PR c++/31337

        * gimplify.c (gimplify_modify_expr): Discard the assignment of
        zero-sized types after calling gimplify_modify_expr_rhs.
        * testsuite/g++.dg/ext/stmtexpr11.C: New.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@127838 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 10 insertions, 8 deletions

diff --git a/gcc/gimplify.c b/gcc/gimplify.c
index cea79919965..aed8ab76949 100644
--- a/gcc/gimplify.c
+++ b/gcc/gimplify.c
@@ -3654,8 +3654,16 @@ gimplify_modify_expr (tree *expr_p, tree *pre_p, tree *post_p, bool want_value)
 	      || TREE_CODE (*expr_p) == GIMPLE_MODIFY_STMT
 	      || TREE_CODE (*expr_p) == INIT_EXPR);
 
-  /* For zero sized types only gimplify the left hand side and right hand side
-     as statements and throw away the assignment.  */
+  /* See if any simplifications can be done based on what the RHS is.  */
+  ret = gimplify_modify_expr_rhs (expr_p, from_p, to_p, pre_p, post_p,
+				  want_value);
+  if (ret != GS_UNHANDLED)
+    return ret;
+
+  /* For zero sized types only gimplify the left hand side and right hand
+     side as statements and throw away the assignment.  Do this after
+     gimplify_modify_expr_rhs so we handle TARGET_EXPRs of addressable
+     types properly.  */
   if (zero_sized_type (TREE_TYPE (*from_p)))
     {
       gimplify_stmt (from_p);
@@ -3666,12 +3674,6 @@ gimplify_modify_expr (tree *expr_p, tree *pre_p, tree *post_p, bool want_value)
       return GS_ALL_DONE;
     }
 
-  /* See if any simplifications can be done based on what the RHS is.  */
-  ret = gimplify_modify_expr_rhs (expr_p, from_p, to_p, pre_p, post_p,
-				  want_value);
-  if (ret != GS_UNHANDLED)
-    return ret;
-
   /* If the value being copied is of variable width, compute the length
      of the copy into a WITH_SIZE_EXPR.   Note that we need to do this
      before gimplifying any of the operands so that we can resolve any