[PATCH] pkl: Fix promotion of initializer in structs

[Mohammad-Reza Nabipoor]

The promotion shouldn't be attempted if initializer has the same type
as the field.

2020-12-13  Mohammad-Reza Nabipoor  <m.nabipoor@yahoo.com>

        * libpoke/pkl-promo.c (pkl_promo_ps_struct_type_field): Skip
        promotion of initializer if it has the same type as the field.
        * testsuite/poke.pkl/struct-types-7.pk: New test.
        * testsuite/Makefile.am (EXTRA_DIST): Update.
---
 ChangeLog                            | 7 +++++++
 libpoke/pkl-promo.c                  | 4 +++-
 testsuite/Makefile.am                | 1 +
 testsuite/poke.pkl/struct-types-7.pk | 9 +++++++++
 4 files changed, 20 insertions(+), 1 deletion(-)
 create mode 100644 testsuite/poke.pkl/struct-types-7.pk

diff --git a/ChangeLog b/ChangeLog
index 26b3b3b8..146dde90 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2020-12-13  Mohammad-Reza Nabipoor  <m.nabipoor@yahoo.com>
+
+       * libpoke/pkl-promo.c (pkl_promo_ps_struct_type_field): Skip
+       promotion of initializer if it has the same type as the field.
+       * testsuite/poke.pkl/struct-types-7.pk: New test.
+       * testsuite/Makefile.am (EXTRA_DIST): Update.
+
 2020-12-13  Jose E. Marchesi  <jemarch@gnu.org>
 
        * libpoke/pvm-val.h (struct pvm_mapinfo): New type.
diff --git a/libpoke/pkl-promo.c b/libpoke/pkl-promo.c
index 3dee6081..cdd890bf 100644
--- a/libpoke/pkl-promo.c
+++ b/libpoke/pkl-promo.c
@@ -1499,7 +1499,9 @@ PKL_PHASE_BEGIN_HANDLER (pkl_promo_ps_struct_type_field)
       PKL_PASS_RESTART = restart;
     }
 
-  if (elem_initializer)
+  if (elem_initializer &&
+      !pkl_ast_type_equal_p (PKL_AST_STRUCT_TYPE_FIELD_TYPE (elem),
+                             PKL_AST_TYPE (elem_initializer)))
     {
       int restart = 0;
       pkl_ast_node elem_type = PKL_AST_STRUCT_TYPE_FIELD_TYPE (elem);
diff --git a/testsuite/Makefile.am b/testsuite/Makefile.am
index 34598128..56252b20 100644
--- a/testsuite/Makefile.am
+++ b/testsuite/Makefile.am
@@ -1645,6 +1645,7 @@ EXTRA_DIST = \
   poke.pkl/struct-types-4.pk \
   poke.pkl/struct-types-5.pk \
   poke.pkl/struct-types-6.pk \
+  poke.pkl/struct-types-7.pk \
   poke.pkl/struct-types-defun-1.pk \
   poke.pkl/struct-types-defun-2.pk \
   poke.pkl/struct-types-defun-3.pk \
diff --git a/testsuite/poke.pkl/struct-types-7.pk 
b/testsuite/poke.pkl/struct-types-7.pk
new file mode 100644
index 00000000..d997c097
--- /dev/null
+++ b/testsuite/poke.pkl/struct-types-7.pk
@@ -0,0 +1,9 @@
+/* { dg-do compile } */
+
+/* This was a bug in promotion of initializer. */
+
+type S =
+  struct
+  {
+    string s = "";
+  };
-- 
2.29.2