Representing type information in a compiler and programming tools framework

• US 20040268307A1
• Filed: 07/21/2003
• Published: 12/30/2004
• Est. Priority Date: 06/27/2003
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Tarditi, David Read Jr., Plesko, Mark Ronald
• Granted Patent: US 7,788,652 B2
• Time in Patent Office: Days
• US Class Current: 717/114
• CPC Class Codes: G06F 8/20 Software design
• CPC Class Codes: G06F 8/437 Type checking

Abstract

A representation of types, type-checker, method and compiler are provided for checking consistency in various forms of an intermediate language. Specifically, the typed intermediate language is suitable for use in representing programs written in multiple (heterogeneous) source languages including typed and untyped languages, loosely and strongly typed languages, and languages with and without garbage collection. Additionally, the type checker architecture is extensible to handle new languages with different types and primitive operations. The representation of types can be implemented as a data structure that represents two or more sets of types with one or more sub-structures for representing classifications of types. Alternatively, the type system can be implemented as a base class at the top of a hierarchy and a plurality of classes hierarchically below the base class can be defined to represent a number of types such as pointer types, container types, and function types.

Claims

1. A method of representing type information via objects of classes in a class hierarchy, wherein the class hierarchy comprises at least one class and a plurality of sub-classes for representing different type classifications, the method comprising:

instantiating one or more objects of one or more of the sub-classes of the hierarchy, wherein the one or more sub-classes represent classifications of types; and

storing information in the one or more objects.

2. The method of claim 1 wherein the one or more objects represent type information of a variable in software during compilation of the software.

3. The method of claim 1 wherein at least one of the objects comprises information for a size of a type represented by the object.

4. The method of claim 1 wherein at least one of the one or more sub-classes inherits from an abstract type that wraps an externally defined type, the abstract type providing a mapping from a typed intermediate language to original source code.

5. The method of claim 1 wherein at least one of the one or more sub-classes represents container types.

6. The method of claim 1 wherein at least one of the one or more sub-classes represents pointer types.

7. The method of claim 1 wherein at least one of the one or more sub-classes represents function types.

8. The method of claim 1 wherein at least one of the one or more sub-classes represents unmanaged array types.

9. The method of claim 1 wherein at least one of the one or more sub-classes represents class types.

10. The method of claim 1 wherein at least one of the one or more sub-classes represents managed array types.

11. The method of claim 1 wherein at least one of the one or more sub-classes represents struct types.

12. The method of claim 1 wherein at least one of the one or more sub-classes represents interface types.

13. The method of claim 1 wherein at least one of the one or more sub-classes represents enumerated types.

14. The method of claim 1 wherein at least one of the one or more sub-classes represents primitive types.

15. The method of claim 14 wherein at least one of the sub-classes representing primitive types represents the following types:

int, float, and void.

16. The method of claim 14 wherein at least one of the sub-classes representing primitive types can represent an unknown type.

17. The method of claim 14 wherein at least one of the sub-classes representing primitive types is extensible to represent one or more additional primitive types.

18. The method of claim 1 wherein at least one of the one or more sub-classes is defined from the group consisting of:

‘

ContainerType’

, ‘

PtrType’

, ‘

FuncType’

, ‘

ClassType’

, ‘

StructType’

, ‘

InterfaceType’

, and ‘

EnumType’

.

19. The method of claim 1 wherein at least one of the one or more sub-classes is defined as ‘

PrimType’

.

20. A computer-readable medium having a software program thereon, the program comprising:

program code for defining a programming class as ‘

PrimType’

;

program code for associating a size with instances of the ‘

PrimType’

class; and

program code for associating a kind of type with instances of the ‘

PrimType’

class.

21. The computer-readable medium of claim 20 wherein the size represents a size of a machine representation of a value.

22. The computer-readable medium of claim 20 wherein the program code for associating a size with instances of the ‘

PrimType’

class defines the size as ‘

BitSize’

.

23. The computer-readable medium of claim 20 wherein the kind of type represents a type classification.

24. The computer-readable medium of claim 20 wherein the program code for associating a kind of primitive type with instances of the ‘

PrimType’

class defines the kind of type as ‘

PrimTypekind’

.

25. The computer-readable medium of claim 20 further comprising program code for associating a type of size with instances of the ‘

PrimType’

class.

26. The computer-readable medium of claim 25 wherein the program code for associating a type of size with instances of the ‘

PrimType’

class defines the type of size as ‘

SizeKind’

.

27. The computer-readable medium of claim 25 wherein the type of size can comprise actual, symbolic, or unknown types of size.

28. The computer-readable medium of claim 20 wherein the class ‘

PrimType’

represents a plurality of types, the plurality of types comprising int, float, unknown, void, condition code, and unsigned int types.

29. A computer-readable medium having computer-executable instructions for implementing a method for representing type classifications, the method comprising:

describing a type classification for representing container types of a plurality of programming languages, wherein the type classification is described as ‘

ContainerType’

.

30. The computer-readable medium of claim 29, wherein the method further comprises:

describing a type classification for representing pointer types of a plurality of programming languages, wherein the type classification is described as ‘

PtrType’

.

31. A method of programmatically defining a type representation, the method comprising:

defining a base class;

defining a plurality of classes hierarchically below the base class, wherein the classes represent at least pointer types, container types and function types of a plurality of programming languages.

32. The method of claim 31 further comprising defining a plurality of classes hierarchically below the class representing container types, wherein the plurality of classes represent at least class types, struct types, interface types, and enumerated types of a plurality of programming languages.

33. The method of claim 32 further comprising defining a class hierarchically below the class representing class types, wherein the class represents unmanaged array types of a plurality of programming languages.

34. The method of claim 31 further comprising defining a class hierarchically one of the plurality of classes, wherein the class represents primitive types of a plurality of programming languages.

35. The method of claim 34 wherein the class further represents an unknown type.

36. A computer-readable medium having a software program thereon, the program comprising:

program code for defining a programming class as ‘

ContainerType’

, wherein an object of class ‘

ContainerType’

is a type representation in an intermediate language for container types in a section of code written in one of a plurality of programming languages;

program code for defining a programming class as ‘

PtrType’

, wherein an object of class ‘

PtrType’

is a type representation in an intermediate language for pointer types in a section of code written in one of a plurality of programming languages;

program code for defining a programming class as ‘

FuncType’

, wherein an object of class ‘

FuncType’

is a type representation in an intermediate language for function types in a section of code written in one of a plurality of programming languages;

program code for defining a programming class as ‘

ClassType’

, wherein an object of class ‘

ClassType’

is a type representation in an intermediate language for class types in a section of code written in one of a plurality of programming languages;

program code for defining a programming class as ‘

StructType’

, wherein an object of class ‘

StructType’

is a type representation in an intermediate language for struct types in a section of code written in one of a plurality of programming languages;

program code for defining a programming class as ‘

InterfaceType’

, wherein an object of class ‘

InterfaceType’

is a type representation in an intermediate language for interface types in a section of code written in one of a plurality of programming languages; and

program code for defining a programming class as ‘

EnumType’

, wherein an object of class ‘

EnumType’

is a type representation in an intermediate language for enumerated types in a section of code written in one of a plurality of programming languages.

37. The computer-readable medium of claim 36 further comprising program code for defining a programming class as ‘

PrimType’

, wherein an object of class ‘

PrimType’

is a type representation in an intermediate language for primitive types in a section of code written in one of a plurality of programming languages.

38. The computer-readable medium of claim 36 further comprising program code for associating a size with an object of any class.

39. The computer-readable medium of claim 36 further comprising program code for associating a kind of type with an object of any class.