Summary

When trying to add a reproducer / regression test for #2886, the test case should fail with a parsing error, similar to what is found in https://godbolt.org/z/WorW4oqG4.

Reproducer

I tried this code (in gcc/testsuite/rust/compile/parens.rs):

pub fn ret_parens(x: i32) -> i32 {
    ((x+1))
}

pub fn arg_ret_parens((x): (i32)) -> (i32) {
    ((x+1))
}

pub fn ret_rpit_parens2(x: i32) -> (i32) {
    ((x+1))
}

pub fn ret_parens3(x: i32) -> i32 {
    ((x+1))
}

Related: #2886

Does the code make use of any (1.49) nightly feature ?

• Nightly

Godbolt link

https://godbolt.org/z/WorW4oqG4

Actual behavior

The test passes, which it should only after a proper fix.

Expected behavior

The test should fail to compile with the following errors:

<source>:7:21: error: Failed to resolve trait by looking up hir node
    7 | fn increment1((x): (i32)) -> i32{
      |                     ^~~
<source>:8:7: error: cannot apply operator '+' to types dyn [] and <integer>
    8 |     ((x+1))
      |       ^
<source>:11:27: error: Failed to resolve trait by looking up hir node
   11 | fn increment2(x: i32) -> (i32) {
      |                           ^~~
Compiler returned: 1

GCC Version

GCC 15.2.1, GCCRS c742973