Types of Compilers скачать в хорошем качестве

Types of Compilers

1. Classification by Output & Platform Native Compiler Definition: A compiler that runs on a specific computer architecture and OS (Operating System) and produces machine code for that same architecture and OS. Example: A standard GCC compiler running on Windows that outputs a .exe to run on Windows. Cross Compiler Definition: A compiler that runs on one architecture/OS but generates code for a different architecture/OS. Use Case: This is essential for embedded systems (e.g., writing code on your powerful laptop to run on a small microcontroller or an Android device). Example: Using a PC to compile code for a Raspberry Pi or Arduino. Source-to-Source Compiler (Transpiler) Definition: Instead of translating high-level code into low-level machine code, it translates high-level code into another high-level language. Example: TypeScript compilers (which convert TypeScript into JavaScript) or Babel (which converts modern JavaScript into older versions for browser compatibility). 2. Classification by Execution Timing Ahead-of-Time (AOT) Compiler Definition: The standard "compile" process. It translates the entire program into machine code before the program is ever run. Pros: Very fast execution speed at runtime; no need for a compiler on the user's machine. Cons: Longer build times; platform-specific executable. Examples: C, C++, Rust. Just-In-Time (JIT) Compiler Definition: Compilation happens during the execution of the program. The source code (or bytecode) is compiled into machine code on the fly as it is needed. Pros: Can optimize for the specific machine it is running on; platform independence (via bytecode). Cons: Slower startup time (because it has to compile first); higher memory usage. Examples: The Java Virtual Machine (JVM), .NET CLR, V8 Engine (JavaScript). 3. Classification by Structure Single-Pass Compiler Definition: It reads the source code once and immediately translates it. The phases (lexical, syntax, semantic, code gen) happen almost simultaneously for each line/unit. Characteristics: Very fast compilation but poor code optimization (it can't see "future" code to make smart decisions). Usage: Early Pascal compilers. Multi-Pass Compiler Definition: It processes the source code (or the syntax tree) multiple times. Pass 1: Scan and verify syntax/semantics. Pass 2: Optimize the logic. Pass 3: Generate code. Characteristics: Slower compilation but produces highly optimized, efficient machine code. Usage: Most modern compilers (GCC, Clang). 4. Specialized Compilers Incremental Compiler: Only recompiles the parts of the code that have been modified, rather than the whole program. This is crucial for large projects to keep build times low. Decompiler: The reverse of a compiler. It attempts to translate low-level machine code back into high-level source code (often used for reverse engineering).