[wasm] Initial signal handler

src/compiler/x64/code-generator-x64.cc

 // Copyright 2013 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/compiler/code-generator.h"
 
 #include <limits>
 
 #include "src/compilation-info.h"
 #include "src/compiler/code-generator-impl.h"
@@ skipping 251 matching lines @@
   Operand const operand_;
   Register const value_;
   Register const scratch0_;
   Register const scratch1_;
   RecordWriteMode const mode_;
 };
 
 class WasmOutOfLineTrap final : public OutOfLineCode {
  public:
   WasmOutOfLineTrap(CodeGenerator* gen, int pc, bool frame_elided,
-                    int32_t position, Instruction* instr)
+                    int32_t position)
       : OutOfLineCode(gen),
         gen_(gen),
         pc_(pc),
         frame_elided_(frame_elided),
-        position_(position),
-        instr_(instr) {}
+        position_(position) {}
 
   // TODO(eholk): Refactor this method to take the code generator as a
   // parameter.
   void Generate() final {
     __ RecordProtectedInstructionLanding(pc_);
 
     if (frame_elided_) {
       __ EnterFrame(StackFrame::WASM_COMPILED);
     }
 
     wasm::TrapReason trap_id = wasm::kTrapMemOutOfBounds;
     int trap_reason = wasm::WasmOpcodes::TrapReasonToMessageId(trap_id);
     __ Push(Smi::FromInt(trap_reason));
     __ Push(Smi::FromInt(position_));

[ahaas, 2017/02/20 09:27:24]

I think it would be better to pass in the instruction and determine the source
position from the stack walk by calling here
CodeGenerator::AssembleSourcePosition(instr_). Passing the source position as a
parameter requires patching the stack trace later, which we should better avoid.
Take a look at AssemblyArchTrap, it uses AssembleSourcePosition already.

[Eric Holk, 2017/02/23 02:16:55]

I added a TODO. It looks like we can and should reuse most of the code from
AssembleArchTrap here too.

-    __ Move(rsi, gen_->isolate()->native_context());
+    __ Move(rsi, Smi::kZero);
     __ CallRuntime(Runtime::kThrowWasmError);
 
-    if (instr_->reference_map() != nullptr) {
-      gen_->RecordSafepoint(instr_->reference_map(), Safepoint::kSimple, 0,
-                            Safepoint::kNoLazyDeopt);
-    }
+    ReferenceMap* reference_map =

[titzer, 2017/02/20 09:50:08]

I don't think we always want to generate a reference map (especially for all
loads/stores), because they consume metadata.

[Eric Holk, 2017/02/23 02:16:55]

Is there a way to call RecordSafepoint without a reference map? AssembleArchTrap
does the same thing as here.

+        new (gen_->code()->zone()) ReferenceMap(gen_->code()->zone());
+    gen_->RecordSafepoint(reference_map, Safepoint::kSimple, 0,
+                          Safepoint::kNoLazyDeopt);
   }
 
  private:
   CodeGenerator* gen_;
   int pc_;
   bool frame_elided_;
   int32_t position_;
-  Instruction* instr_;
 };
 
 void EmitOOLTrapIfNeeded(Zone* zone, CodeGenerator* codegen,
                          InstructionCode opcode, size_t input_count,
-                         X64OperandConverter& i, int pc, Instruction* instr) {
+                         X64OperandConverter& i, int pc) {
   const X64MemoryProtection protection =
       static_cast<X64MemoryProtection>(MiscField::decode(opcode));
   if (protection == X64MemoryProtection::kProtected) {
     const bool frame_elided = !codegen->frame_access_state()->has_frame();
     const int32_t position = i.InputInt32(input_count - 1);
-    new (zone) WasmOutOfLineTrap(codegen, pc, frame_elided, position, instr);
+    new (zone) WasmOutOfLineTrap(codegen, pc, frame_elided, position);
   }
 }
 }  // namespace
 
 
 #define ASSEMBLE_UNOP(asm_instr)         \
   do {                                   \
     if (instr->Output()->IsRegister()) { \
       __ asm_instr(i.OutputRegister());  \
     } else {                             \
@@ skipping 1517 matching lines @@
                   i.InputOperand(0));
       }
       break;
     }
     case kSSEFloat64SilenceNaN:
       __ Xorpd(kScratchDoubleReg, kScratchDoubleReg);
       __ Subsd(i.InputDoubleRegister(0), kScratchDoubleReg);
       break;
     case kX64Movsxbl:
       EmitOOLTrapIfNeeded(zone(), this, opcode, instr->InputCount(), i,
-                          __ pc_offset(), instr);
+                          __ pc_offset());
       ASSEMBLE_MOVX(movsxbl);
       __ AssertZeroExtended(i.OutputRegister());
       break;
     case kX64Movzxbl:
       EmitOOLTrapIfNeeded(zone(), this, opcode, instr->InputCount(), i,
-                          __ pc_offset(), instr);
+                          __ pc_offset());
       ASSEMBLE_MOVX(movzxbl);
       __ AssertZeroExtended(i.OutputRegister());
       break;
     case kX64Movsxbq:
       EmitOOLTrapIfNeeded(zone(), this, opcode, instr->InputCount(), i,
-                          __ pc_offset(), instr);
+                          __ pc_offset());
       ASSEMBLE_MOVX(movsxbq);
       break;
     case kX64Movzxbq:
       EmitOOLTrapIfNeeded(zone(), this, opcode, instr->InputCount(), i,
-                          __ pc_offset(), instr);
+                          __ pc_offset());
       ASSEMBLE_MOVX(movzxbq);
       __ AssertZeroExtended(i.OutputRegister());
       break;
     case kX64Movb: {
       EmitOOLTrapIfNeeded(zone(), this, opcode, instr->InputCount(), i,
-                          __ pc_offset(), instr);
+                          __ pc_offset());
       size_t index = 0;
       Operand operand = i.MemoryOperand(&index);
       if (HasImmediateInput(instr, index)) {
         __ movb(operand, Immediate(i.InputInt8(index)));
       } else {
         __ movb(operand, i.InputRegister(index));
       }
       break;
     }
     case kX64Movsxwl:
       EmitOOLTrapIfNeeded(zone(), this, opcode, instr->InputCount(), i,
-                          __ pc_offset(), instr);
+                          __ pc_offset());
       ASSEMBLE_MOVX(movsxwl);
       __ AssertZeroExtended(i.OutputRegister());
       break;
     case kX64Movzxwl:
       EmitOOLTrapIfNeeded(zone(), this, opcode, instr->InputCount(), i,
-                          __ pc_offset(), instr);
+                          __ pc_offset());
       ASSEMBLE_MOVX(movzxwl);
       __ AssertZeroExtended(i.OutputRegister());
       break;
     case kX64Movsxwq:
       EmitOOLTrapIfNeeded(zone(), this, opcode, instr->InputCount(), i,
-                          __ pc_offset(), instr);
+                          __ pc_offset());
       ASSEMBLE_MOVX(movsxwq);
       break;
     case kX64Movzxwq:
       EmitOOLTrapIfNeeded(zone(), this, opcode, instr->InputCount(), i,
-                          __ pc_offset(), instr);
+                          __ pc_offset());
       ASSEMBLE_MOVX(movzxwq);
       __ AssertZeroExtended(i.OutputRegister());
       break;
     case kX64Movw: {
       EmitOOLTrapIfNeeded(zone(), this, opcode, instr->InputCount(), i,
-                          __ pc_offset(), instr);
+                          __ pc_offset());
       size_t index = 0;
       Operand operand = i.MemoryOperand(&index);
       if (HasImmediateInput(instr, index)) {
         __ movw(operand, Immediate(i.InputInt16(index)));
       } else {
         __ movw(operand, i.InputRegister(index));
       }
       break;
     }
     case kX64Movl:
       EmitOOLTrapIfNeeded(zone(), this, opcode, instr->InputCount(), i,
-                          __ pc_offset(), instr);
+                          __ pc_offset());
       if (instr->HasOutput()) {
         if (instr->addressing_mode() == kMode_None) {
           if (instr->InputAt(0)->IsRegister()) {
             __ movl(i.OutputRegister(), i.InputRegister(0));
           } else {
             __ movl(i.OutputRegister(), i.InputOperand(0));
           }
         } else {
           __ movl(i.OutputRegister(), i.MemoryOperand());
         }
         __ AssertZeroExtended(i.OutputRegister());
       } else {
         size_t index = 0;
         Operand operand = i.MemoryOperand(&index);
         if (HasImmediateInput(instr, index)) {
           __ movl(operand, i.InputImmediate(index));
         } else {
           __ movl(operand, i.InputRegister(index));
         }
       }
       break;
     case kX64Movsxlq:
       EmitOOLTrapIfNeeded(zone(), this, opcode, instr->InputCount(), i,
-                          __ pc_offset(), instr);
+                          __ pc_offset());
       ASSEMBLE_MOVX(movsxlq);
       break;
     case kX64Movq:
       EmitOOLTrapIfNeeded(zone(), this, opcode, instr->InputCount(), i,
-                          __ pc_offset(), instr);
+                          __ pc_offset());
       if (instr->HasOutput()) {
         __ movq(i.OutputRegister(), i.MemoryOperand());
       } else {
         size_t index = 0;
         Operand operand = i.MemoryOperand(&index);
         if (HasImmediateInput(instr, index)) {
           __ movq(operand, i.InputImmediate(index));
         } else {
           __ movq(operand, i.InputRegister(index));
         }
       }
       break;
     case kX64Movss:
       EmitOOLTrapIfNeeded(zone(), this, opcode, instr->InputCount(), i,
-                          __ pc_offset(), instr);
+                          __ pc_offset());
       if (instr->HasOutput()) {
         __ movss(i.OutputDoubleRegister(), i.MemoryOperand());
       } else {
         size_t index = 0;
         Operand operand = i.MemoryOperand(&index);
         __ movss(operand, i.InputDoubleRegister(index));
       }
       break;
     case kX64Movsd:
       EmitOOLTrapIfNeeded(zone(), this, opcode, instr->InputCount(), i,
-                          __ pc_offset(), instr);
+                          __ pc_offset());
       if (instr->HasOutput()) {
         __ Movsd(i.OutputDoubleRegister(), i.MemoryOperand());
       } else {
         size_t index = 0;
         Operand operand = i.MemoryOperand(&index);
         __ Movsd(operand, i.InputDoubleRegister(index));
       }
       break;
     case kX64BitcastFI:
       if (instr->InputAt(0)->IsFPStackSlot()) {
@@ skipping 868 matching lines @@
     int padding_size = last_lazy_deopt_pc_ + space_needed - current_pc;
     __ Nop(padding_size);
   }
 }
 
 #undef __
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8