com.android.tools.lint.detector.api

Class ConstantEvaluator

java.lang.Object

com.android.tools.lint.detector.api.ConstantEvaluator

public class ConstantEvaluator
extends java.lang.Object

Evaluates constant expressions

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ConstantEvaluator.LastAssignmentFinder

Constructor Summary

Constructors

Constructor and Description
ConstantEvaluator() Creates a new constant evaluator

Method Summary

Modifier and Type	Method and Description
ConstantEvaluator	allowFieldInitializers()
ConstantEvaluator	allowUnknowns() Whether we allow computing values where some terms are unknown.
static java.lang.Object	evaluate(com.android.tools.lint.detector.api.JavaContext context, com.intellij.psi.PsiElement node) Evaluates the given node and returns the constant value it resolves to, if any.
static java.lang.Object	evaluate(com.android.tools.lint.detector.api.JavaContext context, org.jetbrains.uast.UElement element) Evaluates the given node and returns the constant value it resolves to, if any.
java.lang.Object	evaluate(com.intellij.psi.PsiElement node) Evaluates the given node and returns the constant value it resolves to, if any
java.lang.Object	evaluate(org.jetbrains.uast.UElement node) Evaluates the given node and returns the constant value it resolves to, if any
static java.lang.String	evaluateString(com.android.tools.lint.detector.api.JavaContext context, com.intellij.psi.PsiElement node, boolean allowUnknown) Evaluates the given node and returns the constant string it resolves to, if any.
static java.lang.String	evaluateString(com.android.tools.lint.detector.api.JavaContext context, org.jetbrains.uast.UElement element, boolean allowUnknown) Evaluates the given node and returns the constant string it resolves to, if any.
static com.intellij.psi.PsiExpression	findLastAssignment(com.intellij.psi.PsiElement usage, com.intellij.psi.PsiVariable variable) Computes the last assignment to a given variable counting backwards from the given context element
static boolean	isArrayLiteral(com.intellij.psi.PsiElement node) Returns true if the node is pointing to a an array literal
static boolean	isArrayLiteral(org.jetbrains.uast.UElement node) Returns true if the node is pointing to a an array literal

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ConstantEvaluator

public ConstantEvaluator()

Creates a new constant evaluator

Method Detail

allowUnknowns

public ConstantEvaluator allowUnknowns()

Whether we allow computing values where some terms are unknown. For example, the expression "foo" + x + "bar" would return null without and "foobar" with.

Returns:

this for constructor chaining

allowFieldInitializers

public ConstantEvaluator allowFieldInitializers()

evaluate

@Nullable
public java.lang.Object evaluate(@Nullable
                                           org.jetbrains.uast.UElement node)

Evaluates the given node and returns the constant value it resolves to, if any

Parameters:

node - the node to compute the constant value for

Returns:

the corresponding constant value - a String, an Integer, a Float, and so on

evaluate

@Nullable
public java.lang.Object evaluate(@Nullable
                                           com.intellij.psi.PsiElement node)

Evaluates the given node and returns the constant value it resolves to, if any

Parameters:

node - the node to compute the constant value for

Returns:

the corresponding constant value - a String, an Integer, a Float, and so on

isArrayLiteral

public static boolean isArrayLiteral(@Nullable
                                     com.intellij.psi.PsiElement node)

Returns true if the node is pointing to a an array literal

isArrayLiteral

public static boolean isArrayLiteral(@Nullable
                                     org.jetbrains.uast.UElement node)

Returns true if the node is pointing to a an array literal

evaluate

@Nullable
public static java.lang.Object evaluate(@Nullable
                                                  com.android.tools.lint.detector.api.JavaContext context,
                                                  @NonNull
                                                  com.intellij.psi.PsiElement node)

Evaluates the given node and returns the constant value it resolves to, if any. Convenience wrapper which creates a new ConstantEvaluator, evaluates the node and returns the result.

Parameters:

context - the context to use to resolve field references, if any

node - the node to compute the constant value for

Returns:

the corresponding constant value - a String, an Integer, a Float, and so on

evaluate

@Nullable
public static java.lang.Object evaluate(@Nullable
                                                  com.android.tools.lint.detector.api.JavaContext context,
                                                  @NonNull
                                                  org.jetbrains.uast.UElement element)

Evaluates the given node and returns the constant value it resolves to, if any. Convenience wrapper which creates a new ConstantEvaluator, evaluates the node and returns the result.

Parameters:

context - the context to use to resolve field references, if any

element - the node to compute the constant value for

Returns:

the corresponding constant value - a String, an Integer, a Float, and so on

evaluateString

@Nullable
public static java.lang.String evaluateString(@Nullable
                                                        com.android.tools.lint.detector.api.JavaContext context,
                                                        @NonNull
                                                        com.intellij.psi.PsiElement node,
                                                        boolean allowUnknown)

Evaluates the given node and returns the constant string it resolves to, if any. Convenience wrapper which creates a new ConstantEvaluator, evaluates the node and returns the result if the result is a string.

Parameters:

context - the context to use to resolve field references, if any

node - the node to compute the constant value for

allowUnknown - whether we should construct the string even if some parts of it are unknown

Returns:

the corresponding string, if any

findLastAssignment

@Nullable
public static com.intellij.psi.PsiExpression findLastAssignment(@NonNull
                                                                          com.intellij.psi.PsiElement usage,
                                                                          @NonNull
                                                                          com.intellij.psi.PsiVariable variable)

Computes the last assignment to a given variable counting backwards from the given context element

Parameters:

usage - the usage site to search backwards from

variable - the variable

Returns:

the last assignment or null

evaluateString

@Nullable
public static java.lang.String evaluateString(@Nullable
                                                        com.android.tools.lint.detector.api.JavaContext context,
                                                        @NonNull
                                                        org.jetbrains.uast.UElement element,
                                                        boolean allowUnknown)

Evaluates the given node and returns the constant string it resolves to, if any. Convenience wrapper which creates a new ConstantEvaluator, evaluates the node and returns the result if the result is a string.

Parameters:

context - the context to use to resolve field references, if any

element - the node to compute the constant value for

allowUnknown - whether we should construct the string even if some parts of it are unknown

Returns:

the corresponding string, if any