[PATCH] pkl: Disallow labels in unions

[Mohammad-Reza Nabipoor]

2022-01-19  Mohammad-Reza Nabipoor  <mnabipoor@gnu.org>

        * libpoke/pkl-typify.c (pkl_typify1_ps_type_struct): Disallow
        labels in unions.
        * doc/poke.texi (Unions): Update.
        * testsuite/poke.pkl/union-diag-9.pk: New test.
        * testsuite/Makefile.am (EXTRA_DIST): Update.
---
 ChangeLog                          |  8 ++++++++
 doc/poke.texi                      |  3 ++-
 libpoke/pkl-typify.c               | 10 +++++++---
 testsuite/Makefile.am              |  1 +
 testsuite/poke.pkl/union-diag-9.pk |  9 +++++++++
 5 files changed, 27 insertions(+), 4 deletions(-)
 create mode 100644 testsuite/poke.pkl/union-diag-9.pk

diff --git a/ChangeLog b/ChangeLog
index edff6c0a..bc0eed90 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2022-01-19  Mohammad-Reza Nabipoor  <mnabipoor@gnu.org>
+
+       * libpoke/pkl-typify.c (pkl_typify1_ps_type_struct): Disallow
+       labels in unions.
+       * doc/poke.texi (Unions): Update.
+       * testsuite/poke.pkl/union-diag-9.pk: New test.
+       * testsuite/Makefile.am (EXTRA_DIST): Update.
+
 2022-01-19  Jose E. Marchesi  <jemarch@gnu.org>
 
        * libpoke/std.pk (openproc): New function.
diff --git a/doc/poke.texi b/doc/poke.texi
index d074c5a8..a4a98f54 100644
--- a/doc/poke.texi
+++ b/doc/poke.texi
@@ -11185,7 +11185,8 @@ means.  Alternatives are considered in turn, in written 
order, and the
 first alternative that can be used without triggering a constraint
 violation exception is selected.
 
-Note that, unlike structs, unions cannot be pinned.
+Note that, unlike structs, unions cannot be pinned. And, like pinned
+structs, they cannot have labels.
 
 @node Union Constructors
 @subsection Union Constructors
diff --git a/libpoke/pkl-typify.c b/libpoke/pkl-typify.c
index 411e6392..cf0a96bc 100644
--- a/libpoke/pkl-typify.c
+++ b/libpoke/pkl-typify.c
@@ -1786,7 +1786,7 @@ PKL_PHASE_END_HANDLER
 
    Pinned unions are not allowed.
 
-   Labels are not allowed in integral structs and pinned structs.
+   Labels are not allowed in integral structs, pinned structs and unions.
    Optional fields are not allowed in integral structs.  */
 
 PKL_PHASE_BEGIN_HANDLER (pkl_typify1_ps_type_struct)
@@ -1877,7 +1877,8 @@ PKL_PHASE_BEGIN_HANDLER (pkl_typify1_ps_type_struct)
       PKL_PASS_ERROR;
     }
 
-  if (PKL_AST_TYPE_S_PINNED_P (struct_type))
+  if (PKL_AST_TYPE_S_PINNED_P (struct_type)
+      || PKL_AST_TYPE_S_UNION_P (struct_type))
     {
       for (field = PKL_AST_TYPE_S_ELEMS (struct_type);
            field;
@@ -1889,7 +1890,10 @@ PKL_PHASE_BEGIN_HANDLER (pkl_typify1_ps_type_struct)
           if (PKL_AST_STRUCT_TYPE_FIELD_LABEL (field))
             {
               PKL_ERROR (PKL_AST_LOC (field),
-                         "labels are not allowed in pinned structs");
+                         "labels are not allowed in %s",
+                         PKL_AST_TYPE_S_PINNED_P (struct_type)
+                           ? "pinned structs"
+                           : "unions");
               PKL_TYPIFY_PAYLOAD->errors++;
               PKL_PASS_ERROR;
             }
diff --git a/testsuite/Makefile.am b/testsuite/Makefile.am
index 709cc89c..876cda66 100644
--- a/testsuite/Makefile.am
+++ b/testsuite/Makefile.am
@@ -2057,6 +2057,7 @@ EXTRA_DIST = \
   poke.pkl/union-diag-6.pk \
   poke.pkl/union-diag-7.pk \
   poke.pkl/union-diag-8.pk \
+  poke.pkl/union-diag-9.pk \
   poke.pkl/union-pretty-print-1.pk \
   poke.pkl/units-1.pk \
   poke.pkl/units-2.pk \
diff --git a/testsuite/poke.pkl/union-diag-9.pk 
b/testsuite/poke.pkl/union-diag-9.pk
new file mode 100644
index 00000000..cbddc810
--- /dev/null
+++ b/testsuite/poke.pkl/union-diag-9.pk
@@ -0,0 +1,9 @@
+/* { dg-do compile } */
+
+/* Labels are now allowed in unions.  */
+
+type Foo = union
+  {
+    int a : a != 10;
+    int b @ 1#B; /* { dg-error "" } */
+  };
-- 
2.34.1