llvm::GCStrategy Class Reference

GCStrategy describes a garbage collector algorithm's code generation requirements, and provides overridable hooks for those needs which cannot be abstractly described. More...

#include "llvm/IR/GCStrategy.h"

Public Member Functions
	GCStrategy ()
virtual	~GCStrategy ()=default
const std::string &	getName () const
	Return the name of the GC strategy.
bool	useStatepoints () const
	Returns true if this strategy is expecting the use of gc.statepoints, and false otherwise.
bool	usesMetadata () const
	If set, appropriate metadata tables must be emitted by the back-end (assembler, JIT, or otherwise).
Statepoint Specific Properties
virtual std::optional< bool >	isGCManagedPointer (const Type *Ty) const
	If the type specified can be reliably distinguished, returns true for pointers to GC managed locations and false for pointers to non-GC managed locations.
bool	useRS4GC () const
	Returns true if the RewriteStatepointsForGC pass should run on functions using this GC.
GCRoot Specific Properties
These properties and overrides only apply to collector strategies using GCRoot.
bool	needsSafePoints () const
	True if safe points need to be inferred on call sites.

Protected Attributes
bool	UseStatepoints = false
bool	UseRS4GC = false
	Uses gc.statepoints as opposed to gc.roots, if set, NeededSafePoints and UsesMetadata should be left at their default values.
bool	NeededSafePoints = false
	If UseStatepoints is set, this determines whether the RewriteStatepointsForGC pass should rewrite this function's calls.
bool	UsesMetadata = false
	If set, backend must emit metadata tables.

Friends
class	GCModuleInfo

Detailed Description

GCStrategy describes a garbage collector algorithm's code generation requirements, and provides overridable hooks for those needs which cannot be abstractly described.

GCStrategy objects must be looked up through the Function. The objects themselves are owned by the Context and must be immutable.

Definition at line 63 of file GCStrategy.h.

Constructor & Destructor Documentation

GCStrategy()

GCStrategy::GCStrategy ( )

default

~GCStrategy()

virtual llvm::GCStrategy::~GCStrategy ( )

virtualdefault

Member Function Documentation

getName()

const std::string & llvm::GCStrategy::getName ( ) const

inline

Return the name of the GC strategy.

This is the value of the collector name string specified on functions which use this strategy.

Definition at line 88 of file GCStrategy.h.

References Name.

isGCManagedPointer()

virtual std::optional< bool > llvm::GCStrategy::isGCManagedPointer ( const Type *  Ty ) const

inlinevirtual

If the type specified can be reliably distinguished, returns true for pointers to GC managed locations and false for pointers to non-GC managed locations.

Note a GCStrategy can always return 'std::nullopt' (i.e. an empty optional indicating it can't reliably distinguish.

Definition at line 101 of file GCStrategy.h.

needsSafePoints()

bool llvm::GCStrategy::needsSafePoints ( ) const

inline

True if safe points need to be inferred on call sites.

Definition at line 127 of file GCStrategy.h.

References NeededSafePoints.

useRS4GC()

bool llvm::GCStrategy::useRS4GC ( ) const

inline

Returns true if the RewriteStatepointsForGC pass should run on functions using this GC.

Definition at line 107 of file GCStrategy.h.

References assert(), UseRS4GC, and useStatepoints().

usesMetadata()

bool llvm::GCStrategy::usesMetadata ( ) const

inline

If set, appropriate metadata tables must be emitted by the back-end (assembler, JIT, or otherwise).

The default stackmap information can be found in the StackMap section as described in the documentation.

Definition at line 118 of file GCStrategy.h.

References UsesMetadata.

useStatepoints()

bool llvm::GCStrategy::useStatepoints ( ) const

inline

Returns true if this strategy is expecting the use of gc.statepoints, and false otherwise.

Definition at line 92 of file GCStrategy.h.

References UseStatepoints.

Referenced by llvm::SelectionDAGBuilder::LowerStatepoint(), and useRS4GC().

Friends And Related Function Documentation

GCModuleInfo

friend class GCModuleInfo

friend

Definition at line 65 of file GCStrategy.h.

Member Data Documentation

NeededSafePoints

bool llvm::GCStrategy::NeededSafePoints = false

protected

If UseStatepoints is set, this determines whether the RewriteStatepointsForGC pass should rewrite this function's calls.

This should only be set if UseStatepoints is set. if set, calls are inferred to be safepoints

Definition at line 79 of file GCStrategy.h.

Referenced by needsSafePoints().

UseRS4GC

bool llvm::GCStrategy::UseRS4GC = false

protected

Uses gc.statepoints as opposed to gc.roots, if set, NeededSafePoints and UsesMetadata should be left at their default values.

Definition at line 74 of file GCStrategy.h.

Referenced by useRS4GC().

UsesMetadata

bool llvm::GCStrategy::UsesMetadata = false

protected

If set, backend must emit metadata tables.

Definition at line 80 of file GCStrategy.h.

Referenced by usesMetadata().

UseStatepoints

bool llvm::GCStrategy::UseStatepoints = false

protected

Definition at line 70 of file GCStrategy.h.

Referenced by useStatepoints().

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

• include/llvm/IR/GCStrategy.h
• lib/IR/GCStrategy.cpp