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1//===- DWARFDataExtractor.cpp ---------------------------------------------===//

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//===----------------------------------------------------------------------===//

9#include "llvm/DebugInfo/DWARF/DWARFDataExtractor.h"

10#include "llvm/DebugInfo/DWARF/DWARFObject.h"

11#include "llvm/DebugInfo/DWARF/DWARFRelocMap.h"

12#include "llvm/Support/Errc.h"

14using namespacellvm;

16std::pair<uint64_t, dwarf::DwarfFormat>

17DWARFDataExtractor::getInitialLength(uint64_t *Off,Error *Err) const{

18ErrorAsOutParameter ErrAsOut(Err);

19if (Err && *Err)

20return {0,dwarf::DWARF32};

22Cursor C(*Off);

23uint64_t Length =getRelocatedValue(C, 4);

24dwarf::DwarfFormat Format =dwarf::DWARF32;

25if (Length ==dwarf::DW_LENGTH_DWARF64) {

26Length =getRelocatedValue(C, 8);

27Format =dwarf::DWARF64;

28 }elseif (Length >=dwarf::DW_LENGTH_lo_reserved) {

29cantFail(C.takeError());

30if (Err)

31 *Err =createStringError(

32errc::invalid_argument,

33"unsupported reserved unit length of value 0x%8.8" PRIx64,Length);

34return {0,dwarf::DWARF32};

35 }

37if (C) {

38 *Off =C.tell();

39return {Length,Format};

40 }

41if (Err)

42 *Err =C.takeError();

43else

44consumeError(C.takeError());

45return {0,dwarf::DWARF32};

46}

48uint64_t DWARFDataExtractor::getRelocatedValue(uint32_t Size,uint64_t *Off,

49uint64_t *SecNdx,

50Error *Err) const{

51if (SecNdx)

52 *SecNdx =object::SectionedAddress::UndefSection;

53if (!Section)

54returngetUnsigned(Off,Size, Err);

56ErrorAsOutParameter ErrAsOut(Err);

57 std::optional<RelocAddrEntry> E = Obj->find(*Section, *Off);

58uint64_t LocData =getUnsigned(Off,Size, Err);

59if (!E || (Err && *Err))

60return LocData;

61if (SecNdx)

62 *SecNdx = E->SectionIndex;

64uint64_t R =

65object::resolveRelocation(E->Resolver, E->Reloc, E->SymbolValue, LocData);

66if (E->Reloc2)

67 R =object::resolveRelocation(E->Resolver, *E->Reloc2, E->SymbolValue2, R);

68return R;

69}

71std::optional<uint64_t>

72DWARFDataExtractor::getEncodedPointer(uint64_t *Offset,uint8_t Encoding,

73uint64_t PCRelOffset) const{

74if (Encoding ==dwarf::DW_EH_PE_omit)

75return std::nullopt;

77uint64_t Result = 0;

78uint64_t OldOffset = *Offset;

79// First get value

80switch (Encoding & 0x0F) {

81casedwarf::DW_EH_PE_absptr:

82switch (getAddressSize()) {

83case 2:

84case 4:

85case 8:

86 Result =getUnsigned(Offset,getAddressSize());

87break;

88default:

89return std::nullopt;

90 }

91break;

92casedwarf::DW_EH_PE_uleb128:

93 Result =getULEB128(Offset);

94break;

95casedwarf::DW_EH_PE_sleb128:

96 Result =getSLEB128(Offset);

97break;

98casedwarf::DW_EH_PE_udata2:

99 Result =getUnsigned(Offset, 2);

100break;

101casedwarf::DW_EH_PE_udata4:

102 Result =getUnsigned(Offset, 4);

103break;

104casedwarf::DW_EH_PE_udata8:

105 Result =getUnsigned(Offset, 8);

106break;

107casedwarf::DW_EH_PE_sdata2:

108 Result =getSigned(Offset, 2);

109break;

110casedwarf::DW_EH_PE_sdata4:

111 Result = SignExtend64<32>(getRelocatedValue(4,Offset));

112break;

113casedwarf::DW_EH_PE_sdata8:

114 Result =getRelocatedValue(8,Offset);

115break;

116default:

117return std::nullopt;

118 }

119// Then add relative offset, if required

120switch (Encoding & 0x70) {

121casedwarf::DW_EH_PE_absptr:

122// do nothing

123break;

124casedwarf::DW_EH_PE_pcrel:

125 Result += PCRelOffset;

126break;

127casedwarf::DW_EH_PE_datarel:

128casedwarf::DW_EH_PE_textrel:

129casedwarf::DW_EH_PE_funcrel:

130casedwarf::DW_EH_PE_aligned:

131default:

132 *Offset = OldOffset;

133return std::nullopt;

134 }

135

136return Result;

137}

uint64_t Size

Definition:ELFObjHandler.cpp:81

Errc.h

llvm::DWARFDataExtractor::getInitialLength

std::pair< uint64_t, dwarf::DwarfFormat > getInitialLength(uint64_t *Off, Error *Err=nullptr) const

Extracts the DWARF "initial length" field, which can either be a 32-bit value smaller than 0xfffffff0...

Definition:DWARFDataExtractor.cpp:17

llvm::DWARFDataExtractor::getRelocatedValue

uint64_t getRelocatedValue(uint32_t Size, uint64_t *Off, uint64_t *SectionIndex=nullptr, Error *Err=nullptr) const

Extracts a value and applies a relocation to the result if one exists for the given offset.

Definition:DWARFDataExtractor.cpp:48

llvm::DWARFDataExtractor::getEncodedPointer

std::optional< uint64_t > getEncodedPointer(uint64_t *Offset, uint8_t Encoding, uint64_t AbsPosOffset=0) const

Extracts a DWARF-encoded pointer in Offset using Encoding.

Definition:DWARFDataExtractor.cpp:72

llvm::DWARFObject::find

virtual std::optional< RelocAddrEntry > find(const DWARFSection &Sec, uint64_t Pos) const =0

llvm::DataExtractor::Cursor

A class representing a position in a DataExtractor, as well as any error encountered during extractio...

Definition:DataExtractor.h:54

llvm::DataExtractor::getUnsigned

uint64_t getUnsigned(uint64_t *offset_ptr, uint32_t byte_size, Error *Err=nullptr) const

Extract an unsigned integer of size byte_size from *offset_ptr.

Definition:DataExtractor.cpp:126

llvm::DataExtractor::getSigned

int64_t getSigned(uint64_t *offset_ptr, uint32_t size) const

Extract an signed integer of size byte_size from *offset_ptr.

Definition:DataExtractor.cpp:142

llvm::DataExtractor::getULEB128

uint64_t getULEB128(uint64_t *offset_ptr, llvm::Error *Err=nullptr) const

Extract a unsigned LEB128 value from *offset_ptr.

Definition:DataExtractor.cpp:221

llvm::DataExtractor::getAddressSize

uint8_t getAddressSize() const

Get the address size for this extractor.

Definition:DataExtractor.h:99

llvm::DataExtractor::getSLEB128

int64_t getSLEB128(uint64_t *OffsetPtr, Error *Err=nullptr) const

Extract a signed LEB128 value from *offset_ptr.

Definition:DataExtractor.cpp:225

llvm::ErrorAsOutParameter

Helper for Errors used as out-parameters.

Definition:Error.h:1130

llvm::Error

Lightweight error class with error context and mandatory checking.

Definition:Error.h:160

@ C

The default llvm calling convention, compatible with C.

Definition:CallingConv.h:34

llvm::dwarf::DwarfFormat

DwarfFormat

Constants that define the DWARF format as 32 or 64 bit.

Definition:Dwarf.h:91

llvm::dwarf::DWARF64

@ DWARF64

Definition:Dwarf.h:91

llvm::dwarf::DWARF32

@ DWARF32

Definition:Dwarf.h:91

llvm::dwarf::DW_EH_PE_textrel

@ DW_EH_PE_textrel

Definition:Dwarf.h:859

llvm::dwarf::DW_EH_PE_datarel

@ DW_EH_PE_datarel

Definition:Dwarf.h:860

llvm::dwarf::DW_EH_PE_pcrel

@ DW_EH_PE_pcrel

Definition:Dwarf.h:858

llvm::dwarf::DW_EH_PE_sdata4

@ DW_EH_PE_sdata4

Definition:Dwarf.h:855

llvm::dwarf::DW_EH_PE_funcrel

@ DW_EH_PE_funcrel

Definition:Dwarf.h:861

llvm::dwarf::DW_EH_PE_aligned

@ DW_EH_PE_aligned

Definition:Dwarf.h:862

llvm::dwarf::DW_EH_PE_udata2

@ DW_EH_PE_udata2

Definition:Dwarf.h:850

llvm::dwarf::DW_EH_PE_sdata8

@ DW_EH_PE_sdata8

Definition:Dwarf.h:856

llvm::dwarf::DW_EH_PE_absptr

@ DW_EH_PE_absptr

Definition:Dwarf.h:847

llvm::dwarf::DW_EH_PE_sdata2

@ DW_EH_PE_sdata2

Definition:Dwarf.h:854

llvm::dwarf::DW_EH_PE_udata4

@ DW_EH_PE_udata4

Definition:Dwarf.h:851

llvm::dwarf::DW_EH_PE_udata8

@ DW_EH_PE_udata8

Definition:Dwarf.h:852

llvm::dwarf::DW_EH_PE_uleb128

@ DW_EH_PE_uleb128

Definition:Dwarf.h:849

llvm::dwarf::DW_EH_PE_sleb128

@ DW_EH_PE_sleb128

Definition:Dwarf.h:853

llvm::dwarf::DW_EH_PE_omit

@ DW_EH_PE_omit

Definition:Dwarf.h:848

llvm::dwarf::DW_LENGTH_lo_reserved

@ DW_LENGTH_lo_reserved

Special values for an initial length field.

Definition:Dwarf.h:54

llvm::dwarf::DW_LENGTH_DWARF64

@ DW_LENGTH_DWARF64

Indicator of 64-bit DWARF format.

Definition:Dwarf.h:55

llvm::object::resolveRelocation

uint64_t resolveRelocation(RelocationResolver Resolver, const RelocationRef &R, uint64_t S, uint64_t LocData)

Definition:RelocationResolver.cpp:875

llvm

This is an optimization pass for GlobalISel generic memory operations.

Definition:AddressRanges.h:18

llvm::Offset

@ Offset

Definition:DWP.cpp:480

llvm::Length

@ Length

Definition:DWP.cpp:480

llvm::createStringError

Error createStringError(std::error_code EC, char const *Fmt, const Ts &... Vals)

Create formatted StringError object.

Definition:Error.h:1291

llvm::errc::invalid_argument

@ invalid_argument

llvm::cantFail

void cantFail(Error Err, const char *Msg=nullptr)

Report a fatal error if Err is a failure value.

Definition:Error.h:756

llvm::ReplacementType::Format

@ Format

llvm::consumeError

void consumeError(Error Err)

Consume a Error without doing anything.

Definition:Error.h:1069

llvm::object::SectionedAddress::UndefSection

static const uint64_t UndefSection

Definition:ObjectFile.h:146