[gcc/devel/rust/master] Check for type paths nr2.0 can't handle yet

[Thomas Schwinge]

https://gcc.gnu.org/g:0a125366559a88a6daa1235a43d6f98651783cf0

commit 0a125366559a88a6daa1235a43d6f98651783cf0
Author: Owen Avery <powerboat9.gamer@gmail.com>
Date:   Tue Jan 21 17:02:35 2025 -0500

    Check for type paths nr2.0 can't handle yet
    
    Some of our tests only work with name resolution 2.0 because the latter
    misinterprets type paths. This change should cause the compiler to error out
    if it would otherwise misinterpret a type path. A fix for type path
    resolution isn't included in this comment, since doing so would make it
    harder to track the meaningfulness of test regressions.
    
    gcc/rust/ChangeLog:
    
            * resolve/rust-late-name-resolver-2.0.cc
            (Late::visit): Error out if a type path has multiple segments,
            as we currently ignore every segment except the last.
    
    gcc/testsuite/ChangeLog:
    
            * rust/compile/nr2/exclude: Add entries.
    
    Signed-off-by: Owen Avery <powerboat9.gamer@gmail.com>

Diff:
---
 gcc/rust/resolve/rust-late-name-resolver-2.0.cc |  8 ++++++++
 gcc/testsuite/rust/compile/nr2/exclude          | 15 +++++++++++++++
 2 files changed, 23 insertions(+)

diff --git a/gcc/rust/resolve/rust-late-name-resolver-2.0.cc b/gcc/rust/resolve/rust-late-name-resolver-2.0.cc
index a7408fbe7b6a..7c6948565202 100644
--- a/gcc/rust/resolve/rust-late-name-resolver-2.0.cc
+++ b/gcc/rust/resolve/rust-late-name-resolver-2.0.cc
@@ -287,6 +287,14 @@ Late::visit (AST::TypePath &type)
   // maybe we can overload `resolve_path<Namespace::Types>` to only do
   // typepath-like path resolution? that sounds good
 
+  if (type.get_segments ().size () != 1)
+    {
+      rust_sorry_at (
+	type.get_locus (),
+	"name resolution 2.0 cannot resolve multi-segment type paths");
+      return;
+    }
+
   auto str = type.get_segments ().back ()->get_ident_segment ().as_string ();
   auto values = ctx.types.peek ().get_values ();
 
diff --git a/gcc/testsuite/rust/compile/nr2/exclude b/gcc/testsuite/rust/compile/nr2/exclude
index d53c14871731..5cc7cf7d64c5 100644
--- a/gcc/testsuite/rust/compile/nr2/exclude
+++ b/gcc/testsuite/rust/compile/nr2/exclude
@@ -58,6 +58,7 @@ iterators1.rs
 lookup_err1.rs
 macros/mbe/macro13.rs
 macros/mbe/macro15.rs
+macros/mbe/macro20.rs
 macros/mbe/macro23.rs
 macros/mbe/macro40.rs
 macros/mbe/macro43.rs
@@ -151,4 +152,18 @@ derive_macro6.rs
 issue-2987.rs
 issue-3139-1.rs
 issue-3139-3.rs
+issue-1019.rs
+issue-1034.rs
+issue-2019-1.rs
+issue-2019-2.rs
+issue-2019-3.rs
+issue-2105.rs
+issue-2190-1.rs
+issue-2190-2.rs
+issue-2304.rs
+issue-2747.rs
+issue-2953-1.rs
+issue-3030.rs
+traits12.rs
+try-trait.rs
 # please don't delete the trailing newline