[PATCH] pkl: fix invalid access to STRUCT_TYPE_FIELD node

[Mohammad-Reza Nabipoor]

Using PKL_AST_STRUCT_TYPE_FIELD_COMPUTED_P accessor on a PKL_AST_DECL
node happend to not cause any problem till the previous commit, in which,
we removed a field and added two new fields.  That change caused
PKL_AST_STRUCT_TYPE_FIELD_COMPUTED_P to return a non-zero value on 32-bit
platforms (i386 and armv7).  The result was a messed up lexical environment.

2023-07-06  Mohammad-Reza Nabipoor  <mnabipoor@gnu.org>

        * libpoke/pkl-gen.pks (struct_mapper): Make sure `@field' is of
        type `PKL_AST_STRUCT_TYPE_FIELD' before using the field accessor.
        (struct_constructor): Likewise.
---
 ChangeLog           |  6 ++++++
 libpoke/pkl-gen.pks | 15 +++++++++++----
 2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index eb347477..200db0a9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2023-07-06  Mohammad-Reza Nabipoor  <mnabipoor@gnu.org>
+
+       * libpoke/pkl-gen.pks (struct_mapper): Make sure `@field' is of
+       type `PKL_AST_STRUCT_TYPE_FIELD' before using the field accessor.
+       (struct_constructor): Likewise.
+
 2023-07-02  Mohammad-Reza Nabipoor  <mnabipoor@gnu.org>
 
        * libpoke/pkl-ast.h (PKL_AST_DECL_PREV_DECL): New macro.
diff --git a/libpoke/pkl-gen.pks b/libpoke/pkl-gen.pks
index 0faa98c9..09177156 100644
--- a/libpoke/pkl-gen.pks
+++ b/libpoke/pkl-gen.pks
@@ -1393,7 +1393,10 @@
  .c     if (PKL_AST_CODE (@field) != PKL_AST_DECL
  .c         || PKL_AST_DECL_KIND (@field) != PKL_AST_DECL_KIND_TYPE)
  .c     {
- .c       if (!PKL_AST_STRUCT_TYPE_FIELD_COMPUTED_P (@field))
+ .c       if (PKL_AST_CODE (@field) == PKL_AST_STRUCT_TYPE_FIELD
+ .c           && PKL_AST_STRUCT_TYPE_FIELD_COMPUTED_P (@field))
+ .c         ;
+ .c       else
  .c         i++;
  .c     }
  .c     continue;
@@ -1698,10 +1701,9 @@
         .label .omitted_field
         .label .got_value
         .label .constructed_value
-        .let @field_initializer = PKL_AST_STRUCT_TYPE_FIELD_INITIALIZER 
(@field)
-        .let @field_type = PKL_AST_STRUCT_TYPE_FIELD_TYPE (@field)
  .c   if (PKL_AST_CODE (@field) != PKL_AST_STRUCT_TYPE_FIELD)
  .c   {
+ .c     assert (PKL_AST_CODE (@field) == PKL_AST_DECL);
  .c     /* This is a declaration.  Generate it.  */
  .c     PKL_GEN_PUSH_CONTEXT;
  .c     PKL_PASS_SUBPASS (@field);
@@ -1713,6 +1715,8 @@
  .c
  .c     continue;
  .c   }
+        .let @field_initializer = PKL_AST_STRUCT_TYPE_FIELD_INITIALIZER 
(@field)
+        .let @field_type = PKL_AST_STRUCT_TYPE_FIELD_TYPE (@field)
  .c     /* If this is a computed field, ignore it.  */
  .c   if (PKL_AST_STRUCT_TYPE_FIELD_COMPUTED_P (@field))
  .c     continue;
@@ -2026,7 +2030,10 @@
  .c     if (PKL_AST_CODE (@field) != PKL_AST_DECL
  .c         || PKL_AST_DECL_KIND (@field) != PKL_AST_DECL_KIND_TYPE)
  .c     {
- .c       if (!PKL_AST_STRUCT_TYPE_FIELD_COMPUTED_P (@field))
+ .c       if (PKL_AST_CODE (@field) == PKL_AST_STRUCT_TYPE_FIELD
+ .c           && PKL_AST_STRUCT_TYPE_FIELD_COMPUTED_P (@field))
+ .c         ;
+ .c       else
  .c         i++;
  .c     }
  .c     continue;
-- 
2.41.0