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Programming: LLVM, Perl and Much More

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  • The MLIR-Targeting "FC" LLVM Fortran Compiler Is Now Open-Source

    Last week we reported on "FC" as a new LLVM Fortran compiler targeting the new MLIR intermediate representation. That new Fortran compiler is now public and open-source.

    While the Flang compiler is being upstreamed at the moment, "FC" is being worked on by consulting firm start-up CompilerTree as an LLVM Fortran compiler that has shifted focus from using the conventional LLVM IR to MLIR as LLVM's new IR developed by Google with a focus on machine learning.

  • LLVM/Clang 10.0 Adds AMD Zen 2 Scheduler Model For Optimized Code Generation

    It's too bad that it has taken so many months after AMD Zen 2 based Ryzen and EPYC processors began shipping to see this compiler support in place, but the good news now is that for the upcoming release of LLVM 10.0 is now the Zen 2 scheduler model being added to the "znver2" target.

    Going back to before the Zen 2 processors began shipping last summer, in February AMD Znver2 support was added for LLVM Clang 9.0. But like the GCC compiler support at the time, it added new instructions supported by these CPUs but didn't update the scheduler model / cost tables. In July AMD-partner SUSE added Znver2 tuning to GCC including a new scheduler model that was wired up for GCC 10 and back-ported to GCC 9.2.

  • AMD Begins Providing PowerPC Builds Of Their "AOMP" GPU Compiler

    AOMP is the AMD GPU compiler for OpenMP and HIP support on GPUs as part of Radeon Open Compute 3.0 (ROCm 3.0). Now they have begun providing PowerPC 64-bit LE builds of AOMP as part of allowing Radeon GPU compute to happen on POWER9 systems.

    As reported on in December, we've been seeing AMDKFD compute driver work for PowerPC that ultimately landed in Linux 5.5. This work has been continuing in user-space with their AOMP GPU compute compiler now also working for PowerPC and AMD even providing PowerPC 64-bit binaries. The actual AOMP lifting for PPC64LE support isn't much considering this compiler is based on LLVM Clang that has long supported the architecture.

  • data-types for representing stream-processing programs

    This year I want to write much more about my PhD work on my blog, and here's my first effort. Most of this material has been languishing as a draft for over a year, so it's past time to get it out!

  • KDAB Challenge Solutions

    Proxy types can be tricky. If we got a QChar (or a reference to a QChar) by accessing a character in a QString with the operator[] as most people would expect to, the automatic type deduction requested by auto current = hello[i] would deduce that current is of type QChar.

    But QString::operator[] does not return a QChar. It returns a QCharRef. Even if we think of it as a reference to a QChar, the compiler does not, and the automatic type deduction can not remove the reference part like it would if the return type was a proper reference (QChar&).

    This means that current will be a value of type QCharRef. When we modify it, it will modify the original string (contrary to what most people expect because of C++’s value semantics).

    One of the solutions here is not to use automatic type deduction and explicitly specify the type of current to be QChar.

  • Introducing GVariant schemas

    GLib supports a binary data format called GVariant, which is commonly used to store various forms of application data. For example, it is used to store the dconf database and as the on-disk data in OSTree repositories.

    The GVariant serialization format is very interesting. It has a recursive type-system (based on the DBus types) and is very compact. At the same time it includes padding to correctly align types for direct CPU reads and has constant time element lookup for arrays and tuples. This make GVariant a very good format for efficient in-memory read-only access.

    Unfortunately the APIs that GLib has for accessing variants are not always great. They are based on using type strings and accessing children via integer indexes. While this is very dynamic and flexible (especially when creating variants) it isn’t a great fit for the case where you have serialized data in a format that is known ahead of time.

  • Create PDF using Perl/PDF::API2

    I wrote a practical and detailed description of Perl's PDF::API2.

    It turns out that PDF::API2 is a library for performing necessary and sufficient PDF operations.

  • Paws XXXXVIII (Way too many 'I' s)

    Well I think it is a first here in the Paws patrol. I spent the day plunging away with CloudFront and I have no new Paws issues but I did learn and important practical lesson about using CloudFront.

  • Organize your email with Notmuch

    Last year, I brought you 19 days of new (to you) productivity tools for 2019. This year, I'm taking a different approach: building an environment that will allow you to be more productive in the new year, using tools you may or may not already be using.

    Maildir is probably one of the most useful mail storage formats out there. And there are a LOT of tools to help with managing your mail. The one I keep coming back to is a little program called Notmuch that indexes, tags, and searches mail messages. And there are several programs that work with Notmuch to make it even easier to handle a large amount of mail.

    [...]

    Tagging messages in bulk is probably more useful, though, since manually updating tags at every run can be really tedious.

    [...]

    In the coming days, I'll show you some other mail clients that will likely integrate with tools you already use. In the meantime, check out some of the other tools that work with Maildir mailboxes—you might find a hidden gem I've not tried yet.

More in Tux Machines

OSS Leftovers

  • Meet the newest Collaborans!

    What better way to start the new year than by highlighting the newest members of our engineering and administrative teams who joined in Q4 2019! Based in Italy, Portugal, the United Kingdom and Greece, these newest Collaborans join our worldwide team of highly skilled engineers, developers and managers who all share a common passion for technology and Open Source.

  • MariaDB X4 brings smart transactions to open source database

    MariaDB has come a long way from its MySQL database roots. The open source database vendor released its new MariaDB X4 platform, providing users with "smart transactions" technology to enable both analytical and transactional databases. MariaDB, based in Redwood City, Calif., was founded in 2009 by the original creator of MySQL, Monty Widenius, as a drop-in replacement for MySQL, after Widenius grew disillusioned with the direction that Oracle was taking the open source database. Oracle acquired MySQL via its acquisition of Sun Microsystems in 2008. Now, in 2020, MariaDB still uses the core MySQL database protocol, but the MariaDB database has diverged significantly in other ways that are manifest in the X4 platform update. The MariaDB X4 release, unveiled Jan. 14, puts the technology squarely in the cloud-native discussion, notably because MariaDB is allowing for specific workloads to be paired with specific storage types at the cloud level, said James Curtis, senior analyst of data, AI and analytics at 451 Research.

  • SecureMyEmail makes really private email surprisingly simple

    The service also allows seamless, key-free transmission to other SecureMyEmail subscribers and to others who use PGP software such as the PGP-compatible free-software GNU Privacy Guard.

  • Copy-left behind: Permissive MIT, Apache open-source licenses on the up as developers snub GNU's GPL

    Permissive open-source software licenses continue to gain popularity at the expense of copyleft licenses, according to a forthcoming report from WhiteSource, a biz that makes software licensing management tools. Permissive licenses include the MIT and Apache 2.0 licenses and are known as such because the permit licensors to do more or less what they want with the covered software, with minimal caveats, and without imposing obligations like sharing code revisions. Copyleft licenses like GPLv2, GPLv3, and LGPLv2.1 convey similar freedom, while, to put it simply, requiring that licensors not release versions or derivatives of the licensed code that restrict said freedom.

Programming: Rust, C and Python

  • Announcing Better Support for Fuzzing with Structured Inputs in Rust

    Today, on behalf of the Rust Fuzzing Authority, I’d like to announce new releases of the arbitrary, libfuzzer-sys, and cargo fuzz crates. Collectively, these releases better support writing fuzz targets that take well-formed instances of custom input types. This enables us to combine powerful, coverage-guided fuzzers with smart test case generation. Install or upgrade cargo fuzz with: cargo install --force cargo-fuzz To upgrade your fuzz targets, bump your libfuzzer-sys dependency to 0.2.0 on crates.io. That should be all that’s needed for most cases. However, if you were already using Arbitrary inputs for your fuzz target, some changes will be required. See the upgrading fuzz targets section below for more details.

  • C vs. Rust: Which to choose for programming hardware abstractions

    Rust is an increasingly popular programming language positioned to be the best choice for hardware interfaces. It's often compared to C for its level of abstraction. This article explains how Rust can handle bitwise operations in a number of ways and offers a solution that provides both safety and ease of use.

  • Leysin Winter sprint 2020: Feb 28 - March 7th

    The next PyPy sprint will be in Leysin, Switzerland, for the fourteenth time. This is a fully public sprint: newcomers and topics other than those proposed below are welcome.

  • Use this Python script to find bugs in your Overcloud

    OpenStack stores and manages a bunch of log files on its Overcloud nodes and Undercloud host. Therefore, it's not easy to use OSP log files to investigate a problem you're having, especially when you don't even know what could have caused the problem. If that's your situation, LogTool makes your life much easier! It saves you the time and work it would otherwise take to investigate the root cause manually. Based on a fuzzy string matching algorithm, LogTool provides all the unique error and warning messages that have occurred in the past. You can export these messages for a particular time period, such as 10 minutes ago, an hour ago, a day ago, and so on, based on timestamp in the log.

Proprietary Stuff and Openwashing

  • Apple may have to abandon Lightning connector cable

    The cable is used to charge and sync many Apple devices, such as the iPhone.

    But members of the European Parliament urged the European Commission on Monday to force tech giants to adopt a single universal charging method.

  • Confidential computing promises secure cloud apps

    Enterprises, governments and other organizations all sit on vast troves of data that cannot be processed due to security and privacy concerns. To address this limitation, researchers and vendors have developed various confidential computing techniques to safely process sensitive data. Confidential computing is particularly important for organizations in heavily regulated industries or sectors where opportunities for running workloads on the public cloud are severely limited, such as government, telecommunications, healthcare and banking. Confidential computing protects data at rest, which enables organizations to deploy sensitive workloads off premises and provides further protection to sensitive workloads on premises. [..]. "If projects and products can show regulators and legislators that the levels of security are sufficient to meet their requirements, then deployment to public clouds becomes plausible for a great many more applications and use cases," said Mike Bursell, chief security architect at Red Hat.

  • Akraino Edge Stack Enables Connected Car, AR/VR, AI Edge, and Telco Access Edge Application Use Cases

    LF Edge, an umbrella organization within the Linux Foundation that aims to establish an open, interoperable framework for edge computing independent of hardware, silicon, cloud, or operating system, today announced the availability of Akraino Edge Stack Release 2 (“Akraino R2”). Akraino’s second release furthers the power of intelligent edge with new and enhanced deployable, self-certified blueprints for a diverse set of edge use cases. Launched in 2018, and now a Stage 3 (or “Impact” stage) project under the LF Edge umbrella, Akraino Edge Stack is creating an open source software stack that supports a high-availability cloud stack optimized for edge computing systems and applications. Designed to improve the state of edge cloud infrastructure for enterprise edge, over-the-top (OTT) edge, and carrier edge networks, it offers users new levels of flexibility to scale edge cloud services quickly, to maximize the applications and functions supported at the edge, and to help ensure the reliability of systems that must be up at all times. “The Akraino community has grown rapidly in the past year, and now includes contributions from 70 percent of LF Edge Premium member companies and countless other ecosystem partners beginning to deploy the blueprints across the globe,” said Arpit Joshipura, general manager, Networking, Automation, Edge and IoT, the Linux Foundation. “With R2, strong community collaboration brings even more blueprints to the ecosystem that support current and future technology at the open source edge.”

  • Microsoft: Application Inspector is now open source, so use it to test code security

Security Leftovers

  • Study Shows The Internet Is Hugely Vulnerable To SIM Hijacking Attacks

    U.S. Wireless carriers are coming under heavy fire for failing to protect their users from the practice of SIM hijacking. The practice usually involves conning or bribing a wireless employee to port a victim's cell phone number right out from underneath them, letting the attacker then pose as the customer to potentially devastating effect. Carriers are facing numerous lawsuits from victims who say attackers used the trick to first steal their identity, then millions in cryptocurrency, or even popular social media accounts.

  • Restoring DNS Privacy

    Stefan and I have been taking last week to add DNS over TLS into IPFire - another step to make DNS more private. Here is what we have done. Cleaning up some mess IPFire has multiple places where DNS servers could be configured. If you were using PPP for your Internet connection, you would have set this up with your dialup settings. If you were using a static IP address, then you would have set up the DNS servers with it in the setup. If you were using DHCP, you had a page on the web user interface to go to. This is not only confusing for the user, but also there were the places in the code where those settings were applied. Now, we have created an entire new page which combines all of it together! You will have a list where you can set all DNS servers and set new settings. [...] This will be release with Core Update 140. Amongst the many new features, we have removed a lot of code that has caused us a lot of trouble in the past and rewritten many things entirely from scratch.

  • Security updates for Friday

    Security updates have been issued by Arch Linux (chromium), Fedora (gnulib, ImageMagick, jetty, ocsinventory-agent, phpMyAdmin, python-django, rubygem-rmagick, thunderbird, and xar), Mageia (e2fsprogs, kernel, and libjpeg), openSUSE (icingaweb2), Oracle (git, java-11-openjdk, and thunderbird), Red Hat (.NET Core), Scientific Linux (git, java-11-openjdk, and thunderbird), SUSE (fontforge and LibreOffice), and Ubuntu (kamailio and thunderbird).