Merge #1633

1633: Implement PhantomData r=CohenArthur a=tamaroning

Fixes #1127 

Added `phantom_data` lang item


Co-authored-by: Raiki Tamura <[email protected]>

Author: bors[bot]

gcc/rust/util/rust-lang-item.h

@@ -73,6 +73,9 @@ class RustLangItem
     MUT_PTR,
     CONST_SLICE_PTR,
 
+    // https://github.com/rust-lang/rust/blob/master/library/core/src/marker.rs
+    PHANTOM_DATA,
+
     // functions
     FN_ONCE,
     FN_ONCE_OUTPUT,
@@ -222,6 +225,10 @@ class RustLangItem
       {
 	return ItemType::CONST_SLICE_PTR;
       }
+    else if (item.compare ("phantom_data") == 0)
+      {
+	return ItemType::PHANTOM_DATA;
+      }
     else if (item.compare ("fn_once") == 0)
       {
 	return ItemType::FN_ONCE;
@@ -308,6 +315,8 @@ class RustLangItem
 	return "mut_ptr";
       case CONST_SLICE_PTR:
 	return "const_slice_ptr";
+      case PHANTOM_DATA:
+	return "phantom_data";
       case FN_ONCE:
 	return "fn_once";
       case FN_ONCE_OUTPUT:

gcc/testsuite/rust/compile/torture/phantom_data.rs

@@ -0,0 +1,11 @@
+// { dg-options "-w" }
+#[lang = "phantom_data"]
+struct PhantomData<T>;
+
+trait Hash {
+    fn hash<H>(&self, state: &mut H);
+}
+
+impl<T> Hash for PhantomData<T> {
+    fn hash<H>(&self, state: &mut H) {}
+}