[gcc r17-4120] gccrs: Add test cases to close out issues

[Arthur Cohen via Gcc-cvs]

https://gcc.gnu.org/g:ddfa66d92e5359d2f2571e7ee85e26ad95c7dab2

commit r17-4120-gddfa66d92e5359d2f2571e7ee85e26ad95c7dab2
Author: Philip Herron <herron.phi...@googlemail.com>
Date:   Sat Aug 15 22:31:35 2026 +0100

    gccrs: Add test cases to close out issues
    
    Fixes Rust-GCC/gccrs#4157
    
    gcc/testsuite/ChangeLog:
    
            * rust/compile/issue-4157-1.rs: New test.
            * rust/compile/issue-4157-2.rs: New test.
    
    Signed-off-by: Philip Herron <herron.phi...@googlemail.com>

Diff:
---
 gcc/testsuite/rust/compile/issue-4157-1.rs | 22 +++++++++++++++
 gcc/testsuite/rust/compile/issue-4157-2.rs | 43 ++++++++++++++++++++++++++++++
 2 files changed, 65 insertions(+)

diff --git a/gcc/testsuite/rust/compile/issue-4157-1.rs 
b/gcc/testsuite/rust/compile/issue-4157-1.rs
new file mode 100644
index 000000000000..9ecb212dd44f
--- /dev/null
+++ b/gcc/testsuite/rust/compile/issue-4157-1.rs
@@ -0,0 +1,22 @@
+#![feature(no_core)]
+#![no_core]
+#![feature(lang_items)]
+
+#[lang = "sized"]
+trait Sized {}
+
+struct MyStruct {}
+struct Nested {
+    nested: MyStruct,
+}
+struct Mix2 {
+    nested: (Nested,),
+}
+
+const MIX_2: Mix2 = Mix2 { nested: ((2,),) };
+// { dg-error "mismatched types, expected .Nested. but got" "" { target *-*-* 
} .-1 }
+
+fn main() {
+    let f = [0; (MIX_2.nested.0).0];
+    // { dg-error "expected tuple or tuple struct, found .Nested." "" { target 
*-*-* } .-1 }
+}
diff --git a/gcc/testsuite/rust/compile/issue-4157-2.rs 
b/gcc/testsuite/rust/compile/issue-4157-2.rs
new file mode 100644
index 000000000000..9d58cd6ad5cf
--- /dev/null
+++ b/gcc/testsuite/rust/compile/issue-4157-2.rs
@@ -0,0 +1,43 @@
+#![feature(no_core)]
+#![no_core]
+#![feature(lang_items)]
+
+#[lang = "sized"]
+trait Sized {}
+
+struct MyStruct {
+    field: usize,
+}
+struct Nested {
+    nested: MyStruct,
+}
+struct Mix2 {
+    nested: (Nested,),
+}
+
+const STRUCT: MyStruct = MyStruct { field: 42 };
+const TUP: (usize,) = (43,);
+const NESTED_S: Nested = Nested {
+    nested: MyStruct { field: 5 },
+};
+const NESTED_T: ((usize,),) = ((4,),);
+const MIX_1: ((Nested,),) = ((MyStruct { field: 3 },),);
+// { dg-error "mismatched types, expected .Nested. but got .MyStruct." "" { 
target *-*-* } .-1 }
+const MIX_2: Mix2 = Mix2 { nested: ((2,),) };
+// { dg-error "mismatched types, expected .Nested. but got" "" { target *-*-* 
} .-1 }
+const INSTANT_1: usize = (MyStruct { field: 1 }).field;
+const INSTANT_2: usize = (4,).0;
+
+fn main() {
+    let h = [0; STRUCT.field];
+    let b = [0; TUP.0];
+    let c = [0; NESTED_S.nested.field];
+    let d = [0; (NESTED_T.0).0];
+    let e = [0; (MIX_1.0).0.nested.field];
+    // { dg-error "failed to resolve TupleIndexExpr receiver" "" { target 
*-*-* } .-1 }
+    // { dg-error "expected algebraic data type got .<tyty::error>." "" { 
target *-*-* } .-2 }
+    let f = [0; (MIX_2.nested.0).0];
+    // { dg-error "expected tuple or tuple struct, found .Nested." "" { target 
*-*-* } .-1 }
+    let g = [0; INSTANT_1];
+    let h = [0; INSTANT_2];
+}