Allow disabling ASan instrumentation for globals

AddressSanitizer adds instrumentation to global variables unless the
[`no_sanitize_address`](https://llvm.org/docs/LangRef.html#global-attributes)
attribute is set on them.

This commit extends the existing `#[no_sanitize(address)]` attribute to
set this; previously it only had the desired effect on functions.

3 files changed, 14 insertions, 0 deletions

diff --git a/compiler/rustc_codegen_llvm/src/base.rs b/compiler/rustc_codegen_llvm/src/base.rs
index 32793894794..f62310bd948 100644
--- a/compiler/rustc_codegen_llvm/src/base.rs
+++ b/compiler/rustc_codegen_llvm/src/base.rs
@@ -172,3 +172,12 @@ pub(crate) fn visibility_to_llvm(linkage: Visibility) -> llvm::Visibility {
         Visibility::Protected => llvm::Visibility::Protected,
     }
 }
+
+pub(crate) fn set_variable_sanitizer_attrs(llval: &Value, attrs: &CodegenFnAttrs) {
+    if attrs.no_sanitize.contains(SanitizerSet::ADDRESS) {
+        unsafe { llvm::LLVMRustSetNoSanitizeAddress(llval) };
+    }
+    if attrs.no_sanitize.contains(SanitizerSet::HWADDRESS) {
+        unsafe { llvm::LLVMRustSetNoSanitizeHWAddress(llval) };
+    }
+}
diff --git a/compiler/rustc_codegen_llvm/src/consts.rs b/compiler/rustc_codegen_llvm/src/consts.rs
index 21d996ef460..ce9f8a2a9ea 100644
--- a/compiler/rustc_codegen_llvm/src/consts.rs
+++ b/compiler/rustc_codegen_llvm/src/consts.rs
@@ -476,6 +476,8 @@ impl<'ll> CodegenCx<'ll, '_> {
                 base::set_link_section(g, attrs);
             }
 
+            base::set_variable_sanitizer_attrs(g, attrs);
+
             if attrs.flags.contains(CodegenFnAttrFlags::USED) {
                 // `USED` and `USED_LINKER` can't be used together.
                 assert!(!attrs.flags.contains(CodegenFnAttrFlags::USED_LINKER));
diff --git a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
index 5fad7583e1a..2679d8ba9fe 100644
--- a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
+++ b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
@@ -2474,4 +2474,7 @@ unsafe extern "C" {
     pub fn LLVMRustIs64BitSymbolicFile(buf_ptr: *const u8, buf_len: usize) -> bool;
 
     pub fn LLVMRustIsECObject(buf_ptr: *const u8, buf_len: usize) -> bool;
+
+    pub fn LLVMRustSetNoSanitizeAddress(Global: &Value);
+    pub fn LLVMRustSetNoSanitizeHWAddress(Global: &Value);
 }