Class Interpreter<V extends Value>
- Type Parameters:
V
- type of the Value used for the analysis.
- Direct Known Subclasses:
BasicInterpreter
,SourceInterpreter
Analyzer
to work
with various semantic interpreters, without needing to duplicate the code to simulate the
transfer of values.-
Field Summary
Modifier and TypeFieldDescriptionprotected final int
The ASM API version supported by this interpreter. -
Constructor Summary
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Method Summary
Modifier and TypeMethodDescriptionabstract V
binaryOperation
(AbstractInsnNode insn, V value1, V value2) Interprets a bytecode instruction with two arguments.abstract V
copyOperation
(AbstractInsnNode insn, V value) Interprets a bytecode instruction that moves a value on the stack or to or from local variables.abstract V
Merges two values.abstract V
naryOperation
(AbstractInsnNode insn, List<? extends V> values) Interprets a bytecode instruction with a variable number of arguments.newEmptyValue
(int local) Creates a new uninitialized value for a local variable.newExceptionValue
(TryCatchBlockNode tryCatchBlockNode, Frame<V> handlerFrame, Type exceptionType) Creates a new value that represents the given exception type.abstract V
newOperation
(AbstractInsnNode insn) Interprets a bytecode instruction without arguments.newParameterValue
(boolean isInstanceMethod, int local, Type type) Creates a new value that represents the given parameter type.newReturnTypeValue
(Type type) Creates a new value that represents the given return type.abstract V
Creates a new value that represents the given type.abstract void
returnOperation
(AbstractInsnNode insn, V value, V expected) Interprets a bytecode return instruction.abstract V
ternaryOperation
(AbstractInsnNode insn, V value1, V value2, V value3) Interprets a bytecode instruction with three arguments.abstract V
unaryOperation
(AbstractInsnNode insn, V value) Interprets a bytecode instruction with a single argument.
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Field Details
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api
protected final int apiThe ASM API version supported by this interpreter. The value of this field must be one of theASM
x values inOpcodes
.
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Constructor Details
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Interpreter
protected Interpreter(int api) Constructs a newInterpreter
.- Parameters:
api
- the ASM API version supported by this interpreter. Must be one of theASM
x values inOpcodes
.
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Method Details
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newValue
Creates a new value that represents the given type.Called for method parameters (including
this
), exception handler variable and withnull
type for variables reserved by long and double types.An interpreter may choose to implement one or more of
newReturnTypeValue(Type)
,newParameterValue(boolean, int, Type)
,newEmptyValue(int)
,newExceptionValue(TryCatchBlockNode, Frame, Type)
to distinguish different types of new value.- Parameters:
type
- a primitive or reference type, or null to represent an uninitialized value.- Returns:
- a value that represents the given type. The size of the returned value must be equal to the size of the given type.
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newParameterValue
Creates a new value that represents the given parameter type. This method is called to initialize the value of a local corresponding to a method parameter in a frame.By default, calls
newValue(type)
.- Parameters:
isInstanceMethod
- true if the method is non-static.local
- the local variable index.type
- a primitive or reference type.- Returns:
- a value that represents the given type. The size of the returned value must be equal to the size of the given type.
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newReturnTypeValue
Creates a new value that represents the given return type. This method is called to initialize the return type value of a frame.By default, calls
newValue(type)
.- Parameters:
type
- a primitive or reference type.- Returns:
- a value that represents the given type. The size of the returned value must be equal to the size of the given type.
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newEmptyValue
Creates a new uninitialized value for a local variable. This method is called to initialize the value of a local that does not correspond to a method parameter, and to reset one half of a size-2 value when the other half is assigned a size-1 value.By default, calls
newValue(null)
.- Parameters:
local
- the local variable index.- Returns:
- a value representing an uninitialized value. The size of the returned value must be equal to 1.
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newExceptionValue
public V newExceptionValue(TryCatchBlockNode tryCatchBlockNode, Frame<V> handlerFrame, Type exceptionType) Creates a new value that represents the given exception type. This method is called to initialize the exception value on the call stack at the entry of an exception handler.By default, calls
newValue(exceptionType)
.- Parameters:
tryCatchBlockNode
- the exception handler.handlerFrame
- the exception handler frame.exceptionType
- the exception type handled by this handler.- Returns:
- a value that represents the given
exceptionType
. The size of the returned value must be equal to 1.
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newOperation
Interprets a bytecode instruction without arguments. This method is called for the following opcodes:ACONST_NULL, ICONST_M1, ICONST_0, ICONST_1, ICONST_2, ICONST_3, ICONST_4, ICONST_5, LCONST_0, LCONST_1, FCONST_0, FCONST_1, FCONST_2, DCONST_0, DCONST_1, BIPUSH, SIPUSH, LDC, JSR, GETSTATIC, NEW
- Parameters:
insn
- the bytecode instruction to be interpreted.- Returns:
- the result of the interpretation of the given instruction.
- Throws:
AnalyzerException
- if an error occurred during the interpretation.
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copyOperation
Interprets a bytecode instruction that moves a value on the stack or to or from local variables. This method is called for the following opcodes:ILOAD, LLOAD, FLOAD, DLOAD, ALOAD, ISTORE, LSTORE, FSTORE, DSTORE, ASTORE, DUP, DUP_X1, DUP_X2, DUP2, DUP2_X1, DUP2_X2, SWAP
- Parameters:
insn
- the bytecode instruction to be interpreted.value
- the value that must be moved by the instruction.- Returns:
- the result of the interpretation of the given instruction. The returned value must be
equal
to the given value. - Throws:
AnalyzerException
- if an error occurred during the interpretation.
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unaryOperation
Interprets a bytecode instruction with a single argument. This method is called for the following opcodes:INEG, LNEG, FNEG, DNEG, IINC, I2L, I2F, I2D, L2I, L2F, L2D, F2I, F2L, F2D, D2I, D2L, D2F, I2B, I2C, I2S, IFEQ, IFNE, IFLT, IFGE, IFGT, IFLE, TABLESWITCH, LOOKUPSWITCH, IRETURN, LRETURN, FRETURN, DRETURN, ARETURN, PUTSTATIC, GETFIELD, NEWARRAY, ANEWARRAY, ARRAYLENGTH, ATHROW, CHECKCAST, INSTANCEOF, MONITORENTER, MONITOREXIT, IFNULL, IFNONNULL
- Parameters:
insn
- the bytecode instruction to be interpreted.value
- the argument of the instruction to be interpreted.- Returns:
- the result of the interpretation of the given instruction.
- Throws:
AnalyzerException
- if an error occurred during the interpretation.
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binaryOperation
public abstract V binaryOperation(AbstractInsnNode insn, V value1, V value2) throws AnalyzerException Interprets a bytecode instruction with two arguments. This method is called for the following opcodes:IALOAD, LALOAD, FALOAD, DALOAD, AALOAD, BALOAD, CALOAD, SALOAD, IADD, LADD, FADD, DADD, ISUB, LSUB, FSUB, DSUB, IMUL, LMUL, FMUL, DMUL, IDIV, LDIV, FDIV, DDIV, IREM, LREM, FREM, DREM, ISHL, LSHL, ISHR, LSHR, IUSHR, LUSHR, IAND, LAND, IOR, LOR, IXOR, LXOR, LCMP, FCMPL, FCMPG, DCMPL, DCMPG, IF_ICMPEQ, IF_ICMPNE, IF_ICMPLT, IF_ICMPGE, IF_ICMPGT, IF_ICMPLE, IF_ACMPEQ, IF_ACMPNE, PUTFIELD
- Parameters:
insn
- the bytecode instruction to be interpreted.value1
- the first argument of the instruction to be interpreted.value2
- the second argument of the instruction to be interpreted.- Returns:
- the result of the interpretation of the given instruction.
- Throws:
AnalyzerException
- if an error occurred during the interpretation.
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ternaryOperation
public abstract V ternaryOperation(AbstractInsnNode insn, V value1, V value2, V value3) throws AnalyzerException Interprets a bytecode instruction with three arguments. This method is called for the following opcodes:IASTORE, LASTORE, FASTORE, DASTORE, AASTORE, BASTORE, CASTORE, SASTORE
- Parameters:
insn
- the bytecode instruction to be interpreted.value1
- the first argument of the instruction to be interpreted.value2
- the second argument of the instruction to be interpreted.value3
- the third argument of the instruction to be interpreted.- Returns:
- the result of the interpretation of the given instruction.
- Throws:
AnalyzerException
- if an error occurred during the interpretation.
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naryOperation
public abstract V naryOperation(AbstractInsnNode insn, List<? extends V> values) throws AnalyzerException Interprets a bytecode instruction with a variable number of arguments. This method is called for the following opcodes:INVOKEVIRTUAL, INVOKESPECIAL, INVOKESTATIC, INVOKEINTERFACE, MULTIANEWARRAY and INVOKEDYNAMIC
- Parameters:
insn
- the bytecode instruction to be interpreted.values
- the arguments of the instruction to be interpreted.- Returns:
- the result of the interpretation of the given instruction.
- Throws:
AnalyzerException
- if an error occurred during the interpretation.
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returnOperation
public abstract void returnOperation(AbstractInsnNode insn, V value, V expected) throws AnalyzerException Interprets a bytecode return instruction. This method is called for the following opcodes:IRETURN, LRETURN, FRETURN, DRETURN, ARETURN
- Parameters:
insn
- the bytecode instruction to be interpreted.value
- the argument of the instruction to be interpreted.expected
- the expected return type of the analyzed method.- Throws:
AnalyzerException
- if an error occurred during the interpretation.
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merge
Merges two values. The merge operation must return a value that represents both values (for instance, if the two values are two types, the merged value must be a common super type of the two types. If the two values are integer intervals, the merged value must be an interval that contains the previous ones. Likewise for other types of values).- Parameters:
value1
- a value.value2
- another value.- Returns:
- the merged value. If the merged value is equal to
value1
, this method must returnvalue1
.
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