LLVM: llvm::lto::Config Struct Reference (original) (raw)

LTO configuration. More...

#include "[llvm/LTO/Config.h](Config%5F8h%5Fsource.html)"

Public Types
enum	VisScheme { FromPrevailing, ELF }
using	ModuleHookFn = std::function<bool(unsigned Task, const Module &)>
	The following callbacks deal with tasks, which normally represent the entire optimization and code generation pipeline for what will become a single native object file.
using	CombinedIndexHookFn
	A combined index hook is called after all per-module indexes have been combined (ThinLTO-specific).

Public Member Functions
LLVM_ABI Error	addSaveTemps (std::string OutputFileName, bool UseInputModulePath=false, const DenseSet< StringRef > &SaveTempsArgs={})
	This is a convenience function that configures this Config object to write temporary files named after the given OutputFileName for each of the LTO phases to disk.

Public Attributes
std::string	CPU
TargetOptions	Options
std::vector< std::string >	MAttrs
std::vector< std::string >	MllvmArgs
std::vector< std::string >	PassPlugins
std::function< void(legacy::PassManager &)>	PreCodeGenPassesHook
	For adding passes that run right before codegen.
std::optional< Reloc::Model >	RelocModel = Reloc::PIC_
std::optional< CodeModel::Model >	CodeModel
CodeGenOptLevel	CGOptLevel = CodeGenOptLevel::Default
CodeGenFileType	CGFileType = CodeGenFileType::ObjectFile
unsigned	OptLevel = 2
bool	VerifyEach = false
bool	DisableVerify = false
bool	Freestanding = false
	Flag to indicate that the optimizer should not assume builtins are present on the target.
bool	CodeGenOnly = false
	Disable entirely the optimizer, including importing for ThinLTO.
bool	RunCSIRInstr = false
	Run PGO context sensitive IR instrumentation.
bool	PGOWarnMismatch = true
	Turn on/off the warning about a hash mismatch in the PGO profile data.
bool	HasWholeProgramVisibility = false
	Asserts whether we can assume whole program visibility during the LTO link.
bool	ValidateAllVtablesHaveTypeInfos = false
	We're validating that all native vtables have corresponding type infos.
bool	AllVtablesHaveTypeInfos = false
	If all native vtables have corresponding type infos, allow usage of RTTI to block devirtualization on types used in native files.
bool	AlwaysEmitRegularLTOObj = false
	Always emit a Regular LTO object even when it is empty because no Regular LTO modules were linked.
bool	KeepSymbolNameCopies = true
	If true, the LTO instance creates copies of the symbol names for LTO::run.
bool	Dtlto = 0
	This flag is used as one of parameters to calculate cache entries and to ensure that in-process cache and out-of-process (DTLTO) cache are distinguished.
VisScheme	VisibilityScheme = FromPrevailing
	Allows non-imported definitions to get the potentially more constraining visibility from the prevailing definition.
std::string	OptPipeline
	If this field is set, the set of passes run in the middle-end optimizer will be the one specified by the string.
std::string	AAPipeline
std::string	OverrideTriple
	Setting this field will replace target triples in input files with this triple.
std::string	DefaultTriple
	Setting this field will replace unspecified target triples in input files with this triple.
std::string	CSIRProfile
	Context Sensitive PGO profile path.
std::string	SampleProfile
	Sample PGO profile path.
std::string	ProfileRemapping
	Name remapping file for profile data.
std::string	DwoDir
	The directory to store .dwo files.
std::string	SplitDwarfFile
	The name for the split debug info file used for the DW_AT_[GNU_]dwo_name attribute in the skeleton CU.
std::string	SplitDwarfOutput
	The path to write a .dwo file to.
std::string	RemarksFilename
	Optimization remarks file path.
std::string	RemarksPasses
	Optimization remarks pass filter.
bool	RemarksWithHotness = false
	Whether to emit optimization remarks with hotness informations.
std::optional< uint64_t >	RemarksHotnessThreshold = 0
	The minimum hotness value a diagnostic needs in order to be included in optimization diagnostics.
std::string	RemarksFormat
	The format used for serializing remarks (default: YAML).
bool	DebugPassManager = false
	Whether to emit the pass manager debuggging informations.
std::string	StatsFile
	Statistics output file path.
std::vector< std::string >	ThinLTOModulesToCompile
	Specific thinLTO modules to compile.
bool	TimeTraceEnabled = false
	Time trace enabled.
unsigned	TimeTraceGranularity = 500
	Time trace granularity.
bool	ShouldDiscardValueNames = true
DiagnosticHandlerFunction	DiagHandler
bool	AddFSDiscriminator = false
	Add FSAFDO discriminators.
std::unique_ptr< raw_ostream >	ResolutionFile
	If this field is set, LTO will write input file paths and symbol resolutions here in llvm-lto2 command line flag format.
PipelineTuningOptions	PTO
	Tunable parameters for passes in the default pipelines.
ModuleHookFn	PreOptModuleHook
	This module hook is called after linking (regular LTO) or loading (ThinLTO) the module, before modifying it.
ModuleHookFn	PostPromoteModuleHook
	This hook is called after promoting any internal functions (ThinLTO-specific).
ModuleHookFn	PostInternalizeModuleHook
	This hook is called after internalizing the module.
ModuleHookFn	PostImportModuleHook
	This hook is called after importing from other modules (ThinLTO-specific).
ModuleHookFn	PostOptModuleHook
	This module hook is called after optimization is complete.
ModuleHookFn	PreCodeGenModuleHook
	This module hook is called before code generation.
CombinedIndexHookFn	CombinedIndexHook

LTO configuration.

A linker can configure LTO by setting fields in this data structure and passing it to the lto::LTO constructor.

Definition at line 42 of file Config.h.

◆ CombinedIndexHookFn

Initial value:

std::function<bool(

Implements a dense probed hash-table based set.

Class to hold module path string table and global value map, and encapsulate methods for operating on...

A combined index hook is called after all per-module indexes have been combined (ThinLTO-specific).

It can be used to implement -save-temps for the combined index.

If this function returns false, any further processing for ThinLTO tasks is aborted.

It is called regardless of whether the backend is in-process, although it is not called from individual backend processes.

Definition at line 263 of file Config.h.

◆ ModuleHookFn

The following callbacks deal with tasks, which normally represent the entire optimization and code generation pipeline for what will become a single native object file.

Each task has a unique identifier between 0 and getMaxTasks()-1, which is supplied to the callback via the Task parameter. A task represents the entire pipeline for ThinLTO and regular (non-parallel) LTO, but a parallel code generation task will be split into N tasks before code generation, where N is the parallelism level.

LTO may decide to stop processing a task at any time, for example if the module is empty or if a module hook (see below) returns false. For this reason, the client should not expect to receive exactly getMaxTasks() native object files. A module hook may be used by a linker to perform actions during the LTO pipeline. For example, a linker may use this function to implement -save-temps. If this function returns false, any further processing for that task is aborted.

Module hooks must be thread safe with respect to the linker's internal data structures. A module hook will never be called concurrently from multiple threads with the same task ID, or the same module.

Note that in out-of-process backend scenarios, none of the hooks will be called for ThinLTO tasks.

Definition at line 230 of file Config.h.

◆ VisScheme

Enumerator
FromPrevailing
ELF

Definition at line 43 of file Config.h.

◆ addSaveTemps()

This is a convenience function that configures this Config object to write temporary files named after the given OutputFileName for each of the LTO phases to disk.

A client can use this function to implement -save-temps.

FIXME: Temporary files derived from ThinLTO backends are currently named after the input file name, rather than the output file name, when UseInputModulePath is set to true.

Specifically, it (1) sets each of the above module hooks and the combined index hook to a function that calls the hook function (if any) that was present in the appropriate field when the addSaveTemps function was called, and writes the module to a bitcode file with a name prefixed by the given output file name, and (2) creates a resolution file whose name is prefixed by the given output file name and sets ResolutionFile to its file handle.

SaveTempsArgs can be specified to select which temps to save. If SaveTempsArgs is not provided, all temps are saved.

Definition at line 87 of file LTOBackend.cpp.

References CombinedIndexHook, llvm::detail::DenseSetImpl< ValueT, MapTy, ValueInfoT >::contains(), llvm::detail::DenseSetImpl< ValueT, MapTy, ValueInfoT >::empty(), llvm::errorCodeToError(), llvm::sys::fs::OF_None, llvm::sys::fs::OF_Text, llvm::sys::fs::OF_TextWithCRLF, PostImportModuleHook, PostInternalizeModuleHook, PostOptModuleHook, PostPromoteModuleHook, PreCodeGenModuleHook, PreOptModuleHook, reportOpenError(), ResolutionFile, ShouldDiscardValueNames, llvm::Error::success(), llvm::utostr(), llvm::WriteBitcodeToFile(), and llvm::writeIndexToFile().

◆ AAPipeline

std::string llvm::lto::Config::AAPipeline

◆ AddFSDiscriminator

bool llvm::lto::Config::AddFSDiscriminator = false

◆ AllVtablesHaveTypeInfos

bool llvm::lto::Config::AllVtablesHaveTypeInfos = false

If all native vtables have corresponding type infos, allow usage of RTTI to block devirtualization on types used in native files.

Definition at line 85 of file Config.h.

◆ AlwaysEmitRegularLTOObj

bool llvm::lto::Config::AlwaysEmitRegularLTOObj = false

Always emit a Regular LTO object even when it is empty because no Regular LTO modules were linked.

This option is useful for some build system which want to know a priori all possible output files.

Definition at line 90 of file Config.h.

◆ CGFileType

◆ CGOptLevel

◆ CodeGenOnly

bool llvm::lto::Config::CodeGenOnly = false

Disable entirely the optimizer, including importing for ThinLTO.

Definition at line 69 of file Config.h.

◆ CodeModel

◆ CombinedIndexHook

CombinedIndexHookFn llvm::lto::Config::CombinedIndexHook

◆ CPU

std::string llvm::lto::Config::CPU

◆ CSIRProfile

std::string llvm::lto::Config::CSIRProfile

◆ DebugPassManager

bool llvm::lto::Config::DebugPassManager = false

◆ DefaultTriple

std::string llvm::lto::Config::DefaultTriple

◆ DiagHandler

◆ DisableVerify

bool llvm::lto::Config::DisableVerify = false

◆ Dtlto

bool llvm::lto::Config::Dtlto = 0	mutable

This flag is used as one of parameters to calculate cache entries and to ensure that in-process cache and out-of-process (DTLTO) cache are distinguished.

Definition at line 100 of file Config.h.

Referenced by llvm::computeLTOCacheKey().

◆ DwoDir

std::string llvm::lto::Config::DwoDir

◆ Freestanding

bool llvm::lto::Config::Freestanding = false

◆ HasWholeProgramVisibility

bool llvm::lto::Config::HasWholeProgramVisibility = false

Asserts whether we can assume whole program visibility during the LTO link.

Definition at line 79 of file Config.h.

◆ KeepSymbolNameCopies

bool llvm::lto::Config::KeepSymbolNameCopies = true

If true, the LTO instance creates copies of the symbol names for LTO::run.

The lld linker uses string saver to keep symbol names alive and doesn't need to create copies, so it can set this field to false.

Definition at line 95 of file Config.h.

◆ MAttrs

std::vectorstd::string llvm::lto::Config::MAttrs

◆ MllvmArgs

std::vectorstd::string llvm::lto::Config::MllvmArgs

◆ Options

◆ OptLevel

unsigned llvm::lto::Config::OptLevel = 2

◆ OptPipeline

std::string llvm::lto::Config::OptPipeline

If this field is set, the set of passes run in the middle-end optimizer will be the one specified by the string.

Only works with the new pass manager as the old one doesn't have this ability.

Definition at line 111 of file Config.h.

Referenced by llvm::computeLTOCacheKey(), and runNewPMPasses().

◆ OverrideTriple

std::string llvm::lto::Config::OverrideTriple

◆ PassPlugins

std::vectorstd::string llvm::lto::Config::PassPlugins

◆ PGOWarnMismatch

bool llvm::lto::Config::PGOWarnMismatch = true

Turn on/off the warning about a hash mismatch in the PGO profile data.

Definition at line 75 of file Config.h.

Referenced by runNewPMPasses().

◆ PostImportModuleHook

ModuleHookFn llvm::lto::Config::PostImportModuleHook

◆ PostInternalizeModuleHook

ModuleHookFn llvm::lto::Config::PostInternalizeModuleHook

◆ PostOptModuleHook

ModuleHookFn llvm::lto::Config::PostOptModuleHook

◆ PostPromoteModuleHook

ModuleHookFn llvm::lto::Config::PostPromoteModuleHook

◆ PreCodeGenModuleHook

ModuleHookFn llvm::lto::Config::PreCodeGenModuleHook

This module hook is called before code generation.

It is similar to the PostOptModuleHook, but for parallel code generation it is called after splitting the module.

Definition at line 252 of file Config.h.

Referenced by addSaveTemps(), and codegen().

◆ PreCodeGenPassesHook

For adding passes that run right before codegen.

Definition at line 55 of file Config.h.

Referenced by codegen().

◆ PreOptModuleHook

ModuleHookFn llvm::lto::Config::PreOptModuleHook

◆ ProfileRemapping

std::string llvm::lto::Config::ProfileRemapping

◆ PTO

◆ RelocModel

◆ RemarksFilename

std::string llvm::lto::Config::RemarksFilename

◆ RemarksFormat

std::string llvm::lto::Config::RemarksFormat

◆ RemarksHotnessThreshold

std::optional<uint64_t> llvm::lto::Config::RemarksHotnessThreshold = 0

The minimum hotness value a diagnostic needs in order to be included in optimization diagnostics.

The threshold is an Optional value, which maps to one of the 3 states:

0 => threshold disabled. All emarks will be printed.
positive int => manual threshold by user. Remarks with hotness exceed threshold will be printed.
None => 'auto' threshold by user. The actual value is not available at command line, but will be synced with hotness threhold from profile summary during compilation.

If threshold option is not specified, it is disabled by default.

Definition at line 171 of file Config.h.

Referenced by llvm::lto::thinBackend().

◆ RemarksPasses

std::string llvm::lto::Config::RemarksPasses

◆ RemarksWithHotness

bool llvm::lto::Config::RemarksWithHotness = false

◆ ResolutionFile

std::unique_ptr<raw_ostream> llvm::lto::Config::ResolutionFile

If this field is set, LTO will write input file paths and symbol resolutions here in llvm-lto2 command line flag format.

This can be used for testing and for running the LTO pipeline outside of the linker with llvm-lto2.

Definition at line 201 of file Config.h.

Referenced by addSaveTemps().

◆ RunCSIRInstr

bool llvm::lto::Config::RunCSIRInstr = false

◆ SampleProfile

std::string llvm::lto::Config::SampleProfile

◆ ShouldDiscardValueNames

bool llvm::lto::Config::ShouldDiscardValueNames = true

◆ SplitDwarfFile

std::string llvm::lto::Config::SplitDwarfFile

The name for the split debug info file used for the DW_AT_[GNU_]dwo_name attribute in the skeleton CU.

This should generally only be used when running an individual backend directly via thinBackend(), as otherwise all objects would use the same .dwo file. Not used as output path.

Definition at line 142 of file Config.h.

Referenced by codegen().

◆ SplitDwarfOutput

std::string llvm::lto::Config::SplitDwarfOutput

The path to write a .dwo file to.

This should generally only be used when running an individual backend directly via thinBackend(), as otherwise all .dwo files will be written to the same path. Not used in skeleton CU.

Definition at line 147 of file Config.h.

Referenced by codegen().

◆ StatsFile

std::string llvm::lto::Config::StatsFile

Statistics output file path.

Definition at line 180 of file Config.h.

◆ ThinLTOModulesToCompile

std::vectorstd::string llvm::lto::Config::ThinLTOModulesToCompile

Specific thinLTO modules to compile.

Definition at line 183 of file Config.h.

◆ TimeTraceEnabled

bool llvm::lto::Config::TimeTraceEnabled = false

Time trace enabled.

Definition at line 186 of file Config.h.

◆ TimeTraceGranularity

unsigned llvm::lto::Config::TimeTraceGranularity = 500

Time trace granularity.

Definition at line 189 of file Config.h.

◆ ValidateAllVtablesHaveTypeInfos

bool llvm::lto::Config::ValidateAllVtablesHaveTypeInfos = false

We're validating that all native vtables have corresponding type infos.

Definition at line 82 of file Config.h.

◆ VerifyEach

bool llvm::lto::Config::VerifyEach = false

◆ VisibilityScheme

VisScheme llvm::lto::Config::VisibilityScheme = FromPrevailing

Allows non-imported definitions to get the potentially more constraining visibility from the prevailing definition.

FromPrevailing is the default because it works for many binary formats. ELF can use the more optimized 'ELF' scheme.

Definition at line 106 of file Config.h.

The documentation for this struct was generated from the following files:

include/llvm/LTO/Config.h
lib/LTO/LTOBackend.cpp