Auto merge of #93439 - abrown:cf-protection, r=nagisa

Add support for control-flow protection

This change adds a flag for configuring control-flow protection in the LLVM backend. In Clang, this flag is exposed as `-fcf-protection` with options `none|branch|return|full`. This convention is followed for `rustc`, though as a codegen option: `rustc -Z cf-protection=<none|branch|return|full>`. Tracking issue for future work is #93754.

1 files changed, 38 insertions, 0 deletions

diff --git a/src/test/codegen/cf-protection.rs b/src/test/codegen/cf-protection.rs
new file mode 100644
index 00000000000..ccbc863f571
--- /dev/null
+++ b/src/test/codegen/cf-protection.rs
@@ -0,0 +1,38 @@
+// Test that the correct module flags are emitted with different control-flow protection flags.
+
+// revisions: undefined none branch return full
+// needs-llvm-components: x86
+// [undefined] compile-flags:
+// [none] compile-flags: -Z cf-protection=none
+// [branch] compile-flags: -Z cf-protection=branch
+// [return] compile-flags: -Z cf-protection=return
+// [full] compile-flags: -Z cf-protection=full
+// compile-flags: --target x86_64-unknown-linux-gnu
+
+#![crate_type = "lib"]
+#![feature(no_core, lang_items)]
+#![no_core]
+
+#[lang="sized"]
+trait Sized { }
+
+// A basic test function.
+pub fn test() {
+}
+
+// undefined-NOT: !"cf-protection-branch"
+// undefined-NOT: !"cf-protection-return"
+
+// none-NOT: !"cf-protection-branch"
+// none-NOT: !"cf-protection-return"
+
+// branch-NOT: !"cf-protection-return"
+// branch: !"cf-protection-branch", i32 1
+// branch-NOT: !"cf-protection-return"
+
+// return-NOT: !"cf-protection-branch"
+// return: !"cf-protection-return", i32 1
+// return-NOT: !"cf-protection-branch"
+
+// full: !"cf-protection-branch", i32 1
+// full: !"cf-protection-return", i32 1