Class Javac
- java.lang.Object
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- javassist.compiler.Javac
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public class Javac extends Object
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Nested Class Summary
Nested Classes Modifier and Type Class Description static class
Javac.CtFieldWithInit
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Field Summary
Fields Modifier and Type Field Description static String
param0Name
static String
proceedName
static String
resultVarName
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description CtMember
compile(String src)
Compiles a method, constructor, or field declaration to a class.Bytecode
compileBody(CtBehavior method, String src)
Compiles a method (or constructor) body.void
compileExpr(String src)
Compiles an exression.void
compileExpr(ASTree e)
Compiles an exression.void
compileStmnt(String src)
Compiles a statement (or a block).Bytecode
getBytecode()
Returns the produced bytecode.static ASTree
parseExpr(String src, SymbolTable st)
Parsers an expression.boolean
recordLocalVariables(CodeAttribute ca, int pc)
Records local variables available at the specified program counter.boolean
recordParamNames(CodeAttribute ca, int numOfLocalVars)
Records parameter names if the LocalVariableAttribute is available.int
recordParams(String target, CtClass[] params, boolean use0, int varNo, boolean isStatic)
Makes variables $0, $1, $2, ..., and $args represent method parameters.int
recordParams(CtClass[] params, boolean isStatic)
Makes variables $0 (this), $1, $2, ..., and $args represent method parameters.void
recordProceed(String target, String method)
Prepares to use $proceed().void
recordProceed(ProceedHandler h)
Prepares to use $proceed().int
recordReturnType(CtClass type, boolean useResultVar)
Prepares to use cast $r, $w, $_, and $type.void
recordSpecialProceed(String target, String classname, String methodname, String descriptor, int methodIndex)
Prepares to use $proceed() representing a private/super's method.void
recordStaticProceed(String targetClass, String method)
Prepares to use $proceed() representing a static method.void
recordType(CtClass t)
Prepares to use $type.int
recordVariable(CtClass type, String name)
Makes the given variable available.void
setMaxLocals(int max)
SetsmaxLocals
tomax
.
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Field Detail
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param0Name
public static final String param0Name
- See Also:
- Constant Field Values
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resultVarName
public static final String resultVarName
- See Also:
- Constant Field Values
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proceedName
public static final String proceedName
- See Also:
- Constant Field Values
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Constructor Detail
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Javac
public Javac(CtClass thisClass)
Constructs a compiler.- Parameters:
thisClass
- the class that a compiled method/field belongs to.
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Method Detail
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getBytecode
public Bytecode getBytecode()
Returns the produced bytecode.
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compile
public CtMember compile(String src) throws CompileError
Compiles a method, constructor, or field declaration to a class. A field declaration can declare only one field.In a method or constructor body, $0, $1, ... and $_ are not available.
- Returns:
- a
CtMethod
,CtConstructor
, orCtField
object. - Throws:
CompileError
- See Also:
recordProceed(String,String)
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compileBody
public Bytecode compileBody(CtBehavior method, String src) throws CompileError
Compiles a method (or constructor) body.- Parameters:
src
- a single statement or a block. If null, this method produces a body returning zero or null.- Throws:
CompileError
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recordLocalVariables
public boolean recordLocalVariables(CodeAttribute ca, int pc) throws CompileError
Records local variables available at the specified program counter. If the LocalVariableAttribute is not available, this method does not record any local variable. It only returns false.- Parameters:
pc
- program counter (>= 0)- Returns:
- false if the CodeAttribute does not include a LocalVariableAttribute.
- Throws:
CompileError
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recordParamNames
public boolean recordParamNames(CodeAttribute ca, int numOfLocalVars) throws CompileError
Records parameter names if the LocalVariableAttribute is available. It returns false unless the LocalVariableAttribute is available.- Parameters:
numOfLocalVars
- the number of local variables used for storing the parameters.- Returns:
- false if the CodeAttribute does not include a LocalVariableAttribute.
- Throws:
CompileError
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recordParams
public int recordParams(CtClass[] params, boolean isStatic) throws CompileError
Makes variables $0 (this), $1, $2, ..., and $args represent method parameters. $args represents an array of all the parameters. It also makes $$ available as a parameter list of method call.This must be called before calling
compileStmnt()
andcompileExpr()
. The correct value ofisStatic
must be recorded before compilation.maxLocals
is updated to include $0,...- Throws:
CompileError
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recordParams
public int recordParams(String target, CtClass[] params, boolean use0, int varNo, boolean isStatic) throws CompileError
Makes variables $0, $1, $2, ..., and $args represent method parameters. $args represents an array of all the parameters. It also makes $$ available as a parameter list of method call. $0 can represent a local variable other than THIS (variable 0). $class is also made available.This must be called before calling
compileStmnt()
andcompileExpr()
. The correct value ofisStatic
must be recorded before compilation.maxLocals
is updated to include $0,...- Parameters:
use0
- true if $0 is used.varNo
- the register number of $0 (use0 is true) or $1 (otherwise).target
- the type of $0 (it can be null if use0 is false). It is used as the name of the type represented by $class.isStatic
- true if the method in which the compiled bytecode is embedded is static.- Throws:
CompileError
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setMaxLocals
public void setMaxLocals(int max)
SetsmaxLocals
tomax
. This method tells the compiler the local variables that have been allocated for the rest of the code. When the compiler needs new local variables, the local variables at the indexmax
,max + 1
, ... are assigned.This method is indirectly called by
recordParams
.
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recordReturnType
public int recordReturnType(CtClass type, boolean useResultVar) throws CompileError
Prepares to use cast $r, $w, $_, and $type. $type is made to represent the specified return type. It also enables to write a return statement with a return value for void method.If the return type is void, ($r) does nothing. The type of $_ is java.lang.Object.
- Parameters:
type
- the return type.useResultVar
- true if $_ is used.- Returns:
- -1 or the variable index assigned to $_.
- Throws:
CompileError
- See Also:
recordType(CtClass)
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recordType
public void recordType(CtClass t)
Prepares to use $type. Note that recordReturnType() overwrites the value of $type.- Parameters:
t
- the type represented by $type.
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recordVariable
public int recordVariable(CtClass type, String name) throws CompileError
Makes the given variable available.- Parameters:
type
- variable typename
- variable name- Throws:
CompileError
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recordProceed
public void recordProceed(String target, String method) throws CompileError
Prepares to use $proceed(). If the return type of $proceed() is void, null is pushed on the stack.- Parameters:
target
- an expression specifying the target object. if null, "this" is the target.method
- the method name.- Throws:
CompileError
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recordStaticProceed
public void recordStaticProceed(String targetClass, String method) throws CompileError
Prepares to use $proceed() representing a static method. If the return type of $proceed() is void, null is pushed on the stack.- Parameters:
targetClass
- the fully-qualified dot-separated name of the class declaring the method.method
- the method name.- Throws:
CompileError
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recordSpecialProceed
public void recordSpecialProceed(String target, String classname, String methodname, String descriptor, int methodIndex) throws CompileError
Prepares to use $proceed() representing a private/super's method. If the return type of $proceed() is void, null is pushed on the stack. This method is for methods invoked by INVOKESPECIAL.- Parameters:
target
- an expression specifying the target object. if null, "this" is the target.classname
- the class name declaring the method.methodname
- the method name.descriptor
- the method descriptor.- Throws:
CompileError
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recordProceed
public void recordProceed(ProceedHandler h)
Prepares to use $proceed().
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compileStmnt
public void compileStmnt(String src) throws CompileError
Compiles a statement (or a block).recordParams()
must be called before invoking this method.Local variables that are not declared in the compiled source text might not be accessible within that source text. Fields and method parameters ($0, $1, ..) are available.
- Throws:
CompileError
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compileExpr
public void compileExpr(String src) throws CompileError
Compiles an exression.recordParams()
must be called before invoking this method.Local variables are not accessible within the compiled source text. Fields and method parameters ($0, $1, ..) are available if
recordParams()
have been invoked.- Throws:
CompileError
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parseExpr
public static ASTree parseExpr(String src, SymbolTable st) throws CompileError
Parsers an expression.- Throws:
CompileError
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compileExpr
public void compileExpr(ASTree e) throws CompileError
Compiles an exression.recordParams()
must be called before invoking this method.Local variables are not accessible within the compiled source text. Fields and method parameters ($0, $1, ..) are available if
recordParams()
have been invoked.- Throws:
CompileError
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