Compile time

In computer science, compile time refers to either the operations performed by a compiler, programming language requirements that must be met by source code for it to be successfully compiled, or properties of the program that can be reasoned about during compilation. Compile time refers to the time duration in which the programming code is converted to the machine code and usually occurs before runtime.


The operations performed at compile time usually include syntax analysis, various kinds of semantic analysis and code generation.
Programming language definitions usually specify compile time requirements that source code must meet to be successfully compiled. For example, languages may stipulate that the amount of storage required by types and variables can be deduced.
Properties of a program that can be reasoned about at compile time include range-checks , deadlock freedom in concurrent languages, or timings .
Compile time occurs before link time and runtime. In some programming languages it may be necessary for some compilation and linking to occur at runtime. There is a trade-off between compile-time and link-time in that many compile time operations can be deferred to link-time without incurring extra run-time.
"Compile time" can also refer to the amount of time required for compilation.