SkSL::TernaryExpression Class Reference

#include <SkSLTernaryExpression.h>

Inheritance diagram for SkSL::TernaryExpression:

Public Member Functions
	TernaryExpression (Position pos, std::unique_ptr< Expression > test, std::unique_ptr< Expression > ifTrue, std::unique_ptr< Expression > ifFalse)
std::unique_ptr< Expression > &	test ()
const std::unique_ptr< Expression > &	test () const
std::unique_ptr< Expression > &	ifTrue ()
const std::unique_ptr< Expression > &	ifTrue () const
std::unique_ptr< Expression > &	ifFalse ()
const std::unique_ptr< Expression > &	ifFalse () const
std::unique_ptr< Expression >	clone (Position pos) const override
std::string	description (OperatorPrecedence parentPrecedence) const override
Public Member Functions inherited from SkSL::Expression
	Expression (Position pos, Kind kind, const Type *type)
Kind	kind () const
virtual const Type &	type () const
bool	isAnyConstructor () const
bool	isIntLiteral () const
bool	isFloatLiteral () const
bool	isBoolLiteral () const
AnyConstructor &	asAnyConstructor ()
const AnyConstructor &	asAnyConstructor () const
bool	isIncomplete (const Context &context) const
virtual ComparisonResult	compareConstant (const Expression &other) const
CoercionCost	coercionCost (const Type &target) const
virtual bool	supportsConstantValues () const
virtual std::optional< double >	getConstantValue (int n) const
std::unique_ptr< Expression >	clone () const
std::string	description () const final
Public Member Functions inherited from SkSL::IRNode
virtual	~IRNode ()
	IRNode (const IRNode &)=delete
IRNode &	operator= (const IRNode &)=delete
Position	position () const
void	setPosition (Position p)
template<typename T >
bool	is () const
template<typename T >
const T &	as () const
template<typename T >
T &	as ()

Static Public Member Functions
static std::unique_ptr< Expression >	Convert (const Context &context, Position pos, std::unique_ptr< Expression > test, std::unique_ptr< Expression > ifTrue, std::unique_ptr< Expression > ifFalse)
static std::unique_ptr< Expression >	Make (const Context &context, Position pos, std::unique_ptr< Expression > test, std::unique_ptr< Expression > ifTrue, std::unique_ptr< Expression > ifFalse)
Static Public Member Functions inherited from SkSL::Poolable
static void *	operator new (const size_t size)
static void	operator delete (void *ptr)

Static Public Attributes
static constexpr Kind	kIRNodeKind = Kind::kTernary

Additional Inherited Members
Public Types inherited from SkSL::Expression
enum class	ComparisonResult { kUnknown = -1 , kNotEqual , kEqual }
using	Kind = ExpressionKind
Public Attributes inherited from SkSL::IRNode
Position	fPosition
Protected Member Functions inherited from SkSL::IRNode
	IRNode (Position position, int kind)
Protected Attributes inherited from SkSL::IRNode
int	fKind

Detailed Description

A ternary expression (test ? ifTrue : ifFalse).

Definition at line 30 of file SkSLTernaryExpression.h.

Constructor & Destructor Documentation

TernaryExpression()

SkSL::TernaryExpression::TernaryExpression ( Position  pos, std::unique_ptr< Expression >  test, std::unique_ptr< Expression >  ifTrue, std::unique_ptr< Expression >  ifFalse  )

inline

Definition at line 34 of file SkSLTernaryExpression.h.

        : INHERITED(pos, kIRNodeKind, &ifTrue->type())
        , fTest(std::move(test))
        , fIfTrue(std::move(ifTrue))
        , fIfFalse(std::move(ifFalse)) {
        SkASSERT(this->ifTrue()->type().matches(this->ifFalse()->type()));
    }

Member Function Documentation

clone()

std::unique_ptr< Expression > SkSL::TernaryExpression::clone ( Position  pos ) const

inlineoverridevirtual

Implements SkSL::Expression.

Definition at line 82 of file SkSLTernaryExpression.h.

                                                                 {
        return std::make_unique<TernaryExpression>(pos, this->test()->clone(),
                                                   this->ifTrue()->clone(),
                                                   this->ifFalse()->clone());
    }

Convert()

std::unique_ptr< Expression > SkSL::TernaryExpression::Convert ( const Context &  context, Position  pos, std::unique_ptr< Expression >  test, std::unique_ptr< Expression >  ifTrue, std::unique_ptr< Expression >  ifFalse  )

static

Definition at line 24 of file SkSLTernaryExpression.cpp.

                                                                                          {
    test = context.fTypes.fBool->coerceExpression(std::move(test), context);
    if (!test || !ifTrue || !ifFalse) {
        return nullptr;
    }
    if (ifTrue->type().componentType().isOpaque()) {
        context.fErrors->error(pos, "ternary expression of opaque type '" +
                                    ifTrue->type().displayName() + "' is not allowed");
        return nullptr;
    }
    const Type* trueType;
    const Type* falseType;
    const Type* resultType;
    Operator equalityOp(Operator::Kind::EQEQ);
    if (!equalityOp.determineBinaryType(context, ifTrue->type(), ifFalse->type(),
                                        &trueType, &falseType, &resultType) ||
        !trueType->matches(*falseType)) {
        Position errorPos = ifTrue->fPosition.rangeThrough(ifFalse->fPosition);
        if (ifTrue->type().isVoid()) {
            context.fErrors->error(errorPos, "ternary expression of type 'void' is not allowed");
        } else {
            context.fErrors->error(errorPos, "ternary operator result mismatch: '" +
                                             ifTrue->type().displayName() + "', '" +
                                             ifFalse->type().displayName() + "'");
        }
        return nullptr;
    }
    if (trueType->isOrContainsArray()) {
        context.fErrors->error(pos, "ternary operator result may not be an array (or struct "
                                    "containing an array)");
        return nullptr;
    }
    ifTrue = trueType->coerceExpression(std::move(ifTrue), context);
    if (!ifTrue) {
        return nullptr;
    }
    ifFalse = falseType->coerceExpression(std::move(ifFalse), context);
    if (!ifFalse) {
        return nullptr;
    }
    return TernaryExpression::Make(context, pos, std::move(test), std::move(ifTrue),
                                   std::move(ifFalse));
}

description()

std::string SkSL::TernaryExpression::description ( OperatorPrecedence  parentPrecedence ) const

overridevirtual

Implements SkSL::Expression.

Definition at line 139 of file SkSLTernaryExpression.cpp.

                                                                                  {
    bool needsParens = (OperatorPrecedence::kTernary >= parentPrecedence);
    return std::string(needsParens ? "(" : "") +
           this->test()->description(OperatorPrecedence::kTernary) + " ? " +
           this->ifTrue()->description(OperatorPrecedence::kTernary) + " : " +
           this->ifFalse()->description(OperatorPrecedence::kTernary) +
           std::string(needsParens ? ")" : "");
}

ifFalse() [1/2]

std::unique_ptr< Expression > & SkSL::TernaryExpression::ifFalse ( )

inline

Definition at line 74 of file SkSLTernaryExpression.h.

                                         {
        return fIfFalse;
    }

ifFalse() [2/2]

const std::unique_ptr< Expression > & SkSL::TernaryExpression::ifFalse ( ) const

inline

Definition at line 78 of file SkSLTernaryExpression.h.

                                                     {
        return fIfFalse;
    }

ifTrue() [1/2]

std::unique_ptr< Expression > & SkSL::TernaryExpression::ifTrue ( )

inline

Definition at line 66 of file SkSLTernaryExpression.h.

                                        {
        return fIfTrue;
    }

ifTrue() [2/2]

const std::unique_ptr< Expression > & SkSL::TernaryExpression::ifTrue ( ) const

inline

Definition at line 70 of file SkSLTernaryExpression.h.

                                                    {
        return fIfTrue;
    }

Make()

std::unique_ptr< Expression > SkSL::TernaryExpression::Make ( const Context &  context, Position  pos, std::unique_ptr< Expression >  test, std::unique_ptr< Expression >  ifTrue, std::unique_ptr< Expression >  ifFalse  )

static

Definition at line 72 of file SkSLTernaryExpression.cpp.

                                                                                       {
    SkASSERT(ifTrue->type().matches(ifFalse->type()));
    SkASSERT(!ifTrue->type().componentType().isOpaque());
    SkASSERT(!context.fConfig->strictES2Mode() || !ifTrue->type().isOrContainsArray());
 
    const Expression* testExpr = ConstantFolder::GetConstantValueForVariable(*test);
    if (testExpr->isBoolLiteral()) {
        // static boolean test, just return one of the branches
        if (testExpr->as<Literal>().boolValue()) {
            ifTrue->fPosition = pos;
            return ifTrue;
        } else {
            ifFalse->fPosition = pos;
            return ifFalse;
        }
    }
 
    if (context.fConfig->fSettings.fOptimize) {
        const Expression* ifTrueExpr  = ConstantFolder::GetConstantValueForVariable(*ifTrue);
        const Expression* ifFalseExpr = ConstantFolder::GetConstantValueForVariable(*ifFalse);
 
        // A ternary with matching true- and false-cases does not need to branch.
        if (Analysis::IsSameExpressionTree(*ifTrueExpr, *ifFalseExpr)) {
            // If `test` has no side-effects, we can eliminate it too, and just return `ifTrue`.
            if (!Analysis::HasSideEffects(*test)) {
                ifTrue->fPosition = pos;
                return ifTrue;
            }
            // Return a comma-expression containing `(test, ifTrue)`.
            return BinaryExpression::Make(context, pos, std::move(test),
                                          Operator::Kind::COMMA, std::move(ifTrue));
        }
 
        // A ternary of the form `test ? expr : false` can be simplified to `test && expr`.
        if (ifFalseExpr->isBoolLiteral() && !ifFalseExpr->as<Literal>().boolValue()) {
            return BinaryExpression::Make(context, pos, std::move(test),
                                          Operator::Kind::LOGICALAND, std::move(ifTrue));
        }
 
        // A ternary of the form `test ? true : expr` can be simplified to `test || expr`.
        if (ifTrueExpr->isBoolLiteral() && ifTrueExpr->as<Literal>().boolValue()) {
            return BinaryExpression::Make(context, pos, std::move(test),
                                          Operator::Kind::LOGICALOR, std::move(ifFalse));
        }
 
        // A ternary of the form `test ? false : true` can be simplified to `!test`.
        if (ifTrueExpr->isBoolLiteral() && !ifTrueExpr->as<Literal>().boolValue() &&
            ifFalseExpr->isBoolLiteral() && ifFalseExpr->as<Literal>().boolValue()) {
            return PrefixExpression::Make(context, pos, Operator::Kind::LOGICALNOT,
                                          std::move(test));
        }
 
        // A ternary of the form `test ? 1 : 0` can be simplified to `cast(test)`.
        if (ifTrueExpr->is<Literal>() && ifTrueExpr->as<Literal>().value() == 1.0 &&
            ifFalseExpr->is<Literal>() && ifFalseExpr->as<Literal>().value() == 0.0) {
            return ConstructorScalarCast::Make(context, pos, ifTrue->type(), std::move(test));
        }
    }
 
    return std::make_unique<TernaryExpression>(pos, std::move(test), std::move(ifTrue),
                                               std::move(ifFalse));
}

test() [1/2]

std::unique_ptr< Expression > & SkSL::TernaryExpression::test ( )

inline

Definition at line 58 of file SkSLTernaryExpression.h.

                                      {
        return fTest;
    }

test() [2/2]

const std::unique_ptr< Expression > & SkSL::TernaryExpression::test ( ) const

inline

Definition at line 62 of file SkSLTernaryExpression.h.

                                                  {
        return fTest;
    }

Member Data Documentation

kIRNodeKind

constexpr Kind SkSL::TernaryExpression::kIRNodeKind = Kind::kTernary

inlinestaticconstexpr

Definition at line 32 of file SkSLTernaryExpression.h.

---

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

• third_party/skia/src/sksl/ir/SkSLTernaryExpression.h
• third_party/skia/src/sksl/ir/SkSLTernaryExpression.cpp