debug-x64.cc revision 3ce2e2076e8e3e60cf1810eec160ea2d8557e9e7 
1// Copyright 2009 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
29#include "v8.h"
30
31#include "codegen-inl.h"
32#include "debug.h"
33
34
35namespace v8 {
36namespace internal {
37
38#ifdef ENABLE_DEBUGGER_SUPPORT
39
40bool Debug::IsDebugBreakAtReturn(v8::internal::RelocInfo* rinfo) {
41  ASSERT(RelocInfo::IsJSReturn(rinfo->rmode()));
42  return rinfo->IsPatchedReturnSequence();
43}
44
45#define __ ACCESS_MASM(masm)
46
47static void Generate_DebugBreakCallHelper(MacroAssembler* masm,
48                                          RegList pointer_regs,
49                                          bool convert_call_to_jmp) {
50  // Save the content of all general purpose registers in memory. This copy in
51  // memory is later pushed onto the JS expression stack for the fake JS frame
52  // generated and also to the C frame generated on top of that. In the JS
53  // frame ONLY the registers containing pointers will be pushed on the
54  // expression stack. This causes the GC to update these pointers so that
55  // they will have the correct value when returning from the debugger.
56  __ SaveRegistersToMemory(kJSCallerSaved);
57
58  // Enter an internal frame.
59  __ EnterInternalFrame();
60
61  // Store the registers containing object pointers on the expression stack to
62  // make sure that these are correctly updated during GC.
63  __ PushRegistersFromMemory(pointer_regs);
64
65#ifdef DEBUG
66  __ RecordComment("// Calling from debug break to runtime - come in - over");
67#endif
68  __ xor_(rax, rax);  // No arguments (argc == 0).
69  __ movq(rbx, ExternalReference::debug_break());
70
71  CEntryDebugBreakStub ceb;
72  __ CallStub(&ceb);
73
74  // Restore the register values containing object pointers from the expression
75  // stack in the reverse order as they where pushed.
76  __ PopRegistersToMemory(pointer_regs);
77
78  // Get rid of the internal frame.
79  __ LeaveInternalFrame();
80
81  // If this call did not replace a call but patched other code then there will
82  // be an unwanted return address left on the stack. Here we get rid of that.
83  if (convert_call_to_jmp) {
84    __ pop(rax);
85  }
86
87  // Finally restore all registers.
88  __ RestoreRegistersFromMemory(kJSCallerSaved);
89
90  // Now that the break point has been handled, resume normal execution by
91  // jumping to the target address intended by the caller and that was
92  // overwritten by the address of DebugBreakXXX.
93  ExternalReference after_break_target =
94      ExternalReference(Debug_Address::AfterBreakTarget());
95  __ movq(kScratchRegister, after_break_target);
96  __ jmp(Operand(kScratchRegister, 0));
97}
98
99
100void Debug::GenerateCallICDebugBreak(MacroAssembler* masm) {
101  // Register state for keyed IC call call (from ic-x64.cc)
102  // ----------- S t a t e -------------
103  //  -- rax: number of arguments
104  // -----------------------------------
105  // The number of arguments in rax is not smi encoded.
106  Generate_DebugBreakCallHelper(masm, 0, false);
107}
108
109
110void Debug::GenerateConstructCallDebugBreak(MacroAssembler* masm) {
111  // Register state just before return from JS function (from codegen-x64.cc).
112  // rax is the actual number of arguments not encoded as a smi, see comment
113  // above IC call.
114  // ----------- S t a t e -------------
115  //  -- rax: number of arguments
116  // -----------------------------------
117  // The number of arguments in rax is not smi encoded.
118  Generate_DebugBreakCallHelper(masm, 0, false);
119}
120
121
122void Debug::GenerateKeyedLoadICDebugBreak(MacroAssembler* masm) {
123  // Register state for keyed IC load call (from ic-x64.cc).
124  // ----------- S t a t e -------------
125  //  No registers used on entry.
126  // -----------------------------------
127  Generate_DebugBreakCallHelper(masm, 0, false);
128}
129
130
131void Debug::GenerateKeyedStoreICDebugBreak(MacroAssembler* masm) {
132  // Register state for keyed IC load call (from ic-x64.cc).
133  // ----------- S t a t e -------------
134  //  -- rax    : value
135  // -----------------------------------
136  // Register rax contains an object that needs to be pushed on the
137  // expression stack of the fake JS frame.
138  Generate_DebugBreakCallHelper(masm, rax.bit(), false);
139}
140
141
142void Debug::GenerateLoadICDebugBreak(MacroAssembler* masm) {
143  // Register state for IC load call (from ic-x64.cc).
144  // ----------- S t a t e -------------
145  //  -- rcx    : name
146  // -----------------------------------
147  Generate_DebugBreakCallHelper(masm, rcx.bit(), false);
148}
149
150
151void Debug::GenerateReturnDebugBreak(MacroAssembler* masm) {
152  // Register state just before return from JS function (from codegen-x64.cc).
153  // ----------- S t a t e -------------
154  //  -- rax: return value
155  // -----------------------------------
156  Generate_DebugBreakCallHelper(masm, rax.bit(), true);
157}
158
159
160void Debug::GenerateStoreICDebugBreak(MacroAssembler* masm) {
161  // REgister state for IC store call (from ic-x64.cc).
162  // ----------- S t a t e -------------
163  //  -- rax    : value
164  //  -- rcx    : name
165  // -----------------------------------
166  Generate_DebugBreakCallHelper(masm, rax.bit() | rcx.bit(), false);
167}
168
169
170void Debug::GenerateStubNoRegistersDebugBreak(MacroAssembler* masm) {
171  // Register state for stub CallFunction (from CallFunctionStub in ic-x64.cc).
172  // ----------- S t a t e -------------
173  //  No registers used on entry.
174  // -----------------------------------
175  Generate_DebugBreakCallHelper(masm, 0, false);
176}
177
178
179#undef __
180
181
182void BreakLocationIterator::ClearDebugBreakAtReturn() {
183  rinfo()->PatchCode(original_rinfo()->pc(),
184                     Debug::kX64JSReturnSequenceLength);
185}
186
187
188bool BreakLocationIterator::IsDebugBreakAtReturn()  {
189  return Debug::IsDebugBreakAtReturn(rinfo());
190}
191
192
193void BreakLocationIterator::SetDebugBreakAtReturn()  {
194  ASSERT(Debug::kX64JSReturnSequenceLength >= Debug::kX64CallInstructionLength);
195  rinfo()->PatchCodeWithCall(Debug::debug_break_return()->entry(),
196      Debug::kX64JSReturnSequenceLength - Debug::kX64CallInstructionLength);
197}
198
199#endif  // ENABLE_DEBUGGER_SUPPORT
200
201} }  // namespace v8::internal
202