This insight was synthesized by AI from public community discussions. We do not display original user posts or comments verbatim—all content has been rewritten and aggregated. Verify before acting on it.
W^X-safe closure/delegate library for C/C++
A header-only C/C++ library that provides safe, portable closure and delegate calling conventions without requiring executable stacks. It would replace GCC's trampoline-based nested function mechanism with a W^X-compliant approach using executable heap with proper mprotect transitions or ABI-level context pointer passing, enabling developers to call nested functions and closures across language boundaries securely.
Why this matters
You are a systems programmer building a C or C++ application that needs to call nested functions or closures across language boundaries. When you try to use GCC's nested function trampolines, your security team rejects the code because it requires an executable stack, violating W^X policies enforced on OpenBSD and increasingly on hardened Linux. You could switch to D for its elegant delegate ABI, but that is not realistic for an existing codebase. You end up manually threading context pointers through every call site, writing fragile boilerplate that breaks when the calling convention changes. There is no off-the-shelf library that gives you a portable, W^X-safe closure abstraction you can drop into your C codebase.
- · Built for Systems programmers, embedded developers, and compiler/runtime engineers who work with nested functions, closures, or cross-language FFI and must comply with W^X security policies.
- · Most likely monetization: Dual license (GPL for open-source, commercial license for proprietary use).
The Pain · Narrative
You are a systems programmer building a C or C++ application that needs to call nested functions or closures across language boundaries. When you try to use GCC's nested function trampolines, your security team rejects the code because it requires an executable stack, violating W^X policies enforced on OpenBSD and increasingly on hardened Linux. You could switch to D for its elegant delegate ABI, but that is not realistic for an existing codebase. You end up manually threading context pointers through every call site, writing fragile boilerplate that breaks when the calling convention changes. There is no off-the-shelf library that gives you a portable, W^X-safe closure abstraction you can drop into your C codebase.
Score Breakdown
Market Signal
Go-to-Market
Embedded and systems developers at security-conscious companies building C/C++ firmware or runtimes that need closure-like functionality without W^X violations
~10K-20K developers globally who work with GCC nested functions or cross-language FFI in security-hardened environments
Hacker News launch paired with targeted outreach to OpenBSD and embedded developer communities
$499/year commercial license, free GPL version for open-source projects
500 GitHub stars and 5 commercial license inquiries within 60 days of launch
MVP Scope · 1–2 weeks
- Implement core closure abstraction as a C header-only library for x86-64 Linux
- Build W^X-safe trampoline replacement using mprotect-based executable heap approach
- Write 10 unit tests covering basic closure creation, calling, and teardown
- Create a simple example showing calling a nested function without executable stack
- Set up CMake build system and CI pipeline with GCC and Clang
- Add ARM64 support with architecture-specific code generation
- Build CLI tool that auto-generates C-callable bridge functions from closure specifications
- Create benchmark suite comparing trampoline-based vs W^X-safe closure performance
- Write documentation explaining the W^X compliance model and security benefits
- Prepare Hacker News launch post with working demo repository
Differentiation
Why This Might Fail
Self-rebuttal — the most important trust signal
- 1The target audience of systems programmers strongly prefers open-source tools and may fork or reimplement the GPL version rather than purchasing commercial licenses, keeping revenue negligible.
- 2The technical complexity of supporting multiple architectures, compilers, and OS security policies creates a maintenance burden that outstrips revenue from a small niche audience.
- 3Compiler vendors (GCC, Clang) may introduce native W^X-safe nested function support, rendering the library obsolete before it achieves significant adoption.
Evidence Summary
How AI synthesized this insight — no verbatim quotes
Approximately 8 commenters discussed the tension between nested function trampolines requiring executable stacks and modern W^X security policies. Multiple users described the fundamental problem of supplying context pointers for nested function calls without writable-and-executable memory. Several noted that alternative ABIs like D's delegates solve this elegantly but require language adoption. The discussion revealed genuine technical pain but no payment signals, consistent with a developer-tools audience expecting open-source solutions.
Action Plan
Validate this opportunity before writing code
Recommended Next Step
Validate
Promising signals, but needs confirmation. Create a landing page, collect email sign-ups, then decide.
Landing Page Copy Kit
Ready-to-paste copy based on real Reddit community language — no editing required
Headline
W^X-safe closure/delegate library for C/C++
Sub-headline
A header-only C/C++ library that provides safe, portable closure and delegate calling conventions without requiring executable stacks. It would replace GCC's trampoline-based nested function mechanism with a W^X-compliant approach using executable heap with proper mprotect transitions or ABI-level context pointer passing, enabling developers to call nested functions and closures across language boundaries securely.
Who It's For
For Systems programmers, embedded developers, and compiler/runtime engineers who work with nested functions, closures, or cross-language FFI and must comply with W^X security policies
Feature List
✓ Portable closure/delegate abstraction header-only API ✓ Automatic W^X-safe code generation for trampoline replacement ✓ Cross-architecture support (x86-64, ARM64, RISC-V) ✓ Code generation CLI tool for auto-creating C-callable bridges from language-specific closures ✓ Integration with CMake and Meson build systems ✓ Parse closure/delegate definitions from D, Rust, Swift, C++ source files ✓ Generate C header files with W^X-safe callback trampolines ✓ Generate thin wrapper libraries per source language
Where to Validate
Share your landing page in r/HN · front_page — that's exactly where these pain points were discovered.
Sign up to unlock full deep analysis
GTM, MVP scope, why-it-might-fail, ActionPlan Copy Kit. Free signup grants 10 detail views/month.
Other opportunities in the same theme
Auto-clustered by AI from related discussions