Translation Software

Need to know

What you need to know

• **Lexical Analysis:** The source code is read, and whitespace/comments are removed. The code is broken down into a stream of 'tokens'. For example, `x = 10;` becomes `IDENTIFIER(x)`, `EQUALS_OP`, `INTEGER_LITERAL(10)`, `SEMICOLON`.
• **Syntax Analysis (Parsing):** The stream of tokens is checked against the grammar rules of the language. The compiler builds a data structure, like a parse tree, to represent the program's structure. If the code breaks a rule (e.g., `x = 10 + ;`), a syntax error is reported.
• **Semantic Analysis:** The meaning of the code is checked. This stage catches errors that are grammatically correct but logically nonsensical, such as trying to add a string to an integer in a strongly-typed language, or using an undeclared variable.
• **Intermediate Code Generation & Optimisation:** The compiler generates a low-level, platform-independent version of the code. It then optimises this code to make it faster or smaller, for example, by removing redundant calculations.
• **Code Generation:** The optimised intermediate code is translated into the final machine code for the target CPU architecture.
• **Linking:** The generated object code is combined with code from libraries (e.g., for printing to the screen) to produce the final executable file.

Explanation

Code Translators: From Our Language to Theirs

1. A programmer writes source code in a high-level language like Python or Visual Basic.
2. The source code is fed into a translator program: either a compiler or an interpreter.
3. A compiler processes the entire file, creating a separate executable file of machine code. An interpreter reads and executes the code one line at a time.
4. The CPU runs the resulting machine code, either from the executable file or as directed by the interpreter, to perform the program's tasks.