Data processing: software development – installation – and managem – Software program development tool – Translation of code
Reexamination Certificate
1999-09-08
2003-06-10
Morse, Gregory (Department: 2122)
Data processing: software development, installation, and managem
Software program development tool
Translation of code
C717S139000, C717S136000, C717S153000, C712S221000, C712S223000, C714S738000
Reexamination Certificate
active
06578194
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to the compiling, loading, and execution of a computer program and, in particular, to the inclusion of extended information in a relocation directory for items that must be relocated into text before program execution, including information on the type of data involved in the relocation and an operation to be performed on the relocated item.
2. Description of the Related Art
Programmers write computer programs in high level languages such as FORTRAN and COBOL that include many descriptive terms that help the programmer write, structure, organize, and debug the program. This high level language program is referred to as the source code and includes data declarations and instructions which operate on that data. All addressing is symbolic, which means that the programmer assigns labels (names) to individual data elements and instructions to use throughout the program. Before the program can be executed, the source code must be transformed to machine readable executable code.
An assembler or compiler, referred to herein as a source translator, translates the source module into an object module, which includes machine readable executable code, data, external symbol definitions and references, address constants, and further bookkeeping information used in the process of transforming the object module into an executable file. Symbol references and address constants in one object module may reference text defined in another object module. The term “text” as defined and used herein means data and/or code. A linkage editor combines one or more object or load modules into a load module in preparation for execution. Typically, the linkage editor combines object modules that contain a single definition of a symbol, i.e., symbol definition, and one or more references to the symbol, i.e., symbol references. If one object module includes a reference to an external symbol defined in another object module, then the linkage editor may resolve this reference with the definition in the load module.
Included in object modules are address constants. An address constant is a cell or field that is filled in later with information characterizing another location or module, such as its address. The information characterizing the referenced symbol will be relocated into the location of the address constant at translation time, bind time, or execution time. The object module includes information on the location of the address constant and the name of the referenced symbol. The referenced symbol can be internal or external to the object module which includes the address constant making the reference. Presently, the address constant is typically used to add the referenced address to the text at the location of the address constant in preparation for the relocation performed at execution time, when the load point of the program is known. The address constant may reference an external symbol. The address constant may contain other types of information, such as offsets, pseudo register vector lengths, constants, etc. During binding operations, the address defined by the external symbol may be relocated into the address constant location. This referenced information may also be relocated into the location of the address constant at execution time. The address constant may reference an external symbol. Further description of the types of address constants and their use is described in the International Business Machines Corporation (IBM) publication “High Level Assembler for MVS & VM & VSE: Language Reference MVS & VM, Release 2,” IBM document no SC26-4940-01 (Copyright IBM Corp., 1995), which publication is incorporated herein by reference in its entirety. Further details of object modules are described in the publication “Linkers and Loaders,” by Leon Presser and John R,. White, ACM Computing Surveys, Vol. 4, No. 32, September 1972, pp. 149-167, which is incorporated by reference herein in its entirety, and the commonly assigned U.S. patent entitled “System and Method for Preparing a Computer Program for Execution,” U.S. Pat. No. 5,553,286, which publication and patent are incorporated herein by reference in its entirety.
Current use of address constants provides only a limited range of operations that may be performed with respect to the referenced item and address constant. There is thus a need in the art for a more robust and flexible address constant that allows further operations to be performed with respect to the referenced item and location of the address constant.
SUMMARY OF THE PREFERRED EMBODIMENTS
Preferred embodiments are directed to a method, system and program for generating an executable file for execution by a computer. The computer receives a plurality of programming language statements comprising a source program. The computer translates the source program into an object module which includes a text portion and a fix-up target defining a location within the text portion. A relocation directory includes information indicating a referenced item; reference type information indicating a type of the referenced item; and operation type information indicating an operation performed on the referenced item and contents of the fix-up target. The computer then processes the reference type and the operation type information in the relocation directory and determines a result of performing the operation specified in the operation type information on the referenced item and the contents of the fix-up target. The computer then relocates into the location of the fix-up target the result of the operation performed on the referenced item and the contents of the fix-up target.
In further embodiments, the referenced item may comprise an address, an offset length, a pseudo register vector length, a numerical value, a set of data, a set of instructions, and a symbol.
In still further embodiments, the operation type information may indicate that the operation comprises addition, subtraction, negating the fix-up target, shifting, multiplication, division, logical AND, logical OR, logical XOR, and moving.
Preferred embodiments expand the types of reference items that may be relocated into the fix-up target field, i.e the address constant location, and the operations which may be performed on the referenced items. Further embodiments further add to the relocation directory to include information which describes the referenced item and the operations to be performed thereon, including information on the expanded operations and reference items of the present invention. In this way, preferred embodiments provide for expanded relocation types and operations to be performed thereon.
REFERENCES:
patent: 4791558 (1988-12-01), Chaitin et al.
patent: 5274820 (1993-12-01), Gillet
patent: 5339419 (1994-08-01), Chan et al.
patent: 5469572 (1995-11-01), Taylor
patent: 5519866 (1996-05-01), Lawrence et al.
patent: 5553286 (1996-09-01), Lee
patent: 5586330 (1996-12-01), Knudsen et al.
patent: 5734822 (1998-03-01), Houha et al.
patent: 5764987 (1998-06-01), Eidt et al.
patent: 5933642 (1999-08-01), Greenbaum et al.
patent: 6106574 (2000-08-01), Baisley et al.
patent: 6112025 (2000-08-01), Mulchandani et al.
patent: 6182283 (2001-01-01), Thomson
patent: 6219830 (2001-04-01), Eidt et al.
patent: 6345384 (2002-02-01), Sato
The Book, Title: Microsoft Press Computer Dictionary, Third Edition, Published by Microsoft Press, 1997, p. 60-61.*
TITLE: An architectural framework for migration from CISC to higher performance platforms, author: Gabriel M. Silberman , Kemal Ebcio, ACM, Aug. 1992.*
TITLE: Object and native code thread mobility among heterogeneous computers (includes sources), author: B. Steensgaard, E. Jul, ACM, Dec. 1995.*
L. Presser, et al., “Linkers and Loaders”, 09/72, Computing Surveys, vol. 4, No. 3, pp. 149-167.
IBM Manuel, “High Level Assembler for MVS & VM & VSM”, Language Reference MVS and VM, Release 2, 3/95, pp. 131-138.
Baumgart Leona Dryden
Ehrman John Robert
Lee Barbara Ann
Lee Richard E.
Das Chameli C.
Konrad Raynes & Victor & Mann LLP
Lee Barbara Ann
Morse Gregory
Victor David W.
LandOfFree
System and method using extended relocation types and... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with System and method using extended relocation types and..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and System and method using extended relocation types and... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3143485