identifiermangling

Identifier mangling, also known as name mangling, is a technique used by some programming languages, particularly C++, to encode function and variable names in the object code. This process is necessary because C++ supports features like function overloading, namespaces, and classes, which can lead to multiple entities having the same source code name but needing to be distinct at the machine code level.

When a C++ compiler encounters an identifier, it transforms it into a unique, longer string. This mangled name typically incorporates information about the identifier's type, its scope (e.g., namespace or class), and its parameters if it's a function. For instance, a function named `print` that takes an integer argument might be mangled into something like `_Z5printi`. The leading underscore and subsequent characters encode the function name, its return type (if explicitly part of the mangling scheme), and the type of its parameter.

The primary purpose of identifier mangling is to prevent name collisions in the final executable or library. Without it, different overloaded functions or functions within different namespaces could have the same name in the object file, making it impossible for the linker to resolve calls correctly.

While essential for C++'s feature set, identifier mangling can sometimes make debugging more challenging, as the names displayed in debuggers or disassembly tools are the mangled versions, not the original source code names. Many debugging tools and development environments provide utilities to demangle these names, converting them back to a more human-readable format. Other languages might use different strategies to handle name uniqueness, such as relying on strict scoping rules or internal symbol tables that do not require such extensive name alteration.