Compile-time data dependency verification
AssigneeInternational Business Machines Corporation
InventorGraham W. Ewart
Life of this patent
Estimating the term…
Abstract
A compiler extension for the compile-time verification of programmer-defined data dependencies. The compiler extension provides for a check statement which takes as an argument a data-verification expression. The data-verification expression has a predetermined value when the programmer-defined data dependency is conformed to in the program. A compile-time error is generated if the data-verification expression does not have the predetermined value on the compilation of the check statement. The successful compilation of the check statement does not result in run-time code or run-time data allocation occurring.
Claims15
A compiler extension residing in a computer system comprising a data verification component for compiling a data-dependency expression contained in a computer program, the data-dependency expression reflecting a programmer-defined relationship between data in the computer program, the data-dependency expression having a one of a first set of predefined values when the program conforms to the programmer-defined relationship between data, and the data-dependency expression having a one of a second set of predefined values different from the first set of predefined values, when the computer program does not conform to the user-defined relationship between data, wherein upon compiling the data-dependency expression, the data verification component generates no run-time code or run-time data storage allocation, and upon compiling the data-dependency expression, the data verification component generates a compile-time error message when the value of the data-dependency expression is in the second set of predefined values, and the data verification component generates no compile-time error message when the value of the data-dependency expression is in the first set of predefined values.
A compiler extension for a programming language compiler residing in a computer system, the compiler extension comprising a data verification construct for accepting as an argument a data-dependency expression in a computer program,
- the data-dependency expression reflecting a programmer-defined relationship between data in the computer program,
- the data-dependency expression having a one of a first set of predefined values when the computer program conforms to the programmer-defined relationship between data, and the data-dependency expression having a one of a second set of predefined values different from the first set of predefined values, when the program does not conform to the user-defined relationship between data,
- wherein upon compilation of the computer program, the programming language compiler generates a compile-time error message for the compilation of the data verification construct when the value of the data-dependency expression is in the second set of predefined values, and no compile-time error message for compilation of the data verification construct when the value of the data-dependency expression is in the first set of predefined values.
A method for verifying programmer-defined data dependencies at compile-time, comprising the steps of
- a) defining a check statement in a computer program, the check statement having an argument,
- b) inserting the check statement in the computer program at points where a data structure having a programmer-defined data dependency is accessed by the computer program,
- c) passing as an argument to check statement, a data-dependency expression having a one of a first set of predefined values when the data structure conforms to the programmer-defined data-dependency and having a one of a second set of predefined values different from the first set of predefined values when the data structure does not conform to the programmer-defined data-dependency,
- the check statement having a definition such that the check statement will compile successfully where the value of the data-dependency expression is in the first set of predefined values, and unsuccessfully where the value of the data-dependency expression is in the second set of predefined values.
Dependencies are inferred from the claim text.