1 //===-- DWARFDebugAranges.cpp -----------------------------------*- C++ -*-===//
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 "DWARFDebugAranges.h"
10 
11 #include <assert.h>
12 #include <stdio.h>
13 
14 #include <algorithm>
15 
16 #include "lldb/Utility/Log.h"
17 #include "lldb/Utility/Stream.h"
18 #include "lldb/Utility/Timer.h"
19 
20 #include "DWARFUnit.h"
21 #include "DWARFDebugInfo.h"
22 #include "LogChannelDWARF.h"
23 #include "SymbolFileDWARF.h"
24 
25 using namespace lldb;
26 using namespace lldb_private;
27 
28 //----------------------------------------------------------------------
29 // Constructor
30 //----------------------------------------------------------------------
31 DWARFDebugAranges::DWARFDebugAranges() : m_aranges() {}
32 
33 //----------------------------------------------------------------------
34 // CountArangeDescriptors
35 //----------------------------------------------------------------------
36 class CountArangeDescriptors {
37 public:
38   CountArangeDescriptors(uint32_t &count_ref) : count(count_ref) {
39     //      printf("constructor CountArangeDescriptors()\n");
40   }
41   void operator()(const DWARFDebugArangeSet &set) {
42     count += set.NumDescriptors();
43   }
44   uint32_t &count;
45 };
46 
47 //----------------------------------------------------------------------
48 // Extract
49 //----------------------------------------------------------------------
50 llvm::Error
51 DWARFDebugAranges::extract(const DWARFDataExtractor &debug_aranges_data) {
52   assert(debug_aranges_data.ValidOffset(0));
53 
54   lldb::offset_t offset = 0;
55 
56   DWARFDebugArangeSet set;
57   Range range;
58   while (debug_aranges_data.ValidOffset(offset)) {
59     llvm::Error error = set.extract(debug_aranges_data, &offset);
60     if (!error)
61       return error;
62 
63     const uint32_t num_descriptors = set.NumDescriptors();
64     if (num_descriptors > 0) {
65       const dw_offset_t cu_offset = set.GetCompileUnitDIEOffset();
66 
67       for (uint32_t i = 0; i < num_descriptors; ++i) {
68         const DWARFDebugArangeSet::Descriptor &descriptor =
69             set.GetDescriptorRef(i);
70         m_aranges.Append(RangeToDIE::Entry(descriptor.address,
71                                            descriptor.length, cu_offset));
72       }
73     }
74     set.Clear();
75   }
76   return llvm::ErrorSuccess();
77 }
78 
79 //----------------------------------------------------------------------
80 // Generate
81 //----------------------------------------------------------------------
82 bool DWARFDebugAranges::Generate(SymbolFileDWARF *dwarf2Data) {
83   Clear();
84   DWARFDebugInfo *debug_info = dwarf2Data->DebugInfo();
85   if (debug_info) {
86     uint32_t cu_idx = 0;
87     const uint32_t num_compile_units = dwarf2Data->GetNumCompileUnits();
88     for (cu_idx = 0; cu_idx < num_compile_units; ++cu_idx) {
89       DWARFUnit *cu = debug_info->GetCompileUnitAtIndex(cu_idx);
90       if (cu)
91         cu->BuildAddressRangeTable(dwarf2Data, this);
92     }
93   }
94   return !IsEmpty();
95 }
96 
97 void DWARFDebugAranges::Dump(Log *log) const {
98   if (log == NULL)
99     return;
100 
101   const size_t num_entries = m_aranges.GetSize();
102   for (size_t i = 0; i < num_entries; ++i) {
103     const RangeToDIE::Entry *entry = m_aranges.GetEntryAtIndex(i);
104     if (entry)
105       log->Printf("0x%8.8x: [0x%" PRIx64 " - 0x%" PRIx64 ")", entry->data,
106                   entry->GetRangeBase(), entry->GetRangeEnd());
107   }
108 }
109 
110 void DWARFDebugAranges::AppendRange(dw_offset_t offset, dw_addr_t low_pc,
111                                     dw_addr_t high_pc) {
112   if (high_pc > low_pc)
113     m_aranges.Append(RangeToDIE::Entry(low_pc, high_pc - low_pc, offset));
114 }
115 
116 void DWARFDebugAranges::Sort(bool minimize) {
117   static Timer::Category func_cat(LLVM_PRETTY_FUNCTION);
118   Timer scoped_timer(func_cat, "%s this = %p", LLVM_PRETTY_FUNCTION,
119                      static_cast<void *>(this));
120 
121   Log *log(LogChannelDWARF::GetLogIfAll(DWARF_LOG_DEBUG_ARANGES));
122   size_t orig_arange_size = 0;
123   if (log) {
124     orig_arange_size = m_aranges.GetSize();
125     log->Printf("DWARFDebugAranges::Sort(minimize = %u) with %" PRIu64
126                 " entries",
127                 minimize, (uint64_t)orig_arange_size);
128   }
129 
130   m_aranges.Sort();
131   m_aranges.CombineConsecutiveEntriesWithEqualData();
132 
133   if (log) {
134     if (minimize) {
135       const size_t new_arange_size = m_aranges.GetSize();
136       const size_t delta = orig_arange_size - new_arange_size;
137       log->Printf("DWARFDebugAranges::Sort() %" PRIu64
138                   " entries after minimizing (%" PRIu64
139                   " entries combined for %" PRIu64 " bytes saved)",
140                   (uint64_t)new_arange_size, (uint64_t)delta,
141                   (uint64_t)delta * sizeof(Range));
142     }
143     Dump(log);
144   }
145 }
146 
147 //----------------------------------------------------------------------
148 // FindAddress
149 //----------------------------------------------------------------------
150 dw_offset_t DWARFDebugAranges::FindAddress(dw_addr_t address) const {
151   const RangeToDIE::Entry *entry = m_aranges.FindEntryThatContains(address);
152   if (entry)
153     return entry->data;
154   return DW_INVALID_OFFSET;
155 }
156