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 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 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 65 UnwindTable::~UnwindTable () 66 { 67 if (m_eh_frame) 68 delete m_eh_frame; 69 } 70 71 FuncUnwindersSP 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 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 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 * 149 UnwindTable::GetEHFrameInfo () 150 { 151 Initialize(); 152 return m_eh_frame; 153 } 154