[DebugInfo] Simplify DWARFDebugAddr.

The patch removes unnecessary members of DWARFDebugAddr and further
simplifies the implementation by separating parsing methods of tables
in the DWARFv5 and pre-standard formats.

Differential Revision: https://reviews.llvm.org/D74197
This commit is contained in:
Igor Kudrin 2020-02-06 14:14:12 +07:00
parent de9604232a
commit dc16612393
6 changed files with 174 additions and 226 deletions

View File

@ -27,69 +27,53 @@ class raw_ostream;
/// The table consists of a header followed by an array of address values from
/// .debug_addr section.
class DWARFDebugAddrTable {
public:
struct Header {
/// The total length of the entries for this table, not including the length
/// field itself.
uint32_t Length = 0;
/// The DWARF version number.
uint16_t Version = 5;
/// The size in bytes of an address on the target architecture. For
/// segmented addressing, this is the size of the offset portion of the
/// address.
uint8_t AddrSize;
/// The size in bytes of a segment selector on the target architecture.
/// If the target system uses a flat address space, this value is 0.
uint8_t SegSize = 0;
};
private:
dwarf::DwarfFormat Format;
uint64_t HeaderOffset;
Header HeaderData;
uint32_t DataSize = 0;
uint64_t Offset;
/// The total length of the entries for this table, not including the length
/// field itself.
uint32_t Length = 0;
/// The DWARF version number.
uint16_t Version;
/// The size in bytes of an address on the target architecture. For
/// segmented addressing, this is the size of the offset portion of the
/// address.
uint8_t AddrSize;
/// The size in bytes of a segment selector on the target architecture.
/// If the target system uses a flat address space, this value is 0.
uint8_t SegSize;
std::vector<uint64_t> Addrs;
public:
void clear();
/// Invalidate Length field to stop further processing.
void invalidateLength() { Length = 0; }
/// Extract an entire table, including all addresses.
Error extract(DWARFDataExtractor Data, uint64_t *OffsetPtr,
uint16_t Version, uint8_t AddrSize,
Error extractAddresses(const DWARFDataExtractor &Data, uint64_t *OffsetPtr,
uint64_t EndOffset);
public:
/// Extract the entire table, including all addresses.
Error extract(const DWARFDataExtractor &Data, uint64_t *OffsetPtr,
uint16_t CUVersion, uint8_t CUAddrSize,
std::function<void(Error)> WarnCallback);
uint64_t getHeaderOffset() const { return HeaderOffset; }
uint8_t getAddrSize() const { return HeaderData.AddrSize; }
/// Extract a DWARFv5 address table.
Error extractV5(const DWARFDataExtractor &Data, uint64_t *OffsetPtr,
uint8_t CUAddrSize, std::function<void(Error)> WarnCallback);
/// Extract a pre-DWARFv5 address table. Such tables do not have a header
/// and consist only of a series of addresses.
/// See https://gcc.gnu.org/wiki/DebugFission for details.
Error extractPreStandard(const DWARFDataExtractor &Data, uint64_t *OffsetPtr,
uint16_t CUVersion, uint8_t CUAddrSize);
void dump(raw_ostream &OS, DIDumpOptions DumpOpts = {}) const;
/// Return the address based on a given index.
Expected<uint64_t> getAddrEntry(uint32_t Index) const;
/// Return the size of the table header including the length
/// but not including the addresses.
uint8_t getHeaderSize() const {
switch (Format) {
case dwarf::DwarfFormat::DWARF32:
return 8; // 4 + 2 + 1 + 1
case dwarf::DwarfFormat::DWARF64:
return 16; // 12 + 2 + 1 + 1
}
llvm_unreachable("Invalid DWARF format (expected DWARF32 or DWARF64)");
}
/// Returns the length of this table, including the length field, or 0 if the
/// length has not been determined (e.g. because the table has not yet been
/// parsed, or there was a problem in parsing).
uint32_t getLength() const;
/// Verify that the given length is valid for this table.
bool hasValidLength() const { return getLength() != 0; }
/// Invalidate Length field to stop further processing.
void invalidateLength() { HeaderData.Length = 0; }
/// Returns the length of the array of addresses.
uint32_t getDataSize() const;
/// Return the full length of this table, including the length field.
/// Return None if the length cannot be identified reliably.
Optional<uint64_t> getFullLength() const;
};
} // end namespace llvm

View File

@ -252,12 +252,13 @@ static void dumpAddrSection(raw_ostream &OS, DWARFDataExtractor &AddrData,
WithColor::error() << toString(std::move(Err)) << '\n';
// Keep going after an error, if we can, assuming that the length field
// could be read. If it couldn't, stop reading the section.
if (!AddrTable.hasValidLength())
break;
Offset = TableOffset + AddrTable.getLength();
} else {
AddrTable.dump(OS, DumpOpts);
if (auto TableLength = AddrTable.getFullLength()) {
Offset = TableOffset + *TableLength;
continue;
}
break;
}
AddrTable.dump(OS, DumpOpts);
}
}

View File

@ -12,145 +12,146 @@
using namespace llvm;
void DWARFDebugAddrTable::clear() {
HeaderData = {};
Error DWARFDebugAddrTable::extractAddresses(const DWARFDataExtractor &Data,
uint64_t *OffsetPtr,
uint64_t EndOffset) {
assert(EndOffset >= *OffsetPtr);
uint64_t DataSize = EndOffset - *OffsetPtr;
assert(Data.isValidOffsetForDataOfSize(*OffsetPtr, DataSize));
if (AddrSize != 4 && AddrSize != 8)
return createStringError(errc::not_supported,
"address table at offset 0x%" PRIx64
" has unsupported address size %" PRIu8
" (4 and 8 are supported)",
Offset, AddrSize);
if (DataSize % AddrSize != 0) {
invalidateLength();
return createStringError(errc::invalid_argument,
"address table at offset 0x%" PRIx64
" contains data of size 0x%" PRIx64
" which is not a multiple of addr size %" PRIu8,
Offset, DataSize, AddrSize);
}
Addrs.clear();
invalidateLength();
size_t Count = DataSize / AddrSize;
Addrs.reserve(Count);
while (Count--)
Addrs.push_back(Data.getRelocatedValue(AddrSize, OffsetPtr));
return Error::success();
}
Error DWARFDebugAddrTable::extract(DWARFDataExtractor Data,
uint64_t *OffsetPtr,
uint16_t Version,
uint8_t AddrSize,
std::function<void(Error)> WarnCallback) {
clear();
HeaderOffset = *OffsetPtr;
// Read and verify the length field.
if (!Data.isValidOffsetForDataOfSize(*OffsetPtr, sizeof(uint32_t)))
Error DWARFDebugAddrTable::extractV5(const DWARFDataExtractor &Data,
uint64_t *OffsetPtr, uint8_t CUAddrSize,
std::function<void(Error)> WarnCallback) {
Offset = *OffsetPtr;
// Check that we can read the unit length field.
if (!Data.isValidOffsetForDataOfSize(Offset, 4))
return createStringError(errc::invalid_argument,
"section is not large enough to contain an "
"address table length at offset 0x%"
PRIx64, *OffsetPtr);
uint16_t UnitVersion;
if (Version == 0) {
WarnCallback(createStringError(errc::invalid_argument,
"DWARF version is not defined in CU,"
" assuming version 5"));
UnitVersion = 5;
} else {
UnitVersion = Version;
}
"section is not large enough to contain an "
"address table length at offset 0x%" PRIx64,
Offset);
// TODO: Add support for DWARF64.
Format = dwarf::DwarfFormat::DWARF32;
if (UnitVersion >= 5) {
HeaderData.Length = Data.getU32(OffsetPtr);
if (HeaderData.Length == dwarf::DW_LENGTH_DWARF64) {
invalidateLength();
return createStringError(errc::not_supported,
"DWARF64 is not supported in .debug_addr at offset 0x%" PRIx64,
HeaderOffset);
}
if (HeaderData.Length + sizeof(uint32_t) < sizeof(Header)) {
uint32_t TmpLength = HeaderData.Length;
invalidateLength();
return createStringError(errc::invalid_argument,
"address table at offset 0x%" PRIx64
" has a unit_length value of 0x%" PRIx32
", which is too small to contain a complete header",
HeaderOffset, TmpLength);
}
uint64_t End = HeaderOffset + getLength();
if (!Data.isValidOffsetForDataOfSize(HeaderOffset, End - HeaderOffset)) {
uint32_t TmpLength = HeaderData.Length;
invalidateLength();
return createStringError(
errc::invalid_argument,
"section is not large enough to contain an address table "
"at offset 0x%" PRIx64 " with a unit_length value of 0x%" PRIx32,
HeaderOffset, TmpLength);
}
HeaderData.Version = Data.getU16(OffsetPtr);
HeaderData.AddrSize = Data.getU8(OffsetPtr);
HeaderData.SegSize = Data.getU8(OffsetPtr);
DataSize = getDataSize();
} else {
HeaderData.Version = UnitVersion;
HeaderData.AddrSize = AddrSize;
// TODO: Support for non-zero SegSize.
HeaderData.SegSize = 0;
DataSize = Data.size();
Length = Data.getU32(OffsetPtr);
if (Length == dwarf::DW_LENGTH_DWARF64) {
invalidateLength();
return createStringError(
errc::not_supported,
"DWARF64 is not supported in .debug_addr at offset 0x%" PRIx64, Offset);
}
// Perform basic validation of the remaining header fields.
if (!Data.isValidOffsetForDataOfSize(*OffsetPtr, Length)) {
uint32_t DiagnosticLength = Length;
invalidateLength();
return createStringError(
errc::invalid_argument,
"section is not large enough to contain an address table "
"at offset 0x%" PRIx64 " with a unit_length value of 0x%" PRIx32,
Offset, DiagnosticLength);
}
uint64_t EndOffset = *OffsetPtr + Length;
// Ensure that we can read the remaining header fields.
if (Length < 4) {
uint32_t DiagnosticLength = Length;
invalidateLength();
return createStringError(
errc::invalid_argument,
"address table at offset 0x%" PRIx64
" has a unit_length value of 0x%" PRIx32
", which is too small to contain a complete header",
Offset, DiagnosticLength);
}
// We support DWARF version 5 for now as well as pre-DWARF5
// implementations of .debug_addr table, which doesn't contain a header
// and consists only of a series of addresses.
if (HeaderData.Version > 5) {
Version = Data.getU16(OffsetPtr);
AddrSize = Data.getU8(OffsetPtr);
SegSize = Data.getU8(OffsetPtr);
// Perform a basic validation of the header fields.
if (Version != 5)
return createStringError(errc::not_supported,
"address table at offset 0x%" PRIx64
" has unsupported version %" PRIu16,
HeaderOffset, HeaderData.Version);
}
// FIXME: For now we just treat version mismatch as an error,
// however the correct way to associate a .debug_addr table
// with a .debug_info table is to look at the DW_AT_addr_base
// attribute in the info table.
if (HeaderData.Version != UnitVersion)
return createStringError(errc::invalid_argument,
"address table at offset 0x%" PRIx64
" has version %" PRIu16
" which is different from the version suggested"
" by the DWARF unit header: %" PRIu16,
HeaderOffset, HeaderData.Version, UnitVersion);
if (HeaderData.AddrSize != 4 && HeaderData.AddrSize != 8)
Offset, Version);
// TODO: add support for non-zero segment selector size.
if (SegSize != 0)
return createStringError(errc::not_supported,
"address table at offset 0x%" PRIx64
" has unsupported address size %" PRIu8
" (4 and 8 are supported)",
HeaderOffset, HeaderData.AddrSize);
if (HeaderData.AddrSize != AddrSize && AddrSize != 0)
"address table at offset 0x%" PRIx64
" has unsupported segment selector size %" PRIu8,
Offset, SegSize);
if (Error Err = extractAddresses(Data, OffsetPtr, EndOffset))
return Err;
if (CUAddrSize && AddrSize != CUAddrSize) {
WarnCallback(createStringError(
errc::invalid_argument,
"address table at offset 0x%" PRIx64 " has address size %" PRIu8
" which is different from CU address size %" PRIu8,
HeaderOffset, HeaderData.AddrSize, AddrSize));
// TODO: add support for non-zero segment selector size.
if (HeaderData.SegSize != 0)
return createStringError(errc::not_supported,
"address table at offset 0x%" PRIx64
" has unsupported segment selector size %" PRIu8,
HeaderOffset, HeaderData.SegSize);
if (DataSize % HeaderData.AddrSize != 0) {
invalidateLength();
return createStringError(errc::invalid_argument,
"address table at offset 0x%" PRIx64
" contains data of size %" PRIu32
" which is not a multiple of addr size %" PRIu8,
HeaderOffset, DataSize, HeaderData.AddrSize);
Offset, AddrSize, CUAddrSize));
}
Data.setAddressSize(HeaderData.AddrSize);
uint32_t AddrCount = DataSize / HeaderData.AddrSize;
for (uint32_t I = 0; I < AddrCount; ++I)
Addrs.push_back(Data.getRelocatedAddress(OffsetPtr));
return Error::success();
}
Error DWARFDebugAddrTable::extractPreStandard(const DWARFDataExtractor &Data,
uint64_t *OffsetPtr,
uint16_t CUVersion,
uint8_t CUAddrSize) {
assert(CUVersion > 0 && CUVersion < 5);
Offset = *OffsetPtr;
Length = 0;
Version = CUVersion;
AddrSize = CUAddrSize;
SegSize = 0;
return extractAddresses(Data, OffsetPtr, Data.size());
}
Error DWARFDebugAddrTable::extract(const DWARFDataExtractor &Data,
uint64_t *OffsetPtr,
uint16_t CUVersion,
uint8_t CUAddrSize,
std::function<void(Error)> WarnCallback) {
if (CUVersion > 0 && CUVersion < 5)
return extractPreStandard(Data, OffsetPtr, CUVersion, CUAddrSize);
if (CUVersion == 0)
WarnCallback(createStringError(errc::invalid_argument,
"DWARF version is not defined in CU,"
" assuming version 5"));
return extractV5(Data, OffsetPtr, CUAddrSize, WarnCallback);
}
void DWARFDebugAddrTable::dump(raw_ostream &OS, DIDumpOptions DumpOpts) const {
if (DumpOpts.Verbose)
OS << format("0x%8.8" PRIx32 ": ", HeaderOffset);
if (HeaderData.Length)
OS << format("0x%8.8" PRIx32 ": ", Offset);
if (Length)
OS << format("Address table header: length = 0x%8.8" PRIx32
", version = 0x%4.4" PRIx16 ", "
"addr_size = 0x%2.2" PRIx8 ", seg_size = 0x%2.2" PRIx8 "\n",
HeaderData.Length, HeaderData.Version, HeaderData.AddrSize,
HeaderData.SegSize);
", version = 0x%4.4" PRIx16 ", addr_size = 0x%2.2" PRIx8
", seg_size = 0x%2.2" PRIx8 "\n",
Length, Version, AddrSize, SegSize);
if (Addrs.size() > 0) {
const char *AddrFmt = (HeaderData.AddrSize == 4) ? "0x%8.8" PRIx64 "\n"
: "0x%16.16" PRIx64 "\n";
const char *AddrFmt =
(AddrSize == 4) ? "0x%8.8" PRIx64 "\n" : "0x%16.16" PRIx64 "\n";
OS << "Addrs: [\n";
for (uint64_t Addr : Addrs)
OS << format(AddrFmt, Addr);
@ -162,22 +163,15 @@ Expected<uint64_t> DWARFDebugAddrTable::getAddrEntry(uint32_t Index) const {
if (Index < Addrs.size())
return Addrs[Index];
return createStringError(errc::invalid_argument,
"Index %" PRIu32 " is out of range in the "
"Index %" PRIu32 " is out of range of the "
"address table at offset 0x%" PRIx64,
Index, HeaderOffset);
Index, Offset);
}
uint32_t DWARFDebugAddrTable::getLength() const {
if (HeaderData.Length == 0)
return 0;
Optional<uint64_t> DWARFDebugAddrTable::getFullLength() const {
if (Length == 0)
return None;
// TODO: DWARF64 support.
return HeaderData.Length + sizeof(uint32_t);
return Length + sizeof(uint32_t);
}
uint32_t DWARFDebugAddrTable::getDataSize() const {
if (DataSize != 0)
return DataSize;
if (getLength() == 0)
return 0;
return getLength() - getHeaderSize();
}

View File

@ -4,7 +4,7 @@
# CHECK: .debug_addr contents:
# CHECK-NOT: {{.}}
# ERR: address table at offset 0x0 contains data of size 7 which is not a multiple of addr size 4
# ERR: address table at offset 0x0 contains data of size 0x7 which is not a multiple of addr size 4
# ERR-NOT: {{.}}
# data size is not multiple of address_size

View File

@ -3,6 +3,7 @@
# RUN: FileCheck %s -input-file %t.err -check-prefix=ERR
# ERR: address table at offset 0x0 has unsupported version 6
# ERR: address table at offset 0x20 has unsupported version 4
# ERR-NOT: {{.}}
# CHECK: .debug_addr contents
@ -40,3 +41,13 @@
.byte 0 # segment_selector_size
.long 0x00000002
.long 0x00000003
.section .debug_addr,"",@progbits
.Ldebug_addr2:
.long 12 # unit_length = .short + .byte + .byte + .long + .long
.short 4 # version
.byte 4 # address_size
.byte 0 # segment_selector_size
.long 0x00000000
.long 0x00000001

View File

@ -1,42 +0,0 @@
# RUN: llvm-mc %s -filetype obj -triple i386-pc-linux -o - | \
# RUN: llvm-dwarfdump -debug-addr - 2> %t.err | FileCheck %s
# RUN: FileCheck %s -input-file %t.err -check-prefix=ERR
# ERR: address table at offset 0x0 has version 4 which is different from the version suggested by the DWARF unit header: 5
# ERR-NOT: {{.}}
# CHECK: .debug_addr contents
# CHECK-NEXT: length = 0x0000000c, version = 0x0005, addr_size = 0x04, seg_size = 0x00
# CHECK-NEXT: Addrs: [
# CHECK-NEXT: 0x00000000
# CHECK-NEXT: 0x00000001
# CHECK-NEXT: ]
# CHECK-NOT: {{.}}
.section .debug_abbrev,"",@progbits
.byte 1 # Abbreviation Code
.section .debug_info,"",@progbits
.Lcu_begin0:
.long 8 # Length of Unit
.short 5 # DWARF version number
.byte 1 # DWARF unit type
.byte 4 # Address Size (in bytes)
.long .debug_abbrev # Offset Into Abbrev. Section
.section .debug_addr,"",@progbits
.Ldebug_addr0:
.long 12 # unit_length = .short + .byte + .byte + .long + .long
.short 4 # version
.byte 4 # address_size
.byte 0 # segment_selector_size
.long 0x00000000
.long 0x00000001
.section .debug_addr,"",@progbits
.Ldebug_addr1:
.long 12 # unit_length = .short + .byte + .byte + .long + .long
.short 5 # version
.byte 4 # address_size
.byte 0 # segment_selector_size
.long 0x00000000
.long 0x00000001