1//===-- DWARFCompileUnit.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 "DWARFCompileUnit.h"
10#include "DWARFDebugAranges.h"
11#include "SymbolFileDWARFDebugMap.h"
12
13#include "lldb/Symbol/CompileUnit.h"
14#include "lldb/Symbol/LineTable.h"
15#include "lldb/Utility/Stream.h"
16
17using namespace lldb;
18using namespace lldb_private;
19
20void DWARFCompileUnit::Dump(Stream *s) const {
21  s->Printf("0x%8.8x: Compile Unit: length = 0x%8.8x, version = 0x%4.4x, "
22            "abbr_offset = 0x%8.8x, addr_size = 0x%2.2x (next CU at "
23            "{0x%8.8x})\n",
24            GetOffset(), GetLength(), GetVersion(), GetAbbrevOffset(),
25            GetAddressByteSize(), GetNextUnitOffset());
26}
27
28void DWARFCompileUnit::BuildAddressRangeTable(
29    DWARFDebugAranges *debug_aranges) {
30  // This function is usually called if there in no .debug_aranges section in
31  // order to produce a compile unit level set of address ranges that is
32  // accurate.
33
34  size_t num_debug_aranges = debug_aranges->GetNumRanges();
35
36  // First get the compile unit DIE only and check if it has a DW_AT_ranges
37  const DWARFDebugInfoEntry *die = GetUnitDIEPtrOnly();
38
39  const dw_offset_t cu_offset = GetOffset();
40  if (die) {
41    DWARFRangeList ranges;
42    const size_t num_ranges =
43        die->GetAttributeAddressRanges(this, ranges, false);
44    if (num_ranges > 0) {
45      // This compile unit has DW_AT_ranges, assume this is correct if it is
46      // present since clang no longer makes .debug_aranges by default and it
47      // emits DW_AT_ranges for DW_TAG_compile_units. GCC also does this with
48      // recent GCC builds.
49      for (size_t i = 0; i < num_ranges; ++i) {
50        const DWARFRangeList::Entry &range = ranges.GetEntryRef(i);
51        debug_aranges->AppendRange(cu_offset, range.GetRangeBase(),
52                                   range.GetRangeEnd());
53      }
54
55      return; // We got all of our ranges from the DW_AT_ranges attribute
56    }
57  }
58  // We don't have a DW_AT_ranges attribute, so we need to parse the DWARF
59
60  // If the DIEs weren't parsed, then we don't want all dies for all compile
61  // units to stay loaded when they weren't needed. So we can end up parsing
62  // the DWARF and then throwing them all away to keep memory usage down.
63  ScopedExtractDIEs clear_dies(ExtractDIEsScoped());
64
65  die = DIEPtr();
66  if (die)
67    die->BuildAddressRangeTable(this, debug_aranges);
68
69  if (debug_aranges->GetNumRanges() == num_debug_aranges) {
70    // We got nothing from the functions, maybe we have a line tables only
71    // situation. Check the line tables and build the arange table from this.
72    SymbolContext sc;
73    sc.comp_unit = m_dwarf.GetCompUnitForDWARFCompUnit(*this);
74    if (sc.comp_unit) {
75      SymbolFileDWARFDebugMap *debug_map_sym_file =
76          m_dwarf.GetDebugMapSymfile();
77      if (debug_map_sym_file == nullptr) {
78        if (LineTable *line_table = sc.comp_unit->GetLineTable()) {
79          LineTable::FileAddressRanges file_ranges;
80          const bool append = true;
81          const size_t num_ranges =
82              line_table->GetContiguousFileAddressRanges(file_ranges, append);
83          for (uint32_t idx = 0; idx < num_ranges; ++idx) {
84            const LineTable::FileAddressRanges::Entry &range =
85                file_ranges.GetEntryRef(idx);
86            debug_aranges->AppendRange(cu_offset, range.GetRangeBase(),
87                                       range.GetRangeEnd());
88          }
89        }
90      } else
91        debug_map_sym_file->AddOSOARanges(&m_dwarf, debug_aranges);
92    }
93  }
94
95  if (debug_aranges->GetNumRanges() == num_debug_aranges) {
96    // We got nothing from the functions, maybe we have a line tables only
97    // situation. Check the line tables and build the arange table from this.
98    SymbolContext sc;
99    sc.comp_unit = m_dwarf.GetCompUnitForDWARFCompUnit(*this);
100    if (sc.comp_unit) {
101      if (LineTable *line_table = sc.comp_unit->GetLineTable()) {
102        LineTable::FileAddressRanges file_ranges;
103        const bool append = true;
104        const size_t num_ranges =
105            line_table->GetContiguousFileAddressRanges(file_ranges, append);
106        for (uint32_t idx = 0; idx < num_ranges; ++idx) {
107          const LineTable::FileAddressRanges::Entry &range =
108              file_ranges.GetEntryRef(idx);
109          debug_aranges->AppendRange(GetOffset(), range.GetRangeBase(),
110                                     range.GetRangeEnd());
111        }
112      }
113    }
114  }
115}
116