Digital Equipment Corporation

The Mathworks, Inc.

William M McKeeman

Shota Aki

Brett W Baker

Charles Gary Nylander

William Richard Nell

Steve Johnson

Michael Karr

John Micco

August G Reinig

Andrew Payne

August C Reinig

The present invention provides an encryption/decryption approach to protect valuable information from being represented in a clear-text form when an application processes the valuable information. The present invention processes a structured input file to create internal data structures and generates an encrypted output file from the extracted internal data structures. The encrypted file of internal data structures can be decrypted to enable further processing of the valuable information without representing the valuable information as clear-text in memory. Further, the decrypted internal data structures are stored at different locations in memory.

Encryption and decryption approach that prevents exposing clear-text in memory

A method and system is provided that allows a well-behaved program to execute more quickly than dynamically typed programming languages did in the past, thereby allowing a the dynamically typed language to be competitive with static declarative programming languages. A method includes converting lines of source code representing functions to byte-codes representing functions, selecting a subsequence of the byte-codes based on the byte-codes and the dynamic run-time properties of program variables, generating processor instructions in a compiler for the subsequence, and interpreting the byte-codes not contained in the subsequence.

Program interpreter

Methods and apparatus for using description information about a function to translate a call to the function in a first language into a call to a corresponding function in a second language. The methods include create description information from a definition of a function associated with a first language that enables translation of a call to the function in the first language into a call to a corresponding function in a second language without requiring processing of the definition of the function. In one aspect, the methods include providing a description file of items, each item including description information about a function associated with a first language, and using the file of description items to translate a first program file from the first language into a second language.

Function call translation

Techniques used in testing software are described. A test generator produces a source program used to test two or more compilers using a differential testing technique. The test generator includes a grammar with added semantic constraints to minimize the generation of non-conforming source programs. The source program is a conforming source program conforming to constraints included in a programming language standard. By using properties of a conforming source code, a differential testing technique is described in which a test failure indicates that one or more of the compilers is not processing the source program correctly in accordance with the programming language standard. If a test failure is detected, the source program causing the test failure is reduced using various reduction and simplification techniques.

Method and apparatus for software testing using a differential testing

A software unit development and test methodology in which a software application or project is dividing into conceptual units. Each unit is first developed and debugged in an isolated testing environment which simulates the actual testing environment through test conditions. Following unit testing, other tested units are incrementally combined and tested in a similar isolated manner. Automatic generation of a testing environment and development system driving debugging and testing software, for measuring testing completeness, and for verifying correctness of future development and maintenance efforts are provided.

Method and apparatus for producing a software test system using

A computer-aided software development system includes programs to implement edit, compile, link and run sequences, all from memory, at very high speed. The compiler operates on an incremental basis, line-by-line, so if only one line is changed in an edit session, then only that line need be recompiled if no other code is affected. Dependency analysis is performed incrementally, without requiring the user to enter dependencies. Scanning is also done incrementally, and the resulting token list saved in memory to be used again where no changes are made. All of the linking tables are saved in memory so there is no need to generate link tables for increments of code where no changes in links are needed. The parser is able to skip lines or blocks of lines of source code which haven't been changed. All of the source code text modules, the token lists, symbol tables, code tables and related data saved from one compile to another are maintained in virtual memory rather than in files so that speed of operation is enhanced. Also, the object code created is maintained in memory rather than in a file, and executed from this memory image, to reduce delays. A virtual memory management arrangement for the system assures that all of the needed data modules and code is present in real memory by page swapping, but with a minimum of page faults, again to enhance operating speed.

Compiler using clean lines table with entries indicating unchanged text

A computer-aided software development system includes programs to implement edit, compile, link and run sequences, all from memory, at very high speed. The compiler operates on an incremental basis, line-byline, so if only one line is changed in an edit session, then only that line need be recompiled if no other code is affected. Dependency analysis is performed incrementally, without requiring the user to enter dependencies. Scanning is also done incrementally, and the resulting token list saved in memory to be used again where no changes are made. All of the linking tables are saved in memory so there is no need to generate link tables for increments of code where no changes in links are needed. The parser is able to skip lines or blocks of lines of source code which haven't been changed. All of the source code text modules, the token lists, symbol tables, code tables and related data saved from one compile to another are maintained in virtual memory rather than in files so that speed of operation is enhanced. Also, the object code created is maintained in memory rather than in a file, and executed from this memory image, to reduce delays. A virtual memory management arrangement for the system assures that all of the needed data modules and code is present in real memory by paging swapping, but with a minimum of page faults, again to enhance operating speed.

Re-execution of edit-compile-run cycles for changed lines of source

A computer-aided software development system includes programs to implement edit, compile, link and run sequences, all from virtual memory, at very high speed. The compiler operates on an incremental basis, line-by-line, so if only one line is changed in an edit session, then only that line need be recompiled if no other code is affected. Scanning is done incrementally, and the resulting token list saved in memory to be used again where no changes are made. All of the linking tables are saved in virtual memory so that there is no need to generate link tables for increments of code where no changes in links are needed. The parser is able to skip lines or blocks of lines of source code which haven't been changed. All of the source code text modules, the token lists, symbol tables, code tables and related data saved from one compile to another are maintained in virtual memory rather than in files so that speed of operation is enhanced; each module or table is on a separate page with no data from other modules or tables interleaved, and whenever data is added to one of these a reallocation is done to make sure each page has no foreign data. Also, the object code created is maintained in memory rather than in a file, and executed from this memory image, to reduce delays. A virtual memory management arrangement for the system assures that all of the needed data modules and code is present in real memory by page swapping, but with a minimum of page faults, again to enhance operating speed.

Virtual memory management for source-code development system

A computer-aided software development system includes programs to implement edit, compile, link and run sequences, all from memory, at very high speed. The compiler operates on an incremental basis, line-by-line, so if only one line is changed in an edit session, then only that line need be recompiled if no other code is affected. Scanning is done incrementally, and the resulting token list saved in memory to be used again where no changes are made. All of the linking tables are saved in memory so there is no need to generate link tables for increments of code where no changes in links are needed. The parser is able to skip lines or blocks of lines of source code which haven't been changed; for this purpose, each line of source text in the editor has a change-tag to indicate whether this line has been changed, and from this change-tag information a descriptor table is built having a clean-lines indication for each line of source code, indicating how many clean lines follow the present line. All of the source code text modules, the token lists, symbol tables, code tables and related data saved from one compile to another are maintained in virtual memory rather than in files so that speed of operation is enhanced. Also, the object code created is maintained in memory rather than in a file, and executed from this memory image, to reduce delays. A virtual memory management arrangement for the system assures that all of the needed data modules and code is present in real memory by page swapping, but with a minimum of page faults, again to enhance operating speed.

Line-skip compiler for source-code development system

A computer-aided software development system includes programs to implement edit, compile, link and run sequences, all from memory, at very high speed. The complier and linker operate on an incremental basis, line-by-line or increment-by-increment, so if only one line is changed in an edit session, then only that line and lines related to it need be recompiled if no other code is affected; linking is also done in a manner to save and re-use parts of link tables and link lists which are not changed from one edit session to another. Scanning is also done incrementally, and the resulting token lists and token tables, and lexical increment tables, are saved in memory to be used again where no changes are made. All of the linking tables are saved in memory so there is no need to generate link tables for increments of code where no changes in links are needed. The compiler is able to skip lines or blocks of lines of source code which haven't been changed. All of the source code text modules, the token lists, symbol tables, code tables, link lists and related data, etc., saved from one compile to another are maintained in virtual memory rather than in files so that speed of operation is enhanced. Also, the object code created is maintained in memory rather than in a file, and executed from this memory image, to reduce delays. A virtual memory management arrangement for the system assures that all of the needed data modules and code is present in real memory in the phase being implemented, with a minimum of page faults and page swapping during the phase, again to enhance operating speed.

Incremental linking in source-code development system

A computer-aided software development system includes programs to implement edit, compile, link and run sequences, all from memory, at very high speed. The compiler operates on an incremental basis, line-by-line, so if only one line is changed in an edit session, then only that line need be recompiled if no other code is affected. Scanning is done incrementally, and the resulting token list saved in memory to be used again where no changes are made. All of the linking tables are saved in memory so there is no need to generate link tables for increments of code where no changes in links are needed. The parser is able to skip lines or blocks of lines of source code which haven't been changed; for this purpose, each line of source text in the editor has a change-tag to indicate whether this line has been changed, and from this change-tag information a clean-lines table is built having a clean-lines indication for each line of source code, indicating how many clean lines follow the present line. All of the source code text modules, the token lists, symbol tables, code tables and related data saved from one compile to another are maintained in virtual memory rather than in files so that speed of operation is enhanced. Also, the object code created is maintained in memory rather than in a file, and executed from this memory image, to reduce delays. A virtual memory management arrangement for the system assures that all of the needed data modules and code is present in real memory by page swapping, but with a minimum of page faults, again to enhance operating speed.

Incremental compiler for source-code development system

A computer-aided software development system includes programs to implement edit, compile, link and run sequences, all from memory, at very high speed. The compiler operates on an incremental basis, line-by-line, so if only one line is changed in an edit session, then only that line need be recompiled if no other code is affected. Scanning is done incrementally, generating a sequential token list which is saved in memory to be used again where no changes are made; increments of the sequential token list are reused when no changes have been made in the increments and related statements. All of the linking tables are also saved in memory so there is no need to generate link tables for increments of code where no changes in links are needed. The parser is able to skip lines or blocks of lines of source code which haven't been changed. All of the source code text modules, the sequential token lists, symbol tables, code tables and related data saved from one compile to another are maintained in virtual memory rather than in files so that speed of operation is enhanced. Also, the object code created is maintained in memory rather than in a file, and executed from this memory image, to reduce delays. A virtual memory management arrangement for the system assures that all of the needed data modules and code is present in real memory by page swapping, but with a minimum of page faults, again to enhance operating speed.

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Hollis, NH, United States of America

William M McKeeman