-#endif
   }
 }
 
 
 void FullCodeGenerator::EffectContext::Plug(Variable* var) const {
   DCHECK(var->IsStackAllocated() || var->IsContextSlot());
 }
 
 
 void FullCodeGenerator::AccumulatorValueContext::Plug(Variable* var) const {
@@ skipping 5063 matching lines @@
     return ON_STACK_REPLACEMENT;
   }
 
   DCHECK(interrupt_address ==
          isolate->builtins()->OsrAfterStackCheck()->entry());
   return OSR_AFTER_STACK_CHECK;
 }
 }  // namespace internal
 }  // namespace v8
 #endif  // V8_TARGET_ARCH_PPC