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 5668838c79f312e2cdfbcee87fc791e20145458b..630abb0d90e0bac5b8d87f761ca73fe79b665a2c 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() {}