DWARFDebugAbbrev.cpp revision 36b56886974eae4f9c5ebc96befd3e7bfe5de338 
1//===-- DWARFDebugAbbrev.cpp ----------------------------------------------===//
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 "DWARFDebugAbbrev.h"
11#include "llvm/Support/Format.h"
12#include "llvm/Support/raw_ostream.h"
13using namespace llvm;
14
15bool DWARFAbbreviationDeclarationSet::extract(DataExtractor data,
16                                              uint32_t* offset_ptr) {
17  const uint32_t beginOffset = *offset_ptr;
18  Offset = beginOffset;
19  clear();
20  DWARFAbbreviationDeclaration abbrevDeclaration;
21  uint32_t prevAbbrAode = 0;
22  while (abbrevDeclaration.extract(data, offset_ptr)) {
23    Decls.push_back(abbrevDeclaration);
24    if (IdxOffset == 0) {
25      IdxOffset = abbrevDeclaration.getCode();
26    } else {
27      if (prevAbbrAode + 1 != abbrevDeclaration.getCode())
28        IdxOffset = UINT32_MAX;// Out of order indexes, we can't do O(1) lookups
29    }
30    prevAbbrAode = abbrevDeclaration.getCode();
31  }
32  return beginOffset != *offset_ptr;
33}
34
35void DWARFAbbreviationDeclarationSet::dump(raw_ostream &OS) const {
36  for (const auto &Decl : Decls)
37    Decl.dump(OS);
38}
39
40const DWARFAbbreviationDeclaration*
41DWARFAbbreviationDeclarationSet::getAbbreviationDeclaration(uint32_t abbrCode)
42  const {
43  if (IdxOffset == UINT32_MAX) {
44    for (const auto &Decl : Decls) {
45      if (Decl.getCode() == abbrCode)
46        return &Decl;
47    }
48  } else {
49    uint32_t idx = abbrCode - IdxOffset;
50    if (idx < Decls.size())
51      return &Decls[idx];
52  }
53  return NULL;
54}
55
56DWARFDebugAbbrev::DWARFDebugAbbrev() :
57  AbbrevCollMap(),
58  PrevAbbrOffsetPos(AbbrevCollMap.end()) {}
59
60
61void DWARFDebugAbbrev::parse(DataExtractor data) {
62  uint32_t offset = 0;
63
64  while (data.isValidOffset(offset)) {
65    uint32_t initial_cu_offset = offset;
66    DWARFAbbreviationDeclarationSet abbrevDeclSet;
67
68    if (abbrevDeclSet.extract(data, &offset))
69      AbbrevCollMap[initial_cu_offset] = abbrevDeclSet;
70    else
71      break;
72  }
73  PrevAbbrOffsetPos = AbbrevCollMap.end();
74}
75
76void DWARFDebugAbbrev::dump(raw_ostream &OS) const {
77  if (AbbrevCollMap.empty()) {
78    OS << "< EMPTY >\n";
79    return;
80  }
81
82  for (const auto &I : AbbrevCollMap) {
83    OS << format("Abbrev table for offset: 0x%8.8" PRIx64 "\n", I.first);
84    I.second.dump(OS);
85  }
86}
87
88const DWARFAbbreviationDeclarationSet*
89DWARFDebugAbbrev::getAbbreviationDeclarationSet(uint64_t cu_abbr_offset) const {
90  DWARFAbbreviationDeclarationCollMapConstIter end = AbbrevCollMap.end();
91  DWARFAbbreviationDeclarationCollMapConstIter pos;
92  if (PrevAbbrOffsetPos != end &&
93      PrevAbbrOffsetPos->first == cu_abbr_offset) {
94    return &(PrevAbbrOffsetPos->second);
95  } else {
96    pos = AbbrevCollMap.find(cu_abbr_offset);
97    PrevAbbrOffsetPos = pos;
98  }
99
100  if (pos != AbbrevCollMap.end())
101    return &(pos->second);
102  return NULL;
103}
104