Treat function pointers like pointers for cast

P-E-P · P-E-P · commit 00d20c9370dd · 2025-08-22T12:47:56.000Z
Function pointers were not allowed to be cast to any integer like type
just like regular pointers were.

gcc/rust/ChangeLog:

	* typecheck/rust-casts.cc (TypeCastRules::cast_rules): Authorize
	cast from function pointer to integer like type.

Signed-off-by: Pierre-Emmanuel Patry &lt;pierre-emmanuel.patry@embecosm.com&gt;
diff --git a/gcc/rust/typecheck/rust-casts.cc b/gcc/rust/typecheck/rust-casts.cc
@@ -277,6 +277,7 @@ TypeCastRules::cast_rules ()
       break;
 
     case TyTy::TypeKind::REF:
+    case TyTy::TypeKind::FNPTR:
     case TyTy::TypeKind::POINTER:
       switch (to.get_ty ()->get_kind ())
 	{
@@ -286,8 +287,9 @@ TypeCastRules::cast_rules ()
 	case TyTy::TypeKind::INT:
 	  {
 	    // refs should not cast to numeric type
-	    bool from_ptr
-	      = from.get_ty ()->get_kind () == TyTy::TypeKind::POINTER;
+	    auto kind = from.get_ty ()->get_kind ();
+	    bool from_ptr = kind == TyTy::TypeKind::POINTER
+			    || kind == TyTy::TypeKind::FNPTR;
 	    if (from_ptr)
 	      {
 		return TypeCoercionRules::CoercionResult{

Original file line number	Diff line number	Diff line change
`@@ -277,6 +277,7 @@ TypeCastRules::cast_rules ()`
`277`	`277`	`break;`
`278`	`278`
`279`	`279`	`case TyTy::TypeKind::REF:`
	`280`	`+ case TyTy::TypeKind::FNPTR:`
`280`	`281`	`case TyTy::TypeKind::POINTER:`
`281`	`282`	`switch (to.get_ty ()->get_kind ())`
`282`	`283`	`{`
`@@ -286,8 +287,9 @@ TypeCastRules::cast_rules ()`
`286`	`287`	`case TyTy::TypeKind::INT:`
`287`	`288`	`{`
`288`	`289`	`// refs should not cast to numeric type`
`289`		`- bool from_ptr`
`290`		`- = from.get_ty ()->get_kind () == TyTy::TypeKind::POINTER;`
	`290`	`+ auto kind = from.get_ty ()->get_kind ();`
	`291`	`+ bool from_ptr = kind == TyTy::TypeKind::POINTER`
	`292`	`+ \|\| kind == TyTy::TypeKind::FNPTR;`
`291`	`293`	`if (from_ptr)`
`292`	`294`	`{`
`293`	`295`	`return TypeCoercionRules::CoercionResult{`