gccrs: Fix SEGV when type path resolver fails outright

When we resolve paths we resolve to Types first we walk each segment to
the last module which has no type but then in the event that the child
of a module is not found we have a null root_tyty which needs to be caught
and turned into an ErrorType node.

Fixes Rust-GCC#3613

gcc/rust/ChangeLog:

	* typecheck/rust-hir-type-check-type.cc (TypeCheckType::resolve_root_path):
	catch nullptr root_tyty

gcc/testsuite/ChangeLog:

	* rust/compile/issue-3613.rs: New test.

Signed-off-by: Philip Herron <herron.philip@googlemail.com>

diff --git a/gcc/rust/typecheck/rust-hir-type-check-type.cc b/gcc/rust/typecheck/rust-hir-type-check-type.cc
index e56fa397e2aff60f605fef82d1a94031924492b0..54f50ec41f18942d857594bc3b7bb60767fb0b58 100644 (file)
--- a/gcc/rust/typecheck/rust-hir-type-check-type.cc
+++ b/gcc/rust/typecheck/rust-hir-type-check-type.cc
@@ -360,6 +360,13 @@ TypeCheckType::resolve_root_path (HIR::TypePath &path, size_t *offset,
                             seg->as_string ().c_str ());
              return new TyTy::ErrorType (path.get_mappings ().get_hirid ());
            }
+         else if (root_tyty == nullptr)
+           {
+             rust_error_at (seg->get_locus (),
+                            "unknown reference for resolved name: %qs",
+                            seg->as_string ().c_str ());
+             return new TyTy::ErrorType (path.get_mappings ().get_hirid ());
+           }
          return root_tyty;
        }
 

diff --git a/gcc/testsuite/rust/compile/issue-3613.rs b/gcc/testsuite/rust/compile/issue-3613.rs
new file mode 100644 (file)
index 0000000..f2e1092
--- /dev/null
+++ b/gcc/testsuite/rust/compile/issue-3613.rs
@@ -0,0 +1,18 @@
+mod m1 {
+    pub enum Baz4 {
+        foo1,
+        foo2,
+    }
+}
+
+fn bar(x: m1::foo) {
+    // { dg-error "unknown reference for resolved name: .foo." "" { target *-*-* } .-1 }
+    match x {
+        m1::foo::foo1 => {}
+        // { dg-error "failed to type resolve root segment" "" { target *-*-* } .-1 }
+        m1::NodePosition::foo2 => {}
+        // { dg-error "failed to type resolve root segment" "" { target *-*-* } .-1 }
+    }
+}
+
+pub fn main() {}