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/**
* Provides classfile parsing, generation, and transformation library.
* The {@code io.github.dmlloyd.classfile} package contains classes for reading, writing, and
* modifying Java class files, as specified in Chapter {@jvms 4} of the
* Java Virtual Machine Specification.
*
* Reading classfiles
* The main class for reading classfiles is {@link io.github.dmlloyd.classfile.ClassModel}; we
* convert bytes into a {@link io.github.dmlloyd.classfile.ClassModel} with {@link
* io.github.dmlloyd.classfile.ClassFile#parse(byte[])}:
*
* {@snippet lang=java :
* ClassModel cm = ClassFile.of().parse(bytes);
* }
*
* There are several additional overloads of {@code parse} that let you specify
* various processing options.
*
* A {@link io.github.dmlloyd.classfile.ClassModel} is an immutable description of a class
* file. It provides accessor methods to get at class metadata (e.g., {@link
* io.github.dmlloyd.classfile.ClassModel#thisClass()}, {@link io.github.dmlloyd.classfile.ClassModel#flags()}),
* as well as subordinate classfile entities ({@link io.github.dmlloyd.classfile.ClassModel#fields()},
* {@link io.github.dmlloyd.classfile.ClassModel#attributes()}). A {@link
* io.github.dmlloyd.classfile.ClassModel} is inflated lazily; most parts of the classfile are
* not parsed until they are actually needed.
*
* We can enumerate the names of the fields and methods in a class by:
* {@snippet lang="java" class="PackageSnippets" region="enumerateFieldsMethods1"}
*
* When we enumerate the methods, we get a {@link io.github.dmlloyd.classfile.MethodModel} for each method; like a
* {@code ClassModel}, it gives us access to method metadata and
* the ability to descend into subordinate entities such as the bytecodes of the
* method body. In this way, a {@code ClassModel} is the root of a
* tree, with children for fields, methods, and attributes, and {@code MethodModel} in
* turn has its own children (attributes, {@code CodeModel}, etc.)
*
* Methods like {@link io.github.dmlloyd.classfile.ClassModel#methods} allows us to traverse the class structure
* explicitly, going straight to the parts we are interested in. This is useful
* for certain kinds of analysis, but if we wanted to process the whole
* classfile, we may want something more organized. A {@link
* io.github.dmlloyd.classfile.ClassModel} also provides us with a view of the classfile as a
* series of class elements, which may include methods, fields, attributes,
* and more, and which can be distinguished with pattern matching. We could
* rewrite the above example as:
* {@snippet lang="java" class="PackageSnippets" region="enumerateFieldsMethods2"}
*
* The models returned as elements from traversing {@code ClassModel} can in
* turn be sources of elements. If we wanted to
* traverse a classfile and enumerate all the classes for which we access fields
* and methods, we can pick out the class elements that describe methods, then
* in turn pick out the method elements that describe the code attribute, and
* finally pick out the code elements that describe field access and invocation
* instructions:
* {@snippet lang="java" class="PackageSnippets" region="gatherDependencies1"}
*
* This same query could alternately be processed as a stream pipeline over
* class elements:
* {@snippet lang="java" class="PackageSnippets" region="gatherDependencies2"}
*
*
Models and elements
* The view of classfiles presented by this API is framed in terms of
* models and elements. Models represent complex structures,
* such as classes, methods, fields, record elements, or the code body of a
* method. Models can be explored either via random-access navigation (such as
* the {@link io.github.dmlloyd.classfile.ClassModel#methods()} accessor) or as a linear
* sequence of elements. (Elements can in turn also be models; a {@link
* io.github.dmlloyd.classfile.FieldModel} is also an element of a class.) For each model type
* (e.g., {@link io.github.dmlloyd.classfile.MethodModel}), there is a corresponding element
* type ({@link io.github.dmlloyd.classfile.MethodElement}). Models and elements are immutable
* and are inflated lazily so creating a model does not necessarily require
* processing its entire content.
*
* The constant pool
* Much of the interesting content in a classfile lives in the constant
* pool. {@link io.github.dmlloyd.classfile.ClassModel} provides a lazily-inflated,
* read-only view of the constant pool via {@link io.github.dmlloyd.classfile.ClassModel#constantPool()}.
* Descriptions of classfile content is often exposed in the form of various
* subtypes of {@link io.github.dmlloyd.classfile.constantpool.PoolEntry}, such as {@link
* io.github.dmlloyd.classfile.constantpool.ClassEntry} or {@link io.github.dmlloyd.classfile.constantpool.Utf8Entry}.
*
* Constant pool entries are also exposed through models and elements; in the
* above traversal example, the {@link io.github.dmlloyd.classfile.instruction.InvokeInstruction}
* element exposed a method for {@code owner} that corresponds to a {@code
* Constant_Class_info} entry in the constant pool.
*
*
Attributes
* Much of the contents of a classfile is stored in attributes; attributes are
* found on classes, methods, fields, record components, and on the {@code Code}
* attribute. Most attributes are surfaced as elements; for example, {@link
* io.github.dmlloyd.classfile.attribute.SignatureAttribute} is a {@link
* io.github.dmlloyd.classfile.ClassElement}, {@link io.github.dmlloyd.classfile.MethodElement}, and {@link
* io.github.dmlloyd.classfile.FieldElement} since it can appear in all of those places, and is
* included when iterating the elements of the corresponding model.
*
* Some attributes are not surfaced as elements; these are attributes that are
* tightly coupled to -- and logically part of -- other parts of the class file.
* These include the {@code BootstrapMethods}, {@code LineNumberTable}, {@code
* StackMapTable}, {@code LocalVariableTable}, and {@code
* LocalVariableTypeTable} attributes. These are processed by the library and
* treated as part of the structure they are coupled to (the entries of the
* {@code BootstrapMethods} attribute are treated as part of the constant pool;
* line numbers and local variable metadata are modeled as elements of {@link
* io.github.dmlloyd.classfile.CodeModel}.)
*
* The {@code Code} attribute, in addition to being modeled as a {@link
* io.github.dmlloyd.classfile.MethodElement}, is also a model in its own right ({@link
* io.github.dmlloyd.classfile.CodeModel}) due to its complex structure.
*
* Each standard attribute has an interface (in {@code jdk.internal.classfile.attribute})
* which exposes the contents of the attribute and provides factories to
* construct the attribute. For example, the {@code Signature} attribute is
* defined by the {@link io.github.dmlloyd.classfile.attribute.SignatureAttribute} class, and
* provides accessors for {@link io.github.dmlloyd.classfile.attribute.SignatureAttribute#signature()}
* as well as factories taking {@link io.github.dmlloyd.classfile.constantpool.Utf8Entry} or
* {@link java.lang.String}.
*
*
Custom attributes
* Attributes are converted between their classfile form and their corresponding
* object form via an {@link io.github.dmlloyd.classfile.AttributeMapper}. An {@code
* AttributeMapper} provides the
* {@link io.github.dmlloyd.classfile.AttributeMapper#readAttribute(AttributedElement,
* ClassReader, int)} method for mapping from the classfile format
* to an attribute instance, and the
* {@link io.github.dmlloyd.classfile.AttributeMapper#writeAttribute(BufWriter,
* io.github.dmlloyd.classfile.Attribute)} method for mapping back to the classfile format. It also
* contains metadata including the attribute name, the set of classfile entities
* where the attribute is applicable, and whether multiple attributes of the
* same kind are allowed on a single entity.
*
* There are built-in attribute mappers (in {@link io.github.dmlloyd.classfile.Attributes}) for
* each of the attribute types defined in section {@jvms 4.7} of The Java Virtual
* Machine Specification, as well as several common nonstandard attributes used by the
* JDK such as {@code CharacterRangeTable}.
*
* Unrecognized attributes are delivered as elements of type {@link
* io.github.dmlloyd.classfile.attribute.UnknownAttribute}, which provide access only to the
* {@code byte[]} contents of the attribute.
*
* For nonstandard attributes, user-provided attribute mappers can be specified
* through the use of the {@link
* io.github.dmlloyd.classfile.ClassFile.AttributeMapperOption#of(java.util.function.Function)}}
* classfile option. Implementations of custom attributes should extend {@link
* io.github.dmlloyd.classfile.CustomAttribute}.
*
*
Options
*
* {@link io.github.dmlloyd.classfile.ClassFile#of(ClassFile.Option[])}
* accepts a list of options. {@link io.github.dmlloyd.classfile.ClassFile.Option} is a base interface
* for some statically enumerated options, as well as factories for more complex options,
* including:
*
* - {@link io.github.dmlloyd.classfile.ClassFile.StackMapsOption}
* -- generate stackmaps (default is {@code STACK_MAPS_WHEN_REQUIRED})
* - {@link io.github.dmlloyd.classfile.ClassFile.AttributeMapperOption#of(java.util.function.Function)}
* -- specify format of custom attributes
* - {@link io.github.dmlloyd.classfile.ClassFile.UnknownAttributesOption}
* -- processing of unrecognized attributes (default is {@code PASS_UNKNOWN_ATTRIBUTES})
* - {@link io.github.dmlloyd.classfile.ClassFile.ConstantPoolSharingOption}}
* -- share constant pool when transforming (default is {@code SHARED_POOL})
* - {@link io.github.dmlloyd.classfile.ClassFile.ClassHierarchyResolverOption#of(ClassHierarchyResolver)}
* -- specify a custom class hierarchy resolver used by stack map generation
* - {@link io.github.dmlloyd.classfile.ClassFile.ConstantPoolSharingOption}}
* -- share constant pool when transforming (default is {@code SHARED_POOL})
* - {@link io.github.dmlloyd.classfile.ClassFile.DeadCodeOption}}
* -- patch out unreachable code (default is {@code PATCH_DEAD_CODE})
* - {@link io.github.dmlloyd.classfile.ClassFile.DeadLabelsOption}}
* -- filter unresolved labels (default is {@code FAIL_ON_DEAD_LABELS})
* - {@link io.github.dmlloyd.classfile.ClassFile.DebugElementsOption}
* -- processing of debug information, such as local variable metadata (default is {@code PASS_DEBUG})
* - {@link io.github.dmlloyd.classfile.ClassFile.LineNumbersOption}
* -- processing of line numbers (default is {@code PASS_LINE_NUMBERS})
* - {@link io.github.dmlloyd.classfile.ClassFile.ShortJumpsOption}
* -- automatically rewrite short jumps to long when necessary (default is {@code FIX_SHORT_JUMPS})
* - {@link io.github.dmlloyd.classfile.ClassFile.StackMapsOption}
* -- generate stackmaps (default is {@code STACK_MAPS_WHEN_REQUIRED})
*
*
* Most options allow you to request that certain parts of the classfile be
* skipped during traversal, such as debug information or unrecognized
* attributes. Some options allow you to suppress generation of portions of the
* classfile, such as stack maps. Many of these options are to access
* performance tradeoffs; processing debug information and line numbers has a
* cost (both in writing and reading.) If you don't need this information, you
* can suppress it with options to gain some performance.
*
*
Writing classfiles
* ClassFile generation is accomplished through builders. For each
* entity type that has a model, there is also a corresponding builder type;
* classes are built through {@link io.github.dmlloyd.classfile.ClassBuilder}, methods through
* {@link io.github.dmlloyd.classfile.MethodBuilder}, etc.
*
* Rather than creating builders directly, builders are provided as an argument
* to a user-provided lambda. To generate the familiar "hello world" program,
* we ask for a class builder, and use that class builder to create method
* builders for the constructor and {@code main} method, and in turn use the
* method builders to create a {@code Code} attribute and use the code builders
* to generate the instructions:
* {@snippet lang="java" class="PackageSnippets" region="helloWorld1"}
*
* The convenience methods {@code ClassBuilder.buildMethodBody} allows us to ask
* {@link ClassBuilder} to create code builders to build method bodies directly,
* skipping the method builder custom lambda:
* {@snippet lang="java" class="PackageSnippets" region="helloWorld2"}
*
* Builders often support multiple ways of expressing the same entity at
* different levels of abstraction. For example, the {@code invokevirtual}
* instruction invoking {@code println} could have been generated with {@link
* io.github.dmlloyd.classfile.CodeBuilder#invokevirtual(java.lang.constant.ClassDesc,
* String, java.lang.constant.MethodTypeDesc) CodeBuilder.invokevirtual}, {@link
* io.github.dmlloyd.classfile.CodeBuilder#invoke(io.github.dmlloyd.classfile.Opcode,
* java.lang.constant.ClassDesc, String, java.lang.constant.MethodTypeDesc,
* boolean) CodeBuilder.invokeInstruction}, or {@link
* io.github.dmlloyd.classfile.CodeBuilder#with(ClassFileElement)
* CodeBuilder.with}.
*
* The convenience method {@code CodeBuilder.invokevirtual} behaves as if it calls
* the convenience method {@code CodeBuilder.invokeInstruction}, which in turn behaves
* as if it calls method {@code CodeBuilder.with}. This composing of method calls on the
* builder enables the composing of transforms (as described later).
*
* Unless otherwise noted, passing a {@code null} argument to a constructor
* or method of any Class-File API class or interface will cause a {@link
* java.lang.NullPointerException NullPointerException} to be thrown. Additionally,
* invoking a method with an array or collection containing a {@code null} element
* will cause a {@code NullPointerException}, unless otherwise specified.
*
* Symbolic information
* To describe symbolic information for classes and types, the API uses the
* nominal descriptor abstractions from {@code java.lang.constant} such as {@link
* java.lang.constant.ClassDesc} and {@link java.lang.constant.MethodTypeDesc},
* which is less error-prone than using raw strings.
*
* If a constant pool entry has a nominal representation then it provides a
* method returning the corresponding nominal descriptor type e.g.
* method {@link io.github.dmlloyd.classfile.constantpool.ClassEntry#asSymbol} returns
* {@code ClassDesc}.
*
* Where appropriate builders provide two methods for building an element with
* symbolic information, one accepting nominal descriptors, and the other
* accepting constant pool entries.
*
*
Consistency checks, syntax checks and verification
* No consistency checks are performed while building or transforming classfiles
* (except for null arguments checks). All builders and classfile elements factory
* methods accepts the provided information without implicit validation.
* However, fatal inconsistencies (like for example invalid code sequence or
* unresolved labels) affects internal tools and may cause exceptions later in
* the classfile building process.
*
* Using nominal descriptors assures the right serial form is applied by the
* ClassFile API library based on the actual context. Also these nominal
* descriptors are validated during their construction, so it is not possible to
* create them with invalid content by mistake. Following example pass class
* name to the {@link java.lang.constant.ClassDesc#of} method for validation
* and the library performs automatic conversion to the right internal form of
* the class name when serialized in the constant pool as a class entry.
* {@snippet lang=java :
* var validClassEntry = constantPoolBuilder.classEntry(ClassDesc.of("mypackage.MyClass"));
* }
*
* On the other hand it is possible to use builders methods and factories accepting
* constant pool entries directly. Constant pool entries can be constructed also
* directly from raw values, with no additional conversions or validations.
* Following example uses intentionally wrong class name form and it is applied
* without any validation or conversion.
* {@snippet lang=java :
* var invalidClassEntry = constantPoolBuilder.classEntry(
* constantPoolBuilder.utf8Entry("mypackage.MyClass"));
* }
*
* More complex verification of a classfile can be achieved by invocation of
* {@link io.github.dmlloyd.classfile.ClassFile#verify}.
*
*
Transforming classfiles
* ClassFile Processing APIs are most frequently used to combine reading and
* writing into transformation, where a classfile is read, localized changes are
* made, but much of the classfile is passed through unchanged. For each kind
* of builder, {@code XxxBuilder} has a method {@code with(XxxElement)} so that
* elements that we wish to pass through unchanged can be handed directly back
* to the builder.
*
* If we wanted to strip out methods whose names starts with "debug", we could
* get an existing {@link io.github.dmlloyd.classfile.ClassModel}, build a new classfile that
* provides a {@link io.github.dmlloyd.classfile.ClassBuilder}, iterate the elements of the
* original {@link io.github.dmlloyd.classfile.ClassModel}, and pass through all of them to
* the builder except the methods we want to drop:
* {@snippet lang="java" class="PackageSnippets" region="stripDebugMethods1"}
*
* This hands every class element, except for those corresponding to methods
* whose names start with {@code debug}, back to the builder. Transformations
* can of course be more complicated, diving into method bodies and instructions
* and transforming those as well, but the same structure is repeated at every
* level, since every entity has corresponding model, builder, and element
* abstractions.
*
* Transformation can be viewed as a "flatMap" operation on the sequence of
* elements; for every element, we could pass it through unchanged, drop it, or
* replace it with one or more elements. Because transformation is such a
* common operation on classfiles, each model type has a corresponding {@code
* XxxTransform} type (which describes a transform on a sequence of {@code
* XxxElement}) and each builder type has {@code transformYyy} methods for transforming
* its child models. A transform is simply a functional interface that takes a
* builder and an element, and an implementation "flatMap"s elements
* into the builder. We could express the above as:
* {@snippet lang="java" class="PackageSnippets" region="stripDebugMethods2"}
*
* {@code ClassTransform.dropping} convenience method allow us to simplify the same
* transformation construction and express the above as:
* {@snippet lang="java" class="PackageSnippets" region="stripDebugMethods3"}
*
*
Lifting transforms
* While the example using transformations are only slightly shorter, the
* advantage of expressing transformation in this way is that the transform
* operations can be more easily combined. Suppose we want to redirect
* invocations of static methods on {@code Foo} to the corresponding method on
* {@code Bar} instead. We could express this as a transformation on {@link
* io.github.dmlloyd.classfile.CodeElement}:
* {@snippet lang="java" class="PackageSnippets" region="fooToBarTransform"}
*
* We can then lift this transformation on code elements into a
* transformation on method elements. This intercepts method elements that
* correspond to a {@code Code} attribute, dives into its code elements, and
* applies the code transform to them, and passes other method elements through
* unchanged:
* {@snippet lang=java :
* MethodTransform mt = MethodTransform.transformingCode(fooToBar);
* }
*
* and further lift the transform on method elements into one on class
* elements:
* {@snippet lang=java :
* ClassTransform ct = ClassTransform.transformingMethods(mt);
* }
*
* or lift the code transform into the class transform directly:
* {@snippet lang=java :
* ClassTransform ct = ClassTransform.transformingMethodBodiess(fooToBar);
* }
*
* and then transform the classfile:
* {@snippet lang=java :
* var cc = ClassFile.of();
* byte[] newBytes = cc.transform(cc.parse(bytes), ct);
* }
*
* This is much more concise (and less error-prone) than the equivalent
* expressed by traversing the classfile structure directly:
* {@snippet lang="java" class="PackageSnippets" region="fooToBarUnrolled"}
*
*
Composing transforms
* Transforms on the same type of element can be composed in sequence, where the
* output of the first is fed to the input of the second. Suppose we want to
* instrument all method calls, where we print the name of a method before
* calling it:
* {@snippet lang="java" class="PackageSnippets" region="instrumentCallsTransform"}
*
* Then we can compose {@code fooToBar} and {@code instrumentCalls} with {@link
* io.github.dmlloyd.classfile.CodeTransform#andThen(io.github.dmlloyd.classfile.CodeTransform)}:
*
* {@snippet lang=java :
* var cc = ClassFile.of();
* byte[] newBytes = cc.transform(cc.parse(bytes),
* ClassTransform.transformingMethods(
* MethodTransform.transformingCode(
* fooToBar.andThen(instrumentCalls))));
* }
*
* Transform {@code instrumentCalls} will receive all code elements produced by
* transform {@code forToBar}, either those code elements from the original classfile
* or replacements (replacing static invocations to {@code Foo} with those to {@code Bar}).
*
*
Constant pool sharing
* Transformation doesn't merely handle the logistics of reading, transforming
* elements, and writing. Most of the time when we are transforming a
* classfile, we are making relatively minor changes. To optimize such cases,
* transformation seeds the new classfile with a copy of the constant pool from
* the original classfile; this enables significant optimizations (methods and
* attributes that are not transformed can be processed by bulk-copying their
* bytes, rather than parsing them and regenerating their contents.) If
* constant pool sharing is not desired it can be suppressed
* with the {@link io.github.dmlloyd.classfile.ClassFile.ConstantPoolSharingOption} option.
* Such suppression may be beneficial when transformation removes many elements,
* resulting in many unreferenced constant pool entries.
*
* Transformation handling of unknown classfile elements
* Custom classfile transformations might be unaware of classfile elements
* introduced by future JDK releases. To achieve deterministic stability,
* classfile transforms interested in consuming all classfile elements should be
* implemented strictly to throw exceptions if running on a newer JDK, if the
* transformed class file is a newer version, or if a new and unknown classfile
* element appears. As for example in the following strict compatibility-checking
* transformation snippets:
* {@snippet lang="java" class="PackageSnippets" region="strictTransform1"}
* {@snippet lang="java" class="PackageSnippets" region="strictTransform2"}
* {@snippet lang="java" class="PackageSnippets" region="strictTransform3"}
*
* Conversely, classfile transforms that are only interested in consuming a portion
* of classfile elements do not need to concern with new and unknown classfile
* elements and may pass them through. Following example shows such future-proof
* code transformation:
* {@snippet lang="java" class="PackageSnippets" region="benevolentTransform"}
*
*
API conventions
*
* The API is largely derived from a data model
* for the classfile format, which defines each element kind (which includes models and
* attributes) and its properties. For each element kind, there is a
* corresponding interface to describe that element, and factory methods to
* create that element. Some element kinds also have convenience methods on the
* corresponding builder (e.g., {@link
* io.github.dmlloyd.classfile.CodeBuilder#invokevirtual(java.lang.constant.ClassDesc,
* String, java.lang.constant.MethodTypeDesc)}).
*
* Most symbolic information in elements is represented by constant pool entries
* (for example, the owner of a field is represented by a {@link
* io.github.dmlloyd.classfile.constantpool.ClassEntry}.) Factories and builders also
* accept nominal descriptors from {@code java.lang.constant} (e.g., {@link
* java.lang.constant.ClassDesc}.)
*
*
Data model
* We define each kind of element by its name, an optional arity indicator (zero
* or more, zero or one, exactly one), and a list of components. The elements
* of a class are fields, methods, and the attributes that can appear on
* classes:
*
* {@snippet lang="text" :
* ClassElement =
* FieldModel*(UtfEntry name, Utf8Entry descriptor)
* | MethodModel*(UtfEntry name, Utf8Entry descriptor)
* | ModuleAttribute?(int flags, ModuleEntry moduleName, UtfEntry moduleVersion,
* List requires, List opens,
* List exports, List provides,
* List uses)
* | ModulePackagesAttribute?(List packages)
* | ModuleTargetAttribute?(Utf8Entry targetPlatform)
* | ModuleHashesAttribute?(Utf8Entry algorithm, List hashes)
* | ModuleResolutionAttribute?(int resolutionFlags)
* | SourceFileAttribute?(Utf8Entry sourceFile)
* | SourceDebugExtensionsAttribute?(byte[] contents)
* | CompilationIDAttribute?(Utf8Entry compilationId)
* | SourceIDAttribute?(Utf8Entry sourceId)
* | NestHostAttribute?(ClassEntry nestHost)
* | NestMembersAttribute?(List nestMembers)
* | RecordAttribute?(List components)
* | EnclosingMethodAttribute?(ClassEntry className, NameAndTypeEntry method)
* | InnerClassesAttribute?(List classes)
* | PermittedSubclassesAttribute?(List permittedSubclasses)
* | DeclarationElement*
* }
*
* where {@code DeclarationElement} are the elements that are common to all declarations
* (classes, methods, fields) and so are factored out:
*
* {@snippet lang="text" :
* DeclarationElement =
* SignatureAttribute?(Utf8Entry signature)
* | SyntheticAttribute?()
* | DeprecatedAttribute?()
* | RuntimeInvisibleAnnotationsAttribute?(List annotations)
* | RuntimeVisibleAnnotationsAttribute?(List annotations)
* | CustomAttribute*
* | UnknownAttribute*
* }
*
* Fields and methods are models with their own elements. The elements of fields
* and methods are fairly simple; most of the complexity of methods lives in the
* {@link io.github.dmlloyd.classfile.CodeModel} (which models the {@code Code} attribute
* along with the code-related attributes: stack map table, local variable table,
* line number table, etc.)
*
* {@snippet lang="text" :
* FieldElement =
* DeclarationElement
* | ConstantValueAttribute?(ConstantValueEntry constant)
*
* MethodElement =
* DeclarationElement
* | CodeModel?()
* | AnnotationDefaultAttribute?(ElementValue defaultValue)
* | MethodParametersAttribute?(List parameters)
* | ExceptionsAttribute?(List exceptions)
* }
*
* {@link io.github.dmlloyd.classfile.CodeModel} is unique in that its elements are ordered.
* Elements of {@code Code} include ordinary bytecodes, as well as a number of pseudo-instructions
* representing branch targets, line number metadata, local variable metadata, and
* catch blocks.
*
* {@snippet lang="text" :
* CodeElement = Instruction | PseudoInstruction
*
* Instruction =
* LoadInstruction(TypeKind type, int slot)
* | StoreInstruction(TypeKind type, int slot)
* | IncrementInstruction(int slot, int constant)
* | BranchInstruction(Opcode opcode, Label target)
* | LookupSwitchInstruction(Label defaultTarget, List cases)
* | TableSwitchInstruction(Label defaultTarget, int low, int high,
* List cases)
* | ReturnInstruction(TypeKind kind)
* | ThrowInstruction()
* | FieldInstruction(Opcode opcode, FieldRefEntry field)
* | InvokeInstruction(Opcode opcode, MemberRefEntry method, boolean isInterface)
* | InvokeDynamicInstruction(InvokeDynamicEntry invokedynamic)
* | NewObjectInstruction(ClassEntry className)
* | NewReferenceArrayInstruction(ClassEntry componentType)
* | NewPrimitiveArrayInstruction(TypeKind typeKind)
* | NewMultiArrayInstruction(ClassEntry componentType, int dims)
* | ArrayLoadInstruction(Opcode opcode)
* | ArrayStoreInstruction(Opcode opcode)
* | TypeCheckInstruction(Opcode opcode, ClassEntry className)
* | ConvertInstruction(TypeKind from, TypeKind to)
* | OperatorInstruction(Opcode opcode)
* | ConstantInstruction(ConstantDesc constant)
* | StackInstruction(Opcode opcode)
* | MonitorInstruction(Opcode opcode)
* | NopInstruction()
*
* PseudoInstruction =
* | LabelTarget(Label label)
* | LineNumber(int line)
* | ExceptionCatch(Label tryStart, Label tryEnd, Label handler, ClassEntry exception)
* | LocalVariable(int slot, UtfEntry name, Utf8Entry type, Label startScope, Label endScope)
* | LocalVariableType(int slot, Utf8Entry name, Utf8Entry type, Label startScope, Label endScope)
* | CharacterRange(int rangeStart, int rangeEnd, int flags, Label startScope, Label endScope)
* }
*
* @since 22
*/
@PreviewFeature(feature = PreviewFeature.Feature.CLASSFILE_API)
package io.github.dmlloyd.classfile;
import io.github.dmlloyd.classfile.extras.PreviewFeature;