gccrs: Fix ICE using constructors for intilizers in statics

We are getting constant expressions for the initilizers for static items
this hits an assertion in the GCC middle-end which is looking for a
constructor so we need to unwrap the constant expression using DECL_INITIAL
as the initilizer to the global static.

Fixes #2080

gcc/rust/ChangeLog:

	* backend/rust-compile-item.cc (CompileItem::visit): unwrap the constant expression

gcc/testsuite/ChangeLog:

	* rust/execute/torture/issue-2080.rs: New test.

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

1 files changed, 3 insertions, 3 deletions

diff --git a/gcc/rust/backend/rust-compile-item.cc b/gcc/rust/backend/rust-compile-item.cc
index b2e9b3f..e1e2bb6 100644
--- a/gcc/rust/backend/rust-compile-item.cc
+++ b/gcc/rust/backend/rust-compile-item.cc
@@ -18,9 +18,7 @@
 
 #include "rust-compile-item.h"
 #include "rust-compile-implitem.h"
-#include "rust-compile-expr.h"
 #include "rust-compile-extern.h"
-#include "rust-constexpr.h"
 
 namespace Rust {
 namespace Compile {
@@ -66,7 +64,9 @@ CompileItem::visit (HIR::StaticItem &var)
     = ctx->get_backend ()->global_variable (name, asm_name, type, is_external,
 					    is_hidden, in_unique_section,
 					    var.get_locus ());
-  ctx->get_backend ()->global_variable_set_init (static_global, value);
+
+  tree init = value == error_mark_node ? error_mark_node : DECL_INITIAL (value);
+  ctx->get_backend ()->global_variable_set_init (static_global, init);
 
   ctx->insert_var_decl (var.get_mappings ().get_hirid (), static_global);
   ctx->push_var (static_global);