Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 1 | // Copyright 2015 the V8 project authors. All rights reserved. |
| 2 | // Use of this source code is governed by a BSD-style license that can be |
| 3 | // found in the LICENSE file. |
| 4 | |
| 5 | #include "src/v8.h" |
| 6 | |
| 7 | #if V8_TARGET_ARCH_S390 |
| 8 | |
| 9 | #include "src/codegen.h" |
| 10 | #include "src/debug/debug.h" |
| 11 | |
| 12 | namespace v8 { |
| 13 | namespace internal { |
| 14 | |
| 15 | #define __ ACCESS_MASM(masm) |
| 16 | |
| 17 | void EmitDebugBreakSlot(MacroAssembler* masm) { |
| 18 | Label check_size; |
| 19 | __ bind(&check_size); |
| 20 | // oill r3, 0 |
| 21 | // oill r3, 0 |
| 22 | __ nop(Assembler::DEBUG_BREAK_NOP); |
| 23 | __ nop(Assembler::DEBUG_BREAK_NOP); |
| 24 | |
| 25 | // lr r0, r0 64-bit only |
| 26 | // lr r0, r0 64-bit only |
| 27 | // lr r0, r0 64-bit only |
| 28 | for (int i = 8; i < Assembler::kDebugBreakSlotLength; i += 2) { |
| 29 | __ nop(); |
| 30 | } |
| 31 | DCHECK_EQ(Assembler::kDebugBreakSlotLength, |
| 32 | masm->SizeOfCodeGeneratedSince(&check_size)); |
| 33 | } |
| 34 | |
| 35 | void DebugCodegen::GenerateSlot(MacroAssembler* masm, RelocInfo::Mode mode) { |
| 36 | // Generate enough nop's to make space for a call instruction. |
| 37 | masm->RecordDebugBreakSlot(mode); |
| 38 | EmitDebugBreakSlot(masm); |
| 39 | } |
| 40 | |
| 41 | void DebugCodegen::ClearDebugBreakSlot(Isolate* isolate, Address pc) { |
| 42 | CodePatcher patcher(isolate, pc, Assembler::kDebugBreakSlotLength); |
| 43 | EmitDebugBreakSlot(patcher.masm()); |
| 44 | } |
| 45 | |
| 46 | void DebugCodegen::PatchDebugBreakSlot(Isolate* isolate, Address pc, |
| 47 | Handle<Code> code) { |
Ben Murdoch | 61f157c | 2016-09-16 13:49:30 +0100 | [diff] [blame] | 48 | DCHECK(code->is_debug_stub()); |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 49 | CodePatcher patcher(isolate, pc, Assembler::kDebugBreakSlotLength); |
| 50 | // Patch the code changing the debug break slot code from |
| 51 | // |
| 52 | // oill r3, 0 |
| 53 | // oill r3, 0 |
| 54 | // oill r3, 0 64-bit only |
| 55 | // lr r0, r0 64-bit only |
| 56 | // |
| 57 | // to a call to the debug break code, using a FIXED_SEQUENCE. |
| 58 | // |
| 59 | // iilf r14, <address> 6-bytes |
| 60 | // basr r14, r14A 2-bytes |
| 61 | // |
| 62 | // The 64bit sequence has an extra iihf. |
| 63 | // |
| 64 | // iihf r14, <high 32-bits address> 6-bytes |
| 65 | // iilf r14, <lower 32-bits address> 6-bytes |
| 66 | // basr r14, r14 2-bytes |
| 67 | patcher.masm()->mov(v8::internal::r14, |
| 68 | Operand(reinterpret_cast<intptr_t>(code->entry()))); |
| 69 | patcher.masm()->basr(v8::internal::r14, v8::internal::r14); |
| 70 | } |
| 71 | |
| 72 | bool DebugCodegen::DebugBreakSlotIsPatched(Address pc) { |
| 73 | Instr current_instr = Assembler::instr_at(pc); |
| 74 | return !Assembler::IsNop(current_instr, Assembler::DEBUG_BREAK_NOP); |
| 75 | } |
| 76 | |
| 77 | void DebugCodegen::GenerateDebugBreakStub(MacroAssembler* masm, |
| 78 | DebugBreakCallHelperMode mode) { |
| 79 | __ RecordComment("Debug break"); |
| 80 | { |
| 81 | FrameScope scope(masm, StackFrame::INTERNAL); |
| 82 | |
| 83 | // Load padding words on stack. |
| 84 | __ LoadSmiLiteral(ip, Smi::FromInt(LiveEdit::kFramePaddingValue)); |
| 85 | for (int i = 0; i < LiveEdit::kFramePaddingInitialSize; i++) { |
| 86 | __ push(ip); |
| 87 | } |
| 88 | __ LoadSmiLiteral(ip, Smi::FromInt(LiveEdit::kFramePaddingInitialSize)); |
| 89 | __ push(ip); |
| 90 | |
| 91 | // Push arguments for DebugBreak call. |
| 92 | if (mode == SAVE_RESULT_REGISTER) { |
| 93 | // Break on return. |
| 94 | __ push(r2); |
| 95 | } else { |
| 96 | // Non-return breaks. |
| 97 | __ Push(masm->isolate()->factory()->the_hole_value()); |
| 98 | } |
| 99 | __ mov(r2, Operand(1)); |
| 100 | __ mov(r3, |
| 101 | Operand(ExternalReference( |
| 102 | Runtime::FunctionForId(Runtime::kDebugBreak), masm->isolate()))); |
| 103 | |
| 104 | CEntryStub ceb(masm->isolate(), 1); |
| 105 | __ CallStub(&ceb); |
| 106 | |
| 107 | if (FLAG_debug_code) { |
| 108 | for (int i = 0; i < kNumJSCallerSaved; i++) { |
| 109 | Register reg = {JSCallerSavedCode(i)}; |
| 110 | // Do not clobber r2 if mode is SAVE_RESULT_REGISTER. It will |
| 111 | // contain return value of the function. |
| 112 | if (!(reg.is(r2) && (mode == SAVE_RESULT_REGISTER))) { |
| 113 | __ mov(reg, Operand(kDebugZapValue)); |
| 114 | } |
| 115 | } |
| 116 | } |
| 117 | |
| 118 | // Don't bother removing padding bytes pushed on the stack |
| 119 | // as the frame is going to be restored right away. |
| 120 | |
| 121 | // Leave the internal frame. |
| 122 | } |
| 123 | |
| 124 | // Now that the break point has been handled, resume normal execution by |
| 125 | // jumping to the target address intended by the caller and that was |
| 126 | // overwritten by the address of DebugBreakXXX. |
| 127 | ExternalReference after_break_target = |
| 128 | ExternalReference::debug_after_break_target_address(masm->isolate()); |
| 129 | __ mov(ip, Operand(after_break_target)); |
| 130 | __ LoadP(ip, MemOperand(ip)); |
| 131 | __ JumpToJSEntry(ip); |
| 132 | } |
| 133 | |
| 134 | void DebugCodegen::GenerateFrameDropperLiveEdit(MacroAssembler* masm) { |
| 135 | // Load the function pointer off of our current stack frame. |
| 136 | __ LoadP(r3, MemOperand(fp, FrameDropperFrameConstants::kFunctionOffset)); |
| 137 | |
| 138 | // Pop return address and frame |
| 139 | __ LeaveFrame(StackFrame::INTERNAL); |
| 140 | |
| 141 | ParameterCount dummy(0); |
| 142 | __ FloodFunctionIfStepping(r3, no_reg, dummy, dummy); |
| 143 | |
| 144 | // Load context from the function. |
| 145 | __ LoadP(cp, FieldMemOperand(r3, JSFunction::kContextOffset)); |
| 146 | |
| 147 | // Clear new.target as a safety measure. |
| 148 | __ LoadRoot(r5, Heap::kUndefinedValueRootIndex); |
| 149 | |
| 150 | // Get function code. |
| 151 | __ LoadP(ip, FieldMemOperand(r3, JSFunction::kSharedFunctionInfoOffset)); |
| 152 | __ LoadP(ip, FieldMemOperand(ip, SharedFunctionInfo::kCodeOffset)); |
| 153 | __ AddP(ip, Operand(Code::kHeaderSize - kHeapObjectTag)); |
| 154 | |
| 155 | // Re-run JSFunction, r3 is function, cp is context. |
| 156 | __ Jump(ip); |
| 157 | } |
| 158 | |
| 159 | const bool LiveEdit::kFrameDropperSupported = true; |
| 160 | |
| 161 | #undef __ |
| 162 | } // namespace internal |
| 163 | } // namespace v8 |
| 164 | |
| 165 | #endif // V8_TARGET_ARCH_S390 |