zwld

Note: This repository has been archived as all development is now being done in zld and the Zig toolchain

Experimental linker for wasm object files. The idea is to implement a linker that stays close to wasm-ld in regards to features so that one day this could potentially be used within the Zig self-hosted compiler to incrementally link Zig code with other wasm object files. With zwld now having been upstreamed, the main development of the linker is done directly within the Zig compiler. Features and improvements will be backported to zwld at one point. Until then, this repository is mostly inactive.

While there's no official specification for linking, zwld follows the wasm tool-convention closely. The initial goal is to support mvp features and have a base skeleton which would provide us with enough information on how to integrate this within the Zig compiler. The first step is to make static linking work as specified by tool-convention, once that is completed, dynamic linking will be tackled.

Usage

Usage: zwld [options] [files...] -o [path]

Options:
-h, --help                         Print this help and exit
-o [path]                          Output path of the binary
--entry <entry>                    Name of entry point symbol
--global-base=<value>              Value from where the global data will start
--import-memory                    Import memory from the host environment
--import-table                     Import function table from the host environment
--initial-memory=<value>           Initial size of the linear memory
--max-memory=<value>               Maximum size of the linear memory
--merge-data-segments              Enable merging data segments
--no-entry                         Do not output any entry point
--stack-first                      Place stack at start of linear memory instead of after data
--stack-size=<value>               Specifies the stack size in bytes
--features=<value>                 Comma-delimited list of used features, inferred by object files if unset

Building

zwld uses the latest Zig, which can either be built from source or you can download the latest binary. Zwld can then be built running the following command:

zig build [-Denable-logging]

Right now zwld only contains debug logging, which is hidden behind the enable-logging flag. It is set to false by default.