caio/clang-p2996
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ELF: Simplify program header iteration

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Instead of GetProgramHeaderCount+GetProgramHeaderByIndex, expose an
ArrayRef of all program headers, to enable range-based iteration.
Instead of GetSegmentDataByIndex, expose GetSegmentData, taking a
program header (reference).

This makes the code simpler by enabling range-based loops and also
allowed to remove some null checks, as it became locally obvious that
some pointers can never be null.

llvm-svn: 348928
This commit is contained in:
Pavel Labath
2018-12-12 14:20:28 +00:00
parent 78de84719b
commit 5ea7ecdb5e
4 changed files with 59 additions and 98 deletions
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98
lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp
View File

@@ -539,14 +539,13 @@ static uint32_t calc_gnu_debuglink_crc32(const void *buf, size_t size) {
uint32_t ObjectFileELF::CalculateELFNotesSegmentsCRC32(
const ProgramHeaderColl &program_headers, DataExtractor &object_data) {
typedef ProgramHeaderCollConstIter Iter;
uint32_t core_notes_crc = 0;
for (Iter I = program_headers.begin(); I != program_headers.end(); ++I) {
if (I->p_type == llvm::ELF::PT_NOTE) {
const elf_off ph_offset = I->p_offset;
const size_t ph_size = I->p_filesz;
for (const ELFProgramHeader &H : program_headers) {
if (H.p_type == llvm::ELF::PT_NOTE) {
const elf_off ph_offset = H.p_offset;
const size_t ph_size = H.p_filesz;
DataExtractor segment_data;
if (segment_data.SetData(object_data, ph_offset, ph_size) != ph_size) {
@@ -806,15 +805,11 @@ bool ObjectFileELF::SetLoadAddress(Target &target, lldb::addr_t value,
if (section_list) {
if (!value_is_offset) {
bool found_offset = false;
for (size_t i = 1, count = GetProgramHeaderCount(); i <= count; ++i) {
const elf::ELFProgramHeader *header = GetProgramHeaderByIndex(i);
if (header == nullptr)
for (const ELFProgramHeader &H : ProgramHeaders()) {
if (H.p_type != PT_LOAD || H.p_offset != 0)
continue;
if (header->p_type != PT_LOAD || header->p_offset != 0)
continue;
value = value - header->p_vaddr;
value = value - H.p_vaddr;
found_offset = true;
break;
}
@@ -1158,8 +1153,8 @@ size_t ObjectFileELF::GetProgramHeaderInfo(ProgramHeaderColl &program_headers,
//----------------------------------------------------------------------
// ParseProgramHeaders
//----------------------------------------------------------------------
size_t ObjectFileELF::ParseProgramHeaders() {
return GetProgramHeaderInfo(m_program_headers, m_data, m_header);
bool ObjectFileELF::ParseProgramHeaders() {
return GetProgramHeaderInfo(m_program_headers, m_data, m_header) != 0;
}
lldb_private::Status
@@ -1705,27 +1700,6 @@ size_t ObjectFileELF::GetSectionHeaderInfo(SectionHeaderColl &section_headers,
return 0;
}
size_t ObjectFileELF::GetProgramHeaderCount() { return ParseProgramHeaders(); }
const elf::ELFProgramHeader *
ObjectFileELF::GetProgramHeaderByIndex(lldb::user_id_t id) {
if (!id || !ParseProgramHeaders())
return NULL;
if (--id < m_program_headers.size())
return &m_program_headers[id];
return NULL;
}
DataExtractor ObjectFileELF::GetSegmentDataByIndex(lldb::user_id_t id) {
const elf::ELFProgramHeader *segment_header = GetProgramHeaderByIndex(id);
if (segment_header == NULL)
return DataExtractor();
return DataExtractor(m_data, segment_header->p_offset,
segment_header->p_filesz);
}
llvm::StringRef
ObjectFileELF::StripLinkerSymbolAnnotations(llvm::StringRef symbol_name) const {
size_t pos = symbol_name.find('@');
@@ -3181,11 +3155,9 @@ void ObjectFileELF::DumpELFProgramHeaders(Stream *s) {
s->PutCString("==== --------------- -------- -------- -------- "
"-------- -------- ------------------------- --------\n");
uint32_t idx = 0;
for (ProgramHeaderCollConstIter I = m_program_headers.begin();
I != m_program_headers.end(); ++I, ++idx) {
s->Printf("[%2u] ", idx);
ObjectFileELF::DumpELFProgramHeader(s, *I);
for (const auto &H : llvm::enumerate(m_program_headers)) {
s->Format("[{0,2}] ", H.index());
ObjectFileELF::DumpELFProgramHeader(s, H.value());
s->EOL();
}
}
@@ -3305,18 +3277,13 @@ bool ObjectFileELF::GetArchitecture(ArchSpec &arch) {
m_arch_spec.TripleOSIsUnspecifiedUnknown()) {
// Core files don't have section headers yet they have PT_NOTE program
// headers that might shed more light on the architecture
if (ParseProgramHeaders()) {
for (size_t i = 1, count = GetProgramHeaderCount(); i <= count; ++i) {
const elf::ELFProgramHeader *header = GetProgramHeaderByIndex(i);
if (header && header->p_type == PT_NOTE && header->p_offset != 0 &&
header->p_filesz > 0) {
DataExtractor data;
if (data.SetData(m_data, header->p_offset, header->p_filesz) ==
header->p_filesz) {
lldb_private::UUID uuid;
RefineModuleDetailsFromNote(data, m_arch_spec, uuid);
}
}
for (const elf::ELFProgramHeader &H : ProgramHeaders()) {
if (H.p_type != PT_NOTE || H.p_offset == 0 || H.p_filesz == 0)
continue;
DataExtractor data;
if (data.SetData(m_data, H.p_offset, H.p_filesz) == H.p_filesz) {
UUID uuid;
RefineModuleDetailsFromNote(data, m_arch_spec, uuid);
}
}
}
@@ -3448,11 +3415,18 @@ size_t ObjectFileELF::ReadSectionData(Section *section,
return buffer_sp->GetByteSize();
}
llvm::ArrayRef<ELFProgramHeader> ObjectFileELF::ProgramHeaders() {
ParseProgramHeaders();
return m_program_headers;
}
DataExtractor ObjectFileELF::GetSegmentData(const ELFProgramHeader &H) {
return DataExtractor(m_data, H.p_offset, H.p_filesz);
}
bool ObjectFileELF::AnySegmentHasPhysicalAddress() {
size_t header_count = ParseProgramHeaders();
for (size_t i = 1; i <= header_count; ++i) {
auto header = GetProgramHeaderByIndex(i);
if (header->p_paddr != 0)
for (const ELFProgramHeader &H : ProgramHeaders()) {
if (H.p_paddr != 0)
return true;
}
return false;
@@ -3463,19 +3437,17 @@ ObjectFileELF::GetLoadableData(Target &target) {
// Create a list of loadable data from loadable segments, using physical
// addresses if they aren't all null
std::vector<LoadableData> loadables;
size_t header_count = ParseProgramHeaders();
bool should_use_paddr = AnySegmentHasPhysicalAddress();
for (size_t i = 1; i <= header_count; ++i) {
for (const ELFProgramHeader &H : ProgramHeaders()) {
LoadableData loadable;
auto header = GetProgramHeaderByIndex(i);
if (header->p_type != llvm::ELF::PT_LOAD)
if (H.p_type != llvm::ELF::PT_LOAD)
continue;
loadable.Dest = should_use_paddr ? header->p_paddr : header->p_vaddr;
loadable.Dest = should_use_paddr ? H.p_paddr : H.p_vaddr;
if (loadable.Dest == LLDB_INVALID_ADDRESS)
continue;
if (header->p_filesz == 0)
if (H.p_filesz == 0)
continue;
auto segment_data = GetSegmentDataByIndex(i);
auto segment_data = GetSegmentData(H);
loadable.Contents = llvm::ArrayRef<uint8_t>(segment_data.GetDataStart(),
segment_data.GetByteSize());
loadables.push_back(loadable);