Compile

Compile is the process of translating source code written in a high-level programming language into a lower-level representation, typically machine code or an intermediate form such as bytecode. This translation is performed by a compiler, a program that reads the source and emits target code. Compilation is a core concept in computing, distinguishing it from interpretation, where code is executed directly by an interpreter. Outside computing, to compile can also mean to gather information from multiple sources into a single collection.

A typical compiler workflow consists of a front end and a back end. The front end performs lexical analysis, parsing, and semantic analysis to check syntax and meaning, while the back end translates the analyzed program into target code and may apply optimizations. The output may be object code that requires linking to form an executable, or standalone optimized machine code. Some compilers emit portable intermediate representations, which can be executed on different architectures with a suitable runtime or translator.

Many languages compile to portable intermediate representations, such as Java to bytecode or .NET languages to CIL, which are then executed by a virtual machine or runtime with just-in-time compilation. Other languages compile directly to native machine code. Modern toolchains often support multiple build configurations, including optimizing and debugging options, and may produce additional debugging, profiling, or information for error reporting.

Cross-compilation and build systems automate compilation for different target architectures and environments. The choice of language, target platform, and compilation strategy affects performance, portability, development efficiency, and security. In contrast to interpreted languages, compiled languages can offer faster startup times and potentially greater runtime efficiency, though they may require longer edit-compile-debug cycles.