1 //===-- DWARFDebugRanges.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 "DWARFDebugRanges.h"
11 #include "SymbolFileDWARF.h"
12 #include "lldb/Core/Stream.h"
13 #include <assert.h>
14 
15 using namespace lldb_private;
16 using namespace std;
17 
18 DWARFDebugRanges::DWARFDebugRanges() : m_range_map() {}
19 
20 DWARFDebugRanges::~DWARFDebugRanges() {}
21 
22 void DWARFDebugRanges::Extract(SymbolFileDWARF *dwarf2Data) {
23   DWARFRangeList range_list;
24   lldb::offset_t offset = 0;
25   dw_offset_t debug_ranges_offset = offset;
26   while (Extract(dwarf2Data, &offset, range_list)) {
27     range_list.Sort();
28     m_range_map[debug_ranges_offset] = range_list;
29     debug_ranges_offset = offset;
30   }
31 }
32 
33 bool DWARFDebugRanges::Extract(SymbolFileDWARF *dwarf2Data,
34                                lldb::offset_t *offset_ptr,
35                                DWARFRangeList &range_list) {
36   range_list.Clear();
37 
38   lldb::offset_t range_offset = *offset_ptr;
39   const DWARFDataExtractor &debug_ranges_data =
40       dwarf2Data->get_debug_ranges_data();
41   uint32_t addr_size = debug_ranges_data.GetAddressByteSize();
42 
43   while (
44       debug_ranges_data.ValidOffsetForDataOfSize(*offset_ptr, 2 * addr_size)) {
45     dw_addr_t begin = debug_ranges_data.GetMaxU64(offset_ptr, addr_size);
46     dw_addr_t end = debug_ranges_data.GetMaxU64(offset_ptr, addr_size);
47     if (!begin && !end) {
48       // End of range list
49       break;
50     }
51     // Extend 4 byte addresses that consists of 32 bits of 1's to be 64 bits
52     // of ones
53     switch (addr_size) {
54     case 2:
55       if (begin == 0xFFFFull)
56         begin = LLDB_INVALID_ADDRESS;
57       break;
58 
59     case 4:
60       if (begin == 0xFFFFFFFFull)
61         begin = LLDB_INVALID_ADDRESS;
62       break;
63 
64     case 8:
65       break;
66 
67     default:
68       assert(!"DWARFRangeList::Extract() unsupported address size.");
69       break;
70     }
71 
72     // Filter out empty ranges
73     if (begin < end)
74       range_list.Append(DWARFRangeList::Entry(begin, end - begin));
75   }
76 
77   // Make sure we consumed at least something
78   return range_offset != *offset_ptr;
79 }
80 
81 void DWARFDebugRanges::Dump(Stream &s,
82                             const DWARFDataExtractor &debug_ranges_data,
83                             lldb::offset_t *offset_ptr,
84                             dw_addr_t cu_base_addr) {
85   uint32_t addr_size = s.GetAddressByteSize();
86   bool verbose = s.GetVerbose();
87 
88   dw_addr_t base_addr = cu_base_addr;
89   while (
90       debug_ranges_data.ValidOffsetForDataOfSize(*offset_ptr, 2 * addr_size)) {
91     dw_addr_t begin = debug_ranges_data.GetMaxU64(offset_ptr, addr_size);
92     dw_addr_t end = debug_ranges_data.GetMaxU64(offset_ptr, addr_size);
93     // Extend 4 byte addresses that consists of 32 bits of 1's to be 64 bits
94     // of ones
95     if (begin == 0xFFFFFFFFull && addr_size == 4)
96       begin = LLDB_INVALID_ADDRESS;
97 
98     s.Indent();
99     if (verbose) {
100       s.AddressRange(begin, end, sizeof(dw_addr_t), " offsets = ");
101     }
102 
103     if (begin == 0 && end == 0) {
104       s.PutCString(" End");
105       break;
106     } else if (begin == LLDB_INVALID_ADDRESS) {
107       // A base address selection entry
108       base_addr = end;
109       s.Address(base_addr, sizeof(dw_addr_t), " Base address = ");
110     } else {
111       // Convert from offset to an address
112       dw_addr_t begin_addr = begin + base_addr;
113       dw_addr_t end_addr = end + base_addr;
114 
115       s.AddressRange(begin_addr, end_addr, sizeof(dw_addr_t),
116                      verbose ? " ==> addrs = " : NULL);
117     }
118   }
119 }
120 
121 bool DWARFDebugRanges::FindRanges(dw_addr_t debug_ranges_base,
122                                   dw_offset_t debug_ranges_offset,
123                                   DWARFRangeList &range_list) const {
124   dw_addr_t debug_ranges_address = debug_ranges_base + debug_ranges_offset;
125   range_map_const_iterator pos = m_range_map.find(debug_ranges_address);
126   if (pos != m_range_map.end()) {
127     range_list = pos->second;
128     return true;
129   }
130   return false;
131 }
132