Source code annotation language

• US 7,584,458 B2
• Filed: 10/02/2003
• Issued: 09/01/2009
• Est. Priority Date: 10/02/2003
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Low, Spencer Wong, Shihara, William Hiroaki, Weise, Daniel W., Ruescher, Hannes, Terek, F. Soner, Hudson, William Hunter, Das, Manuvir, Agarwal, Sameet Harishanker, Fahndrich, Manuel Alfred, Venkatapathy, Ramanathan
• Primary Examiner(s): Kiss; Eric B
• Application Number:
  US10/679,254
• Publication Number:
  US 20050076331A1
• Time in Patent Office: 2,161 Days
• Field of Search: 717/126, 714/38, 726/25
• US Class Current: 717/126
• CPC Class Codes: G06F 11/328 Computer systems status display G06F11/327 takes precedence
• CPC Class Codes: G06F 11/3624 by performing operations on the source code, e.g. via a compiler

Abstract

Techniques and tools for implementing a source code annotation language are described. In one aspect, keywords are added to a function interface to define a contract for the function independent of function call context. In another aspect, annotations are inserted at global variables, formal parameters, return values, or user-defined types. The annotations include, for example, properties and qualifiers. A property can indicate, for example, a characteristic of a buffer. In another aspect, an annotation indicates that a value has usability properties sufficient to allow a function to rely on the value, where the usability properties depend on value type.

Claims

1. In a computer system comprising a computer, a method of annotating computer program code stored on a computer-readable medium, the method comprising:

inserting, by the computer, one or more in-line code annotations at one or more annotation targets in source code;

wherein the one or more in-line code annotations comprise at least one annotation on a first pointer to a buffer, wherein the at least one annotation comprises a property that indicates a characteristic of the buffer, wherein the property that indicates the characteristic of the buffer takes a size argument, and wherein the size argument comprises a location of a second pointer associated with the buffer; and

wherein the at least one annotation on the first pointer is placed in an argument list to a function call that uses the first pointer as a parameter.

2. The method of claim 1 wherein the characteristic is a readable extent of the buffer.

3. The method of claim 2 further comprising using the location of the second pointer associated with the buffer to determine the readable extent of the buffer.

4. The method of claim 1 wherein the characteristic is a writable extent of the buffer.

5. The method of claim 4 further comprising using the location of the second pointer associated with the buffer to determine the writable extent of the buffer.

6. The method of claim 1 wherein the at least one annotation includes an annotation prefix.

7. The method of claim 1 further comprising using the location of the second pointer associated with the buffer to determine size of the buffer.

8. The method of claim 1 wherein the second pointer associated with the buffer is an end pointer for the buffer.

9. The method of claim 1 wherein the second pointer associated with the buffer is an internal pointer for the buffer.

10. In a computer system comprising a computer, a method of annotating computer program code stored on a computer-readable medium, wherein the computer program code is operable to cause computer execution to perform according to instructions in the computer program code, the method comprising:

inserting, by the computer, an annotation at a first value having a first value type in the computer program code;

wherein the annotation comprises a first instance of a keyword, the first instance of the keyword indicating that the first value satisfies all usability properties necessary to allow a first function to rely on the first value, wherein other instances of the keyword identical to the first instance are operable to indicate that other values having different respective value types satisfy all usability properties necessary to allow functions to rely on the respective other values, wherein use of the keyword associates a pre-determined set of usability properties with a value type, and wherein the usability properties depend on the value type.

11. The method of claim 10 wherein the first value type is scalar, void, pointer, user-defined type, or struct.

12. The method of claim 10 wherein the first value is a reference parameter.

13. The method of claim 10 wherein the first value is a pointer, wherein an object pointed to by the pointer has one or more readable elements, the one or more readable elements of the object each having usability properties sufficient to allow the first function to rely on the one or more readable elements.

14. The method of claim 10 wherein the annotation further comprises an except qualifier.

15. The method of claim 10 wherein if the first value type is a pointer, the usability properties necessary to allow the first function to rely on the first value comprises the pointer pointing to a buffer with at least one readable element.

16. The method of claim 10 wherein if the first value type is a scalar, the usability properties necessary to allow the first function to rely on the first value comprises the scalar being initialized.

17. In a computer system comprising a computer, a method of annotating computer program code stored on a computer-readable medium, the method comprising:

inserting, by the computer, an annotation having an annotation argument comprising a second value type in the computer program code, wherein the annotation annotates a variable having a first value type;

wherein the annotation changes the first value type of the variable to the second value type of the annotation argument.

18. The method of claim 17 wherein the first value type is a legacy value type.

19. The method of claim 17 wherein the second value type has a null-termination characteristic.

20. The method of claim 17 wherein the second value type must be a visible type at program point where the annotation is placed.

21. In a computer system comprising a computer, a method of annotating computer-executable program code stored on a computer-readable medium, the method comprising:

adding, by the computer, an annotation to a pointer in the computer-executable program code, wherein the annotation describes transferring buffer properties from a second pointer to the pointer; and

including a location parameter with the annotation, wherein the location parameter describes a logical buffer pointed to by the pointer.

22. One or more computer-readable storage media having encoded thereon computer-executable instructions for performing a method of annotating computer program source code, the method comprising:

inserting, by a computer, one or more in-line code annotations at one or more annotation targets in the computer program source code;

wherein the one or more in-line code annotations comprise at least one annotation on a first pointer to a buffer, wherein the at least one annotation comprises a property that indicates a characteristic of the buffer, wherein the property that indicates the characteristic of the buffer takes a size argument, and wherein the size argument comprises a location of a second pointer associated with the buffer; and

wherein the at least one annotation on the first pointer is placed in an argument list to a function call that uses the first pointer as a parameter.

23. One or more computer-readable storage media having encoded thereon computer-executable instructions for performing a method of annotating computer program source code, the method comprising:

inserting, by a computer, an annotation at a first value having a first value type in the computer program source code;

wherein the annotation comprises a first instance of a keyword, the first instance of the keyword indicating that the first value satisfies all usability properties necessary to allow a first function to rely on the first value, wherein other instances of the keyword identical to the first instance are operable to indicate that other values having different respective value types satisfy all usability properties necessary to allow functions to rely on the respective other values, wherein use of the keyword associates a pre-determined set of usability properties with a value type, and wherein the usability properties depend on the value type.

24. One or more computer-readable storage media having encoded thereon computer-executable instructions for performing a method of annotating computer program source code stored on a computer-readable medium, the method comprising:

inserting, by a computer, an annotation having an annotation argument comprising a second value type in the computer program source code, wherein the annotation annotates a variable having a first value type;

wherein the annotation changes the first value type of the variable to the second value type of the annotation argument.