Problem Solving in Computing: Compilation and Debugging

Problem Solving in Computing (PRL1013)

• Course focuses on developing solutions in computing.
• Key learning units include coding, compilation, execution, and debugging techniques.

Subtopics

• Coding
• Compilation
• Execution
• Debugging

Part 1.2: Compiler, Execution, & Debugging

Compilation

• Definition: The process of converting high-level programming language code (like C++) into machine code that computers understand.
• Purpose: To translate human-readable code into a format computers can process.
• The Compilation Process: Consists of stages:
  • Preprocessing: Manages directives (e.g., #include, #define).
  • Compilation: Transforms preprocessed code into assembly code.
  • Assembly: Converts assembly code into machine code, creating an object file.
  • Linking: Combines object files with libraries to produce a final executable file.

Compiler

• Definition: A program or tool that executes the compilation process.
• Analogy: Like a translator, converting one language (e.g., C++) to another (e.g., machine code).

Common C++ Compilers

• GCC (GNU Compiler Collection):
  • Supports multiple languages (C, C++,...).
  • Cross-platform compatible.
  • Open-source and community-driven.
• Clang:
  • Known for speed and efficiency.
  • Focuses on C, C++, and Objective-C.
  • Provides detailed error messages.
• MSVC (Microsoft Visual C++):
  • Optimized for Windows.
  • Integrates with Visual Studio.
  • Offers robust tools for Windows application development.

Types of Compilation

• Ahead-of-Time (AOT): Compiles code before execution.
• Just-in-Time (JIT): Compiles code during execution.
• Interpretation: Executes high-level code line by line.

Importance of Compilation

• Error Checking: Identifies syntax and type errors.
• Optimization: Improves code performance.
• Portability: Enables high-level code to run on various hardware.

Execution

• Definition: The process of running a compiled program on a computer's processor to perform tasks and produce results.
• Purpose: Converts compiled machine code into actions (like calculations, data processing, and displaying results).

Execution vs. Compilation

• Execution: Runs compiled machine code. Involves dynamic resource management during code running.
• Compilation: Translates code into machine code before execution. Focuses on the correctness of the syntax before running.

Execution Flow

• Loading: Operating system loads the executable file into memory.
• Linking: If dynamic libraries are needed, the operating system links them during runtime.
• Initialization: Program initializes variables and sets up the execution environment.
• Execution: CPU executes instructions sequentially.
• Termination: Program finishes execution and releases resources.

Types of Execution Environments

• Local Execution: Running on personal or server computers.
• Online Compilers: Web-based environments that compile and execute code.
• Embedded Systems: Running programs on specialized hardware.

Common Execution Issues

• Runtime Errors: Errors during execution.
• Logical Errors: Program runs without crashing but produces incorrect results.
• Resource Leaks: Failure to release allocated resources, causing performance issues.
• Performance Bottlenecks: Inefficient algorithms slow down execution.

Debugging

• Definition: Process of identifying, isolating, and fixing errors in a program.
• Purpose: Improve program reliability and performance.

Common Types of Bugs

• Syntax Errors: Mistakes in code structure preventing compilation.
• Runtime Errors: Errors occurring during program execution.
• Logical Errors: Mistakes in logic producing incorrect results.

Debugging Techniques

• Print Statements: Tracing variable values.
• Breakpoints: Pausing execution and investigating variables.
• Step Execution: Executing code line-by-line to observe behavior.

Best Practices for Debugging

• Understanding the Code: Familiarize yourself with the code structure.
• Reproducing the Bug: Consistently reproduce the issue.
• Using Version Control: Track changes to identify when bugs were introduced.
• Taking Breaks: Clear your mind when stuck.
• Documenting Findings: Record identified bugs and fixes.