Class: ExecutableFunction

• Inheritance
• Description
• Class protocol
  • queries
• Instance protocol
  • accessing
  • error handling
  • printing & storing
  • private-accessing
  • queries

Inheritance:

   Object
   |
   +--ExecutableFunction
      |
      +--CompiledCode
      |
      +--ExternalFunction

Package:

stx:libbasic

Category:

Kernel-Methods

Version:

rev: 1.71 date: 2022/12/08 15:56:48

user: stefan

file: ExecutableFunction.st directory: libbasic

module: stx stc-classLibrary: libbasic

Description:

This is an abstract class, to merge common attributes of all kinds of
executable code objects; i.e. non-ST functions, Blocks and Methods
and whatever there might be in the future.

Instances of ExecutableCode are not meant to be created by user code -
the compilers create instances of subclasses, such as Method & Block
(the VM would not even know what to do with such an instance, and triggered
 and exception, if ever encountered during block/method execution).


NOTICE: layout known by runtime system and compiler - do not change


[Instance variables:]
  code        <not_an_object>   the function pointer to the machine code.
                                Not accessible from smalltalk code.
                                (notice the '*' in the instVarNames definition)


[Class variables:]
  ExecutionErrorSignal          parent of all execution errors
                                (not raised itself)

  InvalidCodeSignal             codeObject is not executable

copyright
COPYRIGHT (c) 1994 by Claus Gittinger
             All Rights Reserved

This software is furnished under a license and may be used
only in accordance with the terms of that license and with the
inclusion of the above copyright notice.   This software may not
be provided or otherwise made available to, or used by, any
other person.  No title to or ownership of the software is
hereby transferred.

Class protocol:

 isAbstract

(comment from inherited method)
Return if this class is an abstract class.
True is returned for Object here; false for subclasses.
Abstract subclasses must redefine this again.

 isBuiltInClass

return true if this class is known by the run-time-system.
Here, true is returned for myself, false for subclasses.

Instance protocol:

 code

return the code field. This is not an object but the address of the machine instructions.
Therefore an externalAddress representing the code-address is returned

 getCode

return the code field. This is not an object but the address of the machine instructions.
Therefore an externalAddress representing the code-address is returned

 instVarAt: index

have to catch instVar access to code - since its no object

 instVarAt: index put: value

have to catch instVar access to code - since its no object

 invalidCode

this error is triggered by the interpreter when something is wrong
with the code object (any error not handled by Method-signals).
In this case, the VM sends this to the bad method/block (the receiver).
Can only happen when the Compiler/runtime system is broken or
someone played around.

 printOn: aStream

append a printed representation of the receiver to aStream

 printStringForBrowserWithSelector: selector
( an extension from the stx:libtool package )

return a printString to represent myself to the user in a browser.

 printStringForBrowserWithSelector: selector inClass: aClass

return a printString to represent myself to the user in a browser.

 code: anAddress

set the code field - DANGER ALERT.
This is not an object but the address of the machine instructions.
Therefore the argument must be an integer representing this address.
You can crash Smalltalk very badly when playing around here ...
This method is for compiler support and very special cases (debugging) only
- do not use

 invalidate

 category

return the category of this codeObject.
Return nil here, to allow alien codeObjects to be handled by the browsers.

 hasCanvasResource

Return true, if this method is an canvas-resource method, false otherwise.
This is done by looking for a #canvas key in the method's resources.

 hasCode

return true, if this codeObject has machinecode to execute.

 hasImageResource

return true, if this method is an image-resource method.
This is done by looking for a #image key in the method's resources.

 hasMenuResource

return true, if this method is a menu-resource method.
This is done by looking for a #image key in the method's resources.

 hasResource

return true, if this codeObject has a resource (false here - only real methods have).

 hasResource: aSymbol

return true if the method has a <resource> definition for aSymbol.

Usage example(s):

Method allInstancesDo:[:m | (m hasResource:#image) ifTrue:[self halt] ].

 isBreakpointed

return true, if this is a wrapper method for a breakpoint.
False is returned here - this method is redefined in WrappedMethod

 isExecutable

return true, if this codeObject is executable.

 isInstrumented

return true, if this is an instrumented method.
False is returned here - this method is redefined in InstrumentedMethod

 isInvalid

return true, if this codeObject is invalidated.
Return false here, to allow alien codeObjects to be handled by the browsers.

 isJavaMethod

(comment from inherited method)
return true if this is a JavaMethod.
false is returned here - the method is only redefined in JavaMethod.

 isLazyMethod

return true, if this is a lazy method.
False is returned here - this method is redefined in LazyMethod

 isMocked
( an extension from the stx:libbasic3 package )

Return true, if the method has been mocked (by means of MessageTracer>>mockMethod:do:

 isObsolete

 isTimed

return true, if this is a wrapper method for a time measurement.
False is returned here - this method is redefined in WrappedMethod

 isTraced

return true, if this is a wrapper method for a trace point.
False is returned here - this method is redefined in WrappedMethod

 isUnloaded

return true, if the objects machine code has been unloaded
from the system (i.e. it is not executable).

 isWrapped

return true, if this is a wrapper method.
False is returned here - this method is redefined in WrappedMethod

 messagesSent

actually: unknown here in this abstract class

 messagesSentToSelf

actually: unknown here in this abstract class

 privacy

return a symbol describing the method's access rights (privacy);
Currently, this is one of #private, #protected, #public or #ignored.

Here we unconditionally return #public, to allow alien code objects
to be handled by the browsers.

 referencesGlobal: aGlobalSymbol

return true, if this method references the global
bound to aGlobalSymbol.
Return false (we don't know) here, to allow alien code objects to be
handled by the browsers.

 referencesGlobalMatching: aMatchPattern

return true, if this method references a global
whose name matches aMatchPattern.
Return false (we don't know) here, to allow alien code objects to be
handled by the browsers.

 referencesLiteral: aLiteral

return true, if this executable references the literal directly (i.e. a flat search).
Return false (we don't know) here, to allow alien code objects to be
handled by the browsers.

 refersToLiteral: aLiteral

return true, if this executable references the literal directly or indirectly (i.e. a deep search).
Return false (we don't know) here, to allow alien code objects to be
handled by the browsers.

 refersToLiteralMatching: aMatchPattern

return true if the receiver or recursively any array element in the
receiver is symbolic and matches aMatchPattern (i.e. a deep search).
Return false (we don't know) here, to allow alien code objects to be
handled by the browsers.

 resources

 sends: aSelectorSymbol

return true, if this code object contains a message-send with aSelectorSymbol as selector.
- due to the simple check in the literal array, also simple uses
of aSelectorSymbol as symbol will return true.
Should ask compiler, if there is really a send.

** This is an obsolete interface - do not use it (it may vanish in future versions) **

 sendsAny: aCollectionOfSelectorSymbols

return true, if this method contains a message-send
to any of aCollectionOfSelectorSymbols.

** This is an obsolete interface - do not use it (it may vanish in future versions) **

 sendsAnySelector: aCollectionOfSelectorSymbols

return true, if this method contains a message-send
to any of aCollectionOfSelectorSymbols.

 sendsSelector: aSelectorSymbol

return true, if this code object contains a message-send with aSelectorSymbol as selector.
- due to the simple check in the literal array, also simple uses
of aSelectorSymbol as symbol will return true.
Should ask compiler, if there is really a send.

 usedGlobals

return a collection with the global names referred to by the receiver.
Uses Parser to parse methods source and extract them.