The blog post "Beware of Fast-Math" warns against indiscriminately using the -ffast-math compiler optimization. While it can significantly improve performance, it relaxes adherence to IEEE 754 floating-point standards, leading to unexpected results in programs that rely on precise floating-point behavior. Specifically, it can alter the order of operations, remove or change rounding operations, and assume no special values like NaN and Inf. This can break seemingly innocuous code, especially comparisons and calculations involving edge cases. The post recommends carefully considering the trade-offs and only using -ffast-math if you understand the implications and have thoroughly tested your code for numerical stability. It also suggests exploring alternative optimizations like -fno-math-errno, -funsafe-math-optimizations, or specific flags targeting individual operations if finer-grained control is needed.
LumoSQL is an experimental project aiming to improve SQLite performance and extensibility by rewriting it in a modular fashion using the Lua programming language. It leverages Lua's JIT compiler and flexible nature to potentially surpass SQLite's speed while maintaining compatibility. This modular architecture allows for easier experimentation with different storage engines, virtual table implementations, and other components. LumoSQL emphasizes careful benchmarking and measurement to ensure performance gains are real and significant. The project's current focus is demonstrating performance improvements, after which features like improved concurrency and new functionality will be explored.
Hacker News users discussed LumoSQL's approach of compiling SQL to native code via LLVM, expressing interest in its potential performance benefits, particularly for read-heavy workloads. Some questioned the practical advantages over existing optimized databases and raised concerns about the complexity of the compilation process and debugging. Others noted the project's early stage and the need for more benchmarks to validate performance claims. Several commenters were curious about how LumoSQL handles schema changes and concurrency control, with some suggesting comparisons to SQLite's approach. The tight integration with SQLite was also a topic of discussion, with some seeing it as a strength for leveraging existing tooling while others wondered about potential limitations.
A Linux kernel driver has been created that allows a rotary phone dial to be used as an input device. The driver translates the pulses generated by the rotary dial into numeric key presses, effectively turning the old-fashioned dial into a USB HID keyboard. It supports both clockwise and counter-clockwise rotation for dialing and navigating menus and also allows for customization of the pulse-to-digit mapping. This project makes it possible to integrate a rotary phone dial into a modern Linux system for unique input control.
Hacker News users generally expressed amusement and appreciation for the novelty of a rotary phone driver for Linux. Some questioned its practical use cases beyond nostalgia and hobby projects, while others suggested potential applications like museum exhibits or integrating rotary phones into modern VoIP systems. Several commenters delved into technical aspects, discussing the specifics of the driver implementation, pulse timing, and potential improvements like debouncing. A few reminisced about their experiences with rotary phones, highlighting the distinct tactile and auditory feedback they provided. There was also lighthearted debate about the proper nomenclature for the device (rotary vs. pulse dial).
The author envisions a future (2025 and beyond) where creating video games without a traditional game engine becomes increasingly viable. This is driven by advancements in web technologies like WebGPU, which offer native performance, and readily available libraries handling complex tasks like physics and rendering. Combined with the growing accessibility of AI tools for asset creation and potentially even gameplay logic, the barrier to entry for game development lowers significantly. This empowers smaller teams and individual developers to bring their unique game ideas to life, focusing on creativity rather than wrestling with complex engine setup and low-level programming. This shift mirrors the transition seen in web development, moving from manual HTML/CSS/JS to higher-level frameworks and tools.
Hacker News users discussed the practicality and appeal of the author's approach to game development. Several commenters questioned the long-term viability of building and maintaining custom engines, citing the significant time investment and potential for reinventing the wheel. Others expressed interest in the minimalist philosophy, particularly for smaller, experimental projects where creative control is paramount. Some pointed out the existing tools like raylib and Love2D that offer a middle ground between full-blown engines and building from scratch. The discussion also touched upon the importance of understanding underlying principles, regardless of the chosen tools. Finally, some users debated the definition of a "game engine" and whether the author's approach qualifies as engine-less.
Kilo is a small, minimalist text editor implemented in less than 1,000 lines of C code. It provides basic functionality including opening, editing, and saving files, along with features like syntax highlighting for C and search functionality. The project prioritizes simplicity and readability of the codebase, serving as an educational resource for learning about text editor implementation. Its compact nature makes it easy to understand and modify, offering a good starting point for building more complex editors or incorporating text editing capabilities into other projects.
Hacker News commenters generally praised Kilo's simplicity and small codebase, finding it a valuable learning resource. Several pointed out that its minimalism makes it easy to understand and modify, contrasting it favorably with more complex editors like Vim and Emacs. Some discussed Kilo's limitations, such as lack of features like undo/redo and its single-line editing mode, but acknowledged these as deliberate design choices in favor of simplicity. A few users shared their experiences adapting and extending Kilo's code for their own purposes, highlighting the editor's educational value. The conciseness of the implementation also sparked discussions on code size as a metric of quality and the benefits of minimal design. Finally, comparisons were drawn to other small text editors like micro and ed, with some commenters expressing preference for Kilo's approach.
This document provides a concise guide for C programmers transitioning to Fortran. It highlights key differences, focusing on Fortran's array handling (multidimensional arrays and array slicing), subroutines and functions (pass-by-reference semantics and intent attributes), derived types (similar to structs), and modules (for encapsulation and namespace management). The guide emphasizes Fortran's column-major array ordering, contrasting it with C's row-major order. It also explains Fortran's powerful array operations and intrinsic functions, allowing for optimized numerical computation. Finally, it touches on common Fortran features like implicit variable declarations, formatting with FORMAT statements, and the use of ALLOCATE and DEALLOCATE for dynamic memory management.
Hacker News users discuss Fortran's continued relevance, particularly in scientific computing, highlighting its performance advantages and ease of use for numerical tasks. Some commenters share personal anecdotes of Fortran's simplicity for array manipulation and its historical dominance. Concerns about ecosystem tooling and developer mindshare are also raised, questioning whether Fortran offers advantages over modern C++ for new projects. The discussion also touches on specific language features like derived types and allocatable arrays, comparing their implementation in Fortran to C++. Several users express interest in learning modern Fortran, spurred by the linked resource.
A developer created a lightweight, native Windows to-do list application using only pure C and the Win32 API, resulting in a tiny executable (278 KB) with no external dependencies or frameworks. The application features basic functionality like adding, checking off, and deleting tasks, persists data to a file, and has a simple, classic Windows UI. The project showcases how a functional application can be built with minimal resources using only core system libraries, demonstrating the power and efficiency of this approach.
Hacker News users generally praised the simplicity and small size of the C-based to-do app. Several commenters appreciated the "back to basics" approach and the lack of dependencies. Some discussed the merits of pure C versus using a framework like Qt, with some arguing for the educational value and performance benefits of the former. A few users pointed out minor potential improvements, such as adding keyboard navigation and configurability. The minimalist nature of the application sparked discussion about the trade-offs between features and complexity in software development. Others expressed interest in the developer's choice of a custom UI library and how it compared to existing options.
The blog post explores methods for determining if an expression is constant at compile time in C. It highlights the limitations of sizeof for this purpose, as it can't differentiate between compile-time and run-time constants, and introduces a technique using C11's _Generic keyword. This method leverages the fact that array sizes must be compile-time constants. By attempting to create an array with the expression as its size inside a _Generic selection, the code can distinguish between compile-time constants (which compile successfully) and run-time values (which result in a compilation error). This allows conditional compilation based on the constexpr-ness of an expression, enabling optimized code paths for constant values.
HN users discuss the nuances and limitations of the presented C++ technique for detecting constant expressions in C. Several point out that constexpr is a C++ feature, not C, and the article's title is misleading. Some discuss alternative approaches in C, like using the preprocessor and #ifdef or build-time evaluation with constant folding. Others highlight the challenges of reliably determining const-ness in C due to factors like linker behavior and external variables. A few commenters delve into the complexities of constexpr itself within C++, including its interaction with different versions of the standard. The overall sentiment suggests the proposed method is not directly applicable to C and that true compile-time constness detection in C remains tricky.
Fui is a lightweight C library designed for directly manipulating the Linux framebuffer within a terminal environment. It provides a simple API for drawing basic shapes, text, and images directly to the screen, bypassing the typical terminal output mechanisms. This allows for creating fast and responsive text-based user interfaces (TUIs) and other graphical elements within the terminal's constraints, offering a performance advantage over traditional terminal drawing methods. Fui aims to be easy to integrate into existing C projects with minimal dependencies.
Hacker News users discuss fui, a C library for framebuffer interaction within a TTY. Several commenters express interest in its potential for creating simple graphical interfaces within a terminal environment and for embedded systems. Some question its practical applications compared to existing solutions like ncurses, highlighting potential limitations in handling complex layouts and input. Others praise the minimalist approach, appreciating its small size and dependency-free nature. The discussion also touches upon the library's suitability for different tasks like creating progress bars or simple games within a terminal and comparing its performance to alternatives. A few commenters share their own experiences using similar framebuffer libraries and offer suggestions for improvements to fui.
JetBrains' C/C++ IDE, CLion, is now free for non-commercial projects, including personal learning, open-source contributions, and academic purposes. This free version offers the full functionality of the professional edition, including code completion, refactoring tools, and debugger integration. Users need a JetBrains Account and must renew their free license annually. While primarily aimed at individuals, some qualifying educational institutions and classroom assistance scenarios can also access free licenses through separate programs.
HN commenters largely expressed positive sentiment towards JetBrains making CLion free for non-commercial use. Several pointed out that this move might be a response to the increasing popularity of VS Code with its extensive C/C++ extensions, putting competitive pressure on CLion. Some appreciated the clarification of what constitutes "non-commercial," allowing open-source developers and hobbyists to use it freely. A few expressed skepticism, wondering if this is a temporary measure or a lead-in to a different pricing model down the line. Others noted the continued absence of a free community edition, unlike other JetBrains IDEs, which might limit broader adoption and contribution. Finally, some discussed the merits of CLion compared to other IDEs and the potential impact of this change on the competitive landscape.
Nnd is a terminal-based debugger presented as a modern alternative to GDB and LLDB. It aims for a simpler, more intuitive user experience with a focus on speed and ease of use. Key features include a built-in disassembler, register view, memory viewer, and expression evaluator. Nnd emphasizes its clean and responsive interface, striving to minimize distractions and improve the overall debugging workflow. The project is open-source and written in Rust, currently supporting debugging on Linux for x86_64, aarch64, and RISC-V architectures.
Hacker News users generally praised nnd for its speed and simplicity compared to GDB and LLDB, particularly appreciating its intuitive TUI interface. Some commenters noted its current limitations, such as a lack of support for certain features like conditional breakpoints and shared libraries, but acknowledged its potential given it's a relatively new project. Several expressed interest in trying it out or contributing to its development. The focus on Rust debugging was also highlighted, with some suggesting its specialized nature in this area could be a significant advantage. A few users compared it favorably to other debugging tools like gdb -tui and even IDE debuggers, suggesting its speed and simplicity could make it a preferred choice for certain tasks.
This GitHub repository contains the source code for QModem 4.51, a classic DOS-based terminal emulation and file transfer program. Released under the GNU General Public License, the code offers a glimpse into the development of early dial-up communication software. It includes functionality for various protocols like XModem, YModem, and ZModem, as well as terminal emulation features. This release appears to be a preservation of the original QModem software, allowing for study and potential modification by interested developers.
Hacker News users discussing the release of QModem 4.51 source code express nostalgia for the software and dial-up BBS era. Several commenters reminisce about using QModem specifically, praising its features and reliability. Some discuss the challenges of transferring files over noisy phone lines and the ingenuity of the error correction techniques employed. A few users delve into the technical details of the code, noting the use of assembly language and expressing interest in exploring its inner workings. There's also discussion about the historical significance of QModem and its contribution to the early internet landscape.
The article details a vulnerability discovered in the Linux kernel's vsock implementation, a mechanism for communication between virtual machines and their hosts. Specifically, a use-after-free vulnerability existed due to improper handling of VM shutdown, allowing a malicious guest VM to trigger a double free and gain control of the host kernel. This was achieved by manipulating vsock's connection handling during the shutdown process, causing the kernel to access freed memory. The vulnerability was ultimately patched by ensuring proper cleanup of vsock connections during VM termination, preventing the double free condition and subsequent exploitation.
Hacker News users discussed the potential attack surface introduced by vsock, generally agreeing with the article's premise but questioning the practicality of exploiting it. Some commenters pointed out that the reliance on shared memory makes vsock vulnerable to manipulation by a compromised host, mitigating the isolation benefits it ostensibly provides. Others noted that while interesting, exploiting vsock likely wouldn't be the easiest or most effective attack vector in most scenarios. The discussion also touched on existing mitigations within the hypervisor and the fact that vsock is often disabled by default, further limiting its exploitability. Several users highlighted the obscurity of vsock, suggesting the real security risk lies in poorly understood and implemented features rather than the protocol itself. A few questioned the article's novelty, claiming these vulnerabilities were already well-known within security circles.
"Compiler Reminders" serves as a concise cheat sheet for compiler development, particularly focusing on parsing and lexing. It covers key concepts like regular expressions, context-free grammars, and popular parsing techniques including recursive descent, LL(1), LR(1), and operator precedence. The post briefly explains each concept and provides simple examples, offering a quick refresher or introduction to the core components of compiler construction. It also touches upon abstract syntax trees (ASTs) and their role in representing parsed code. The post is meant as a handy reference for common compiler-related terminology and techniques, not a comprehensive guide.
HN users largely praised the article for its clear and concise explanations of compiler optimizations. Several commenters shared anecdotes of encountering similar optimization-related bugs, highlighting the practical importance of understanding these concepts. Some discussed specific compiler behaviors and corner cases, including the impact of volatile keyword and undefined behavior. A few users mentioned related tools and resources, like Compiler Explorer and Matt Godbolt's talks. The overall sentiment was positive, with many finding the article a valuable refresher or introduction to compiler optimizations.
Learn-C.org offers a free, interactive C tutorial directly in your web browser. It provides a comprehensive learning path, starting with the basics of C syntax and progressing through more complex topics like pointers, memory management, and data structures. The platform features a built-in code editor and compiler, allowing users to write, run, and test their C code in real-time without needing to install any local development environment. This hands-on approach aims to make learning C more accessible and engaging for beginners.
HN users generally praised the interactive C tutorial for its accessibility and ease of use. Several commenters appreciated the browser-based nature, eliminating the need for local setup. Some highlighted the value of instant feedback and the clear explanations, making it beneficial for beginners. A few mentioned existing interactive C resources like "Programming in C" by Stephen Kochan and online compilers, comparing them to this new tutorial. One user suggested potential improvements, such as incorporating exercises and quizzes. Overall, the sentiment was positive, viewing it as a helpful tool for learning C.
This blog post details how to implement a simplified printf function for bare-metal environments, specifically ARM Cortex-M microcontrollers, without relying on a full operating system. The author walks through creating a minimal version that supports basic format specifiers like %c, %s, %u, %x, and %d, bypassing the complexities of a standard C library. The implementation utilizes a UART for output and includes a custom integer to string conversion function. By directly manipulating registers and memory, the post demonstrates a lightweight printf suitable for resource-constrained embedded systems.
HN commenters largely praised the article for its clear explanation of implementing printf in a bare-metal environment. Several appreciated the author's focus on simplicity and avoiding unnecessary complexity. Some discussed the tradeoffs between code size and performance, with suggestions for further optimization. One commenter pointed out the potential issues with the implementation's handling of floating-point numbers, particularly in embedded systems where floating-point support might not be available. Others offered alternative approaches, including using smaller, more specialized printf implementations or relying on semihosting for debugging. The overall sentiment was positive, with many finding the article educational and well-written.
GCC 15.1, the latest stable release of the GNU Compiler Collection, is now available. This release brings substantial improvements across multiple languages, including C, C++, Fortran, D, Ada, and Go. Key enhancements include improved experimental support for C++26 and C2x standards, enhanced diagnostics and warnings, optimizations for performance and code size, and expanded platform support. Users can expect better compile times and generated code quality. This release represents a significant step forward for the GCC project and offers developers a more robust and feature-rich compiler suite.
HN commenters largely focused on specific improvements in GCC 15. Several praised the improved diagnostics, making debugging easier. Some highlighted the Modula-2 language support improvements as a welcome addition. Others discussed the benefits of the enhanced C++23 and C2x support, including modules and improved ranges. A few commenters noted the continuing, though slow, progress on static analysis features. There was also some discussion on the challenges of supporting multiple architectures and languages within a single compiler project like GCC.
Microsoft has removed its official C/C++ extension from downstream forks of VS Code, including VSCodium and Open VSX Registry. This means users of these open-source alternatives will lose access to features like IntelliSense, debugging, and other language-specific functionalities provided by the proprietary extension. While the core VS Code editor remains open source, the extension relies on proprietary components and Microsoft has chosen to restrict its availability solely to its official, Microsoft-branded VS Code builds. This move has sparked controversy, with some accusing Microsoft of "embrace, extend, extinguish" tactics against open-source alternatives. Users of affected forks will need to find alternative C/C++ extensions or switch to the official Microsoft build to regain the lost functionality.
Hacker News users discuss the implications of Microsoft's decision to restrict the C/C++ extension in VS Code forks, primarily focusing on the potential impact on open-source projects like VSCodium. Some commenters express concern about Microsoft's motivations, viewing it as an anti-competitive move to push users towards the official Microsoft build. Others believe it's a reasonable measure to protect Microsoft's investment and control the quality of the extension's distribution. The technical aspects of how Microsoft enforces this restriction are also discussed, with some suggesting workarounds like manually installing the extension or using alternative extensions. A few users point out that the core VS Code editor remains open-source and the real issue lies in the proprietary extensions being closed off. The discussion also touches upon the broader topic of open-source sustainability and the challenges faced by projects reliant on large companies.
This blog post explores different strategies for memory allocation within WebAssembly modules, particularly focusing on the trade-offs between using the built-in malloc (provided by wasm-libc) and implementing a custom allocator. It highlights the performance overhead of wasm-libc's malloc due to its generality and thread safety features. The author presents a leaner, custom bump allocator as a more performant alternative for single-threaded scenarios, showcasing its implementation and integration with a linear memory. Finally, it discusses the option of delegating allocation to JavaScript and the potential complexities involved in managing memory across the WebAssembly/JavaScript boundary.
Hacker News users discussed the implications of WebAssembly's lack of built-in allocator, focusing on the challenges and opportunities it presents. Several commenters highlighted the performance benefits of using a custom allocator tailored to the specific application, rather than relying on a general-purpose one. The discussion touched on various allocation strategies, including linear allocation, arena allocation, and using allocators from the host environment. Some users expressed concern about the added complexity for developers, while others saw it as a positive feature allowing for greater control and optimization. The possibility of standardizing certain allocator interfaces within WebAssembly was also brought up, though acknowledged as a complex undertaking. Some commenters shared their experiences with custom allocators in WebAssembly, mentioning reduced binary sizes and improved performance as key advantages.
A developer created an incredibly small, playable first-person shooter inspired by Doom that fits entirely within the data capacity of a QR code. The game, called "Backrooms DOOM," leverages extremely limited graphics and simple gameplay mechanics to achieve this feat. Scanning the QR code redirects to a webpage where the game can be played directly in a browser.
Hacker News users generally expressed admiration for the technical achievement of fitting a Doom-like game into a QR code. Several commenters questioned the actual playability, citing the extremely limited resolution and controls. Some discussed the clever compression techniques likely used, and others shared similar projects, like fitting Wolfenstein 3D into a tweet or creating even smaller games. A few questioned the use of the term "Doom-like," suggesting it was more of a tech demo than a truly comparable experience. The practicality was debated, with some seeing it as a fun novelty while others considered it more of a technical exercise. There was some discussion about the potential of pushing this concept further with future advancements in QR code capacity or display technology.
Yes, it's technically still possible to write a plain C iOS app in 2025 (and beyond). While Apple pushes developers towards Swift and SwiftUI, and Objective-C is slowly fading, the underlying iOS APIs are still C-based. This means you can use C, potentially with some Objective-C bridging for UI elements or higher-level functionalities, to create a functional app. However, this approach is significantly harder and less efficient than using Swift or Objective-C, lacking modern tools, libraries, and simplified memory management. Maintaining and updating a C-based iOS app would also be a considerable challenge compared to using more modern, officially supported languages and frameworks. Therefore, while possible, it's not generally recommended for practical development.
Hacker News users discussed the practicality and challenges of writing a plain C iOS app in 2025. Several commenters pointed out that while technically possible, using only C would be incredibly difficult and time-consuming, requiring significant workarounds to interact with essential iOS frameworks (mostly written in Objective-C and Swift). Some suggested leveraging existing C libraries and frameworks like SDL or raylib for cross-platform compatibility and easier graphics handling. Others questioned the motivation behind such an endeavor, given the availability of more suitable languages and tools for iOS development. The general consensus was that while a pure C app is theoretically achievable, it's a highly impractical approach for modern iOS development. Some pointed out that Apple's increasing restrictions on low-level access make a pure C app even more challenging going forward.
"Hacktical C" is a free, online guide to the C programming language aimed at aspiring security researchers and exploit developers. It covers fundamental C concepts like data types, control flow, and memory management, but with a specific focus on how these concepts are relevant to low-level programming and exploitation techniques. The guide emphasizes practical application, featuring numerous code examples and exercises demonstrating buffer overflows, format string vulnerabilities, and other common security flaws. It also delves into topics like interacting with the operating system, working with assembly language, and reverse engineering, all within the context of utilizing C for offensive security purposes.
Hacker News users largely praised "Hacktical C" for its clear writing style and focus on practical application, particularly for those interested in systems programming and security. Several commenters appreciated the author's approach of explaining concepts through real-world examples, like crafting shellcode and exploiting vulnerabilities. Some highlighted the book's coverage of lesser-known C features and quirks, making it valuable even for experienced programmers. A few pointed out potential improvements, such as adding more exercises or expanding on certain topics. Overall, the sentiment was positive, with many recommending the book for anyone looking to deepen their understanding of C and its use in low-level programming.
The blog post details the author's experience using the -fsanitize=undefined compiler flag with Picolibc, a small C library. While initially encountering numerous undefined behavior issues, particularly related to signed integer overflow and misaligned memory access, the author systematically addressed them through careful code review and debugging. This process highlighted the value of undefined behavior sanitizers in catching subtle bugs that might otherwise go unnoticed, ultimately leading to a more robust and reliable Picolibc implementation. The author demonstrates how even seemingly simple C code can harbor hidden undefined behaviors, emphasizing the importance of rigorous testing and the utility of tools like -fsanitize=undefined in ensuring code correctness.
HN users discuss the blog post's exploration of undefined behavior sanitizers. Several commend the author's clear explanation of the intricacies of undefined behavior and the utility of sanitizers like UBSan. Some users share their own experiences and tips regarding sanitizers, including the importance of using them during development and the potential performance overhead they can introduce. One commenter highlights the surprising behavior of signed integer overflow and the challenges it presents for developers. Others point out the value of sanitizers, particularly in embedded and safety-critical systems. The small size and portability of Picolibc are also noted favorably in the context of using sanitizers. A few users express a general appreciation for the blog post's educational value and the author's engaging writing style.
The cg_clif project has made significant progress in compiling Rust to C, achieving a 95.9% pass rate on the Rust test suite. This compiler leverages Cranelift as a backend and utilizes a custom ABI for passing Rust data structures. Notably, it's now functional on more unusual platforms like wasm32-wasi and thumbv6m-none-eabi (for embedded ARM devices). While performance isn't a primary focus currently, basic functionality and compatibility are progressing rapidly, demonstrating the potential for compiling Rust to a portable C representation.
Hacker News users discussed the impressive 95.9% test pass rate of the Rust-to-C compiler, particularly its ability to target unusual platforms like the Sega Saturn and Sony PlayStation. Some expressed skepticism about the practical applications, questioning the performance implications and debugging challenges of such a complex transpilation process. Others highlighted the potential benefits for code reuse and portability, enabling Rust code to run on legacy or resource-constrained systems. The project's novelty and ambition were generally praised, with several commenters expressing interest in the developer's approach and future developments. Some also debated the suitability of "compiler" versus "transpiler" to describe the project. There was also discussion around specific technical aspects, like memory management and the handling of Rust's borrow checker within the C output.
GCC 15 introduces several usability enhancements. Improved diagnostics offer more concise and helpful error messages, including location information within macros and clearer explanations for common mistakes. The new -fanalyzer option provides static analysis capabilities to detect potential issues like double-free errors and use-after-free vulnerabilities. Link-time optimization (LTO) is more robust with improved diagnostics, and the compiler can now generate more efficient code for specific targets like Arm and x86. Additionally, improved support for C++20 and C2x features simplifies development with modern language standards. Finally, built-in functions for common mathematical operations have been optimized, potentially improving performance without requiring code changes.
Hacker News users generally expressed appreciation for the continued usability improvements in GCC. Several commenters highlighted the value of the improved diagnostics, particularly the location information and suggestions, making debugging significantly easier. Some discussed the importance of such advancements for both novice and experienced programmers. One commenter noted the surprisingly rapid adoption of these improvements in Fedora's GCC packages. Others touched on broader topics like the challenges of maintaining large codebases and the benefits of static analysis tools. A few users shared personal anecdotes of wrestling with confusing GCC error messages in the past, emphasizing the positive impact of these changes.
C3 is a new programming language designed as a modern alternative to C. It aims to be safer and easier to use while maintaining C's performance and low-level control. Key features include optional memory safety through compile-time checks and garbage collection, improved syntax and error messages, and built-in modularity. The project is actively under development and includes a self-hosting compiler written in C3. The goal is to provide a practical language for systems programming and other performance-sensitive domains while mitigating common C pitfalls.
HN users discuss C3's goals and features, expressing both interest and skepticism. Several question the need for another C-like language, especially given the continued development of C and C++. Some appreciate the focus on safety and preventing common C errors, while others find the changes too drastic a departure from C's philosophy. There's debate about the practicality of automatic memory management in systems programming, and some concern over the runtime overhead it might introduce. The project's early stage is noted, and some express reservations about its long-term viability and community adoption. Others are more optimistic, praising the clear documentation and expressing interest in following its progress. The use of Python for the compiler is also a point of discussion.
This guide provides a curated list of compiler flags for GCC, Clang, and MSVC, designed to harden C and C++ code against security vulnerabilities. It focuses on options that enable various exploit mitigations, such as stack protectors, control-flow integrity (CFI), address space layout randomization (ASLR), and shadow stacks. The guide categorizes flags by their protective mechanisms, emphasizing practical usage with clear explanations and examples. It also highlights potential compatibility issues and performance impacts, aiming to help developers choose appropriate hardening options for their projects. By leveraging these compiler-based defenses, developers can significantly reduce the risk of successful exploits targeting their software.
Hacker News users generally praised the OpenSSF's compiler hardening guide for C and C++. Several commenters highlighted the importance of such guides in improving overall software security, particularly given the prevalence of C and C++ in critical systems. Some discussed the practicality of implementing all the recommendations, noting potential performance trade-offs and the need for careful consideration depending on the specific project. A few users also mentioned the guide's usefulness for learning more about compiler options and their security implications, even for experienced developers. Some wished for similar guides for other languages, and others offered additional suggestions for hardening, like using static and dynamic analysis tools. One commenter pointed out the difference between control-flow hijacking mitigations and memory safety, emphasizing the limitations of the former.
This paper explores practical strategies for hardening C and C++ software against memory safety vulnerabilities without relying on memory-safe languages or rewriting entire codebases. It focuses on compiler-based mitigations, leveraging techniques like Control-Flow Integrity (CFI) and Shadow Stacks, and highlights how these can be effectively deployed even in complex, legacy projects with limited resources. The paper emphasizes the importance of a layered security approach, combining static and dynamic analysis tools with runtime protections to minimize attack surfaces and contain the impact of potential exploits. It argues that while a complete shift to memory-safe languages is ideal, these mitigation techniques offer valuable interim protection and represent a pragmatic approach for enhancing the security of existing C/C++ software in the real world.
Hacker News users discussed the practicality and effectiveness of the proposed "TypeArmor" system for securing C/C++ code. Some expressed skepticism about its performance overhead and the complexity of retrofitting it onto existing projects, questioning its viability compared to rewriting in memory-safe languages like Rust. Others were more optimistic, viewing TypeArmor as a potentially valuable tool for hardening legacy codebases where rewriting is not feasible. The discussion touched upon the trade-offs between security and performance, the challenges of integrating such a system into real-world projects, and the overall feasibility of achieving robust memory safety in C/C++ without fundamental language changes. Several commenters also pointed out limitations of TypeArmor, such as its inability to handle certain complex pointer manipulations and the potential for vulnerabilities in the TypeArmor system itself. The general consensus seemed to be cautious interest, acknowledging the potential benefits while remaining pragmatic about the inherent difficulties of securing C/C++.
This blog post explains why the author chose C to build their personal website. Motivated by a desire for a fun, challenging project and greater control over performance and resource usage, they opted against higher-level frameworks. While acknowledging C's complexity and development time, the author highlights the benefits of minimal dependencies, small executable size, and the learning experience gained. Ultimately, the decision was driven by personal preference and the satisfaction derived from crafting a website from scratch using a language they enjoy.
Hacker News users generally praised the author's technical skills and the site's performance, with several expressing admiration for the clean code and minimalist approach. Some questioned the practicality and maintainability of using C for a website, particularly regarding long-term development and potential security risks. Others discussed the benefits of learning C and low-level programming, while some debated the performance advantages compared to other languages and frameworks. A few users shared their own experiences with similar projects and alternative approaches to achieving high performance. A significant point of discussion was the lack of server-side rendering, which some felt hindered the site's SEO.
LVGL is a free and open-source graphics library providing everything you need to create embedded GUIs with easy-to-use graphical elements, beautiful visual effects, and a low memory footprint. It's designed to be platform-agnostic, supporting a wide range of input devices and hardware from microcontrollers to powerful embedded systems like the Raspberry Pi. Key features include scalable vector graphics, animations, anti-aliasing, Unicode support, and a flexible style system for customizing the look and feel of the interface. With its rich set of widgets, themes, and an active community, LVGL simplifies the development process of visually appealing and responsive embedded GUIs.
HN commenters generally praise LVGL's ease of use, beautiful output, and good documentation. Several note its suitability for microcontrollers, especially with limited resources. Some express concern about its memory footprint, even with optimizations, and question its performance compared to other GUI libraries. A few users share their positive experiences integrating LVGL into their projects, highlighting its straightforward integration and active community. Others discuss the licensing (MIT) and its suitability for commercial products. The lack of a GPU dependency is mentioned as both a positive and negative, offering flexibility but potentially impacting performance for complex graphics. Finally, some comments compare LVGL to other embedded GUI libraries, with varying opinions on its relative strengths and weaknesses.
Summary of Comments ( 169 )
https://news.ycombinator.com/item?id=44142472
Hacker News users discussed potential downsides of using
-ffast-math, even beyond the documented changes to IEEE compliance. One commenter highlighted the risk of silent changes in code behavior across compiler versions or optimization levels, making debugging difficult. Another pointed out that using-ffast-mathcan lead to unexpected issues with code that relies on specific floating-point behavior, such as comparisons or NaN handling. Some suggested that the performance gains are often small and not worth the risks, especially given the potential for subtle, hard-to-track bugs. The consensus seemed to be that-ffast-mathshould be used cautiously and only when its impact is thoroughly understood and tested, with a preference for more targeted optimizations where possible. A few users mentioned specific instances where-ffast-mathcaused problems in real-world projects, further reinforcing the need for careful consideration.The Hacker News post "Beware of Fast-Math" (https://news.ycombinator.com/item?id=44142472) has generated a robust discussion around the trade-offs between speed and accuracy when using the "-ffast-math" compiler optimization flag. Several commenters delve into the nuances of when this optimization is acceptable and when it's dangerous.
One of the most compelling threads starts with a commenter highlighting the importance of understanding the specific mathematical properties being relied upon in a given piece of code. They emphasize that "-ffast-math" can break assumptions about associativity and distributivity, leading to unexpected results. This leads to a discussion about the importance of careful testing and profiling to ensure that the optimization doesn't introduce subtle bugs. Another commenter chimes in to suggest that using stricter floating-point settings during development and then selectively enabling "-ffast-math" in performance-critical sections after thorough testing can be a good strategy.
Another noteworthy comment chain focuses on the implications for different fields. One commenter mentions that in game development, where performance is often paramount and small inaccuracies in physics calculations are generally acceptable, "-ffast-math" can be a valuable tool. However, another commenter counters this by pointing out that even in games, seemingly minor errors can accumulate and lead to noticeable glitches or exploits. They suggest that developers should carefully consider the potential consequences before enabling the optimization.
Several commenters share personal anecdotes about encountering issues related to "-ffast-math." One recounts a debugging nightmare caused by the optimization silently changing the behavior of their code. This reinforces the general sentiment that while the performance gains can be tempting, the potential for hidden bugs makes it crucial to proceed with caution.
The discussion also touches on alternatives to "-ffast-math." Some commenters suggest exploring other optimization techniques, such as using SIMD instructions or writing optimized code for specific hardware, before resorting to a compiler flag that can have such unpredictable side effects.
Finally, a few commenters highlight the importance of compiler-specific documentation. They point out that the exact behavior of "-ffast-math" can vary between compilers, further emphasizing the need for careful testing and understanding the specific implications for the chosen compiler.
In summary, the comments on the Hacker News post paint a nuanced picture of the "-ffast-math" optimization. While acknowledging the potential for performance improvements, the overall consensus is that it should be used judiciously and with a thorough understanding of its potential pitfalls. The commenters emphasize the importance of testing, profiling, and considering alternative optimization strategies before enabling this potentially problematic flag.