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[llvm-readobj/llvm-readelf] - Implement GNU style dumper of the SHT_G…
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…NU_verneed section.

It was not implemented yet, we had only LLVM style dumper implemented.
Section description is here: https://refspecs.linuxfoundation.org/LSB_2.0.1/LSB-Core/LSB-Core/symverrqmts.html

Differential revision: https://reviews.llvm.org/D62516

llvm-svn: 362080
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George Rimar committed May 30, 2019
1 parent 3a34bcc commit e3406c4
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Showing 3 changed files with 193 additions and 15 deletions.
107 changes: 107 additions & 0 deletions llvm/test/tools/llvm-readobj/elf-verneed-flags.yaml
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@@ -0,0 +1,107 @@
## Check how llvm-readobj/llvm-readelf tools dump the flags of SHT_GNU_verneed
## section entries.

# RUN: yaml2obj %s -o %t
# RUN: llvm-readobj -V %t | FileCheck %s --check-prefix=LLVM-VERDEF
# RUN: llvm-readelf -V %t | FileCheck %s --check-prefix=GNU-VERDEF

# LLVM-VERDEF: SHT_GNU_verneed {
# LLVM-VERDEF-NEXT: Dependency {
# LLVM-VERDEF-NEXT: Version: 1
# LLVM-VERDEF-NEXT: Count: 6
# LLVM-VERDEF-NEXT: FileName: dso.so.0
# LLVM-VERDEF-NEXT: Entries [
# LLVM-VERDEF-NEXT: Entry {
# LLVM-VERDEF-NEXT: Hash: 0
# LLVM-VERDEF-NEXT: Flags: Base (0x1)
# LLVM-VERDEF-NEXT: Index: 0
# LLVM-VERDEF-NEXT: Name: base
# LLVM-VERDEF-NEXT: }
# LLVM-VERDEF-NEXT: Entry {
# LLVM-VERDEF-NEXT: Hash: 0
# LLVM-VERDEF-NEXT: Flags: Weak (0x2)
# LLVM-VERDEF-NEXT: Index: 0
# LLVM-VERDEF-NEXT: Name: weak
# LLVM-VERDEF-NEXT: }
# LLVM-VERDEF-NEXT: Entry {
# LLVM-VERDEF-NEXT: Hash: 0
# LLVM-VERDEF-NEXT: Flags: Info (0x4)
# LLVM-VERDEF-NEXT: Index: 0
# LLVM-VERDEF-NEXT: Name: info
# LLVM-VERDEF-NEXT: }
# LLVM-VERDEF-NEXT: Entry {
# LLVM-VERDEF-NEXT: Hash: 0
# LLVM-VERDEF-NEXT: Flags: 0x7
# LLVM-VERDEF-NEXT: Index: 0
# LLVM-VERDEF-NEXT: Name: all
# LLVM-VERDEF-NEXT: }
# LLVM-VERDEF-NEXT: Entry {
# LLVM-VERDEF-NEXT: Hash: 0
# LLVM-VERDEF-NEXT: Flags: 0x8
# LLVM-VERDEF-NEXT: Index: 0
# LLVM-VERDEF-NEXT: Name: unknown
# LLVM-VERDEF-NEXT: }
# LLVM-VERDEF-NEXT: Entry {
# LLVM-VERDEF-NEXT: Hash: 0
# LLVM-VERDEF-NEXT: Flags: 0xF
# LLVM-VERDEF-NEXT: Index: 0
# LLVM-VERDEF-NEXT: Name: all_and_unknown
# LLVM-VERDEF-NEXT: }
# LLVM-VERDEF-NEXT: ]
# LLVM-VERDEF-NEXT: }
# LLVM-VERDEF-NEXT: }

# GNU-VERDEF: Version needs section '.gnu.version_r' contains 1 entries:
# GNU-VERDEF-NEXT: Addr: 0000000000000000 Offset: 0x000200 Link: 6 (.dynstr)
# GNU-VERDEF-NEXT: 0x0000: Version: 1 File: dso.so.0 Cnt: 6
# GNU-VERDEF-NEXT: 0x0010: Name: base Flags: BASE Version: 0
# GNU-VERDEF-NEXT: 0x0020: Name: weak Flags: WEAK Version: 0
# GNU-VERDEF-NEXT: 0x0030: Name: info Flags: INFO Version: 0
# GNU-VERDEF-NEXT: 0x0040: Name: all Flags: BASE | WEAK | INFO Version: 0
# GNU-VERDEF-NEXT: 0x0050: Name: unknown Flags: <unknown> Version: 0
# GNU-VERDEF-NEXT: 0x0060: Name: all_and_unknown Flags: BASE | WEAK | INFO | <unknown> Version: 0

--- !ELF
FileHeader:
Class: ELFCLASS64
Data: ELFDATA2LSB
Type: ET_EXEC
Machine: EM_X86_64
Entry: 0x0000000000201000
Sections:
- Name: .gnu.version_r
Type: SHT_GNU_verneed
Link: .dynstr
Info: 0x0000000000000001
Dependencies:
- Version: 1
File: dso.so.0
Entries:
- Name: base
Hash: 0
Flags: 0x1
Other: 0
- Name: weak
Hash: 0
Flags: 0x2
Other: 0
- Name: info
Hash: 0
Flags: 0x4
Other: 0
- Name: all
Hash: 0
Flags: 0x7
Other: 0
- Name: unknown
Hash: 0
Flags: 0x8
Other: 0
- Name: all_and_unknown
Hash: 0
Flags: 0xf
Other: 0
## Needed to trigger .dynstr creation, which is required by .gnu.version_r
DynamicSymbols:
- Name: f1
Binding: STB_GLOBAL
13 changes: 10 additions & 3 deletions llvm/test/tools/llvm-readobj/elf-versioninfo.test
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Expand Up @@ -173,6 +173,13 @@ DynamicSymbols:
# GNU-NEXT: Addr: 0000000000000000 Offset: 0x000280 Link: 7 (.dynsym)
# GNU-NEXT: 000: 0 (*local*) 2 (VERSION1) 3 (VERSION2) 4 (v1)
# GNU-NEXT: 004: 5 (v2) 6 (v3)

# GNU: Dumper for .gnu.version_d is not implemented
# GNU: Dumper for .gnu.version_r is not implemented
# GNU-EMPTY:
# GNU-NEXT: Dumper for .gnu.version_d is not implemented
# GNU-EMPTY:
# GNU-NEXT: Version needs section '.gnu.version_r' contains 2 entries:
# GNU-NEXT: Addr: 0000000000000000 Offset: 0x0002cc Link: 8 (.dynstr)
# GNU-NEXT: 0x0000: Version: 1 File: verneed1.so.0 Cnt: 2
# GNU-NEXT: 0x0010: Name: v1 Flags: none Version: 4
# GNU-NEXT: 0x0020: Name: v2 Flags: none Version: 5
# GNU-NEXT: 0x0030: Version: 1 File: verneed2.so.0 Cnt: 1
# GNU-NEXT: 0x0040: Name: v3 Flags: none Version: 6
88 changes: 76 additions & 12 deletions llvm/tools/llvm-readobj/ELFDumper.cpp
View file
Expand Up @@ -3424,22 +3424,30 @@ void GNUStyle<ELFT>::printDynamicRelocations(const ELFO *Obj) {
}

template <class ELFT>
void GNUStyle<ELFT>::printVersionSymbolSection(const ELFFile<ELFT> *Obj,
const Elf_Shdr *Sec) {
if (!Sec)
return;

static void printGNUVersionSectionProlog(formatted_raw_ostream &OS,
const Twine &Name, unsigned EntriesNum,
const ELFFile<ELFT> *Obj,
const typename ELFT::Shdr *Sec) {
StringRef SecName = unwrapOrError(Obj->getSectionName(Sec));
uint64_t Entries = Sec->sh_size / sizeof(Elf_Versym);

OS << "Version symbols section '" << SecName << "' "
<< "contains " << Entries << " entries:\n";
OS << Name << " section '" << SecName << "' "
<< "contains " << EntriesNum << " entries:\n";

const Elf_Shdr *SymTab = unwrapOrError(Obj->getSection(Sec->sh_link));
const typename ELFT::Shdr *SymTab =
unwrapOrError(Obj->getSection(Sec->sh_link));
StringRef SymTabName = unwrapOrError(Obj->getSectionName(SymTab));
OS << " Addr: " << format_hex_no_prefix(Sec->sh_addr, 16)
<< " Offset: " << format_hex(Sec->sh_offset, 8)
<< " Link: " << Sec->sh_link << " (" << SymTabName << ")\n";
}

template <class ELFT>
void GNUStyle<ELFT>::printVersionSymbolSection(const ELFFile<ELFT> *Obj,
const Elf_Shdr *Sec) {
if (!Sec)
return;

unsigned Entries = Sec->sh_size / sizeof(Elf_Versym);
printGNUVersionSectionProlog(OS, "Version symbols", Entries, Obj, Sec);

const uint8_t *VersymBuf =
reinterpret_cast<const uint8_t *>(Obj->base() + Sec->sh_offset);
Expand Down Expand Up @@ -3491,6 +3499,28 @@ void GNUStyle<ELFT>::printVersionDefinitionSection(const ELFFile<ELFT> *Obj,

StringRef SecName = unwrapOrError(Obj->getSectionName(Sec));
OS << "Dumper for " << SecName << " is not implemented\n";
OS << '\n';
}

static std::string verNeedFlagToString(unsigned Flags) {
if (Flags == 0)
return "none";

std::string Ret;
auto AddFlag = [&Ret, &Flags](unsigned Flag, StringRef Name) {
if (!(Flags & Flag))
return;
if (!Ret.empty())
Ret += " | ";
Ret += Name;
Flags &= ~Flag;
};

AddFlag(VER_FLG_BASE, "BASE");
AddFlag(VER_FLG_WEAK, "WEAK");
AddFlag(VER_FLG_INFO, "INFO");
AddFlag(~0, "<unknown>");
return Ret;
}

template <class ELFT>
Expand All @@ -3499,8 +3529,42 @@ void GNUStyle<ELFT>::printVersionDependencySection(const ELFFile<ELFT> *Obj,
if (!Sec)
return;

StringRef SecName = unwrapOrError(Obj->getSectionName(Sec));
OS << "Dumper for " << SecName << " is not implemented\n";
unsigned VerneedNum = Sec->sh_info;
printGNUVersionSectionProlog(OS, "Version needs", VerneedNum, Obj, Sec);

ArrayRef<uint8_t> SecData = unwrapOrError(Obj->getSectionContents(Sec));

const Elf_Shdr *StrTabSec = unwrapOrError(Obj->getSection(Sec->sh_link));
StringRef StringTable = {
reinterpret_cast<const char *>(Obj->base() + StrTabSec->sh_offset),
StrTabSec->sh_size};

const uint8_t *VerneedBuf = SecData.data();
for (unsigned I = 0; I < VerneedNum; ++I) {
const Elf_Verneed *Verneed =
reinterpret_cast<const Elf_Verneed *>(VerneedBuf);

OS << format(" 0x%04x: Version: %u File: %s Cnt: %u\n",
reinterpret_cast<const uint8_t *>(Verneed) - SecData.begin(),
(unsigned)Verneed->vn_version,
StringTable.drop_front(Verneed->vn_file).data(),
(unsigned)Verneed->vn_cnt);

const uint8_t *VernauxBuf = VerneedBuf + Verneed->vn_aux;
for (unsigned J = 0; J < Verneed->vn_cnt; ++J) {
const Elf_Vernaux *Vernaux =
reinterpret_cast<const Elf_Vernaux *>(VernauxBuf);

OS << format(" 0x%04x: Name: %s Flags: %s Version: %u\n",
reinterpret_cast<const uint8_t *>(Vernaux) - SecData.begin(),
StringTable.drop_front(Vernaux->vna_name).data(),
verNeedFlagToString(Vernaux->vna_flags).c_str(),
(unsigned)Vernaux->vna_other);
VernauxBuf += Vernaux->vna_next;
}
VerneedBuf += Verneed->vn_next;
}
OS << '\n';
}

// Hash histogram shows statistics of how efficient the hash was for the
Expand Down

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