shafik

What is the Strict Aliasing Rule and Why do we care?

(OR Type Punning, Undefined Behavior and Alignment, Oh My!)

What is strict aliasing? First we will describe what is aliasing and then we can learn what being strict about it means.

In C and C++ aliasing has to do with what expression types we are allowed to access stored values through. In both C and C++ the standard specifies which expression types are allowed to alias which types. The compiler and optimizer are allowed to assume we follow the aliasing rules strictly, hence the term strict aliasing rule. If we attempt to access a value using a type not allowed it is classified as undefined behavior(UB). Once we have undefined behavior all bets are off, the results of our program are no longer reliable.

Unfortunately with strict aliasing violations, we will often obtain the results we expect, leaving the possibility the a future version of a compiler with a new optimization will break code we th

troyfontaine

Methods of Signing Git Commits on MacOS

Last updated March 13, 2024

This Gist explains how to sign commits using gpg in a step-by-step fashion. Previously, krypt.co was heavily mentioned, but I've only recently learned they were acquired by Akamai and no longer update their previous free products. Those mentions have been removed.

Additionally, 1Password now supports signing Git commits with SSH keys and makes it pretty easy-plus you can easily configure Git Tower to use it for both signing and ssh.

For using a GUI-based GIT tool such as Tower or Github Desktop, follow the steps here for signing your commits with GPG.

datagrok

Ideas for improvements to git log --graph

I will maybe someday get around to dusting off my C and making these changes myself unless someone else does it first.

Make the graph for --topo-order less wiggly

Imagine a long-running development branch periodically merges from master. The git log --graph --all --topo-order is not as simple as it could be, as of git version 1.7.10.4.

It doesn't seem like a big deal in this example, but when you're trying to follow the history trails in ASCII and you've got several different branches displayed at once, it gets difficult quickly.