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[lldb] Simplify ObjectFile::FindPlugin (NFC)
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Use early return to reduce the levels of indentation. Extract logic to
find object in container into helper function.
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@JDevlieghere
JDevlieghere committed Dec 23, 2020
1 parent 74b3ace commit d97e9f1
Showing 1 changed file with 104 additions and 124 deletions.
228 changes: 104 additions & 124 deletions lldb/source/Symbol/ObjectFile.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -28,141 +28,121 @@ using namespace lldb_private;

char ObjectFile::ID;

static ObjectFileSP
CreateObjectFromContainer(const lldb::ModuleSP &module_sp, const FileSpec *file,
lldb::offset_t file_offset, lldb::offset_t file_size,
DataBufferSP &data_sp, lldb::offset_t &data_offset) {
ObjectContainerCreateInstance callback;
for (uint32_t idx = 0;
(callback = PluginManager::GetObjectContainerCreateCallbackAtIndex(
idx)) != nullptr;
++idx) {
std::unique_ptr<ObjectContainer> object_container_up(callback(
module_sp, data_sp, data_offset, file, file_offset, file_size));
if (object_container_up)
return object_container_up->GetObjectFile(file);
}
return {};
}

ObjectFileSP
ObjectFile::FindPlugin(const lldb::ModuleSP &module_sp, const FileSpec *file,
lldb::offset_t file_offset, lldb::offset_t file_size,
DataBufferSP &data_sp, lldb::offset_t &data_offset) {
ObjectFileSP object_file_sp;

if (module_sp) {
LLDB_SCOPED_TIMERF(
"ObjectFile::FindPlugin (module = %s, file = %p, file_offset = "
"0x%8.8" PRIx64 ", file_size = 0x%8.8" PRIx64 ")",
module_sp->GetFileSpec().GetPath().c_str(),
static_cast<const void *>(file), static_cast<uint64_t>(file_offset),
static_cast<uint64_t>(file_size));
if (file) {
FileSpec archive_file;
ObjectContainerCreateInstance create_object_container_callback;

if (!data_sp) {
const bool file_exists = FileSystem::Instance().Exists(*file);
// We have an object name which most likely means we have a .o file in
// a static archive (.a file). Try and see if we have a cached archive
// first without reading any data first
if (file_exists && module_sp->GetObjectName()) {
for (uint32_t idx = 0;
(create_object_container_callback =
PluginManager::GetObjectContainerCreateCallbackAtIndex(
idx)) != nullptr;
++idx) {
std::unique_ptr<ObjectContainer> object_container_up(
create_object_container_callback(module_sp, data_sp,
data_offset, file, file_offset,
file_size));

if (object_container_up)
object_file_sp = object_container_up->GetObjectFile(file);

if (object_file_sp.get())
return object_file_sp;
}
}
// Ok, we didn't find any containers that have a named object, now lets
// read the first 512 bytes from the file so the object file and object
// container plug-ins can use these bytes to see if they can parse this
// file.
if (file_size > 0) {
data_sp = FileSystem::Instance().CreateDataBuffer(file->GetPath(),
512, file_offset);
data_offset = 0;
}
}
LLDB_SCOPED_TIMERF(
"ObjectFile::FindPlugin (module = %s, file = %p, file_offset = "
"0x%8.8" PRIx64 ", file_size = 0x%8.8" PRIx64 ")",
module_sp->GetFileSpec().GetPath().c_str(),
static_cast<const void *>(file), static_cast<uint64_t>(file_offset),
static_cast<uint64_t>(file_size));

if (!module_sp)
return {};

if (!file)
return {};

if (!data_sp) {
const bool file_exists = FileSystem::Instance().Exists(*file);
// We have an object name which most likely means we have a .o file in
// a static archive (.a file). Try and see if we have a cached archive
// first without reading any data first
if (file_exists && module_sp->GetObjectName()) {
ObjectFileSP object_file_sp = CreateObjectFromContainer(
module_sp, file, file_offset, file_size, data_sp, data_offset);
if (object_file_sp)
return object_file_sp;
}
// Ok, we didn't find any containers that have a named object, now lets
// read the first 512 bytes from the file so the object file and object
// container plug-ins can use these bytes to see if they can parse this
// file.
if (file_size > 0) {
data_sp = FileSystem::Instance().CreateDataBuffer(file->GetPath(), 512,
file_offset);
data_offset = 0;
}
}

if (!data_sp || data_sp->GetByteSize() == 0) {
// Check for archive file with format "/path/to/archive.a(object.o)"
llvm::SmallString<256> path_with_object;
module_sp->GetFileSpec().GetPath(path_with_object);

ConstString archive_object;
const bool must_exist = true;
if (ObjectFile::SplitArchivePathWithObject(
path_with_object, archive_file, archive_object, must_exist)) {
file_size = FileSystem::Instance().GetByteSize(archive_file);
if (file_size > 0) {
file = &archive_file;
module_sp->SetFileSpecAndObjectName(archive_file, archive_object);
// Check if this is a object container by iterating through all
// object container plugin instances and then trying to get an
// object file from the container plugins since we had a name.
// Also, don't read
// ANY data in case there is data cached in the container plug-ins
// (like BSD archives caching the contained objects within an
// file).
for (uint32_t idx = 0;
(create_object_container_callback =
PluginManager::GetObjectContainerCreateCallbackAtIndex(
idx)) != nullptr;
++idx) {
std::unique_ptr<ObjectContainer> object_container_up(
create_object_container_callback(module_sp, data_sp,
data_offset, file,
file_offset, file_size));

if (object_container_up)
object_file_sp = object_container_up->GetObjectFile(file);

if (object_file_sp.get())
return object_file_sp;
}
// We failed to find any cached object files in the container plug-
// ins, so lets read the first 512 bytes and try again below...
data_sp = FileSystem::Instance().CreateDataBuffer(
archive_file.GetPath(), 512, file_offset);
}
}
if (!data_sp || data_sp->GetByteSize() == 0) {
// Check for archive file with format "/path/to/archive.a(object.o)"
llvm::SmallString<256> path_with_object;
module_sp->GetFileSpec().GetPath(path_with_object);

FileSpec archive_file;
ConstString archive_object;
const bool must_exist = true;
if (ObjectFile::SplitArchivePathWithObject(path_with_object, archive_file,
archive_object, must_exist)) {
file_size = FileSystem::Instance().GetByteSize(archive_file);
if (file_size > 0) {
file = &archive_file;
module_sp->SetFileSpecAndObjectName(archive_file, archive_object);
// Check if this is a object container by iterating through all
// object container plugin instances and then trying to get an
// object file from the container plugins since we had a name.
// Also, don't read
// ANY data in case there is data cached in the container plug-ins
// (like BSD archives caching the contained objects within an
// file).
ObjectFileSP object_file_sp = CreateObjectFromContainer(
module_sp, file, file_offset, file_size, data_sp, data_offset);
if (object_file_sp)
return object_file_sp;
// We failed to find any cached object files in the container plug-
// ins, so lets read the first 512 bytes and try again below...
data_sp = FileSystem::Instance().CreateDataBuffer(
archive_file.GetPath(), 512, file_offset);
}
}
}

if (data_sp && data_sp->GetByteSize() > 0) {
// Check if this is a normal object file by iterating through all
// object file plugin instances.
ObjectFileCreateInstance create_object_file_callback;
for (uint32_t idx = 0;
(create_object_file_callback =
PluginManager::GetObjectFileCreateCallbackAtIndex(idx)) !=
nullptr;
++idx) {
object_file_sp.reset(create_object_file_callback(
module_sp, data_sp, data_offset, file, file_offset, file_size));
if (object_file_sp.get())
return object_file_sp;
}

// Check if this is a object container by iterating through all object
// container plugin instances and then trying to get an object file
// from the container.
for (uint32_t idx = 0;
(create_object_container_callback =
PluginManager::GetObjectContainerCreateCallbackAtIndex(
idx)) != nullptr;
++idx) {
std::unique_ptr<ObjectContainer> object_container_up(
create_object_container_callback(module_sp, data_sp, data_offset,
file, file_offset, file_size));

if (object_container_up)
object_file_sp = object_container_up->GetObjectFile(file);

if (object_file_sp.get())
return object_file_sp;
}
}
if (data_sp && data_sp->GetByteSize() > 0) {
// Check if this is a normal object file by iterating through all
// object file plugin instances.
ObjectFileCreateInstance callback;
for (uint32_t idx = 0;
(callback = PluginManager::GetObjectFileCreateCallbackAtIndex(idx)) !=
nullptr;
++idx) {
ObjectFileSP object_file_sp(callback(module_sp, data_sp, data_offset,
file, file_offset, file_size));
if (object_file_sp.get())
return object_file_sp;
}

// Check if this is a object container by iterating through all object
// container plugin instances and then trying to get an object file
// from the container.
ObjectFileSP object_file_sp = CreateObjectFromContainer(
module_sp, file, file_offset, file_size, data_sp, data_offset);
if (object_file_sp)
return object_file_sp;
}

// We didn't find it, so clear our shared pointer in case it contains
// anything and return an empty shared pointer
object_file_sp.reset();
return object_file_sp;
return {};
}

ObjectFileSP ObjectFile::FindPlugin(const lldb::ModuleSP &module_sp,
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