Representation of an OpenMP canonical loop. More...

#include "clang/AST/StmtOpenMP.h"

Inheritance diagram for clang::OMPCanonicalLoop:

Public Member Functions
SourceLocation	getBeginLoc () const

SourceLocation	getEndLoc () const


child_range	children ()
	Return this AST node's children.

const_child_range	children () const


Stmt *	getLoopStmt ()
	The wrapped syntactic loop statement (ForStmt or CXXForRangeStmt).

const Stmt *	getLoopStmt () const

void	setLoopStmt (Stmt *S)


CapturedStmt *	getDistanceFunc ()
	The function that computes the number of loop iterations.

const CapturedStmt *	getDistanceFunc () const

void	setDistanceFunc (CapturedStmt *S)


CapturedStmt *	getLoopVarFunc ()
	The function that computes the loop user variable from a logical iteration counter.

const CapturedStmt *	getLoopVarFunc () const

void	setLoopVarFunc (CapturedStmt *S)


DeclRefExpr *	getLoopVarRef ()
	Reference to the loop user variable as accessed in the loop body.

const DeclRefExpr *	getLoopVarRef () const

void	setLoopVarRef (DeclRefExpr *E)

Public Member Functions inherited from clang::Stmt
void *	operator new (size_t bytes, const ASTContext &C, unsigned alignment=8)

void *	operator new (size_t bytes, const ASTContext *C, unsigned alignment=8)

void *	operator new (size_t bytes, void *mem) noexcept

void	operator delete (void *, const ASTContext &, unsigned) noexcept

void	operator delete (void , const ASTContext , unsigned) noexcept

void	operator delete (void *, size_t) noexcept

void	operator delete (void , void ) noexcept

	Stmt ()=delete

	Stmt (const Stmt &)=delete

	Stmt (Stmt &&)=delete

Stmt &	operator= (const Stmt &)=delete

Stmt &	operator= (Stmt &&)=delete

	Stmt (StmtClass SC)

StmtClass	getStmtClass () const

const char *	getStmtClassName () const

SourceRange	getSourceRange () const LLVM_READONLY
	SourceLocation tokens are not useful in isolation - they are low level value objects created/interpreted by SourceManager.

SourceLocation	getBeginLoc () const LLVM_READONLY

SourceLocation	getEndLoc () const LLVM_READONLY

void	dump () const
	Dumps the specified AST fragment and all subtrees to `llvm::errs()`.

void	dump (raw_ostream &OS, const ASTContext &Context) const

int64_t	getID (const ASTContext &Context) const

void	dumpColor () const
	dumpColor - same as dump(), but forces color highlighting.

void	dumpPretty (const ASTContext &Context) const
	dumpPretty/printPretty - These two methods do a "pretty print" of the AST back to its original source language syntax.

void	printPretty (raw_ostream &OS, PrinterHelper Helper, const PrintingPolicy &Policy, unsigned Indentation=0, StringRef NewlineSymbol="\n", const ASTContext Context=nullptr) const

void	printPrettyControlled (raw_ostream &OS, PrinterHelper Helper, const PrintingPolicy &Policy, unsigned Indentation=0, StringRef NewlineSymbol="\n", const ASTContext Context=nullptr) const

void	printJson (raw_ostream &Out, PrinterHelper *Helper, const PrintingPolicy &Policy, bool AddQuotes) const
	Pretty-prints in JSON format.

void	viewAST () const
	viewAST - Visualize an AST rooted at this Stmt* using GraphViz.

Stmt *	IgnoreContainers (bool IgnoreCaptured=false)
	Skip no-op (attributed, compound) container stmts and skip captured stmt at the top, if IgnoreCaptured is true.

const Stmt *	IgnoreContainers (bool IgnoreCaptured=false) const

const Stmt *	stripLabelLikeStatements () const
	Strip off all label-like statements.

Stmt *	stripLabelLikeStatements ()

child_range	children ()

const_child_range	children () const

child_iterator	child_begin ()

child_iterator	child_end ()

const_child_iterator	child_begin () const

const_child_iterator	child_end () const

void	Profile (llvm::FoldingSetNodeID &ID, const ASTContext &Context, bool Canonical, bool ProfileLambdaExpr=false) const
	Produce a unique representation of the given statement.

void	ProcessODRHash (llvm::FoldingSetNodeID &ID, ODRHash &Hash) const
	Calculate a unique representation for a statement that is stable across compiler invocations.

Static Public Member Functions
static OMPCanonicalLoop *	create (const ASTContext &Ctx, Stmt LoopStmt, CapturedStmt DistanceFunc, CapturedStmt LoopVarFunc, DeclRefExpr LoopVarRef)
	Create a new OMPCanonicalLoop.

static OMPCanonicalLoop *	createEmpty (const ASTContext &Ctx)
	Create an empty OMPCanonicalLoop for deserialization.

static bool	classof (const Stmt *S)

Static Public Member Functions inherited from clang::Stmt
static void	addStmtClass (const StmtClass s)

static void	EnableStatistics ()

static void	PrintStats ()

static Likelihood	getLikelihood (ArrayRef< const Attr * > Attrs)

static Likelihood	getLikelihood (const Stmt *S)

static const Attr *	getLikelihoodAttr (const Stmt *S)

static Likelihood	getLikelihood (const Stmt Then, const Stmt Else)

static std::tuple< bool, const Attr , const Attr >	determineLikelihoodConflict (const Stmt Then, const Stmt Else)

Friends
class	ASTStmtReader

class	ASTStmtWriter

Additional Inherited Members
Public Types inherited from clang::Stmt
enum	StmtClass { NoStmtClass = 0 }

enum	Likelihood { LH_Unlikely = -1 , LH_None , LH_Likely }
	The likelihood of a branch being taken. More...

using	child_iterator = StmtIterator
	Child Iterators: All subclasses must implement 'children' to permit easy iteration over the substatements/subexpressions of an AST node.

using	const_child_iterator = ConstStmtIterator

using	child_range = llvm::iterator_range< child_iterator >

using	const_child_range = llvm::iterator_range< const_child_iterator >

Protected Types inherited from clang::Stmt
enum	{ NumStmtBits = 8 }

enum	{ NumExprBits = NumStmtBits + 5 + llvm::BitWidth<ExprDependence> }

enum	{ NumCallExprBits = 32 }

enum	{ NumOverloadExprBits = NumExprBits + 1 }

template<typename T >
using	ConstCastIterator = CastIterator< T, const T const, const Stmt const >
	Const iterator for iterating over Stmt * arrays that contain only T *.

using	ExprIterator = CastIterator< Expr >

using	ConstExprIterator = ConstCastIterator< Expr >

Protected Member Functions inherited from clang::Stmt
void *	operator new (size_t bytes) noexcept

void	operator delete (void *data) noexcept

	Stmt (StmtClass SC, EmptyShell)
	Construct an empty statement.

Protected Attributes inherited from clang::Stmt
union {
StmtBitfields StmtBits

NullStmtBitfields NullStmtBits

CompoundStmtBitfields CompoundStmtBits

LabelStmtBitfields LabelStmtBits

AttributedStmtBitfields AttributedStmtBits

IfStmtBitfields IfStmtBits

SwitchStmtBitfields SwitchStmtBits

WhileStmtBitfields WhileStmtBits

DoStmtBitfields DoStmtBits

ForStmtBitfields ForStmtBits

GotoStmtBitfields GotoStmtBits

ContinueStmtBitfields ContinueStmtBits

BreakStmtBitfields BreakStmtBits

ReturnStmtBitfields ReturnStmtBits

SwitchCaseBitfields SwitchCaseBits

ExprBitfields ExprBits

ConstantExprBitfields ConstantExprBits

PredefinedExprBitfields PredefinedExprBits

DeclRefExprBitfields DeclRefExprBits

FloatingLiteralBitfields FloatingLiteralBits

StringLiteralBitfields StringLiteralBits

CharacterLiteralBitfields CharacterLiteralBits

UnaryOperatorBitfields UnaryOperatorBits

UnaryExprOrTypeTraitExprBitfields UnaryExprOrTypeTraitExprBits

ArrayOrMatrixSubscriptExprBitfields ArrayOrMatrixSubscriptExprBits

CallExprBitfields CallExprBits

MemberExprBitfields MemberExprBits

CastExprBitfields CastExprBits

BinaryOperatorBitfields BinaryOperatorBits

InitListExprBitfields InitListExprBits

ParenListExprBitfields ParenListExprBits

GenericSelectionExprBitfields GenericSelectionExprBits

PseudoObjectExprBitfields PseudoObjectExprBits

SourceLocExprBitfields SourceLocExprBits

StmtExprBitfields StmtExprBits

CXXOperatorCallExprBitfields CXXOperatorCallExprBits

CXXRewrittenBinaryOperatorBitfields CXXRewrittenBinaryOperatorBits

CXXBoolLiteralExprBitfields CXXBoolLiteralExprBits

CXXNullPtrLiteralExprBitfields CXXNullPtrLiteralExprBits

CXXThisExprBitfields CXXThisExprBits

CXXThrowExprBitfields CXXThrowExprBits

CXXDefaultArgExprBitfields CXXDefaultArgExprBits

CXXDefaultInitExprBitfields CXXDefaultInitExprBits

CXXScalarValueInitExprBitfields CXXScalarValueInitExprBits

CXXNewExprBitfields CXXNewExprBits

CXXDeleteExprBitfields CXXDeleteExprBits

TypeTraitExprBitfields TypeTraitExprBits

DependentScopeDeclRefExprBitfields DependentScopeDeclRefExprBits

CXXConstructExprBitfields CXXConstructExprBits

ExprWithCleanupsBitfields ExprWithCleanupsBits

CXXUnresolvedConstructExprBitfields CXXUnresolvedConstructExprBits

CXXDependentScopeMemberExprBitfields CXXDependentScopeMemberExprBits

OverloadExprBitfields OverloadExprBits

UnresolvedLookupExprBitfields UnresolvedLookupExprBits

UnresolvedMemberExprBitfields UnresolvedMemberExprBits

CXXNoexceptExprBitfields CXXNoexceptExprBits

SubstNonTypeTemplateParmExprBitfields SubstNonTypeTemplateParmExprBits

LambdaExprBitfields LambdaExprBits

RequiresExprBitfields RequiresExprBits

CoawaitExprBitfields CoawaitBits

ObjCIndirectCopyRestoreExprBitfields ObjCIndirectCopyRestoreExprBits

OpaqueValueExprBitfields OpaqueValueExprBits

};

Detailed Description

Representation of an OpenMP canonical loop.

OpenMP 1.0 C/C++, section 2.4.1 for Construct; canonical-shape OpenMP 2.0 C/C++, section 2.4.1 for Construct; canonical-shape OpenMP 2.5, section 2.5.1 Loop Construct; canonical form OpenMP 3.1, section 2.5.1 Loop Construct; canonical form OpenMP 4.0, section 2.6 Canonical Loop Form OpenMP 4.5, section 2.6 Canonical Loop Form OpenMP 5.0, section 2.9.1 Canonical Loop Form OpenMP 5.1, section 2.11.1 Canonical Loop Nest Form

An OpenMP canonical loop is a for-statement or range-based for-statement with additional requirements that ensure that the number of iterations is known before entering the loop and allow skipping to an arbitrary iteration. The OMPCanonicalLoop AST node wraps a ForStmt or CXXForRangeStmt that is known to fulfill OpenMP's canonical loop requirements because of being associated to an OMPLoopBasedDirective. That is, the general structure is:

OMPLoopBasedDirective [- CapturedStmt ] [- CapturedDecl] OMPCanonicalLoop - ForStmt/CXXForRangeStmt `- Stmt

One or multiple CapturedStmt/CapturedDecl pairs may be inserted by some directives such as OMPParallelForDirective, but others do not need them (such as OMPTileDirective). In The OMPCanonicalLoop and ForStmt/CXXForRangeStmt pair is repeated for loop associated with the directive. A OMPCanonicalLoop must not appear in the AST unless associated with a OMPLoopBasedDirective. In an imperfectly nested loop nest, the OMPCanonicalLoop may also be wrapped in a CompoundStmt:

[...] OMPCanonicalLoop - ForStmt/CXXForRangeStmt `- CompoundStmt |- Leading in-between code (if any) |- OMPCanonicalLoop | - ForStmt/CXXForRangeStmt |- ... `- Trailing in-between code (if any)

The leading/trailing in-between code must not itself be a OMPCanonicalLoop to avoid confusion which loop belongs to the nesting.

There are three different kinds of iteration variables for different purposes:

Loop user variable: The user-accessible variable with different value for each iteration.
Loop iteration variable: The variable used to identify a loop iteration; for range-based for-statement, this is the hidden iterator '__begin'. For other loops, it is identical to the loop user variable. Must be a random-access iterator, pointer or integer type.
Logical iteration counter: Normalized loop counter starting at 0 and incrementing by one at each iteration. Allows abstracting over the type of the loop iteration variable and is always an unsigned integer type appropriate to represent the range of the loop iteration variable. Its value corresponds to the logical iteration number in the OpenMP specification.

This AST node provides two captured statements:

The distance function which computes the number of iterations.
The loop user variable function that computes the loop user variable when given a logical iteration number.

These captured statements provide the link between C/C++ semantics and the logical iteration counters used by the OpenMPIRBuilder which is language-agnostic and therefore does not know e.g. how to advance a random-access iterator. The OpenMPIRBuilder will use this information to apply simd, workshare-loop, distribute, taskloop and loop directives to the loop. For compatibility with the non-OpenMPIRBuilder codegen path, an OMPCanonicalLoop can itself also be wrapped into the CapturedStmts of an OMPLoopDirective and skipped when searching for the associated syntactical loop.

Example: std::vector<std::string> Container{1,2,3}; for (std::string Str : Container) Body(Str); which is syntactic sugar for approximately: auto &&__range = Container; auto __begin = std::begin(__range); auto __end = std::end(__range); for (; __begin != __end; ++__begin) { std::String Str = *__begin; Body(Str); } In this example, the loop user variable is Str, the loop iteration variable is __begin of type std::vector<std::string>::iterator and the logical iteration number type is size_t (unsigned version of std::vector<std::string>::iterator::difference_type aka ptrdiff_t). Therefore, the distance function will be [&](size_t &Result) { Result = __end - __begin; } and the loop variable function is [&,__begin](std::vector<std::string>::iterator &Result, size_t Logical) { Result = __begin + Logical; } The variable __begin, aka the loop iteration variable, is captured by value because it is modified in the loop body, but both functions require the initial value. The OpenMP specification explicitly leaves unspecified when the loop expressions are evaluated such that a capture by reference is sufficient.

Definition at line 142 of file StmtOpenMP.h.

Member Function Documentation

◆ children() [1/2]

child_range clang::OMPCanonicalLoop::children ( )

inline

Return this AST node's children.

Definition at line 189 of file StmtOpenMP.h.

◆ children() [2/2]

const_child_range clang::OMPCanonicalLoop::children ( ) const

inline

Definition at line 192 of file StmtOpenMP.h.

◆ classof()

static bool clang::OMPCanonicalLoop::classof ( const Stmt * S )

inlinestatic

Definition at line 180 of file StmtOpenMP.h.

◆ create()

static OMPCanonicalLoop * clang::OMPCanonicalLoop::create	(	const ASTContext &	Ctx,
		Stmt *	LoopStmt,
		CapturedStmt *	DistanceFunc,
		CapturedStmt *	LoopVarFunc,
		DeclRefExpr *	LoopVarRef
	)

inlinestatic

Create a new OMPCanonicalLoop.

Definition at line 163 of file StmtOpenMP.h.

Referenced by clang::SemaOpenMP::ActOnOpenMPCanonicalLoop().

◆ createEmpty()

static OMPCanonicalLoop * clang::OMPCanonicalLoop::createEmpty ( const ASTContext & Ctx )

inlinestatic

Create an empty OMPCanonicalLoop for deserialization.

Definition at line 176 of file StmtOpenMP.h.

◆ getBeginLoc()

SourceLocation clang::OMPCanonicalLoop::getBeginLoc ( ) const

inline

Definition at line 184 of file StmtOpenMP.h.

References clang::Stmt::getBeginLoc(), and getLoopStmt().

◆ getDistanceFunc() [1/2]

CapturedStmt * clang::OMPCanonicalLoop::getDistanceFunc ( )

inline

The function that computes the number of loop iterations.

Can be evaluated before entering the loop but after the syntactical loop's init statement(s).

Function signature: void(LogicalTy &Result) Any values necessary to compute the distance are captures of the closure.

Definition at line 215 of file StmtOpenMP.h.

◆ getDistanceFunc() [2/2]

const CapturedStmt * clang::OMPCanonicalLoop::getDistanceFunc ( ) const

inline

Definition at line 218 of file StmtOpenMP.h.

◆ getEndLoc()

SourceLocation clang::OMPCanonicalLoop::getEndLoc ( ) const

inline

Definition at line 185 of file StmtOpenMP.h.

References clang::Stmt::getEndLoc(), and getLoopStmt().

◆ getLoopStmt() [1/2]

Stmt * clang::OMPCanonicalLoop::getLoopStmt ( )

inline

The wrapped syntactic loop statement (ForStmt or CXXForRangeStmt).

Definition at line 199 of file StmtOpenMP.h.

Referenced by getBeginLoc(), and getEndLoc().

◆ getLoopStmt() [2/2]

const Stmt * clang::OMPCanonicalLoop::getLoopStmt ( ) const

inline

Definition at line 200 of file StmtOpenMP.h.

◆ getLoopVarFunc() [1/2]

CapturedStmt * clang::OMPCanonicalLoop::getLoopVarFunc ( )

inline

The function that computes the loop user variable from a logical iteration counter.

Can be evaluated as first statement in the loop.

Function signature: void(LoopVarTy &Result, LogicalTy Number) Any other values required to compute the loop user variable (such as start value, step size) are captured by the closure. In particular, the initial value of loop iteration variable is captured by value to be unaffected by previous iterations.

Definition at line 236 of file StmtOpenMP.h.

◆ getLoopVarFunc() [2/2]

const CapturedStmt * clang::OMPCanonicalLoop::getLoopVarFunc ( ) const

inline

Definition at line 239 of file StmtOpenMP.h.

◆ getLoopVarRef() [1/2]

DeclRefExpr * clang::OMPCanonicalLoop::getLoopVarRef ( )

inline

Reference to the loop user variable as accessed in the loop body.

Definition at line 250 of file StmtOpenMP.h.

◆ getLoopVarRef() [2/2]

const DeclRefExpr * clang::OMPCanonicalLoop::getLoopVarRef ( ) const

inline

Definition at line 253 of file StmtOpenMP.h.

◆ setDistanceFunc()

void clang::OMPCanonicalLoop::setDistanceFunc ( CapturedStmt * S )

inline

Definition at line 221 of file StmtOpenMP.h.

◆ setLoopStmt()

void clang::OMPCanonicalLoop::setLoopStmt ( Stmt * S )

inline

Definition at line 201 of file StmtOpenMP.h.

◆ setLoopVarFunc()

void clang::OMPCanonicalLoop::setLoopVarFunc ( CapturedStmt * S )

inline

Definition at line 242 of file StmtOpenMP.h.

◆ setLoopVarRef()

void clang::OMPCanonicalLoop::setLoopVarRef ( DeclRefExpr * E )

inline

Definition at line 256 of file StmtOpenMP.h.

Friends And Related Function Documentation

◆ ASTStmtReader

friend class ASTStmtReader

friend

Definition at line 143 of file StmtOpenMP.h.

◆ ASTStmtWriter

friend class ASTStmtWriter

friend

Definition at line 144 of file StmtOpenMP.h.

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

include/clang/AST/StmtOpenMP.h

Public Member Functions

Static Public Member Functions

Friends

Additional Inherited Members

Detailed Description

Member Function Documentation

◆ children() [1/2]

◆ children() [2/2]

◆ classof()

◆ create()

◆ createEmpty()

◆ getBeginLoc()

◆ getDistanceFunc() [1/2]

◆ getDistanceFunc() [2/2]

◆ getEndLoc()

◆ getLoopStmt() [1/2]

◆ getLoopStmt() [2/2]

◆ getLoopVarFunc() [1/2]

◆ getLoopVarFunc() [2/2]

◆ getLoopVarRef() [1/2]

◆ getLoopVarRef() [2/2]

◆ setDistanceFunc()

◆ setLoopStmt()

◆ setLoopVarFunc()

◆ setLoopVarRef()

Friends And Related Function Documentation

◆ ASTStmtReader

◆ ASTStmtWriter