1// Copyright 2006-2008 the V8 project authors. All rights reserved. 2// Redistribution and use in source and binary forms, with or without 3// modification, are permitted provided that the following conditions are 4// met: 5// 6// * Redistributions of source code must retain the above copyright 7// notice, this list of conditions and the following disclaimer. 8// * Redistributions in binary form must reproduce the above 9// copyright notice, this list of conditions and the following 10// disclaimer in the documentation and/or other materials provided 11// with the distribution. 12// * Neither the name of Google Inc. nor the names of its 13// contributors may be used to endorse or promote products derived 14// from this software without specific prior written permission. 15// 16// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 28#include "v8.h" 29 30#include "codegen-inl.h" 31#include "debug.h" 32 33namespace v8 { 34namespace internal { 35 36#ifdef ENABLE_DEBUGGER_SUPPORT 37bool BreakLocationIterator::IsDebugBreakAtReturn() { 38 return Debug::IsDebugBreakAtReturn(rinfo()); 39} 40 41 42void BreakLocationIterator::SetDebugBreakAtReturn() { 43 // Patch the code changing the return from JS function sequence from 44 // mov sp, fp 45 // ldmia sp!, {fp, lr} 46 // add sp, sp, #4 47 // bx lr 48 // to a call to the debug break return code. 49 // mov lr, pc 50 // ldr pc, [pc, #-4] 51 // <debug break return code entry point address> 52 // bktp 0 53 CodePatcher patcher(rinfo()->pc(), 4); 54 patcher.masm()->mov(v8::internal::lr, v8::internal::pc); 55 patcher.masm()->ldr(v8::internal::pc, MemOperand(v8::internal::pc, -4)); 56 patcher.Emit(Debug::debug_break_return()->entry()); 57 patcher.masm()->bkpt(0); 58} 59 60 61// Restore the JS frame exit code. 62void BreakLocationIterator::ClearDebugBreakAtReturn() { 63 rinfo()->PatchCode(original_rinfo()->pc(), 64 Assembler::kJSReturnSequenceLength); 65} 66 67 68// A debug break in the exit code is identified by a call. 69bool Debug::IsDebugBreakAtReturn(RelocInfo* rinfo) { 70 ASSERT(RelocInfo::IsJSReturn(rinfo->rmode())); 71 return rinfo->IsPatchedReturnSequence(); 72} 73 74 75#define __ ACCESS_MASM(masm) 76 77 78static void Generate_DebugBreakCallHelper(MacroAssembler* masm, 79 RegList pointer_regs) { 80 // Save the content of all general purpose registers in memory. This copy in 81 // memory is later pushed onto the JS expression stack for the fake JS frame 82 // generated and also to the C frame generated on top of that. In the JS 83 // frame ONLY the registers containing pointers will be pushed on the 84 // expression stack. This causes the GC to update these pointers so that 85 // they will have the correct value when returning from the debugger. 86 __ SaveRegistersToMemory(kJSCallerSaved); 87 88 __ EnterInternalFrame(); 89 90 // Store the registers containing object pointers on the expression stack to 91 // make sure that these are correctly updated during GC. 92 // Use sp as base to push. 93 __ CopyRegistersFromMemoryToStack(sp, pointer_regs); 94 95#ifdef DEBUG 96 __ RecordComment("// Calling from debug break to runtime - come in - over"); 97#endif 98 __ mov(r0, Operand(0)); // no arguments 99 __ mov(r1, Operand(ExternalReference::debug_break())); 100 101 CEntryStub ceb(1, ExitFrame::MODE_DEBUG); 102 __ CallStub(&ceb); 103 104 // Restore the register values containing object pointers from the expression 105 // stack in the reverse order as they where pushed. 106 // Use sp as base to pop. 107 __ CopyRegistersFromStackToMemory(sp, r3, pointer_regs); 108 109 __ LeaveInternalFrame(); 110 111 // Finally restore all registers. 112 __ RestoreRegistersFromMemory(kJSCallerSaved); 113 114 // Now that the break point has been handled, resume normal execution by 115 // jumping to the target address intended by the caller and that was 116 // overwritten by the address of DebugBreakXXX. 117 __ mov(ip, Operand(ExternalReference(Debug_Address::AfterBreakTarget()))); 118 __ ldr(ip, MemOperand(ip)); 119 __ Jump(ip); 120} 121 122 123void Debug::GenerateLoadICDebugBreak(MacroAssembler* masm) { 124 // Calling convention for IC load (from ic-arm.cc). 125 // ----------- S t a t e ------------- 126 // -- r0 : receiver 127 // -- r2 : name 128 // -- lr : return address 129 // -- [sp] : receiver 130 // ----------------------------------- 131 // Registers r0 and r2 contain objects that need to be pushed on the 132 // expression stack of the fake JS frame. 133 Generate_DebugBreakCallHelper(masm, r0.bit() | r2.bit()); 134} 135 136 137void Debug::GenerateStoreICDebugBreak(MacroAssembler* masm) { 138 // Calling convention for IC store (from ic-arm.cc). 139 // ----------- S t a t e ------------- 140 // -- r0 : value 141 // -- r1 : receiver 142 // -- r2 : name 143 // -- lr : return address 144 // ----------------------------------- 145 // Registers r0, r1, and r2 contain objects that need to be pushed on the 146 // expression stack of the fake JS frame. 147 Generate_DebugBreakCallHelper(masm, r0.bit() | r1.bit() | r2.bit()); 148} 149 150 151void Debug::GenerateKeyedLoadICDebugBreak(MacroAssembler* masm) { 152 // ---------- S t a t e -------------- 153 // -- lr : return address 154 // -- sp[0] : key 155 // -- sp[4] : receiver 156 Generate_DebugBreakCallHelper(masm, 0); 157} 158 159 160void Debug::GenerateKeyedStoreICDebugBreak(MacroAssembler* masm) { 161 // ---------- S t a t e -------------- 162 // -- lr : return address 163 // -- sp[0] : key 164 // -- sp[4] : receiver 165 Generate_DebugBreakCallHelper(masm, 0); 166} 167 168 169void Debug::GenerateCallICDebugBreak(MacroAssembler* masm) { 170 // Calling convention for IC call (from ic-arm.cc) 171 // ----------- S t a t e ------------- 172 // -- r0: number of arguments 173 // -- r1: receiver 174 // -- lr: return address 175 // ----------------------------------- 176 // Register r1 contains an object that needs to be pushed on the expression 177 // stack of the fake JS frame. r0 is the actual number of arguments not 178 // encoded as a smi, therefore it cannot be on the expression stack of the 179 // fake JS frame as it can easily be an invalid pointer (e.g. 1). r0 will be 180 // pushed on the stack of the C frame and restored from there. 181 Generate_DebugBreakCallHelper(masm, r1.bit()); 182} 183 184 185void Debug::GenerateConstructCallDebugBreak(MacroAssembler* masm) { 186 // In places other than IC call sites it is expected that r0 is TOS which 187 // is an object - this is not generally the case so this should be used with 188 // care. 189 Generate_DebugBreakCallHelper(masm, r0.bit()); 190} 191 192 193void Debug::GenerateReturnDebugBreak(MacroAssembler* masm) { 194 // In places other than IC call sites it is expected that r0 is TOS which 195 // is an object - this is not generally the case so this should be used with 196 // care. 197 Generate_DebugBreakCallHelper(masm, r0.bit()); 198} 199 200 201void Debug::GenerateStubNoRegistersDebugBreak(MacroAssembler* masm) { 202 // ----------- S t a t e ------------- 203 // No registers used on entry. 204 // ----------------------------------- 205 Generate_DebugBreakCallHelper(masm, 0); 206} 207 208 209#undef __ 210 211#endif // ENABLE_DEBUGGER_SUPPORT 212 213} } // namespace v8::internal 214