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Diffstat (limited to 'src/doc')
| -rw-r--r-- | src/doc/rustc/src/codegen-options/index.md | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/src/doc/rustc/src/codegen-options/index.md b/src/doc/rustc/src/codegen-options/index.md index 0201b88417a..484242d86fe 100644 --- a/src/doc/rustc/src/codegen-options/index.md +++ b/src/doc/rustc/src/codegen-options/index.md @@ -7,6 +7,29 @@ a version of this list for your exact compiler by running `rustc -C help`. This option is deprecated and does nothing. +## branch-protection + +This option lets you enable branch authentication instructions on AArch64. +This option is ignored for non-AArch64 architectures. +It takes some combination of the following values, separated by a `+`. + +- `pac-ret` - Enable pointer authentication for non-leaf functions. +- `leaf` - Enable pointer authentication for all functions, including leaf functions. +- `b-key` - Sign return addresses with key B, instead of the default key A. +- `bti` - Enable branch target identification. + +`leaf` and `b-key` are only valid if `pac-ret` was previously specified. +For example, `-C branch-protection=bti+pac-ret+leaf` is valid, but +`-C branch-protection=bti+leaf+pac-ret` is not. + +Repeated values are ignored. +For example, `-C branch-protection=pac-ret+leaf+pac-ret` is equivalent to +`-C branch-protection=pac-ret+leaf`. + +Rust's standard library does not ship with BTI or pointer authentication enabled by default. \ +In Cargo projects the standard library can be recompiled with pointer authentication using the nightly +[build-std](https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#build-std) feature. + ## code-model This option lets you choose which code model to use. \ |