Rollup merge of #148849 - saethlin:windows-stack-protectors, r=wesleywiser

Set -Cpanic=abort in windows-msvc stack protector tests

I ran into a test failure with the 32-bit windows test on #117192, one of the tests has been incorrectly passing (until my change!) because it is picking up the stack protector from another function. I've tried to prevent that happening again by adding CHECK-DAGs for the start and end of each function.

I've also done my best to correct the comments, some were based on the fact that we used to run these tests with unwinding panics, but LLVM doesn't add protectors to function with SEH funclets so it's must more straightforward for these tests to use `-Cpanic=abort`.

Author: JonathanBrouwer

tests/assembly-llvm/stack-protector/stack-protector-heuristics-effect-windows-32bit.rs

@@ -7,7 +7,7 @@
 //@ [strong] compile-flags: -Z stack-protector=strong
 //@ [basic] compile-flags: -Z stack-protector=basic
 //@ [none] compile-flags: -Z stack-protector=none
-//@ compile-flags: -C opt-level=2 -Z merge-functions=disabled
+//@ compile-flags: -C opt-level=2 -Z merge-functions=disabled -Cpanic=abort -Cdebuginfo=1
 
 #![crate_type = "lib"]
 #![allow(internal_features)]
@@ -39,6 +39,8 @@ pub fn array_char(f: fn(*const char)) {
     // basic: __security_check_cookie
     // none-NOT: __security_check_cookie
     // missing-NOT: __security_check_cookie
+
+    // CHECK-DAG: .cv_fpo_endproc
 }
 
 // CHECK-LABEL: array_u8_1
@@ -55,6 +57,8 @@ pub fn array_u8_1(f: fn(*const u8)) {
     // basic-NOT: __security_check_cookie
     // none-NOT: __security_check_cookie
     // missing-NOT: __security_check_cookie
+
+    // CHECK-DAG: .cv_fpo_endproc
 }
 
 // CHECK-LABEL: array_u8_small:
@@ -72,6 +76,8 @@ pub fn array_u8_small(f: fn(*const u8)) {
     // basic-NOT: __security_check_cookie
     // none-NOT: __security_check_cookie
     // missing-NOT: __security_check_cookie
+
+    // CHECK-DAG: .cv_fpo_endproc
 }
 
 // CHECK-LABEL: array_u8_large:
@@ -88,6 +94,8 @@ pub fn array_u8_large(f: fn(*const u8)) {
     // basic: __security_check_cookie
     // none-NOT: __security_check_cookie
     // missing-NOT: __security_check_cookie
+
+    // CHECK-DAG: .cv_fpo_endproc
 }
 
 #[derive(Copy, Clone)]
@@ -107,6 +115,8 @@ pub fn array_bytesizednewtype_9(f: fn(*const ByteSizedNewtype)) {
     // basic: __security_check_cookie
     // none-NOT: __security_check_cookie
     // missing-NOT: __security_check_cookie
+
+    // CHECK-DAG: .cv_fpo_endproc
 }
 
 // CHECK-LABEL: local_var_addr_used_indirectly
@@ -134,6 +144,8 @@ pub fn local_var_addr_used_indirectly(f: fn(bool)) {
     // basic-NOT: __security_check_cookie
     // none-NOT: __security_check_cookie
     // missing-NOT: __security_check_cookie
+
+    // CHECK-DAG: .cv_fpo_endproc
 }
 
 // CHECK-LABEL: local_string_addr_taken
@@ -143,28 +155,15 @@ pub fn local_string_addr_taken(f: fn(&String)) {
     f(&x);
 
     // Taking the address of the local variable `x` leads to stack smash
-    // protection with the `strong` heuristic, but not with the `basic`
-    // heuristic. It does not matter that the reference is not mut.
-    //
-    // An interesting note is that a similar function in C++ *would* be
-    // protected by the `basic` heuristic, because `std::string` has a char
-    // array internally as a small object optimization:
-    // ```
-    // cat <<EOF | clang++ -O2 -fstack-protector -S -x c++ - -o - | grep stack_chk
-    // #include <string>
-    // void f(void (*g)(const std::string&)) {
-    //     std::string x;
-    //     g(x);
-    // }
-    // EOF
-    // ```
-    //
+    // protection. It does not matter that the reference is not mut.
 
     // all: __security_check_cookie
-    // strong-NOT: __security_check_cookie
-    // basic-NOT: __security_check_cookie
+    // strong: __security_check_cookie
+    // basic: __security_check_cookie
     // none-NOT: __security_check_cookie
     // missing-NOT: __security_check_cookie
+
+    // CHECK-DAG: .cv_fpo_endproc
 }
 
 pub trait SelfByRef {
@@ -194,6 +193,8 @@ pub fn local_var_addr_taken_used_locally_only(factory: fn() -> i32, sink: fn(i32
     // basic-NOT: __security_check_cookie
     // none-NOT: __security_check_cookie
     // missing-NOT: __security_check_cookie
+
+    // CHECK-DAG: .cv_fpo_endproc
 }
 
 pub struct Gigastruct {
@@ -231,6 +232,8 @@ pub fn local_large_var_moved(f: fn(Gigastruct)) {
     // basic: __security_check_cookie
     // none-NOT: __security_check_cookie
     // missing-NOT: __security_check_cookie
+
+    // CHECK-DAG: .cv_fpo_endproc
 }
 
 // CHECK-LABEL: local_large_var_cloned
@@ -260,6 +263,8 @@ pub fn local_large_var_cloned(f: fn(Gigastruct)) {
     // basic: __security_check_cookie
     // none-NOT: __security_check_cookie
     // missing-NOT: __security_check_cookie
+
+    // CHECK-DAG: .cv_fpo_endproc
 }
 
 extern "C" {
@@ -300,6 +305,8 @@ pub fn alloca_small_compile_time_constant_arg(f: fn(*mut ())) {
     // basic-NOT: __security_check_cookie
     // none-NOT: __security_check_cookie
     // missing-NOT: __security_check_cookie
+
+    // CHECK-DAG: .cv_fpo_endproc
 }
 
 // CHECK-LABEL: alloca_large_compile_time_constant_arg
@@ -312,6 +319,8 @@ pub fn alloca_large_compile_time_constant_arg(f: fn(*mut ())) {
     // basic-NOT: __security_check_cookie
     // none-NOT: __security_check_cookie
     // missing-NOT: __security_check_cookie
+
+    // CHECK-DAG: .cv_fpo_endproc
 }
 
 // CHECK-LABEL: alloca_dynamic_arg
@@ -324,14 +333,14 @@ pub fn alloca_dynamic_arg(f: fn(*mut ()), n: usize) {
     // basic-NOT: __security_check_cookie
     // none-NOT: __security_check_cookie
     // missing-NOT: __security_check_cookie
+
+    // CHECK-DAG: .cv_fpo_endproc
 }
 
 // The question then is: in what ways can Rust code generate array-`alloca`
 // LLVM instructions? This appears to only be generated by
 // rustc_codegen_ssa::traits::Builder::array_alloca() through
-// rustc_codegen_ssa::mir::operand::OperandValue::store_unsized(). FWICT
-// this is support for the "unsized locals" unstable feature:
-// https://doc.rust-lang.org/unstable-book/language-features/unsized-locals.html.
+// rustc_codegen_ssa::mir::operand::OperandValue::store_unsized().
 
 // CHECK-LABEL: unsized_fn_param
 #[no_mangle]
@@ -346,14 +355,11 @@ pub fn unsized_fn_param(s: [u8], l: bool, f: fn([u8])) {
     // alloca, and is therefore not protected by the `strong` or `basic`
     // heuristics.
 
-    // We should have a __security_check_cookie call in `all` and `strong` modes but
-    // 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
     // strong-NOT: __security_check_cookie
-
     // basic-NOT: __security_check_cookie
     // none-NOT: __security_check_cookie
     // missing-NOT: __security_check_cookie
+
+    // CHECK-DAG: .cv_fpo_endproc
 }