Name mangling

active-rfcs/0000-name-mangling.md

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+# Name
+
+- Start Date: 2021-12-05
+- RFC PR: [#2](https://github.com/boa-lang/rfcs/pull/2)
+- Implementation PR: (leave this empty)
+<!-- When when linking to the implementation PR, it should be done in the format of boa-lang/<repo>#<PR number> -->
+
+## Summary
+
+Defines how name mangling will work.
+
+## Basic example
+
+A method of the class `foo` with the signature `method(data: int) -> string` in the module `bar.baz` would be mangled to `boad2m3barm3bazc3fooi6methodp2t3i32t3i32r5string`
+## Motivation
+
+Most languages "mangle" names of symbols, in order to allow for things like namespacing, overloading, and class/struct methods. This RFC defines how Boa can mangle names
+
+## Detailed design
+
+For purposes of this RFC, "string" refers to a number n followed by n characters.
+Additionally, "constant string" is a literal string of characters
+
+### Function name mangling
+A function name will be mangled according to the following scheme
+- Leader: always the constant string `boa`
+- Module: a mangled module name
+- Class (optional): the constant string `c` followed by a string representing the class name
+- Method type (Required if class exists): `i` (for instance methods) or `s` (for static methods)
+- Function name: a string representing the name of the function in Boa code
+- Parameters: the constant string `p` followed by Parameter Descriptors
+  - Parameter Descriptors: the constant string `t` followed by a string representing the type name. If the type is a class, the class name is also mangled
+- Return type: the constant string `r` followed by the type name
+
+### Class name mangling:
+A class name will be mangled according to the following scheme:
+- Leader: always the constant string `boaclass`
+- Module: a mangled module name
+- Class name: the constant string `n` followed by a string representing the class name
+
+### Module name mangling:
+A module name is mangled according to the following scheme
+- Depth: the contstant string `d` followed by the modules "depth" (henceforth referred to as d) in the module tree. `std` has a depth of `1` and `std.math` has a depth of `2`
+- Module names: d repetitions of the following: the constant string `m` followed by a string representing the module name
+
+## Drawbacks
+
+- Generating a mangled name can be slightly costly, and can lead to confusing binaries. A possibility to disable mangling for certain symbols should be considered in the future
+
+## Alternatives
+
+No mangling: this dumps all functions into the same global namespace, and disallows duplicate named functions
+
+## Prior art
+Rust: https://rust-lang.github.io/rfcs/2603-rust-symbol-name-mangling-v0.html
+https://en.wikipedia.org/wiki/Name_mangling has many other examples