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Showing posts from May, 2020

Debugging with GCC: GIMPLE

GCC and GIMPLE One of the very first thing GCC asks the GSoC applicants to do, even before writing the application, is to try various different debugging techniques using GCC. I was personally familiar with the basic, compile-with-g-flag-and-use-gdb method. Turns out, there's more: GIMPLE. A Simple but Non-trivial Program Problem Description The instruction asks to compile a simple but non-trivial program with some flags that generates debugging information: -O3 -S -fdump-tree-all -fdump-ipa-all -fdump-rtl-all . Because I was keep reading on ways to debug GCC just prior to the statement, I immediately thought "GCC" and tried make -j8 CXXFLAGS="-O3 -S -fdump-tree-all -fdump-ipa-all -fdump-rtl-all" . This was a mistake: turns out, GCC can't be compiled with those flags. Thankfully, GCC developers have a very active IRC channel for me to signal SOS. Resolution jakub and segher were quick to respond to my call for help. jakub: it isn't meant that y

Setting up IRC

About IRC Internet Relay Chat was once the most popular real-time communication method that uses computer for a large spectrum of community groups. While it has largely been supplanted by more contemporarly methods for most people, IRC is still a prefered means of communication among older software projects like GCC. The Client As an old technology that is also very favored among programmers, IRC has many clients with different flavors, from GUI to CLI to headless. As a linux user with strong attraction to tmux, I chose weechat. Depending on your distro or OS, install your client first. Configuring Weechat I will be using GCC channel in OFTC server as the example. How are we configuring this? While Weechat has a configuration file, Weechat officially advises against using the file to configure the program behavior. Instead, it promotes `/set` dialog within the client to set the proper configuration. Connect to server Let's first connect to server. The `#gcc` channel is host

Act 3 Scene 1

Wait, what? The last post ended with completing Act1 Scene1, with hints to Act1 Scene2. Yeah, a lot happened since. Goblin Camp Some of the last work in the blog was about the Goblin Camp, a revival project of an abandoned source code, which in turn was inspired by a great game, Dwarf Fortress. Since then, I learned more about data structures, and object design patterns. With each enlightenment in programming, I was more and more aware why this code was abandoned multiple times by different groups. I became one of them. This doesn't mean my goal of marrying parallel programming with the great game concept is abandoned: ever since the last communication, I also took a course on GPU programming, and it is giving me new ideas and goals. It just would not be happening with the existing Goblin Camp. More on this in the future. And this concluded my Act 1. How about Act2 My Act 2 began with my Coop placement at Fundserv. It was truly a learning experience, in the best sense of the wor