add attribute check and removal bindings

Author: Shourya742

compiler/rustc_codegen_llvm/src/attributes.rs

@@ -32,10 +32,18 @@ pub(crate) fn has_attr(llfn: &Value, idx: AttributePlace, attr: AttributeKind) -
     llvm::HasAttributeAtIndex(llfn, idx, attr)
 }
 
+pub(crate) fn has_string_attr(llfn: &Value, name: *const i8) -> bool {
+    llvm::HasStringAttribute(llfn, name)
+}
+
 pub(crate) fn remove_from_llfn(llfn: &Value, place: AttributePlace, kind: AttributeKind) {
     llvm::RemoveRustEnumAttributeAtIndex(llfn, place, kind);
 }
 
+pub(crate) fn remove_string_attr_from_llfn(llfn: &Value, name: *const i8) {
+    llvm::RemoveStringAttrFromFn(llfn, name);
+}
+
 /// Get LLVM attribute for the provided inline heuristic.
 #[inline]
 fn inline_attr<'ll>(cx: &CodegenCx<'ll, '_>, inline: InlineAttr) -> Option<&'ll Attribute> {

compiler/rustc_codegen_llvm/src/llvm/enzyme_ffi.rs

@@ -19,6 +19,8 @@ unsafe extern "C" {
     pub(crate) fn LLVMRustVerifyFunction(V: &Value, action: LLVMRustVerifierFailureAction) -> Bool;
     pub(crate) fn LLVMRustHasAttributeAtIndex(V: &Value, i: c_uint, Kind: AttributeKind) -> bool;
     pub(crate) fn LLVMRustGetArrayNumElements(Ty: &Type) -> u64;
+    pub(crate) fn LLVMRustHasFnAttribute(F: &Value, Name: *const c_char) -> bool;
+    pub(crate) fn LLVMRustRemoveFnAttribute(F: &Value, Name: *const c_char);
 }
 
 unsafe extern "C" {

compiler/rustc_codegen_llvm/src/llvm/ffi.rs

@@ -1160,7 +1160,11 @@ unsafe extern "C" {
 
     pub(crate) fn LLVMGetFirstFunction(M: &Module) -> Option<&Value>;
     pub(crate) fn LLVMGetNextFunction(Fn: &Value) -> Option<&Value>;
-    pub(crate) fn LLVMRustRemoveEnumAttributeAtIndex(Fn: &Value, index: c_uint, kind: AttributeKind);
+    pub(crate) fn LLVMRustRemoveEnumAttributeAtIndex(
+        Fn: &Value,
+        index: c_uint,
+        kind: AttributeKind,
+    );
 
     pub(crate) fn LLVMDeleteGlobal(GlobalVar: &Value);
     pub(crate) fn LLVMGetInitializer(GlobalVar: &Value) -> Option<&Value>;

compiler/rustc_codegen_llvm/src/llvm/mod.rs

@@ -41,11 +41,27 @@ pub(crate) fn AddFunctionAttributes<'ll>(
     }
 }
 
-pub(crate) fn HasAttributeAtIndex<'ll>(llfn: &'ll Value, idx: AttributePlace, kind: AttributeKind) -> bool {
+pub(crate) fn HasAttributeAtIndex<'ll>(
+    llfn: &'ll Value,
+    idx: AttributePlace,
+    kind: AttributeKind,
+) -> bool {
     unsafe { LLVMRustHasAttributeAtIndex(llfn, idx.as_uint(), kind) }
 }
 
-pub(crate) fn RemoveRustEnumAttributeAtIndex(llfn: &Value, place: AttributePlace, kind: AttributeKind) {
+pub(crate) fn HasStringAttribute<'ll>(llfn: &'ll Value, name: *const i8) -> bool {
+    unsafe { LLVMRustHasFnAttribute(llfn, name) }
+}
+
+pub(crate) fn RemoveStringAttrFromFn<'ll>(llfn: &'ll Value, name: *const i8) {
+    unsafe { LLVMRustRemoveFnAttribute(llfn, name) }
+}
+
+pub(crate) fn RemoveRustEnumAttributeAtIndex(
+    llfn: &Value,
+    place: AttributePlace,
+    kind: AttributeKind,
+) {
     unsafe {
         LLVMRustRemoveEnumAttributeAtIndex(llfn, place.as_uint(), kind);
     }

compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp

@@ -979,6 +979,24 @@ extern "C" void LLVMRustRemoveEnumAttributeAtIndex(LLVMValueRef F, size_t index,
   LLVMRemoveEnumAttributeAtIndex(F, index, fromRust(RustAttr));
 }
 
+
+extern "C" bool LLVMRustHasFnAttribute(LLVMValueRef F, const char *Name) {
+  if (auto *Fn = dyn_cast<Function>(unwrap<Value>(F))) {
+    return Fn->hasFnAttribute(Name);
+  }
+  return false;
+}
+
+
+extern "C" void LLVMRustRemoveFnAttribute(LLVMValueRef Fn, const char *Name) {
+  auto *F = dyn_cast<Function>(unwrap<Value>(Fn));
+  assert(F);
+  assert(F->hasFnAttribute(Name) &&
+         "Function does not have the attribute to be removed");
+  F->removeFnAttr(Name);
+}
+
+
 extern "C" void LLVMRustGlobalAddMetadata(LLVMValueRef Global, unsigned Kind,
                                           LLVMMetadataRef MD) {
   unwrap<GlobalObject>(Global)->addMetadata(Kind, *unwrap<MDNode>(MD));