fix ICE in CMSE type validation

compiler/rustc_hir_analysis/src/hir_ty_lowering/cmse.rs

@@ -72,8 +72,11 @@ fn is_valid_cmse_inputs<'tcx>(
     let mut span = None;
     let mut accum = 0u64;
 
-    for (index, arg_def) in fn_sig.inputs().iter().enumerate() {
-        let layout = tcx.layout_of(ParamEnv::reveal_all().and(*arg_def.skip_binder()))?;
+    // this type is only used for layout computation, which does not rely on regions
+    let fn_sig = tcx.instantiate_bound_regions_with_erased(fn_sig);
+
+    for (index, ty) in fn_sig.inputs().iter().enumerate() {
+        let layout = tcx.layout_of(ParamEnv::reveal_all().and(*ty))?;
 
         let align = layout.layout.align().abi.bytes();
         let size = layout.layout.size().bytes();
@@ -98,7 +101,10 @@ fn is_valid_cmse_output<'tcx>(
     tcx: TyCtxt<'tcx>,
     fn_sig: ty::PolyFnSig<'tcx>,
 ) -> Result<bool, &'tcx LayoutError<'tcx>> {
-    let mut ret_ty = fn_sig.output().skip_binder();
+    // this type is only used for layout computation, which does not rely on regions
+    let fn_sig = tcx.instantiate_bound_regions_with_erased(fn_sig);
+
+    let mut ret_ty = fn_sig.output();
     let layout = tcx.layout_of(ParamEnv::reveal_all().and(ret_ty))?;
     let size = layout.layout.size().bytes();
 

tests/ui/cmse-nonsecure/cmse-nonsecure-call/generics.rs

@@ -12,10 +12,31 @@ impl Copy for u32 {}
 struct Wrapper<T>(T);
 
 struct Test<T: Copy> {
-    f1: extern "C-cmse-nonsecure-call" fn<U: Copy>(U, u32, u32, u32) -> u64, //~ ERROR cannot find type `U` in this scope
-    //~^ ERROR function pointer types may not have generic parameters
+    f1: extern "C-cmse-nonsecure-call" fn<U: Copy>(U, u32, u32, u32) -> u64,
+    //~^ ERROR cannot find type `U` in this scope
+    //~| ERROR function pointer types may not have generic parameters
     f2: extern "C-cmse-nonsecure-call" fn(impl Copy, u32, u32, u32) -> u64,
     //~^ ERROR `impl Trait` is not allowed in `fn` pointer parameters
     f3: extern "C-cmse-nonsecure-call" fn(T, u32, u32, u32) -> u64, //~ ERROR [E0798]
     f4: extern "C-cmse-nonsecure-call" fn(Wrapper<T>, u32, u32, u32) -> u64, //~ ERROR [E0798]
 }
+
+type WithReference = extern "C-cmse-nonsecure-call" fn(&usize);
+
+trait Trait {}
+type WithTraitObject = extern "C-cmse-nonsecure-call" fn(&dyn Trait) -> &dyn Trait;
+//~^ ERROR return value of `"C-cmse-nonsecure-call"` function too large to pass via registers [E0798]
+
+type WithStaticTraitObject =
+    extern "C-cmse-nonsecure-call" fn(&'static dyn Trait) -> &'static dyn Trait;
+//~^ ERROR return value of `"C-cmse-nonsecure-call"` function too large to pass via registers [E0798]
+
+#[repr(transparent)]
+struct WrapperTransparent<'a>(&'a dyn Trait);
+
+type WithTransparentTraitObject =
+    extern "C-cmse-nonsecure-call" fn(WrapperTransparent) -> WrapperTransparent;
+//~^ ERROR return value of `"C-cmse-nonsecure-call"` function too large to pass via registers [E0798]
+
+type WithVarArgs = extern "C-cmse-nonsecure-call" fn(u32, ...);
+//~^ ERROR C-variadic function must have a compatible calling convention, like `C` or `cdecl` [E0045]

tests/ui/cmse-nonsecure/cmse-nonsecure-call/generics.stderr

@@ -22,26 +22,59 @@ LL | struct Test<T: Copy, U> {
    |                    +++
 
 error[E0562]: `impl Trait` is not allowed in `fn` pointer parameters
-  --> $DIR/generics.rs:17:43
+  --> $DIR/generics.rs:18:43
    |
 LL |     f2: extern "C-cmse-nonsecure-call" fn(impl Copy, u32, u32, u32) -> u64,
    |                                           ^^^^^^^^^
    |
    = note: `impl Trait` is only allowed in arguments and return types of functions and methods
 
 error[E0798]: function pointers with the `"C-cmse-nonsecure-call"` ABI cannot contain generics in their type
-  --> $DIR/generics.rs:19:9
+  --> $DIR/generics.rs:20:9
    |
 LL |     f3: extern "C-cmse-nonsecure-call" fn(T, u32, u32, u32) -> u64,
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0798]: function pointers with the `"C-cmse-nonsecure-call"` ABI cannot contain generics in their type
-  --> $DIR/generics.rs:20:9
+  --> $DIR/generics.rs:21:9
    |
 LL |     f4: extern "C-cmse-nonsecure-call" fn(Wrapper<T>, u32, u32, u32) -> u64,
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: aborting due to 5 previous errors
+error[E0798]: return value of `"C-cmse-nonsecure-call"` function too large to pass via registers
+  --> $DIR/generics.rs:27:73
+   |
+LL | type WithTraitObject = extern "C-cmse-nonsecure-call" fn(&dyn Trait) -> &dyn Trait;
+   |                                                                         ^^^^^^^^^^ this type doesn't fit in the available registers
+   |
+   = note: functions with the `"C-cmse-nonsecure-call"` ABI must pass their result via the available return registers
+   = note: the result must either be a (transparently wrapped) i64, u64 or f64, or be at most 4 bytes in size
+
+error[E0798]: return value of `"C-cmse-nonsecure-call"` function too large to pass via registers
+  --> $DIR/generics.rs:31:62
+   |
+LL |     extern "C-cmse-nonsecure-call" fn(&'static dyn Trait) -> &'static dyn Trait;
+   |                                                              ^^^^^^^^^^^^^^^^^^ this type doesn't fit in the available registers
+   |
+   = note: functions with the `"C-cmse-nonsecure-call"` ABI must pass their result via the available return registers
+   = note: the result must either be a (transparently wrapped) i64, u64 or f64, or be at most 4 bytes in size
+
+error[E0798]: return value of `"C-cmse-nonsecure-call"` function too large to pass via registers
+  --> $DIR/generics.rs:38:62
+   |
+LL |     extern "C-cmse-nonsecure-call" fn(WrapperTransparent) -> WrapperTransparent;
+   |                                                              ^^^^^^^^^^^^^^^^^^ this type doesn't fit in the available registers
+   |
+   = note: functions with the `"C-cmse-nonsecure-call"` ABI must pass their result via the available return registers
+   = note: the result must either be a (transparently wrapped) i64, u64 or f64, or be at most 4 bytes in size
+
+error[E0045]: C-variadic function must have a compatible calling convention, like `C` or `cdecl`
+  --> $DIR/generics.rs:41:20
+   |
+LL | type WithVarArgs = extern "C-cmse-nonsecure-call" fn(u32, ...);
+   |                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ C-variadic function must have a compatible calling convention
+
+error: aborting due to 9 previous errors
 
-Some errors have detailed explanations: E0412, E0562, E0798.
-For more information about an error, try `rustc --explain E0412`.
+Some errors have detailed explanations: E0045, E0412, E0562, E0798.
+For more information about an error, try `rustc --explain E0045`.