Development system with improved methods for recompiling dependent code modules

• US 5,978,585 A
• Filed: 03/27/1997
• Issued: 11/02/1999
• Est. Priority Date: 03/27/1997
• Status: Expired due to Term

• Current Assignee: CodeGear (Idera, Inc.)
• Original Assignee: Inprise Corporation (Open Text Corporation)
• Inventors: Crelier, Regis
• Primary Examiner(s): Downs, Robert W.
• Assistant Examiner(s): DAS, CHAMELI
• Application Number:
  US08/826,453
• Time in Patent Office: 950 Days
• Field of Search: 395/705, 395/700, 395/183.16
• US Class Current: 717/145
• CPC Class Codes: G06F 8/48 Incremental compilation software reuse G06F8/36

Abstract

A development system providing methodology for improving system performance by decreasing recompilation of dependent source modules is described. During operation, the system keeps track of several pieces of information. From the outset, the system has kept track of the timestamps of sources (e.g., A.java file in a Java system) and compiled files thereof (e.g., A.class class file in a Java system). Examination of the timestamps leads to detection of those files which have been modified. The system will recompile A.java in the following circumstances: (1) A.class is not found, (2) A.java has a different timestamp, or (3) A.class has a different timestamp. Otherwise, the system does not invoke a recompile. If a recompilation in not required, the system then looks to the imports for determining whether the imports are consistent. Here, the system checks the timestamps of imports, possibly recompiling one or more of the modules providing the imports. If the imports have been recompiled, then the system must check the root module for determining whether it remains consistent with the imports--that is, whether A is still consistent with its imports. If not, the system recompiles the source file (e.g., A.java).

Claims

1. In a development system for creating a software program by a process which includes compiling a hierarchy of interdependent source code modules, wherein some of the source code modules are dependent on imports comprising symbol information imported from others of the source code modules, a method for recompiling only those particular source code modules which require recompilation when a modification occurs to any one of said source code modules, the method comprising:

(a) beginning with a source code module which serves as a root source code module of said hierarchy of interdependent source code modules, determining whether a particular source code module under examination has itself been modified;

(b) if the particular source code module has itself been modified, recompiling the particular source code module, including invoking the method for each source code module which provides imports to the particular source code module, for determining which source code modules providing imports require recompilation, and thereafter terminating execution of the method; and

(c) if the particular source code module has not itself been modified, examining each import of the particular source code module by performing substeps of;

(i) if none of the imports have themselves been modified since last compiling the particular source code module, terminating execution of the method,

(ii) if some of the imports have themselves been modified since last compiling the particular source code module, invoking the method for each source code module which provides imports to the particular source code module, for determining which source code modules providing imports require recompilation,

(iii) if any of the imports have been recompiled and if the particular source code module extends from imports which have changed symbol information and which have been recompiled, recompiling the particular source code module and thereafter terminating execution of the method, and

(iv) if any of the imports have been recompiled and if the particular source code module does not extend from imports which have changed symbol information and which have been recompiled, performing substeps of;

determining whether any of the imports include a symbol which has changed and which is used by the particular source code module, and

recompiling the particular source code module if any import includes a symbol which has changed and which is used by the particular source code module, and thereafter terminating execution of the method.

2. The method of claim 1, wherein said source code modules include Java-compatible source code module.

3. The method of claim 2, wherein said root source code module comprises a Java-compatible source code module having a main method.

4. The method of claim 1, wherein said symbol information comprises symbol information for variables defined in the software program.

5. The method of claim 4, wherein said symbol information for variables comprises name and type information for variables.

6. The method of claim 1, wherein said symbol information comprises symbol information for methods defined in the software program.

7. The method of claim 6, wherein said symbol information for methods comprises name and parameter information for methods.

8. The method of claim 7, wherein said symbol information for methods further comprises exception handling information for methods.

9. The method of claim 1, wherein imports include symbol information for variables and methods imported into a first source module from a second source code module, so that said first source module can employ variables and methods imported from the second source code module.

10. The method of claim 1, wherein said recompiling steps includes compiling source code statements into a compiled object module.

11. The method of claim 10, wherein said source code statements comprise Java-compatible source code statements and wherein said compiled object module Java-compatible compiled class files.

12. The method of claim 11, wherein each of the compiled object module Java-compatible compiled class files.

13. The method of claim 1, wherein each recompiled source code module generates a compiled opcode module.

14. The method of claim 13, wherein said software program dynamically loads compiled opcode modules, as each is required at runtime.

15. The method of claim 1, wherein step (a) includes:

determining whether a particular source code module under examination has a changed timestamp, when compared to when the particular source code module was last compiled.

16. The method of claim 1, wherein step (a) includes:

determining whether a particular source code module under examination has never been compiled.

17. The method of claim 1, wherein said determination of whether any of the imports include a symbol which has changed includes:

computing a fingerprint for each symbol of a given import and comparing the computed fingerprint to a prior fingerprint for when the symbol was last compiled.

18. The method of claim 17, wherein said computed fingerprint includes a checksum derived from the given symbol.