CpuProfiler: ia32. put right address to the stack, so the callee would be able to resolve it into t…

src/ia32/lithium-codegen-ia32.cc

 // Copyright 2012 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_IA32
 
 #include "src/base/bits.h"
 #include "src/code-factory.h"
@@ skipping 359 matching lines @@
   if (!instr->IsLazyBailout() && !instr->IsGap()) {
     safepoints_.BumpLastLazySafepointIndex();
   }
 }
 
 
 void LCodeGen::GenerateBodyInstructionPost(LInstruction* instr) { }
 
 
 bool LCodeGen::GenerateJumpTable() {
+  if (!jump_table_.length()) return !is_aborted();
+
   Label needs_frame;
-  if (jump_table_.length() > 0) {
-    Comment(";;; -------------------- Jump table --------------------");
-  }
+  Comment(";;; -------------------- Jump table --------------------");
+
   for (int i = 0; i < jump_table_.length(); i++) {
     Deoptimizer::JumpTableEntry* table_entry = &jump_table_[i];
     __ bind(&table_entry->label);
     Address entry = table_entry->address;
     DeoptComment(table_entry->deopt_info);
     if (table_entry->needs_frame) {
       DCHECK(!info()->saves_caller_doubles());
-      __ push(Immediate(ExternalReference::ForDeoptEntry(entry)));
-      if (needs_frame.is_bound()) {
-        __ jmp(&needs_frame);
-      } else {
-        __ bind(&needs_frame);
-        __ push(MemOperand(ebp, StandardFrameConstants::kContextOffset));
-        // This variant of deopt can only be used with stubs. Since we don't
-        // have a function pointer to install in the stack frame that we're
-        // building, install a special marker there instead.
-        DCHECK(info()->IsStub());
-        __ push(Immediate(Smi::FromInt(StackFrame::STUB)));
-        // Push a PC inside the function so that the deopt code can find where
-        // the deopt comes from. It doesn't have to be the precise return
-        // address of a "calling" LAZY deopt, it only has to be somewhere
-        // inside the code body.
-        Label push_approx_pc;
-        __ call(&push_approx_pc);
-        __ bind(&push_approx_pc);
-        // Push the continuation which was stashed were the ebp should
-        // be. Replace it with the saved ebp.
-        __ push(MemOperand(esp, 3 * kPointerSize));
-        __ mov(MemOperand(esp, 4 * kPointerSize), ebp);
-        __ lea(ebp, MemOperand(esp, 4 * kPointerSize));
-        __ ret(0);  // Call the continuation without clobbering registers.
-      }
+      // Put deopt entry to the place where it will be used by ret(0)
+      __ mov(MemOperand(esp, -5 * kPointerSize),
+             Immediate(ExternalReference::ForDeoptEntry(entry)));

[Jarin, 2015/03/17 12:44:22]

This will not work because an asynchronous signal handler can clobber the stack
below the top.

Why cannot you just push it here?

+      // Save pc to the stack for 'from' argument of deoptimizer.
+      __ call(&needs_frame);
     } else {
       if (info()->saves_caller_doubles()) RestoreCallerDoubles();
       __ call(entry, RelocInfo::RUNTIME_ENTRY);
     }
   }
+  if (needs_frame.is_linked()) {
+    __ bind(&needs_frame);
+    __ push(MemOperand(ebp, StandardFrameConstants::kContextOffset));
+    // This variant of deopt can only be used with stubs. Since we don't
+    // have a function pointer to install in the stack frame that we're
+    // building, install a special marker there instead.
+    DCHECK(info()->IsStub());
+    __ push(Immediate(Smi::FromInt(StackFrame::STUB)));
+    // Copy the saved pc to the place where it would be used by Deoptimizer.
+    __ push(MemOperand(esp, 2 * kPointerSize));
+    // Replace the original saved pc in the stack with ebp.
+    __ mov(MemOperand(esp, 3 * kPointerSize), ebp);
+    __ lea(ebp, MemOperand(esp, 3 * kPointerSize));
+    // Move esp on top of entry address that has been saved earlier.
+    __ sub(esp, Immediate(kPointerSize));
+    __ ret(0);  // Call the continuation without clobbering registers.
+  }
   return !is_aborted();
 }
 
 
 bool LCodeGen::GenerateDeferredCode() {
   DCHECK(is_generating());
   if (deferred_.length() > 0) {
     for (int i = 0; !is_aborted() && i < deferred_.length(); i++) {
       LDeferredCode* code = deferred_[i];
 
@@ skipping 5350 matching lines @@
   CallRuntime(Runtime::kPushBlockContext, 2, instr);
   RecordSafepoint(Safepoint::kNoLazyDeopt);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32