llvm-project

674f3083 - [BOLT][BTI] Add needed BTIs in LongJmp or refuse to optimize binary (#171149)

[BOLT][BTI] Add needed BTIs in LongJmp or refuse to optimize binary (#171149) This patch adds BTI landing pads to ShortJmp/LongJmp targets in the LongJmp pass when optimizing BTI binaries. BOLT does not have the ability to add BTI to all types of functions. This patch aims to insert the landing pad where possible, and emit an error and exit where it currently is not. BOLT cannot insert BTIs into several function "types", including: - ignored functions, - PLT functions, - other functions without a CFG. Additional context: In #161206, BOLT gained the ability to decode the .note.gnu.property section, and warn about lack of BTI support for BOLT. However, this warning is misleading: the emitted binary may not need extra BTI landing pads. With this patch, the emitted binary will be "BTI-safe".