[PATCH] libpoke, etc: Re-write `ASTREF`/`ASTDEREF` as an inline function

[Mohammad-Reza Nabipoor]

2020-11-29  Mohammad-Reza Nabipoor  <m.nabipoor@yahoo.com>

        * libpoke/pkl-ast.h (ASTREF): Re-write the macro as inline function
        with `always_inline` and `warn_unused_result` attributes.
        (ASTDEREF): Likewise.
        * libpoke/pkl-gen.c (pkl_gen_pr_type_struct): Use returned value of
        `ASTREF`.
        * libpoke/pkl-pass.c (pkl_do_pass_1): Likewise.
        * libpoke/pkl-promo.c (promote_integral): Likewise.
        (promote_offset): Likewise.
        (promote_array): Likewise.
        (pkl_promo_ps_op_div): Likewise.
        (pkl_promo_ps_op_rela): Likewise.
        (pkl_promo_ps_type_array): Likewise.
        (pkl_promo_ps_map): Likewise.
        (pkl_promo_ps_struct_type_field): Likewise.
        * libpoke/pkl-tab.y (offset_type_specifier): Likewise.
        (struct_type_field): Likewise.
        (stmt): Likewise.
        * libpoke/pkl-typify.c (pkl_typify1_ps_struct_type_field): Likewise.
        * libpoke/pkl-ast.c (pkl_ast_reverse): Use returned value of `ASTDEREF`.
        * etc/hacking.org (Memory Management): Update.
        * HACKING: Regenerate.
---
 ChangeLog            | 24 ++++++++++++++++++++++++
 HACKING              | 30 +++++++++---------------------
 etc/hacking.org      | 16 +++++-----------
 libpoke/pkl-ast.c    |  4 ++--
 libpoke/pkl-ast.h    | 22 ++++++++++++++++------
 libpoke/pkl-gen.c    |  2 +-
 libpoke/pkl-pass.c   |  2 +-
 libpoke/pkl-promo.c  | 16 ++++++++--------
 libpoke/pkl-tab.y    |  6 +++---
 libpoke/pkl-typify.c |  6 +++---
 10 files changed, 72 insertions(+), 56 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 341ee267..6c514325 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,27 @@
+2020-11-29  Mohammad-Reza Nabipoor  <m.nabipoor@yahoo.com>
+
+       * libpoke/pkl-ast.h (ASTREF): Re-write the macro as inline function
+       with `always_inline` and `warn_unused_result` attributes.
+       (ASTDEREF): Likewise.
+       * libpoke/pkl-gen.c (pkl_gen_pr_type_struct): Use returned value of
+       `ASTREF`.
+       * libpoke/pkl-pass.c (pkl_do_pass_1): Likewise.
+       * libpoke/pkl-promo.c (promote_integral): Likewise.
+       (promote_offset): Likewise.
+       (promote_array): Likewise.
+       (pkl_promo_ps_op_div): Likewise.
+       (pkl_promo_ps_op_rela): Likewise.
+       (pkl_promo_ps_type_array): Likewise.
+       (pkl_promo_ps_map): Likewise.
+       (pkl_promo_ps_struct_type_field): Likewise.
+       * libpoke/pkl-tab.y (offset_type_specifier): Likewise.
+       (struct_type_field): Likewise.
+       (stmt): Likewise.
+       * libpoke/pkl-typify.c (pkl_typify1_ps_struct_type_field): Likewise.
+       * libpoke/pkl-ast.c (pkl_ast_reverse): Use returned value of `ASTDEREF`.
+       * etc/hacking.org (Memory Management): Update.
+       * HACKING: Regenerate.
+
 2020-11-29  Mohammad-Reza Nabipoor  <m.nabipoor@yahoo.com>
 
        * libpoke/libpoke.h (pk_call): Remove `__attribute__ ((sentinel))`.
diff --git a/HACKING b/HACKING
index 41e6bc21..d11f2c80 100644
--- a/HACKING
+++ b/HACKING
@@ -1,9 +1,9 @@
-                       __________________________
+                      __________________________
 
-                        GNU POKE - HACKING NOTES
+                       GNU POKE - HACKING NOTES
 
-                            The poke hackers
-                       __________________________
+                           The poke hackers
+                      __________________________
 
 
 Table of Contents
@@ -1743,7 +1743,7 @@ with GNU poke.  If not, see 
<https://www.gnu.org/licenses/>.
 
   The AST uses reference counting in order to manage the memory used by
   the nodes.  Every time you store a pointer to an AST node, you should
-  use the macro `ASTREF' in order to increase its counter:
+  use the `ASTREF' in order to increase its counter:
 
   ,----
   | pkl_ast_node foo = ASTREF (node);
@@ -1758,27 +1758,15 @@ with GNU poke.  If not, see 
<https://www.gnu.org/licenses/>.
   `----
 
 
-  There is a little caveat: the way ASTREF is defined, it requires a
-  l-value to work properly.  Therefore, this doesn't work:
-
-  ,----
-  | pkl_ast_node foo = ASTREF (PKL_AST_TYPE (node));
-  `----
-
-
-  instead, write:
-
-  ,----
-  | pkl_ast_node type = PKL_AST_TYPE (node);
-  | pkl_ast_node foo = ASTREF (type);
-  `----
+  To make sure you get the reference counting right, it's required to
+  use the returned value of `ASTREF'.
 
 
 13.2 Using ASTDEREF
 ~~~~~~~~~~~~~~~~~~~
 
-  `ASTDEREF' decreases the reference counter of the provided AST node.
-  The passed value should be a l-value.
+  `ASTDEREF' decreases the reference counter of the provided AST
+  node. It's required to use the returned value of `ASTDEREF'.
 
   In practice you will seldom find yourself in the need to use
   `ASTDEREF'.  Just make sure that every `ASTREF' is paired with a
diff --git a/etc/hacking.org b/etc/hacking.org
index 88160deb..4d5e5158 100644
--- a/etc/hacking.org
+++ b/etc/hacking.org
@@ -1369,9 +1369,10 @@ Each pickle in =pickles/FOO.pk= shall have a testsuite in
 
 ** Using ASTREF
 
+
    The AST uses reference counting in order to manage the memory used
    by the nodes.  Every time you store a pointer to an AST node, you
-   should use the macro =ASTREF= in order to increase its counter:
+   should use the =ASTREF= in order to increase its counter:
 
    : pkl_ast_node foo = ASTREF (node);
 
@@ -1380,20 +1381,13 @@ Each pickle in =pickles/FOO.pk= shall have a testsuite 
in
 
    : pkl_ast_node new = pkl_ast_make_struct (ast, 5, elems_node);
 
-   There is a little caveat: the way ASTREF is defined, it requires a
-   l-value to work properly.  Therefore, this doesn't work:
-
-   : pkl_ast_node foo = ASTREF (PKL_AST_TYPE (node));
-
-   instead, write:
-
-   : pkl_ast_node type = PKL_AST_TYPE (node);
-   : pkl_ast_node foo = ASTREF (type);
+   To make sure you get the reference counting right, it's required to
+   use the returned value of =ASTREF=.
 
 ** Using ASTDEREF
 
    =ASTDEREF= decreases the reference counter of the provided AST
-   node.  The passed value should be a l-value.
+   node. It's required to use the returned value of =ASTDEREF=.
 
    In practice you will seldom find yourself in the need to use
    =ASTDEREF=.  Just make sure that every =ASTREF= is paired with a
diff --git a/libpoke/pkl-ast.c b/libpoke/pkl-ast.c
index 768cddda..92c60a21 100644
--- a/libpoke/pkl-ast.c
+++ b/libpoke/pkl-ast.c
@@ -2321,11 +2321,11 @@ pkl_ast_reverse (pkl_ast_node ast)
 {
   pkl_ast_node prev = NULL, decl, next;
 
-  ASTDEREF (ast);
+  ast = ASTDEREF (ast);
   for (decl = ast; decl != NULL; decl = next)
     {
       next = PKL_AST_CHAIN (decl);
-      ASTDEREF (next);
+      next = ASTDEREF (next);
       PKL_AST_CHAIN (decl) = ASTREF (prev);
       prev = decl;
     }
diff --git a/libpoke/pkl-ast.h b/libpoke/pkl-ast.h
index f1f7f664..333f5d69 100644
--- a/libpoke/pkl-ast.h
+++ b/libpoke/pkl-ast.h
@@ -226,12 +226,6 @@ typedef union pkl_ast_node *pkl_ast_node;
 #define PKL_AST_REGISTERED_P(AST) ((AST)->common.registered_p)
 #define PKL_AST_REFCOUNT(AST) ((AST)->common.refcount)
 
-/* NOTE: both ASTREF and ASTDEREF need an l-value!  */
-#define ASTREF(AST) ((AST) ? (++((AST)->common.refcount), (AST)) \
-                     : NULL)
-#define ASTDEREF(AST) ((AST) ? (--((AST)->common.refcount), (AST)) \
-                       : NULL)
-
 struct pkl_ast_loc
 {
   int first_line;
@@ -1894,6 +1888,22 @@ union pkl_ast_node
   struct pkl_ast_print_stmt_arg print_stmt_arg;
 };
 
+static inline pkl_ast_node __attribute__ ((always_inline, warn_unused_result))
+ASTREF (pkl_ast_node ast)
+{
+  if (ast)
+    ++ast->common.refcount;
+  return ast;
+}
+
+static inline pkl_ast_node __attribute__ ((always_inline, warn_unused_result))
+ASTDEREF (pkl_ast_node ast)
+{
+  if (ast)
+    --ast->common.refcount;
+  return ast;
+}
+
 /* The `pkl_ast' struct defined below contains a PKL abstract syntax tree.
 
    AST contains the tree of linked nodes, starting with a
diff --git a/libpoke/pkl-gen.c b/libpoke/pkl-gen.c
index d929aa4b..7b31eb38 100644
--- a/libpoke/pkl-gen.c
+++ b/libpoke/pkl-gen.c
@@ -3014,7 +3014,7 @@ PKL_PHASE_BEGIN_HANDLER (pkl_gen_pr_type_struct)
         PKL_GEN_PAYLOAD->in_constructor = 1;
 
         pkl_asm_label (PKL_GEN_ASM, label);
-        ASTREF(s); pkl_ast_node_free (s);
+        s = ASTREF(s); pkl_ast_node_free (s);
       }
 
       if (type_struct_constructor != PVM_NULL)
diff --git a/libpoke/pkl-pass.c b/libpoke/pkl-pass.c
index c1d2bb1e..8364bc2d 100644
--- a/libpoke/pkl-pass.c
+++ b/libpoke/pkl-pass.c
@@ -616,7 +616,7 @@ pkl_do_pass_1 (pkl_compiler compiler,
      this function will be stored in some other node (or the top-level
      AST structure).  */
   if (node != node_orig)
-    ASTREF (node);
+    node = ASTREF (node);
 
  _exit:
   if (level != 0
diff --git a/libpoke/pkl-promo.c b/libpoke/pkl-promo.c
index 41577655..1479f0c5 100644
--- a/libpoke/pkl-promo.c
+++ b/libpoke/pkl-promo.c
@@ -63,7 +63,7 @@ promote_integral (pkl_ast ast,
           PKL_AST_TYPE (*a) = ASTREF (desired_type);
           PKL_AST_LOC (*a) = loc;
           PKL_AST_LOC (desired_type) = loc;
-          ASTREF (*a);
+          *a = ASTREF (*a);
           *restart = 1;
         }
 
@@ -125,7 +125,7 @@ promote_offset (pkl_ast ast,
           *a = pkl_ast_make_cast (ast, type, ASTDEREF (*a));
           PKL_AST_TYPE (*a) = ASTREF (type);
           PKL_AST_LOC (*a) = loc;
-          ASTREF (*a);
+          *a = ASTREF (*a);
           *restart = 1;
         }
 
@@ -183,7 +183,7 @@ promote_array (pkl_ast ast,
     *a = pkl_ast_make_cast (ast, type, ASTDEREF (*a));
     PKL_AST_TYPE (*a) = ASTREF (type);
     PKL_AST_LOC (*a) = loc;
-    ASTREF (*a);
+    *a = ASTREF (*a);
     *restart = 1;
     return 1;
   }
@@ -257,7 +257,7 @@ PKL_PHASE_BEGIN_HANDLER (pkl_promo_ps_op_div)
 
         pkl_ast_node unit_bit = pkl_ast_make_integer (PKL_PASS_AST, 1);
 
-        ASTREF (unit_bit);
+        unit_bit = ASTREF (unit_bit);
         PKL_AST_LOC (unit_bit) = PKL_AST_LOC (exp);
 
         if (!promote_offset (PKL_PASS_AST,
@@ -597,7 +597,7 @@ PKL_PHASE_BEGIN_HANDLER (pkl_promo_ps_op_rela)
                         && PKL_AST_TYPE_I_SIGNED_P (op2_base_type));
 
         pkl_ast_node unit_bit = pkl_ast_make_integer (PKL_PASS_AST, 1);
-        ASTREF (unit_bit);
+        unit_bit = ASTREF (unit_bit);
         PKL_AST_LOC (unit_bit) = PKL_AST_LOC (exp);
 
         if (!promote_offset (PKL_PASS_AST,
@@ -878,7 +878,7 @@ PKL_PHASE_BEGIN_HANDLER (pkl_promo_ps_type_array)
       {
         pkl_ast_node unit_bit = pkl_ast_make_integer (PKL_PASS_AST, 1);
 
-        ASTREF (unit_bit);
+        unit_bit = ASTREF (unit_bit);
         PKL_AST_LOC (unit_bit) = PKL_AST_LOC (PKL_PASS_NODE);
 
         if (!promote_offset (PKL_PASS_AST,
@@ -1385,7 +1385,7 @@ PKL_PHASE_BEGIN_HANDLER (pkl_promo_ps_map)
 
   pkl_ast_node unit_bit = pkl_ast_make_integer (PKL_PASS_AST, 1);
 
-  ASTREF (unit_bit);
+  unit_bit = ASTREF (unit_bit);
   PKL_AST_LOC (unit_bit) = PKL_AST_LOC (PKL_PASS_NODE);
 
   if (!promote_offset (PKL_PASS_AST,
@@ -1614,7 +1614,7 @@ PKL_PHASE_BEGIN_HANDLER (pkl_promo_ps_struct_type_field)
                 PKL_PASS_ERROR;
               }
 
-            ASTREF (unit_bit); pkl_ast_node_free (unit_bit);
+            unit_bit = ASTREF (unit_bit); pkl_ast_node_free (unit_bit);
             break;
           }
         default:
diff --git a/libpoke/pkl-tab.y b/libpoke/pkl-tab.y
index 14e26f78..bcd9d14f 100644
--- a/libpoke/pkl-tab.y
+++ b/libpoke/pkl-tab.y
@@ -1434,7 +1434,7 @@ offset_type_specifier:
                                                  $2,
                                                  PKL_AST_DECL_INITIAL (decl));
 
-                  ASTREF ($4); pkl_ast_node_free ($4);
+                  $4 = ASTREF ($4); pkl_ast_node_free ($4);
                   PKL_AST_LOC ($$) = @$;
                 }
         | OFFSETCONSTR simple_type_specifier ',' INTEGER '>'
@@ -1724,7 +1724,7 @@ struct_type_field:
                     {
                       PKL_AST_LOC ($3) = @3;
                       PKL_AST_TYPE ($3) = pkl_ast_make_string_type 
(pkl_parser->ast);
-                      ASTREF (PKL_AST_TYPE ($3));
+                      PKL_AST_TYPE ($3) = ASTREF (PKL_AST_TYPE ($3));
                       PKL_AST_LOC (PKL_AST_TYPE ($3)) = @3;
                     }
                 }
@@ -2220,7 +2220,7 @@ stmt:
                   PKL_AST_LOC ($$) = @$;
 
                   /* Free the identifier.  */
-                  ASTREF ($3); pkl_ast_node_free ($3);
+                  $3 = ASTREF ($3); pkl_ast_node_free ($3);
 
                   /* Annotate the contained BREAK and CONTINUE
                      statements with their lexical level within this
diff --git a/libpoke/pkl-typify.c b/libpoke/pkl-typify.c
index fecccc92..c21fa07a 100644
--- a/libpoke/pkl-typify.c
+++ b/libpoke/pkl-typify.c
@@ -2583,7 +2583,7 @@ PKL_PHASE_BEGIN_HANDLER (pkl_typify1_ps_struct_type_field)
           PKL_PASS_ERROR;
         }
 
-      ASTREF (bool_type); pkl_ast_node_free (bool_type);
+      bool_type = ASTREF (bool_type); pkl_ast_node_free (bool_type);
     }
 
   /* Ditto for the optcond.  */
@@ -2603,7 +2603,7 @@ PKL_PHASE_BEGIN_HANDLER (pkl_typify1_ps_struct_type_field)
           PKL_PASS_ERROR;
         }
 
-      ASTREF (bool_type); pkl_ast_node_free (bool_type);
+      bool_type = ASTREF (bool_type); pkl_ast_node_free (bool_type);
     }
 
   /* If specified, the type of the initializer of a struct field
@@ -2653,7 +2653,7 @@ expected %s, got %s",
           PKL_PASS_ERROR;
         }
 
-      ASTREF (offset_type); pkl_ast_node_free (offset_type);
+      offset_type = ASTREF (offset_type); pkl_ast_node_free (offset_type);
     }
 }
 PKL_PHASE_END_HANDLER
-- 
2.29.2