modified: compiler/rustc_codegen_llvm/src/attributes.rs modified: compiler/rustc_middle/src/ty/context.rs modified: compiler/rustc_mir_transform/src/lib.rs new file: compiler/rustc_mir_transform/src/stack_protector.rs modified: compiler/rustc_target/src/spec/mod.rs modified: tests/assembly-llvm/stack-protector/stack-protector-heuristics-effect-windows-64bit.rs modified: tests/assembly-llvm/stack-protector/stack-protector-heuristics-effect.rs

Author: cezarbbb

compiler/rustc_mir_transform/src/stack_protector.rs

@@ -41,7 +41,11 @@ impl<'tcx> crate::MirPass<'tcx> for StackProtectorFinder {
             }
 
             let instance = Instance::mono(tcx, def_id);
-            let Ok(fn_abi) = tcx.fn_abi_of_instance(ty::TypingEnv::fully_monomorphized().as_query_input((instance, ty::List::empty())),) else { return;};
+            let Ok(fn_abi) = tcx.fn_abi_of_instance(ty::TypingEnv::fully_monomorphized().as_query_input((instance, ty::List::empty())),)
+            else { 
+                // FIXME: Finding when an Err() message is returned.
+                return; 
+            };
 
             // for arg in fn_abi.args.iter() {
             //     if matches!(&arg.mode, PassMode::Indirect { attrs: _, meta_attrs: _, on_stack: false }) {

tests/assembly-llvm/stack-protector/stack-protector-heuristics-effect-windows-64bit.rs

@@ -280,10 +280,6 @@ pub fn local_large_var_cloned(f: fn(Gigastruct)) {
     // ```
 
     // all: __security_check_cookie
-    
-    // FIXME: How does the rust compiler handle moves of large structures?
-    // rusty-NOT: __security_check_cookie
-    
     // strong: __security_check_cookie
     // basic: __security_check_cookie
     // none-NOT: __security_check_cookie
@@ -322,14 +318,8 @@ extern "C" {
 #[no_mangle]
 pub fn alloca_small_compile_time_constant_arg(f: fn(*mut ())) {
     f(unsafe { alloca(8) });
- 
-    // all: __security_check_cookie
-
-    // FIXME: Rusty thinks a function that returns a mutable raw pointer may
-    // be a stack memory allocation function, so it performs stack smash protection.
-    // Is it possible to optimize the heuristics?
-    // rusty: __security_check_cookie
 
+    // all: __security_check_cookie
     // strong-NOT: __security_check_cookie
     // basic-NOT: __security_check_cookie
     // none-NOT: __security_check_cookie
@@ -386,10 +376,10 @@ pub fn unsized_fn_param(s: [u8], l: bool, f: fn([u8])) {
     // LLVM does not support generating stack protectors in functions with funclet
     // based EH personalities.
     // https://github.com/llvm/llvm-project/blob/37fd3c96b917096d8a550038f6e61cdf0fc4174f/llvm/lib/CodeGen/StackProtector.cpp#L103C1-L109C4
-
     // all-NOT: __security_check_cookie
     // rusty-NOT: __security_check_cookie
     // strong-NOT: __security_check_cookie
+
     // basic-NOT: __security_check_cookie
     // none-NOT: __security_check_cookie
     // missing-NOT: __security_check_cookie