1 //===-- UnwindTable.cpp -----------------------------------------*- C++ -*-===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9
10 #include "lldb/Symbol/UnwindTable.h"
11
12 #include <stdio.h>
13
14 #include "lldb/Core/Module.h"
15 #include "lldb/Core/Section.h"
16 #include "lldb/Symbol/ObjectFile.h"
17 #include "lldb/Symbol/FuncUnwinders.h"
18 #include "lldb/Symbol/SymbolContext.h"
19 #include "lldb/Symbol/DWARFCallFrameInfo.h"
20 #include "lldb/Target/UnwindAssembly.h"
21
22 // There is one UnwindTable object per ObjectFile.
23 // It contains a list of Unwind objects -- one per function, populated lazily -- for the ObjectFile.
24 // Each Unwind object has multiple UnwindPlans for different scenarios.
25
26 using namespace lldb;
27 using namespace lldb_private;
28
UnwindTable(ObjectFile & objfile)29 UnwindTable::UnwindTable (ObjectFile& objfile) :
30 m_object_file (objfile),
31 m_unwinds (),
32 m_initialized (false),
33 m_assembly_profiler (NULL),
34 m_eh_frame (NULL)
35 {
36 }
37
38 // We can't do some of this initialization when the ObjectFile is running its ctor; delay doing it
39 // until needed for something.
40
41 void
Initialize()42 UnwindTable::Initialize ()
43 {
44 if (m_initialized)
45 return;
46
47 SectionList* sl = m_object_file.GetSectionList ();
48 if (sl)
49 {
50 SectionSP sect = sl->FindSectionByType (eSectionTypeEHFrame, true);
51 if (sect.get())
52 {
53 m_eh_frame = new DWARFCallFrameInfo(m_object_file, sect, eRegisterKindGCC, true);
54 }
55 }
56
57 ArchSpec arch;
58 if (m_object_file.GetArchitecture (arch))
59 {
60 m_assembly_profiler = UnwindAssembly::FindPlugin (arch);
61 m_initialized = true;
62 }
63 }
64
~UnwindTable()65 UnwindTable::~UnwindTable ()
66 {
67 if (m_eh_frame)
68 delete m_eh_frame;
69 }
70
71 FuncUnwindersSP
GetFuncUnwindersContainingAddress(const Address & addr,SymbolContext & sc)72 UnwindTable::GetFuncUnwindersContainingAddress (const Address& addr, SymbolContext &sc)
73 {
74 FuncUnwindersSP no_unwind_found;
75
76 Initialize();
77
78 // There is an UnwindTable per object file, so we can safely use file handles
79 addr_t file_addr = addr.GetFileAddress();
80 iterator end = m_unwinds.end ();
81 iterator insert_pos = end;
82 if (!m_unwinds.empty())
83 {
84 insert_pos = m_unwinds.lower_bound (file_addr);
85 iterator pos = insert_pos;
86 if ((pos == m_unwinds.end ()) || (pos != m_unwinds.begin() && pos->second->GetFunctionStartAddress() != addr))
87 --pos;
88
89 if (pos->second->ContainsAddress (addr))
90 return pos->second;
91 }
92
93 AddressRange range;
94 if (!sc.GetAddressRange(eSymbolContextFunction | eSymbolContextSymbol, 0, false, range) || !range.GetBaseAddress().IsValid())
95 {
96 // Does the eh_frame unwind info has a function bounds for this addr?
97 if (m_eh_frame == NULL || !m_eh_frame->GetAddressRange (addr, range))
98 {
99 return no_unwind_found;
100 }
101 }
102
103 FuncUnwindersSP func_unwinder_sp(new FuncUnwinders(*this, m_assembly_profiler, range));
104 m_unwinds.insert (insert_pos, std::make_pair(range.GetBaseAddress().GetFileAddress(), func_unwinder_sp));
105 // StreamFile s(stdout);
106 // Dump (s);
107 return func_unwinder_sp;
108 }
109
110 // Ignore any existing FuncUnwinders for this function, create a new one and don't add it to the
111 // UnwindTable. This is intended for use by target modules show-unwind where we want to create
112 // new UnwindPlans, not re-use existing ones.
113
114 FuncUnwindersSP
GetUncachedFuncUnwindersContainingAddress(const Address & addr,SymbolContext & sc)115 UnwindTable::GetUncachedFuncUnwindersContainingAddress (const Address& addr, SymbolContext &sc)
116 {
117 FuncUnwindersSP no_unwind_found;
118 Initialize();
119
120 AddressRange range;
121 if (!sc.GetAddressRange(eSymbolContextFunction | eSymbolContextSymbol, 0, false, range) || !range.GetBaseAddress().IsValid())
122 {
123 // Does the eh_frame unwind info has a function bounds for this addr?
124 if (m_eh_frame == NULL || !m_eh_frame->GetAddressRange (addr, range))
125 {
126 return no_unwind_found;
127 }
128 }
129
130 FuncUnwindersSP func_unwinder_sp(new FuncUnwinders(*this, m_assembly_profiler, range));
131 return func_unwinder_sp;
132 }
133
134
135 void
Dump(Stream & s)136 UnwindTable::Dump (Stream &s)
137 {
138 s.Printf("UnwindTable for '%s':\n", m_object_file.GetFileSpec().GetPath().c_str());
139 const_iterator begin = m_unwinds.begin();
140 const_iterator end = m_unwinds.end();
141 for (const_iterator pos = begin; pos != end; ++pos)
142 {
143 s.Printf ("[%u] 0x%16.16" PRIx64 "\n", (unsigned)std::distance (begin, pos), pos->first);
144 }
145 s.EOL();
146 }
147
148 DWARFCallFrameInfo *
GetEHFrameInfo()149 UnwindTable::GetEHFrameInfo ()
150 {
151 Initialize();
152 return m_eh_frame;
153 }
154