Difference between revisions of "LDC contributor's guide"
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=== Formatting, etc. === | === Formatting, etc. === | ||
| − | * Hard rules: | + | * Hard rules: 2 spaces for indentation, LF newlines. |
* Use include guards consistently, in the format ''LDC_<dir>_<filename>'', e.g. ''LDC_GEN_DVALUE_H''. | * Use include guards consistently, in the format ''LDC_<dir>_<filename>'', e.g. ''LDC_GEN_DVALUE_H''. | ||
* Includes are placed at the top of the file, sorted lexicographically and grouped in the following order: | * Includes are placed at the top of the file, sorted lexicographically and grouped in the following order: | ||
Revision as of 13:06, 3 January 2016
This page is a work-in-progress collection of tips for LDC contributors and development guidelines.
Contents
Continuous Integration
The LDC project uses two different CI systems: Travis CI, which is Ubuntu x86 only but also tests pull requests, and ci.lycus.org, which has three different x86_64 Linux slaves.
Any efforts to get regular builds running on Windows and OS X would be very much appreciated.
To run the test suite locally, use ctest (e.g. ctest -j3 --output-on-failure) in the CMake root directory. To work on a specific test case, you might want to look into the -R and --verbose options to ctest.
Style guidelines
Generally, use your good taste and try to use a style similar to the surrounding code. Many parts of the LLVM Coding Standards are directly applicable to LDC as well.
Formatting, etc.
- Hard rules: 2 spaces for indentation, LF newlines.
- Use include guards consistently, in the format LDC_<dir>_<filename>, e.g. LDC_GEN_DVALUE_H.
- Includes are placed at the top of the file, sorted lexicographically and grouped in the following order:
- Main include corresponding to the .cpp file, if any.
- DMD and other LDC includes.
- LLVM/libconfig includes.
- System includes.
APIs and idioms
- Avoid making changes to the front end sources (dmd and dmd2) as much as reasonably possible. If modifications are necessary, be sure to enclose the deviations from the upstream source #if IN_LLVM blocks, and keep the original source code around for easier comparison. Add a comment referring to the relevant issue on our tracker, or the upstream DMD commit in case of a straight backport. This makes it much easier to resolve any merge conflicts when folding in new frontend releases.
- Use llvm_unreachable("message") instead of assert(0 && "message") (from llvm/Support/ErrorHandling.h). Not only might it lead to slightly better codegen, it also prevents »variable might be used uninitialized« and similar compiler warnings.
Merging a new DMD release
Eventually, we will want to write up a checklist of what to consider when merging a new frontend release. Right now, just a few points to consider:
- Check if there were any new command line options added to DMD. if so, also handle them in LDMD.
Updating the dmd-testsuite repository
The dmd-testsuite repository is derived from the upstream DMD repository by the update-dmd-testsuite.sh script in the ldc-scripts repository. Just run it without arguments, and it should update the repository with the latest commits/tags (given that you have Git installed and an SSH key configured for github.com). The changes should apply to the remote repository in a fast-forward fashion, never force a push.
After this is done, when merging a new DMD frontend release, just merge the v2.<xyz> tag into the ldc branch, manually resolving any merge conflicts as necessary (most changes should definitely be upstreamed).
Releasing a new version of LDC
There is a separate page describing the LDC release process: How to release LDC.
