Object Code Relocation Analysis for Function Change Detection

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing hot update systems fail to accurately determine which functions within a computer program are changed by a source code modification, particularly due to issues with implicit casting and extraneous differences when analyzing at the source code layer, rather than the object code layer.

Innovation Solution

The method operates at the object code layer, using modified compilers to generate relocations for function and data structure references, and compares pre and post object code to identify changed functions by excluding equivalent relocation differences.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If source code layer analysis is used to determine changed functions, then the method is simple to implement, but it fails to handle implicit casting and function inlining correctly

Engineering Contradiction:

Improveease of implementationVSAvoidaccuracy of changed function detection

Core Design Contradiction:

Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent replaces source code layer analysis with object code layer analysis. Instead of manually parsing source code to detect changes, the system uses compiled object code with relocation entries to automatically identify changed functions. This substitution of analysis layer resolves the contradiction by providing precise detection of implicit casting and inlining effects that source code analysis misses.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces relocation entries as an intermediary mechanism between source code modifications and function change detection. These relocation entries serve as a mediator that captures the actual runtime impact of source code changes, enabling accurate detection without requiring direct source code parsing or semantic analysis.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Device complexity

If source code layer analysis is used, then no compiler modification is needed, but extraneous differences are introduced due to location assumptions in object code

Engineering Contradiction:

Improvesystem complexityVSAvoidprecision of function change detection

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent performs preliminary action by modifying the compiler to generate relocation entries during the compilation phase. This preliminary preparation enables precise difference detection later without requiring complex analysis during the actual comparison, as the relocation entries are already in place to guide accurate matching.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent changes the parameter of analysis from source code text to object code relocation entries. By shifting the analysis domain to object code and using relocation entries as the comparison parameter, the system eliminates extraneous differences caused by location assumptions while maintaining the ability to detect actual function changes.

Inventive Principle:

Principle #35Parameter changes

3Measurement precision

If object code layer analysis is used, then accuracy of changed function detection is improved, but compiler modification is required

Engineering Contradiction:

Improveaccuracy of changed function detectionVSAvoidcompiler modification requirement

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies self-service by having the compiler itself generate the relocation entries needed for analysis. Instead of requiring external tools to create analysis data, the compiler automatically produces relocation entries as part of its normal operation, eliminating the need for complex external analysis systems while maintaining precision.

Inventive Principle:

Principle #25Self-service

4Measurement precision

If implicit casting effects are considered, then complete function change detection is achieved, but programming language semantics knowledge is required

Engineering Contradiction:

Improvecompleteness of function change detectionVSAvoidrequirement for language semantics knowledge

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent substitutes semantic analysis with mechanical relocation entry comparison. Instead of requiring knowledge of C language semantics to understand implicit casting, the system uses objective relocation entry data that automatically reflects the impact of casting changes, eliminating the need for semantic interpretation while maintaining complete detection accuracy.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentUS8612951B2Method of determining which computer program functions are changed by an arbitrary source code modification

Publication Date: 2013.12.17 ORACLE INT CORP

AI summary

A method of determining which computer program functions are changed by a source code modification to a computer program's source code. The method includes compiling the computer program's source code, using a compiler that generates a relocation entry for each program access to a program function or a program data item. The method further includes compiling source code resulting from modifying the computer program's source code with the source code modification, using a compiler that generates a relocation entry for each program access to a program function or a program data item The method further includes constructing a list of object code differences by comparing the compiled source code, and excluding from the list specified object code differences.