| # Unified Headers |
| |
| [Issue #120](https://github.com/android-ndk/ndk/issues/120) |
| |
| Before NDK r14, we had a set of libc headers for each API version. In many cases |
| these headers were incorrect. Many exposed APIs that didn't exist, and others |
| didn't expose APIs that did. |
| |
| In NDK r14 (as an opt in feature) we unified these into a single set of headers, |
| called unified headers. This single header path is used for *every* platform |
| level. API level guards are handled with `#ifdef`. These headers can be found in |
| [prebuilts/ndk/platform/sysroot]. |
| |
| Unified headers are built directly from the Android platform, so they are up to |
| date and correct (or at the very least, any bugs in the NDK headers will also be |
| a bug in the platform headers, which means we're much more likely to find them). |
| |
| In r15 unified headers are used by default. In r16, the old headers have been |
| removed. |
| |
| [prebuilts/ndk/headers]: https://android.googlesource.com/platform/prebuilts/ndk/+/dev/platform/sysroot/usr/include |
| |
| ## Supporting Unified Headers in Your Build System |
| |
| See the [Build System Maintainers] doc. |
| |
| [Build System Maintainers]: BuildSystemMaintainers.md |
