MIPS: Support LiveEdit.

Port r21895 (210f7aa)

BUG=368580
LOG=Y
R=jkummerow@chromium.org, palfia@homejinni.com

Review URL: https://codereview.chromium.org/349703002

Patch from Balazs Kilvady <kilvadyb@homejinni.com>.

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21905 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

diff --git a/src/mips/debug-mips.cc b/src/mips/debug-mips.cc
index fc05211..48771d3 100644 (file)
--- a/src/mips/debug-mips.cc
+++ b/src/mips/debug-mips.cc
@@ -101,6 +101,16 @@ static void Generate_DebugBreakCallHelper(MacroAssembler* masm,
   {
     FrameScope scope(masm, StackFrame::INTERNAL);
 
+    // Load padding words on stack.
+    __ li(at, Operand(Smi::FromInt(LiveEdit::kFramePaddingValue)));
+    __ Subu(sp, sp,
+            Operand(kPointerSize * LiveEdit::kFramePaddingInitialSize));
+    for (int i = LiveEdit::kFramePaddingInitialSize - 1; i >= 0; i--) {
+      __ sw(at, MemOperand(sp, kPointerSize * i));
+    }
+    __ li(at, Operand(Smi::FromInt(LiveEdit::kFramePaddingInitialSize)));
+    __ push(at);
+
     // Store the registers containing live values on the expression stack to
     // make sure that these are correctly updated during GC. Non object values
     // are stored as a smi causing it to be untouched by GC.
@@ -147,6 +157,9 @@ static void Generate_DebugBreakCallHelper(MacroAssembler* masm,
       }
     }
 
+    // Don't bother removing padding bytes pushed on the stack
+    // as the frame is going to be restored right away.
+
     // Leave the internal frame.
   }
 
@@ -290,16 +303,36 @@ void DebugCodegen::GenerateSlotDebugBreak(MacroAssembler* masm) {
 
 
 void DebugCodegen::GeneratePlainReturnLiveEdit(MacroAssembler* masm) {
-  masm->Abort(kLiveEditFrameDroppingIsNotSupportedOnMips);
+  __ Ret();
 }
 
 
 void DebugCodegen::GenerateFrameDropperLiveEdit(MacroAssembler* masm) {
-  masm->Abort(kLiveEditFrameDroppingIsNotSupportedOnMips);
+  ExternalReference restarter_frame_function_slot =
+      ExternalReference::debug_restarter_frame_function_pointer_address(
+          masm->isolate());
+  __ li(at, Operand(restarter_frame_function_slot));
+  __ sw(zero_reg, MemOperand(at, 0));
+
+  // We do not know our frame height, but set sp based on fp.
+  __ Subu(sp, fp, Operand(kPointerSize));
+
+  __ Pop(ra, fp, a1);  // Return address, Frame, Function.
+
+  // Load context from the function.
+  __ lw(cp, FieldMemOperand(a1, JSFunction::kContextOffset));
+
+  // Get function code.
+  __ lw(at, FieldMemOperand(a1, JSFunction::kSharedFunctionInfoOffset));
+  __ lw(at, FieldMemOperand(at, SharedFunctionInfo::kCodeOffset));
+  __ Addu(t9, at, Operand(Code::kHeaderSize - kHeapObjectTag));
+
+  // Re-run JSFunction, r1 is function, cp is context.
+  __ Jump(t9);
 }
 
 
-const bool LiveEdit::kFrameDropperSupported = false;
+const bool LiveEdit::kFrameDropperSupported = true;
 
 #undef __
 

diff --git a/src/objects.h b/src/objects.h
index 7877600..53741aa 100644 (file)
--- a/src/objects.h
+++ b/src/objects.h
@@ -1153,8 +1153,6 @@ template <class C> inline bool Is(Object* obj);
   V(kLiveBytesCountOverflowChunkSize, "Live Bytes Count overflow chunk size") \
   V(kLiveEditFrameDroppingIsNotSupportedOnARM64,                              \
     "LiveEdit frame dropping is not supported on arm64")                      \
-  V(kLiveEditFrameDroppingIsNotSupportedOnMips,                               \
-    "LiveEdit frame dropping is not supported on mips")                       \
   V(kLiveEdit, "LiveEdit")                                                    \
   V(kLookupVariableInCountOperation,                                          \
     "Lookup variable in count operation")                                     \

diff --git a/test/mjsunit/mjsunit.status b/test/mjsunit/mjsunit.status
index eb4fe35..34ea1d5 100644 (file)
--- a/test/mjsunit/mjsunit.status
+++ b/test/mjsunit/mjsunit.status
@@ -346,13 +346,6 @@
   # should be platform-independent.
   'regress/regress-1132': [SKIP],
 
-  # Stack manipulations in LiveEdit is not implemented for this arch.
-  'debug-liveedit-check-stack': [SKIP],
-  'debug-liveedit-stack-padding': [SKIP],
-  'debug-liveedit-restart-frame': [SKIP],
-  'debug-liveedit-double-call': [SKIP],
-  'harmony/generators-debug-liveedit': [SKIP],
-
   # Currently always deopt on minus zero
   'math-floor-of-div-minus-zero': [SKIP],
 }],  # 'arch == mipsel or arch == mips'