huntedbytheirs
180c1107b6
Establish the repository layout per Vox guidelines (layouts/C.md, building/C.md): Autotools build (GCC-only, C23), five compatibility profiles (--enable-onlyposix/--enable-muslmimic/--enable-muslext/ --enable-spoof, default vlibc), alongside/overwrite install methods, vlibc-gcc/vlibc-clang drivers, static-linking requirement (except spoof), benchmark harness, and tooling (.clang-format/.clang-tidy/ .clangd + compile_commands.json).
31 lines
1.7 KiB
Markdown
31 lines
1.7 KiB
Markdown
# Compatibility
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vlibc offers five compatibility profiles, selected at configure time. They are
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mutually exclusive; the default is `vlibc`.
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| Level | Flag | Profile | What it provides |
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|-------|----------------------|-------------|---------------------------------------------------------|
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| 1 | `--enable-onlyposix` | `onlyposix` | Pure POSIX, nothing more — the lightest possible build. |
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| 2 | `--enable-muslmimic` | `muslmimic` | musl-like, still light, with musl-compatible features. |
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| 3 | `--enable-muslext` | `muslext` | An extension of musl, adding more. |
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| 4 | `--enable-spoof` | `spoof` | A glibc replica: emulates glibc for drop-in compatibility, higher than `muslext` or `vlibc` full. |
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| 5 | *(default)* | `vlibc` | glibc-extended: glibc minus its baggage, plus extended standard features. High (but not spoof-level) glibc compatibility. |
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## Differences from glibc
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- **No legacy baggage.** vlibc targets modern, standard-conforming behavior and
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drops glibc's deprecated and non-standard behaviors unless a profile
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explicitly restores them.
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- **Extended standard features.** The `vlibc` profile adds extensions on top of
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the C and POSIX standards that glibc does not provide.
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- **Spoofing is opt-in.** The `--enable-spoof` profile re-enables the
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long-standing legacy behaviors that scripts rely on, for drop-in
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compatibility with existing binaries and build systems.
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## Full static linking
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Every profile except `spoof` must be able to link fully statically. The
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`spoof` profile is exempt: its glibc-emulation layer depends on dynamic
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facilities (e.g. `dlopen`-based compatibility shims) that a static build cannot
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provide.
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