xref: /llvm-project/lldb/source/Breakpoint/BreakpointSite.cpp (revision 7dbbd2b251412b7b0809aabe672f3f57f0805dbb)
1 //===-- BreakpointSite.cpp ------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include <cinttypes>
10 
11 #include "lldb/Breakpoint/BreakpointSite.h"
12 
13 #include "lldb/Breakpoint/Breakpoint.h"
14 #include "lldb/Breakpoint/BreakpointLocation.h"
15 #include "lldb/Utility/Stream.h"
16 
17 using namespace lldb;
18 using namespace lldb_private;
19 
20 BreakpointSite::BreakpointSite(const BreakpointLocationSP &constituent,
21                                lldb::addr_t addr, bool use_hardware)
22     : StoppointSite(GetNextID(), addr, 0, use_hardware),
23       m_type(eSoftware), // Process subclasses need to set this correctly using
24                          // SetType()
25       m_saved_opcode(), m_trap_opcode(),
26       m_enabled(false) // Need to create it disabled, so the first enable turns
27                        // it on.
28 {
29   m_constituents.Add(constituent);
30 }
31 
32 BreakpointSite::~BreakpointSite() {
33   BreakpointLocationSP bp_loc_sp;
34   const size_t constituent_count = m_constituents.GetSize();
35   for (size_t i = 0; i < constituent_count; i++) {
36     m_constituents.GetByIndex(i)->ClearBreakpointSite();
37   }
38 }
39 
40 break_id_t BreakpointSite::GetNextID() {
41   static break_id_t g_next_id = 0;
42   return ++g_next_id;
43 }
44 
45 // RETURNS - true if we should stop at this breakpoint, false if we
46 // should continue.
47 
48 bool BreakpointSite::ShouldStop(StoppointCallbackContext *context) {
49   m_hit_counter.Increment();
50   // ShouldStop can do a lot of work, and might even come back and hit
51   // this breakpoint site again.  So don't hold the m_constituents_mutex the
52   // whole while.  Instead make a local copy of the collection and call
53   // ShouldStop on the copy.
54   BreakpointLocationCollection constituents_copy;
55   {
56     std::lock_guard<std::recursive_mutex> guard(m_constituents_mutex);
57     constituents_copy = m_constituents;
58   }
59   return constituents_copy.ShouldStop(context);
60 }
61 
62 bool BreakpointSite::IsBreakpointAtThisSite(lldb::break_id_t bp_id) {
63   std::lock_guard<std::recursive_mutex> guard(m_constituents_mutex);
64   const size_t constituent_count = m_constituents.GetSize();
65   for (size_t i = 0; i < constituent_count; i++) {
66     if (m_constituents.GetByIndex(i)->GetBreakpoint().GetID() == bp_id)
67       return true;
68   }
69   return false;
70 }
71 
72 void BreakpointSite::Dump(Stream *s) const {
73   if (s == nullptr)
74     return;
75 
76   s->Printf("BreakpointSite %u: addr = 0x%8.8" PRIx64
77             "  type = %s breakpoint  hit_count = %-4u",
78             GetID(), (uint64_t)m_addr, IsHardware() ? "hardware" : "software",
79             GetHitCount());
80 }
81 
82 void BreakpointSite::GetDescription(Stream *s, lldb::DescriptionLevel level) {
83   std::lock_guard<std::recursive_mutex> guard(m_constituents_mutex);
84   if (level != lldb::eDescriptionLevelBrief)
85     s->Printf("breakpoint site: %d at 0x%8.8" PRIx64, GetID(),
86               GetLoadAddress());
87   m_constituents.GetDescription(s, level);
88 }
89 
90 std::optional<uint32_t> BreakpointSite::GetSuggestedStackFrameIndex() {
91 
92   std::optional<uint32_t> result;
93   std::lock_guard<std::recursive_mutex> guard(m_constituents_mutex);
94   for (BreakpointLocationSP loc_sp : m_constituents.BreakpointLocations()) {
95     std::optional<uint32_t> loc_frame_index =
96         loc_sp->GetSuggestedStackFrameIndex();
97     if (loc_frame_index) {
98       if (result)
99         result = std::max(*loc_frame_index, *result);
100       else
101         result = loc_frame_index;
102     }
103   }
104   return result;
105 }
106 
107 bool BreakpointSite::IsInternal() const { return m_constituents.IsInternal(); }
108 
109 uint8_t *BreakpointSite::GetTrapOpcodeBytes() { return &m_trap_opcode[0]; }
110 
111 const uint8_t *BreakpointSite::GetTrapOpcodeBytes() const {
112   return &m_trap_opcode[0];
113 }
114 
115 size_t BreakpointSite::GetTrapOpcodeMaxByteSize() const {
116   return sizeof(m_trap_opcode);
117 }
118 
119 bool BreakpointSite::SetTrapOpcode(const uint8_t *trap_opcode,
120                                    uint32_t trap_opcode_size) {
121   if (trap_opcode_size > 0 && trap_opcode_size <= sizeof(m_trap_opcode)) {
122     m_byte_size = trap_opcode_size;
123     ::memcpy(m_trap_opcode, trap_opcode, trap_opcode_size);
124     return true;
125   }
126   m_byte_size = 0;
127   return false;
128 }
129 
130 uint8_t *BreakpointSite::GetSavedOpcodeBytes() { return &m_saved_opcode[0]; }
131 
132 const uint8_t *BreakpointSite::GetSavedOpcodeBytes() const {
133   return &m_saved_opcode[0];
134 }
135 
136 bool BreakpointSite::IsEnabled() const { return m_enabled; }
137 
138 void BreakpointSite::SetEnabled(bool enabled) { m_enabled = enabled; }
139 
140 void BreakpointSite::AddConstituent(const BreakpointLocationSP &constituent) {
141   std::lock_guard<std::recursive_mutex> guard(m_constituents_mutex);
142   m_constituents.Add(constituent);
143 }
144 
145 size_t BreakpointSite::RemoveConstituent(lldb::break_id_t break_id,
146                                          lldb::break_id_t break_loc_id) {
147   std::lock_guard<std::recursive_mutex> guard(m_constituents_mutex);
148   m_constituents.Remove(break_id, break_loc_id);
149   return m_constituents.GetSize();
150 }
151 
152 size_t BreakpointSite::GetNumberOfConstituents() {
153   std::lock_guard<std::recursive_mutex> guard(m_constituents_mutex);
154   return m_constituents.GetSize();
155 }
156 
157 BreakpointLocationSP BreakpointSite::GetConstituentAtIndex(size_t index) {
158   std::lock_guard<std::recursive_mutex> guard(m_constituents_mutex);
159   return m_constituents.GetByIndex(index);
160 }
161 
162 bool BreakpointSite::ValidForThisThread(Thread &thread) {
163   std::lock_guard<std::recursive_mutex> guard(m_constituents_mutex);
164   return m_constituents.ValidForThisThread(thread);
165 }
166 
167 void BreakpointSite::BumpHitCounts() {
168   std::lock_guard<std::recursive_mutex> guard(m_constituents_mutex);
169   for (BreakpointLocationSP loc_sp : m_constituents.BreakpointLocations()) {
170     loc_sp->BumpHitCount();
171   }
172 }
173 
174 bool BreakpointSite::IntersectsRange(lldb::addr_t addr, size_t size,
175                                      lldb::addr_t *intersect_addr,
176                                      size_t *intersect_size,
177                                      size_t *opcode_offset) const {
178   // The function should be called only for software breakpoints.
179   lldbassert(GetType() == Type::eSoftware);
180 
181   if (m_byte_size == 0)
182     return false;
183 
184   const lldb::addr_t bp_end_addr = m_addr + m_byte_size;
185   const lldb::addr_t end_addr = addr + size;
186   // Is the breakpoint end address before the passed in start address?
187   if (bp_end_addr <= addr)
188     return false;
189 
190   // Is the breakpoint start address after passed in end address?
191   if (end_addr <= m_addr)
192     return false;
193 
194   if (intersect_addr || intersect_size || opcode_offset) {
195     if (m_addr < addr) {
196       if (intersect_addr)
197         *intersect_addr = addr;
198       if (intersect_size)
199         *intersect_size =
200             std::min<lldb::addr_t>(bp_end_addr, end_addr) - addr;
201       if (opcode_offset)
202         *opcode_offset = addr - m_addr;
203     } else {
204       if (intersect_addr)
205         *intersect_addr = m_addr;
206       if (intersect_size)
207         *intersect_size =
208             std::min<lldb::addr_t>(bp_end_addr, end_addr) - m_addr;
209       if (opcode_offset)
210         *opcode_offset = 0;
211     }
212   }
213   return true;
214 }
215 
216 size_t BreakpointSite::CopyConstituentsList(
217     BreakpointLocationCollection &out_collection) {
218   std::lock_guard<std::recursive_mutex> guard(m_constituents_mutex);
219   for (BreakpointLocationSP loc_sp : m_constituents.BreakpointLocations()) {
220     out_collection.Add(loc_sp);
221   }
222   return out_collection.GetSize();
223 }
224