Kompilointiprosessi

Kompilointiprosessi (the compilation process) is the sequence of steps that a compiler performs to transform source code written in a high‑level programming language into executable machine code. The process typically consists of several distinct stages, each responsible for a specific transformation of the program representation.

The first stage is lexical and syntactic analysis, where the compiler reads the source text, splits it into tokens, and builds an abstract syntax tree (AST) that represents the program's grammatical structure. The AST is then verified against the language’s semantic rules, resolving namespaces, types and scopes. Successful semantic analysis produces a fully typed internal representation that is free from syntax or type errors.

Next the compiler often converts the type‑checked AST into an intermediate representation (IR). The IR is a lower‑level, often three‑address code or similar form that is easier to optimize. Various optimizations are applied at this level – dead‑code elimination, loop transformations, constant folding, and register allocation among them. Some modern compilers perform target‑specific optimizations during IR generation, tailoring the code to the architecture’s instruction set.

After optimization, the IR is translated into assembly code for the target architecture. An assembler turns this assembly into object files containing machine code and relocation information. The final phase is linking, in which a linker combines one or more object files, resolves external references, applies runtime libraries, and produces an executable binary. Link‑time optimizations may merge and further optimize across module boundaries.

The resulting executable can be statically or dynamically linked against libraries, affecting the final file size and loading behavior. When the program is run, the operating system loads the binary into memory, and the CPU executes the machine code. Understanding each phase of the kompilointiprosessi provides insight into how high‑level abstractions are efficiently mapped to hardware.