1 //===-- DWARFDebugArangeSet.cpp ---------------------------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 #include "DWARFDebugArangeSet.h"
13 #include "lldb/Core/Stream.h"
14 #include "SymbolFileDWARF.h"
16 using namespace lldb_private;
18 DWARFDebugArangeSet::DWARFDebugArangeSet() :
19 m_offset(DW_INVALID_OFFSET),
21 m_arange_descriptors()
25 m_header.cu_offset = 0;
26 m_header.addr_size = 0;
27 m_header.seg_size = 0;
31 DWARFDebugArangeSet::Clear()
33 m_offset = DW_INVALID_OFFSET;
36 m_header.cu_offset = 0;
37 m_header.addr_size = 0;
38 m_header.seg_size = 0;
39 m_arange_descriptors.clear();
43 DWARFDebugArangeSet::SetHeader
51 m_header.version = version;
52 m_header.cu_offset = cu_offset;
53 m_header.addr_size = addr_size;
54 m_header.seg_size = seg_size;
58 DWARFDebugArangeSet::Compact()
60 if (m_arange_descriptors.empty())
63 // Iterate through all arange descriptors and combine any ranges that
64 // overlap or have matching boundaries. The m_arange_descriptors are assumed
65 // to be in ascending order after being built by adding descriptors
66 // using the AddDescriptor method.
68 while (i + 1 < m_arange_descriptors.size())
70 if (m_arange_descriptors[i].end_address() >= m_arange_descriptors[i+1].address)
72 // The current range ends at or exceeds the start of the next address range.
73 // Compute the max end address between the two and use that to make the new
75 const dw_addr_t max_end_addr = std::max(m_arange_descriptors[i].end_address(), m_arange_descriptors[i+1].end_address());
76 m_arange_descriptors[i].length = max_end_addr - m_arange_descriptors[i].address;
77 // Now remove the next entry as it was just combined with the previous one.
78 m_arange_descriptors.erase(m_arange_descriptors.begin()+i+1);
82 // Discontiguous address range, just proceed to the next one.
87 //----------------------------------------------------------------------
88 // Compare function DWARFDebugArangeSet::Descriptor structures
89 //----------------------------------------------------------------------
90 static bool DescriptorLessThan (const DWARFDebugArangeSet::Descriptor& range1, const DWARFDebugArangeSet::Descriptor& range2)
92 return range1.address < range2.address;
95 //----------------------------------------------------------------------
96 // Add a range descriptor and keep things sorted so we can easily
97 // compact the ranges before being saved or used.
98 //----------------------------------------------------------------------
100 DWARFDebugArangeSet::AddDescriptor(const DWARFDebugArangeSet::Descriptor& range)
102 if (m_arange_descriptors.empty())
104 m_arange_descriptors.push_back(range);
108 DescriptorIter end = m_arange_descriptors.end();
109 DescriptorIter pos = lower_bound(m_arange_descriptors.begin(), end, range, DescriptorLessThan);
110 const dw_addr_t range_end_addr = range.end_address();
113 const dw_addr_t found_end_addr = pos->end_address();
114 if (range.address < pos->address)
116 if (range_end_addr < pos->address)
118 // Non-contiguous entries, add this one before the found entry
119 m_arange_descriptors.insert(pos, range);
121 else if (range_end_addr == pos->address)
123 // The top end of 'range' is the lower end of the entry
124 // pointed to by 'pos'. We can combine range with the
125 // entry we found by setting the starting address and
126 // increasing the length since they don't overlap.
127 pos->address = range.address;
128 pos->length += range.length;
132 // We can combine these two and make sure the largest end
133 // address is used to make end address.
134 pos->address = range.address;
135 pos->length = std::max(found_end_addr, range_end_addr) - pos->address;
138 else if (range.address == pos->address)
140 pos->length = std::max(pos->length, range.length);
145 // NOTE: 'pos' points to entry past the end which is ok for insert,
146 // don't use otherwise!!!
147 const dw_addr_t max_addr = m_arange_descriptors.back().end_address();
148 if (max_addr < range.address)
150 // Non-contiguous entries, add this one before the found entry
151 m_arange_descriptors.insert(pos, range);
153 else if (max_addr == range.address)
155 m_arange_descriptors.back().length += range.length;
159 m_arange_descriptors.back().length = std::max(max_addr, range_end_addr) - m_arange_descriptors.back().address;
165 DWARFDebugArangeSet::Extract(const DWARFDataExtractor &data, lldb::offset_t *offset_ptr)
167 if (data.ValidOffset(*offset_ptr))
169 m_arange_descriptors.clear();
170 m_offset = *offset_ptr;
172 // 7.20 Address Range Table
174 // Each set of entries in the table of address ranges contained in
175 // the .debug_aranges section begins with a header consisting of: a
176 // 4-byte length containing the length of the set of entries for this
177 // compilation unit, not including the length field itself; a 2-byte
178 // version identifier containing the value 2 for DWARF Version 2; a
179 // 4-byte offset into the.debug_infosection; a 1-byte unsigned integer
180 // containing the size in bytes of an address (or the offset portion of
181 // an address for segmented addressing) on the target system; and a
182 // 1-byte unsigned integer containing the size in bytes of a segment
183 // descriptor on the target system. This header is followed by a series
184 // of tuples. Each tuple consists of an address and a length, each in
185 // the size appropriate for an address on the target architecture.
186 m_header.length = data.GetDWARFInitialLength(offset_ptr);
187 m_header.version = data.GetU16(offset_ptr);
188 m_header.cu_offset = data.GetDWARFOffset(offset_ptr);
189 m_header.addr_size = data.GetU8(offset_ptr);
190 m_header.seg_size = data.GetU8(offset_ptr);
192 // Try to avoid reading invalid arange sets by making sure:
193 // 1 - the version looks good
194 // 2 - the address byte size looks plausible
195 // 3 - the length seems to make sense
196 // size looks plausible
197 if ((m_header.version >= 2 && m_header.version <= 5) &&
198 (m_header.addr_size == 4 || m_header.addr_size == 8) &&
199 (m_header.length > 0))
201 if (data.ValidOffset(m_offset + sizeof(m_header.length) + m_header.length - 1))
203 // The first tuple following the header in each set begins at an offset
204 // that is a multiple of the size of a single tuple (that is, twice the
205 // size of an address). The header is padded, if necessary, to the
206 // appropriate boundary.
207 const uint32_t header_size = *offset_ptr - m_offset;
208 const uint32_t tuple_size = m_header.addr_size << 1;
209 uint32_t first_tuple_offset = 0;
210 while (first_tuple_offset < header_size)
211 first_tuple_offset += tuple_size;
213 *offset_ptr = m_offset + first_tuple_offset;
215 Descriptor arangeDescriptor;
217 static_assert(sizeof(arangeDescriptor.address) == sizeof(arangeDescriptor.length),
218 "DWARFDebugArangeSet::Descriptor.address and DWARFDebugArangeSet::Descriptor.length must have same size");
220 while (data.ValidOffset(*offset_ptr))
222 arangeDescriptor.address = data.GetMaxU64(offset_ptr, m_header.addr_size);
223 arangeDescriptor.length = data.GetMaxU64(offset_ptr, m_header.addr_size);
225 // Each set of tuples is terminated by a 0 for the address and 0
227 if (arangeDescriptor.address || arangeDescriptor.length)
228 m_arange_descriptors.push_back(arangeDescriptor);
230 break; // We are done if we get a zero address and length
233 #if defined (LLDB_CONFIGURATION_DEBUG)
236 printf ("warning: .debug_arange set length is too large arange data at 0x%8.8x: length=0x%8.8x, version=0x%4.4x, cu_offset=0x%8.8x, addr_size=%u, seg_size=%u\n",
246 #if defined (LLDB_CONFIGURATION_DEBUG)
249 printf ("warning: .debug_arange set has bad header at 0x%8.8x: length=0x%8.8x, version=0x%4.4x, cu_offset=0x%8.8x, addr_size=%u, seg_size=%u\n",
259 return !m_arange_descriptors.empty();
266 DWARFDebugArangeSet::GetOffsetOfNextEntry() const
268 return m_offset + m_header.length + 4;
273 DWARFDebugArangeSet::Dump(Stream *s) const
275 s->Printf("Address Range Header: length = 0x%8.8x, version = 0x%4.4x, cu_offset = 0x%8.8x, addr_size = 0x%2.2x, seg_size = 0x%2.2x\n",
276 m_header.length ,m_header.version, m_header.cu_offset, m_header.addr_size, m_header.seg_size);
278 const uint32_t hex_width = m_header.addr_size * 2;
279 DescriptorConstIter pos;
280 DescriptorConstIter end = m_arange_descriptors.end();
281 for (pos = m_arange_descriptors.begin(); pos != end; ++pos)
282 s->Printf("[0x%*.*" PRIx64 " - 0x%*.*" PRIx64 ")\n",
283 hex_width, hex_width, pos->address,
284 hex_width, hex_width, pos->end_address());
288 class DescriptorContainsAddress
291 DescriptorContainsAddress (dw_addr_t address) : m_address(address) {}
292 bool operator() (const DWARFDebugArangeSet::Descriptor& desc) const
294 return (m_address >= desc.address) && (m_address < (desc.address + desc.length));
297 const dw_addr_t m_address;
301 DWARFDebugArangeSet::FindAddress(dw_addr_t address) const
303 DescriptorConstIter end = m_arange_descriptors.end();
304 DescriptorConstIter pos = std::find_if( m_arange_descriptors.begin(), end, // Range
305 DescriptorContainsAddress(address));// Predicate
307 return m_header.cu_offset;
309 return DW_INVALID_OFFSET;