Method and apparatus for performing native binding

• US 8,108,842 B2
• Filed: 10/01/2008
• Issued: 01/31/2012
• Est. Priority Date: 07/15/2003
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Brown, Alexander B., North, Geraint M., Weigel, Frank Thomas, Knight, Gareth Anthony
• Primary Examiner(s): Deng, Anna
• Application Number:
  US12/243,497
• Publication Number:
  US 20090094586A1
• Time in Patent Office: 1,217 Days
• Field of Search: 717/136, 717/137
• US Class Current: 717/136
• CPC Class Codes: G06F 8/52 Binary to binary
• CPC Class Codes: G06F 9/4484 Executing subprograms
• CPC Class Codes: G06F 9/4486 Formation of subprogram jump address
• CPC Class Codes: G06F 9/45516 Runtime code conversion or optimisation

Abstract

A native binding technique is provided for inserting calls to native functions during translation of subject code to target code, such that function calls in the subject program to subject code functions are replaced in target code with calls to native equivalents of the same functions. Parameters of native function calls are transformed from target code representations to be consistent with native code representations, native code calling conventions, and native function prototypes.

Claims

1. A method of translating subject program code executable by a subject processor into target program code executable by a target processor, said method comprising the steps of:

(a) dividing the subject code into a plurality of subject code units;

(b) translating one or more of the subject code units into one or more target code units via an intermediate representation; and

(c) executing the target code units on the target processor;

wherein the step (b) comprises (b1) identifying at least one of the subject code units as having a corresponding native code unit, wherein the native code unit is executable natively by the target processor, and (b2) identifying the native code unit which corresponds to the identified subject code unit;

wherein the steps (b1) and (b2) are performed by encountering an external call command as a translator-specific instruction interpreted as an illegal instruction by the subject processor during translation of the subject code, decoding the external call command, and adding to the intermediate representation based on the external call command; and

wherein the step (c) comprises executing the corresponding native code unit instead of executing a translated version of the identified subject code unit.

2. The method of claim 1, wherein the external call commands are variable length instructions including multiple sub-component instructions.

3. The method of claim 2, wherein the multiple sub-component instructions include an Escape sub-component instruction that identifies a type of external call command represented by the other sub-component instructions of the external call command, and the step (b) further comprises detecting the Escape sub-component instruction.

4. The method of claim 1, wherein the identified subject program code unit corresponds to a subject function and the identified native code unit corresponds to a native function.

5. The method of claim 4, wherein the method further comprises:

transforming zero or more function parameters from a target code representation to a native code representation;

invoking the native function with the transformed function parameters according to a prototype of the native function; and

transforming zero or more return values of the invoked native function from a native code representation to a target code representation.

6. The method of claim 5, wherein at least one of the transformations in the transforming steps generates an intermediate representation of the transformation which is added to the intermediate representation.

7. The method of claim 5, wherein the method further comprises:

transforming in target code all subject register values from the target code representation to the native code representation;

invoking from target code a native code call stub function with the transformed subject register values according to a uniform call stub interface; and

invoking from the native code call stub function the native function with particular subject register values and/or parameter stack according to the prototype of the native function.

8. The method of claim 1, further comprising inserting in the target code a call stub to the native code unit during translation of the subject code when encountering the external call command.

9. The method of claim 1, wherein the subject code unit to be executed is a system call.

10. The method of claim 1, wherein the subject code unit to be executed is a library function.

11. The method of claim 1, comprising performing a dynamic binary translation of the subject program code into the target program code by using a translator executing on the target processor interleaved with execution of the target program code and the native code by the target processor.

12. A computer-readable storage medium having software resident thereon in the form of computer-readable code executable by a computer to perform a method of translating subject program code executable by a subject processor into target program code executable by a target processor, said method comprising the steps of:

(a) dividing the subject code into a plurality of subject code units;

(b) translating one or more of the subject code units into one or more target code units via an intermediate representation; and

(c) executing the target code units on the target processor;

wherein the step (b) comprises (b1) identifying at least one of the subject code units as having a corresponding native code unit, wherein the native code unit is executable natively by the target processor, and (b2) identifying the native code unit which corresponds to the identified subject code unit;

wherein the steps (b1) and (b2) are performed by encountering an external call command as a translator-specific instruction interpreted as an illegal instruction by the subject processor during translation of the subject code, decoding the external call command, and adding to the intermediate representation based on the external call command; and

wherein the step (c) comprises executing the corresponding native code unit instead of executing a translated version of the identified subject code unit.

13. A computer apparatus, comprising:

a target processor; and

a memory arranged to store subject program code executable by a subject processor, and translator code to translate the subject program code into a target program code that is executed by the target processor, wherein the translator code when executed by the processor performs the steps of;

(a) dividing the subject code into a plurality of subject code units;

(b) translating one or more of the subject code units into one or more target code units via an intermediate representation; and

(c) executing the target code units on the target processor;

wherein the step (b) comprises (b1) identifying at least one of the subject code units as having a corresponding native code unit, wherein the native code unit is executable natively by the target processor, and (b2) identifying the native code unit which corresponds to the identified subject code unit;

wherein the steps (b1) and (b2) are performed by encountering an external call command as a translator-specific instruction interpreted as an illegal instruction by the subject processor during translation of the subject code, decoding the external call command, and adding to the intermediate representation based on the external call command; and

wherein the step (c) comprises executing the corresponding native code unit instead of executing a translated version of the identified subject code unit.

14. A method of translating subject program code executable by a subject processor into target program code executable by a target processor, said method comprising the steps of:

(a) dividing the subject code into a plurality of subject code units;

(b) translating one or more of the subject code units into one or more target code units via an intermediate representation; and

(c) executing the target code units on the target processor;

wherein the step (b) comprises (b1) identifying at least one of the subject code units as having a corresponding native code unit, wherein the native code unit is executable natively by the target processor, and (b2) identifying the native code unit which corresponds to the identified subject code unit;

wherein the steps (b1) and (b2) are performed by encountering an external call command as a translator-specific instruction during translation of the subject code, decoding the external call command, and adding to the intermediate representation based on the external call command;

wherein the external call commands are variable length instructions including multiple sub-component instructions, and wherein the multiple sub-component instructions include an Escape sub-component instruction that identifies a type of external call command represented by the other sub-component instructions of the external call command, and the step (b) further comprises detecting the Escape sub-component instruction; and

wherein the step (c) comprises executing the corresponding native code unit instead of executing a translated version of the identified subject code unit.