IdeaWell

Project ideas from Hacker News discussions.

SDCC – Small Device C Compiler

Original Article

Hacker News Discussion

📝 Discussion Summary (Click to expand)

Theme 1: SDCC’s quirks and reliability concerns
Many commenters note that while SDCC is a valuable open‑source 8051 compiler, it exhibits unpredictable bugs—especially aggressive loop optimizations that break code unless volatile is used.
- “SDCC has the best OSS 8051 compiler. It is buggy as hell, but it is free.” – dmitrygr
- “the compiler optimized away some ‘empty’ loops a little bit too aggressively without realizing that these loops were setting output pins.” – raphman
- “when you have large code, bugs will find you… adding them together … will produce an access to garbage memory after 5‑6 additions.” – dmitrygr

Theme 2: Exploring alternatives and work‑arounds
Users discuss other compiler options (LLM‑generated cc51, Mikroe compilers, GCC for newer MCUs) and stress best practices like using volatile or filing bug reports.
- “just yesterday I asked an LLM to generate a C compiler for the 8051 … Within 1.5 hour it was correctly compiling my project at 60% of the size of what SDCC generates.” – Jyaif
- “If it has not to be SDCC, Mikroe compilers have support for them across C, BASIC and Pascal compilers.” – pjmlp
- “Please file a bug report, if you haven’t done so.” – uecker

Theme 3: Shift toward modern MCU platforms
Several participants argue that newer 32‑bit cores (STM32, ESP32, RP2350, nRF) offer better toolchains, performance, and power efficiency, making legacy 8‑bit work less attractive.
- “STM32/ESP32/RP2350 or nRF for low power stuff are far less effort these days, and give much better value.” – Joel_Mckay
- “PIC does still have a few key use‑cases, but most people will hit the stack depth limits pretty quickly in C.” – Joel_Mckay
- “great chips now that have free gcc support, reasonable power draw, and 32bit float support (ATSAM3X8E …).” – Joel_Mckay

🚀 Project Ideas

VolatileGuard: Static Analysis Tool for Detecting Optimizer‑Unsafe Loops in Embedded C

Summary

  • Scans C source for loops that may be removed by aggressive optimizers when they have side‑effects (e.g., toggling I/O pins) and flags missing volatile or __attribute__((used)) annotations.
  • Provides quick fixes and compiler‑specific pragma suggestions for SDCC, GCC, and other embedded toolchains.

Details

Key Value
Target Audience Firmware developers using SDCC, GCC, or other optimizing compilers for 8‑bit/32‑bit MCUs
Core Feature AST‑based detection of loops with observable side‑effects lacking proper volatility markings
Tech Stack Python (libclang/tree‑sitter), pytest for validation, optional WASM for web demo
Difficulty Medium
Monetization Hobby

Notes

  • HN users complained about SDCC “optimizing away some ‘empty’ loops a little bit too aggressively without realizing that these loops were setting output pins” (raphman) and similar GCC/Cortex‑M issues (technothrasher).
  • Gives them an automated way to catch the class of bugs that forced them to add volatile manually, reducing debugging time and improving code reliability.

MultiSim Test Harness: Cross‑Simulator Validation Framework for 8051 Compilers

Summary

  • Runs a compiler’s test suite (e.g., SDCC’s) on two or more independent 8051 simulators (such as sim51 and minitel_sim) to detect false‑positives/negatives caused by shared bugs.
  • Generates a unified report highlighting divergences and provides CI integration for continuous confidence.

Details

Key Value
Target Audience Compiler maintainers, open‑source project contributors, and embedded teams validating 8051 toolchains
Core Feature Automated execution of regression tests across multiple simulators with diff‑based result aggregation
Tech Stack Docker (to isolate simulators), Bash/Python orchestration, JSON report schema, GitHub Actions
Difficulty Medium
Monetization Hobby

Notes

  • The discussion highlighted concerns about “common‑mode errors in both your compiler and emulator resulting in false confidence” (oasisaimlessly) and the desire for trustworthy validation.
  • MultiSim directly addresses this need, offering a practical utility that commenters would likely adopt and discuss on HN.

LLVM‑8051 Backend Drop‑in for SDCC: Modern Optimizer for Legacy 8‑bit MCUs

Summary

  • Provides a drop‑in replacement for SDCC’s code‑generation phase using an LLVM‑based 8051 backend, delivering better optimization (size/speed) while preserving SDCC’s front‑end compatibility.
  • Includes a thin driver script (sdcc-llvm) that invokes clang/LLVM with the appropriate target and links with SDCC runtime libraries.

Details

Key Value
Target Audience Developers frustrated with SDCC’s optimizer quirks and seeking improved code size/performance for 8051, STM8, and similar MCUs
Core Feature LLVM‑based code generation for 8051 architecture, integrated as an optional SDCC backend
Tech Stack LLVM (C++), CMake, SDCC source (as library), optional Rust bindings for driver
Difficulty High
Monetization Hobby

Notes

  • Jyaif’s LLVM‑generated compiler (cc51) achieved “60% of the size of what SDCC generates” and passed the SDCC test suite, showing strong demand for a better optimizer (Jyaif).
  • Offering this as a drop‑in keeps existing build systems intact, making it an attractive upgrade path that HN commenters would likely experiment with and discuss.

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