X87: Debugger: use debug break slot to break on call.

port 8965b683 (r29561)

original commit message:

    Break point at calls are currently set via IC. To change this, we
    need to set debug break slots instead. We also need to distinguish
    those debug break slots as calls to support step-in.

    To implement this, we add a data field to debug break reloc info to
    indicate non-call debug breaks or in case of call debug breaks, the
    number of arguments. We can later use this to find the callee on the
    evaluation stack in Debug::PrepareStep.

BUG=

Review URL: https://codereview.chromium.org/1233823002

Cr-Commit-Position: refs/heads/master@{#29630}

src/x87/assembler-x87.h

@@ -956,6 +956,8 @@ class Assembler : public AssemblerBase {
 
   // Mark address of a debug break slot.
   void RecordDebugBreakSlot();
+  void RecordDebugBreakSlotForCall(int argc);
+  void RecordDebugBreakSlotForConstructCall();
 
   // Record a comment relocation entry that can be used by a disassembler.
   // Use --code-comments to enable.

src/x87/debug-x87.cc

@@ -70,9 +70,7 @@ void BreakLocation::SetDebugBreakAtSlot() {
 #define __ ACCESS_MASM(masm)
 
 static void Generate_DebugBreakCallHelper(MacroAssembler* masm,
-                                          RegList object_regs,
-                                          RegList non_object_regs,
-                                          bool convert_call_to_jmp) {
+                                          RegList object_regs) {
   // Enter an internal frame.
   {
     FrameScope scope(masm, StackFrame::INTERNAL);
@@ -87,22 +85,12 @@ static void Generate_DebugBreakCallHelper(MacroAssembler* masm,
     // make sure that these are correctly updated during GC. Non object values
     // are stored as a smi causing it to be untouched by GC.
     DCHECK((object_regs & ~kJSCallerSaved) == 0);
-    DCHECK((non_object_regs & ~kJSCallerSaved) == 0);
-    DCHECK((object_regs & non_object_regs) == 0);
     for (int i = 0; i < kNumJSCallerSaved; i++) {
       int r = JSCallerSavedCode(i);
       Register reg = { r };
       if ((object_regs & (1 << r)) != 0) {
         __ push(reg);
       }
-      if ((non_object_regs & (1 << r)) != 0) {
-        if (FLAG_debug_code) {
-          __ test(reg, Immediate(0xc0000000));
-          __ Assert(zero, kUnableToEncodeValueAsSmi);
-        }
-        __ SmiTag(reg);
-        __ push(reg);
-      }
     }
 
 #ifdef DEBUG
@@ -131,11 +119,6 @@ static void Generate_DebugBreakCallHelper(MacroAssembler* masm,
         __ pop(reg);
         taken = true;
       }
-      if ((non_object_regs & (1 << r)) != 0) {
-        __ pop(reg);
-        __ SmiUntag(reg);
-        taken = true;
-      }
       if (!taken) {
         unused_reg = reg;
       }
@@ -152,11 +135,9 @@ static void Generate_DebugBreakCallHelper(MacroAssembler* masm,
     // Get rid of the internal frame.
   }
 
-  // If this call did not replace a call but patched other code then there will
-  // be an unwanted return address left on the stack. Here we get rid of that.
-  if (convert_call_to_jmp) {
-    __ add(esp, Immediate(kPointerSize));
-  }
+  // This call did not replace a call , so there will be an unwanted
+  // return address left on the stack. Here we get rid of that.
+  __ add(esp, Immediate(kPointerSize));
 
   // Now that the break point has been handled, resume normal execution by
   // jumping to the target address intended by the caller and that was
@@ -167,62 +148,12 @@ static void Generate_DebugBreakCallHelper(MacroAssembler* masm,
 }
 
 
-void DebugCodegen::GenerateCallICStubDebugBreak(MacroAssembler* masm) {
-  // Register state for CallICStub
-  // ----------- S t a t e -------------
-  //  -- edx    : type feedback slot (smi)
-  //  -- edi    : function
-  // -----------------------------------
-  Generate_DebugBreakCallHelper(masm, edx.bit() | edi.bit(),
-                                0, false);
-}
-
-
 void DebugCodegen::GenerateReturnDebugBreak(MacroAssembler* masm) {
   // Register state just before return from JS function (from codegen-x87.cc).
   // ----------- S t a t e -------------
   //  -- eax: return value
   // -----------------------------------
-  Generate_DebugBreakCallHelper(masm, eax.bit(), 0, true);
-}
-
-
-void DebugCodegen::GenerateCallFunctionStubDebugBreak(MacroAssembler* masm) {
-  // Register state for CallFunctionStub (from code-stubs-x87.cc).
-  // ----------- S t a t e -------------
-  //  -- edi: function
-  // -----------------------------------
-  Generate_DebugBreakCallHelper(masm, edi.bit(), 0, false);
-}
-
-
-void DebugCodegen::GenerateCallConstructStubDebugBreak(MacroAssembler* masm) {
-  // Register state for CallConstructStub (from code-stubs-x87.cc).
-  // eax is the actual number of arguments not encoded as a smi see comment
-  // above IC call.
-  // ----------- S t a t e -------------
-  //  -- eax: number of arguments (not smi)
-  //  -- edi: constructor function
-  // -----------------------------------
-  // The number of arguments in eax is not smi encoded.
-  Generate_DebugBreakCallHelper(masm, edi.bit(), eax.bit(), false);
-}
-
-
-void DebugCodegen::GenerateCallConstructStubRecordDebugBreak(
-    MacroAssembler* masm) {
-  // Register state for CallConstructStub (from code-stubs-x87.cc).
-  // eax is the actual number of arguments not encoded as a smi see comment
-  // above IC call.
-  // ----------- S t a t e -------------
-  //  -- eax: number of arguments (not smi)
-  //  -- ebx: feedback array
-  //  -- edx: feedback slot (smi)
-  //  -- edi: constructor function
-  // -----------------------------------
-  // The number of arguments in eax is not smi encoded.
-  Generate_DebugBreakCallHelper(masm, ebx.bit() | edx.bit() | edi.bit(),
-                                eax.bit(), false);
+  Generate_DebugBreakCallHelper(masm, eax.bit());
 }
 
 
@@ -230,7 +161,6 @@ void DebugCodegen::GenerateSlot(MacroAssembler* masm) {
   // Generate enough nop's to make space for a call instruction.
   Label check_codesize;
   __ bind(&check_codesize);
-  __ RecordDebugBreakSlot();
   __ Nop(Assembler::kDebugBreakSlotLength);
   DCHECK_EQ(Assembler::kDebugBreakSlotLength,
             masm->SizeOfCodeGeneratedSince(&check_codesize));
@@ -238,7 +168,7 @@ void DebugCodegen::GenerateSlot(MacroAssembler* masm) {
 
 
 void DebugCodegen::GenerateSlotDebugBreak(MacroAssembler* masm) {
-  Generate_DebugBreakCallHelper(masm, 0, 0, true);
+  Generate_DebugBreakCallHelper(masm, 0);
 }
 
 

src/x87/full-codegen-x87.cc

@@ -2198,6 +2198,7 @@ void FullCodeGenerator::VisitYield(Yield* expr) {
       CallIC(ic, TypeFeedbackId::None());
       __ mov(edi, eax);
       __ mov(Operand(esp, 2 * kPointerSize), edi);
+      SetCallPosition(expr, 1);
       CallFunctionStub stub(isolate(), 1, CALL_AS_METHOD);
       __ CallStub(&stub);
 
@@ -3015,7 +3016,7 @@ void FullCodeGenerator::EmitCall(Call* expr, CallICState::CallType call_type) {
     VisitForStackValue(args->at(i));
   }
 
-  SetExpressionPosition(expr);
+  SetCallPosition(expr, arg_count);
   Handle<Code> ic = CodeFactory::CallIC(isolate(), arg_count, call_type).code();
   __ Move(edx, Immediate(SmiFromSlot(expr->CallFeedbackICSlot())));
   __ mov(edi, Operand(esp, (arg_count + 1) * kPointerSize));
@@ -3146,7 +3147,7 @@ void FullCodeGenerator::VisitCall(Call* expr) {
 
     PrepareForBailoutForId(expr->EvalId(), NO_REGISTERS);
 
-    SetExpressionPosition(expr);
+    SetCallPosition(expr, arg_count);
     CallFunctionStub stub(isolate(), arg_count, NO_CALL_FUNCTION_FLAGS);
     __ mov(edi, Operand(esp, (arg_count + 1) * kPointerSize));
     __ CallStub(&stub);
@@ -3217,7 +3218,7 @@ void FullCodeGenerator::VisitCallNew(CallNew* expr) {
 
   // Call the construct call builtin that handles allocation and
   // constructor invocation.
-  SetExpressionPosition(expr);
+  SetConstructCallPosition(expr);
 
   // Load function and argument count into edi and eax.
   __ Move(eax, Immediate(arg_count));
@@ -3260,7 +3261,7 @@ void FullCodeGenerator::EmitSuperConstructorCall(Call* expr) {
 
   // Call the construct call builtin that handles allocation and
   // constructor invocation.
-  SetExpressionPosition(expr);
+  SetConstructCallPosition(expr);
 
   // Load function and argument count into edi and eax.
   __ Move(eax, Immediate(arg_count));
@@ -4682,7 +4683,7 @@ void FullCodeGenerator::EmitCallJSRuntimeFunction(CallRuntime* expr) {
   ZoneList<Expression*>* args = expr->arguments();
   int arg_count = args->length();
 
-  SetExpressionPosition(expr);
+  SetCallPosition(expr, arg_count);
   CallFunctionStub stub(isolate(), arg_count, NO_CALL_FUNCTION_FLAGS);
   __ mov(edi, Operand(esp, (arg_count + 1) * kPointerSize));
   __ CallStub(&stub);