Editing Name mangling (section)

{{Short description|Technique in compiler construction}}
{{About|name mangling in computer languages|name mangling in file systems|filename mangling|other uses|Name conflict (disambiguation){{!}}Name conflict}}
{{Multiple issues|{{original research|date=September 2016}}{{More citations needed|date=December 2011}}}}

In [[compiler]] construction, '''name mangling''' (also called '''name decoration''') is a technique used to solve various problems caused by the need to resolve unique names for programming entities in many modern [[programming language]]s.

It provides means to encode added information in the name of a [[Function (computer programming)|function]], [[Record (computer science)|structure]], [[Class (computer programming)|class]] or another [[data type]], to pass more semantic information from the [[compiler]] to the [[Linker (computing)|linker]].

The need for name mangling arises where a language allows different entities to be named with the same [[identifier]] as long as they occupy a different [[namespace]] (typically defined by a module, class, or explicit ''namespace'' directive) or have different [[type signature]]s (such as in [[function overloading]]). It is required in these uses because each signature might require different, specialized [[calling convention]] in the [[machine code]].

Any [[object code]] produced by compilers is usually linked with other pieces of object code (produced by the same or another compiler) by a type of program called a [[Linker (computing)|linker]]. The linker needs a great deal of information on each program entity. For example, to correctly link a function it needs its name, the number of [[Argument of a function|arguments]] and their types, and so on.

The simple programming languages of the 1970s, like [[C (programming language)|C]], only distinguished [[subroutine]]s by their name, ignoring other information including [[Parameter (computer programming)|parameter]] and return types.
Later languages, like [[C++]], defined stricter requirements for routines to be considered "equal", such as the parameter types, return type, and calling convention of a function. These requirements enable method overloading and detection of some bugs (such as using different definitions of a function when compiling different [[source code]] files).
These stricter requirements needed to work with extant [[programming tool]]s and conventions. Thus, added requirements were encoded in the name of the symbol, since that was the only information a traditional linker had about a symbol.