coroutines: Fix unused value found by static analysis.

This fixes up the zero-initialization of the coro frame pointer
to avoid an unused assigned value, spotted by Martin Liska with
static analysis.

gcc/cp/ChangeLog:

	* coroutines.cc (morph_fn_to_coro): Revise initialization
	of the frame pointer to avoid an unused value.

diff --git a/gcc/cp/coroutines.cc b/gcc/cp/coroutines.cc
index b79e2c66b702bfda0cee8a7d9750dcc29c4c963d..c4df488ac020891f1c2230f4bb7cc9232522f706 100644 (file)
--- a/gcc/cp/coroutines.cc
+++ b/gcc/cp/coroutines.cc
@@ -3889,11 +3889,9 @@ morph_fn_to_coro (tree orig, tree *resumer, tree *destroyer)
   /* The decl_expr for the coro frame pointer, initialize to zero so that we
      can pass it to the IFN_CO_FRAME (since there's no way to pass a type,
      directly apparently).  This avoids a "used uninitialized" warning.  */
-  tree r = build_stmt (fn_start, DECL_EXPR, coro_fp);
   tree zeroinit = build1 (CONVERT_EXPR, coro_frame_ptr, integer_zero_node);
-  r = build2 (INIT_EXPR, TREE_TYPE (coro_fp), coro_fp, zeroinit);
-  r = coro_build_cvt_void_expr_stmt (r, fn_start);
-  add_stmt (r);
+  DECL_INITIAL (coro_fp) = zeroinit;
+  add_decl_expr (coro_fp);
 
   /* The CO_FRAME internal function is a mechanism to allow the middle end
      to adjust the allocation in response to optimisations.  We provide the
@@ -4047,7 +4045,7 @@ morph_fn_to_coro (tree orig, tree *resumer, tree *destroyer)
     }
 
   tree allocated = build1 (CONVERT_EXPR, coro_frame_ptr, new_fn);
-  r = build2 (INIT_EXPR, TREE_TYPE (coro_fp), coro_fp, allocated);
+  tree r = build2 (INIT_EXPR, TREE_TYPE (coro_fp), coro_fp, allocated);
   r = coro_build_cvt_void_expr_stmt (r, fn_start);
   add_stmt (r);