[COMMITTED 027/220] gccrs: Fix NR2 ICE in visit_attributes

[arthur . cohen]

From: Tom Schollenberger <tss2...@g.rit.edu>

Undefined attribute macros have no proc macro definition, which results
in a failing `rust_assert`. This changes that assert to an if statement,
that returns early if there is no proc macro definition. Fixes #3661.

gcc/rust/ChangeLog:

        * resolve/rust-early-name-resolver-2.0.cc (Early::visit_attributes): 
rust_assert to if

gcc/testsuite/ChangeLog:

        * rust/compile/issue-3661.rs: Test NR2 has expected behavior

Signed-off-by: Tom Schollenberger <tss2...@g.rit.edu>
---
 gcc/rust/resolve/rust-early-name-resolver-2.0.cc |  3 ++-
 gcc/testsuite/rust/compile/issue-3661.rs         | 10 ++++++++++
 2 files changed, 12 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/rust/compile/issue-3661.rs

diff --git a/gcc/rust/resolve/rust-early-name-resolver-2.0.cc 
b/gcc/rust/resolve/rust-early-name-resolver-2.0.cc
index 1e29c7967b8..b00bd1ee7f8 100644
--- a/gcc/rust/resolve/rust-early-name-resolver-2.0.cc
+++ b/gcc/rust/resolve/rust-early-name-resolver-2.0.cc
@@ -350,7 +350,8 @@ Early::visit_attributes (std::vector<AST::Attribute> &attrs)
          auto pm_def = mappings.lookup_attribute_proc_macro_def (
            definition->get_node_id ());
 
-         rust_assert (pm_def.has_value ());
+         if (!pm_def.has_value ())
+           return;
 
          mappings.insert_attribute_proc_macro_invocation (attr.get_path (),
                                                           pm_def.value ());
diff --git a/gcc/testsuite/rust/compile/issue-3661.rs 
b/gcc/testsuite/rust/compile/issue-3661.rs
new file mode 100644
index 00000000000..8d03c3630d5
--- /dev/null
+++ b/gcc/testsuite/rust/compile/issue-3661.rs
@@ -0,0 +1,10 @@
+pub macro m($inner_str:expr) {
+    #[m = $inner_str] 
+    // { dg-error "macro not found" "" { target *-*-* } .-1 }
+
+    struct S;
+}
+
+fn main() {
+    m!(stringify!(foo));
+}
-- 
2.49.0