remove CString dependence with StringRef

Author: Shourya742

compiler/rustc_codegen_llvm/src/attributes.rs

@@ -1,7 +1,4 @@
 //! Set and unset common attributes on LLVM values.
-
-use std::ffi::c_char;
-
 use rustc_attr_parsing::{InlineAttr, InstructionSetAttr, OptimizeAttr};
 use rustc_codegen_ssa::traits::*;
 use rustc_hir::def_id::DefId;
@@ -34,15 +31,15 @@ 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 c_char) -> bool {
+pub(crate) fn has_string_attr(llfn: &Value, name: &str) -> 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 c_char) {
+pub(crate) fn remove_string_attr_from_llfn(llfn: &Value, name: &str) {
     llvm::RemoveStringAttrFromFn(llfn, name);
 }
 

compiler/rustc_codegen_llvm/src/back/lto.rs

@@ -671,21 +671,19 @@ pub(crate) fn run_pass_manager(
             SimpleCx::new(module.module_llvm.llmod(), &module.module_llvm.llcx, cgcx.pointer_size);
 
         for function in cx.get_functions() {
-            let enzyme_marker = CString::new("enzyme_marker").unwrap();
-            let marker_ptr = enzyme_marker.as_ptr();
-
-            if attributes::has_string_attr(function, marker_ptr) {
+            let enzyme_marker = "enzyme_marker";
+            if attributes::has_string_attr(function, enzyme_marker) {
                 // Sanity check: Ensure 'noinline' is present before replacing it.
                 assert!(
                     !attributes::has_attr(function, Function, llvm::AttributeKind::NoInline),
                     "Expected __enzyme function to have 'noinline' before adding 'alwaysinline'"
                 );
 
                 attributes::remove_from_llfn(function, Function, llvm::AttributeKind::NoInline);
-                attributes::remove_string_attr_from_llfn(function, marker_ptr);
+                attributes::remove_string_attr_from_llfn(function, enzyme_marker);
 
                 assert!(
-                    !attributes::has_string_attr(function, marker_ptr),
+                    !attributes::has_string_attr(function, enzyme_marker),
                     "Expected function to not have 'enzyme_marker'"
                 );
 

compiler/rustc_codegen_llvm/src/llvm/enzyme_ffi.rs

@@ -19,8 +19,12 @@ 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);
+    pub(crate) fn LLVMRustHasFnAttribute(
+        F: &Value,
+        Name: *const c_char,
+        NameLen: libc::size_t,
+    ) -> bool;
+    pub(crate) fn LLVMRustRemoveFnAttribute(F: &Value, Name: *const c_char, NameLen: libc::size_t);
     pub(crate) fn LLVMGetFirstFunction(M: &Module) -> Option<&Value>;
     pub(crate) fn LLVMGetNextFunction(Fn: &Value) -> Option<&Value>;
     pub(crate) fn LLVMRustRemoveEnumAttributeAtIndex(

compiler/rustc_codegen_llvm/src/llvm/mod.rs

@@ -1,6 +1,6 @@
 #![allow(non_snake_case)]
 
-use std::ffi::{CStr, CString, c_char};
+use std::ffi::{CStr, CString};
 use std::ptr;
 use std::str::FromStr;
 use std::string::FromUtf8Error;
@@ -49,12 +49,12 @@ pub(crate) fn HasAttributeAtIndex<'ll>(
     unsafe { LLVMRustHasAttributeAtIndex(llfn, idx.as_uint(), kind) }
 }
 
-pub(crate) fn HasStringAttribute<'ll>(llfn: &'ll Value, name: *const c_char) -> bool {
-    unsafe { LLVMRustHasFnAttribute(llfn, name) }
+pub(crate) fn HasStringAttribute<'ll>(llfn: &'ll Value, name: &str) -> bool {
+    unsafe { LLVMRustHasFnAttribute(llfn, name.as_c_char_ptr(), name.len()) }
 }
 
-pub(crate) fn RemoveStringAttrFromFn<'ll>(llfn: &'ll Value, name: *const c_char) {
-    unsafe { LLVMRustRemoveFnAttribute(llfn, name) }
+pub(crate) fn RemoveStringAttrFromFn<'ll>(llfn: &'ll Value, name: &str) {
+    unsafe { LLVMRustRemoveFnAttribute(llfn, name.as_c_char_ptr(), name.len()) }
 }
 
 pub(crate) fn RemoveRustEnumAttributeAtIndex(

compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp

@@ -979,16 +979,16 @@ LLVMRustRemoveEnumAttributeAtIndex(LLVMValueRef F, size_t index,
   LLVMRemoveEnumAttributeAtIndex(F, index, fromRust(RustAttr));
 }
 
-extern "C" bool LLVMRustHasFnAttribute(LLVMValueRef F, const char *Name) {
+extern "C" bool LLVMRustHasFnAttribute(LLVMValueRef F, const char *Name, size_t NameLen) {
   if (auto *Fn = dyn_cast<Function>(unwrap<Value>(F))) {
-    return Fn->hasFnAttribute(Name);
+    return Fn->hasFnAttribute(StringRef(Name, NameLen));
   }
   return false;
 }
 
-extern "C" void LLVMRustRemoveFnAttribute(LLVMValueRef Fn, const char *Name) {
+extern "C" void LLVMRustRemoveFnAttribute(LLVMValueRef Fn, const char *Name, size_t NameLen) {
   if (auto *F = dyn_cast<Function>(unwrap<Value>(Fn))) {
-    F->removeFnAttr(Name);
+    F->removeFnAttr(StringRef(Name, NameLen));
   }
 }