From aefc738c17164e4756abe2152ba8728ea722837d Mon Sep 17 00:00:00 2001
From: Ivan Maidanski <ivmai@mail.ru>
Date: Thu, 5 Jul 2018 20:00:49 +0300
Subject: [PATCH] Remove PUSH_OBJ multi-line macro (code refactoring)

* finalize.c (GC_normal_finalize_mark_proc): Call GC_push_obj instead
of PUSH_OBJ.
* include/private/gc_pmark.h (PUSH_CONTENTS_HDR): Likewise.
* mark.c (GC_push_marked): Likewise.
* mark.c [ENABLE_DISCLAIM] (GC_push_unconditionally): Likewise.
* finalize.c (GC_normal_finalize_mark_proc): Remove hhdr local
variable.
* include/private/gc_pmark.h (PUSH_OBJ): Transform macro to inline
function; rename to GC_push_obj; update comment; return mark_stack_top.
---
 finalize.c                 |  6 ++----
 include/private/gc_pmark.h | 37 +++++++++++++++++++++----------------
 mark.c                     | 14 ++++++++------
 3 files changed, 31 insertions(+), 26 deletions(-)

diff --git a/finalize.c b/finalize.c
index 59d0375..64a0ec2 100644
--- a/finalize.c
+++ b/finalize.c
@@ -634,10 +634,8 @@ GC_API GC_await_finalize_proc GC_CALL GC_get_await_finalize_proc(void)
 /* overflow is handled by the caller, and is not a disaster.            */
 STATIC void GC_normal_finalize_mark_proc(ptr_t p)
 {
-    hdr * hhdr = HDR(p);
-
-    PUSH_OBJ(p, hhdr, GC_mark_stack_top,
-             &(GC_mark_stack[GC_mark_stack_size]));
+    GC_mark_stack_top = GC_push_obj(p, HDR(p), GC_mark_stack_top,
+                                    GC_mark_stack + GC_mark_stack_size);
 }
 
 /* This only pays very partial attention to the mark descriptor.        */
diff --git a/include/private/gc_pmark.h b/include/private/gc_pmark.h
index 8cd61b1..30e7eef 100644
--- a/include/private/gc_pmark.h
+++ b/include/private/gc_pmark.h
@@ -121,20 +121,23 @@ GC_EXTERN size_t GC_mark_stack_size;
 GC_INNER mse * GC_signal_mark_stack_overflow(mse *msp);
 
 /* Push the object obj with corresponding heap block header hhdr onto   */
-/* the mark stack.                                                      */
-#define PUSH_OBJ(obj, hhdr, mark_stack_top, mark_stack_limit) \
-  do { \
-    word _descr = (hhdr) -> hb_descr; \
-    GC_ASSERT(!HBLK_IS_FREE(hhdr)); \
-    if (_descr != 0) { \
-        mark_stack_top++; \
-        if ((word)mark_stack_top >= (word)(mark_stack_limit)) { \
-          mark_stack_top = GC_signal_mark_stack_overflow(mark_stack_top); \
-        } \
-        mark_stack_top -> mse_start = (obj); \
-        mark_stack_top -> mse_descr.w = _descr; \
-    } \
-  } while (0)
+/* the mark stack.  Returns the updated mark_stack_top value.           */
+GC_INLINE mse * GC_push_obj(ptr_t obj, hdr * hhdr,  mse * mark_stack_top,
+                            mse * mark_stack_limit)
+{
+  word descr = hhdr -> hb_descr;
+
+  GC_ASSERT(!HBLK_IS_FREE(hhdr));
+  if (descr != 0) {
+    mark_stack_top++;
+    if ((word)mark_stack_top >= (word)mark_stack_limit) {
+      mark_stack_top = GC_signal_mark_stack_overflow(mark_stack_top);
+    }
+    mark_stack_top -> mse_start = obj;
+    mark_stack_top -> mse_descr.w = descr;
+  }
+  return mark_stack_top;
+}
 
 /* Push the contents of current onto the mark stack if it is a valid    */
 /* ptr to a currently unmarked object.  Mark it.                        */
@@ -316,7 +319,8 @@ GC_INNER mse * GC_signal_mark_stack_overflow(mse *msp);
                       (unsigned)GC_gc_no, (void *)base, (void *)(source))); \
     INCR_MARKS(hhdr); \
     GC_STORE_BACK_PTR((ptr_t)(source), base); \
-    PUSH_OBJ(base, hhdr, mark_stack_top, mark_stack_limit); \
+    mark_stack_top = GC_push_obj(base, hhdr, mark_stack_top, \
+                                 mark_stack_limit); \
   } while (0)
 #endif /* MARK_BIT_PER_GRANULE */
 
@@ -375,7 +379,8 @@ GC_INNER mse * GC_signal_mark_stack_overflow(mse *msp);
                       (unsigned)GC_gc_no, (void *)base, (void *)(source))); \
     INCR_MARKS(hhdr); \
     GC_STORE_BACK_PTR((ptr_t)(source), base); \
-    PUSH_OBJ(base, hhdr, mark_stack_top, mark_stack_limit); \
+    mark_stack_top = GC_push_obj(base, hhdr, mark_stack_top, \
+                                 mark_stack_limit); \
   } while (0)
 #endif /* MARK_BIT_PER_OBJ */
 
diff --git a/mark.c b/mark.c
index d5fae4e..95dab2a 100644
--- a/mark.c
+++ b/mark.c
@@ -1885,10 +1885,11 @@ STATIC void GC_push_marked(struct hblk *h, hdr *hhdr)
       GC_mark_stack_top_reg = GC_mark_stack_top;
       for (p = h -> hb_body, bit_no = 0; (word)p <= (word)lim;
            p += sz, bit_no += MARK_BIT_OFFSET(sz)) {
-         if (mark_bit_from_hdr(hhdr, bit_no)) {
-           /* Mark from fields inside the object */
-             PUSH_OBJ(p, hhdr, GC_mark_stack_top_reg, mark_stack_limit);
-         }
+        if (mark_bit_from_hdr(hhdr, bit_no)) {
+          /* Mark from fields inside the object. */
+          GC_mark_stack_top_reg = GC_push_obj(p, hhdr, GC_mark_stack_top_reg,
+                                              mark_stack_limit);
+        }
       }
       GC_mark_stack_top = GC_mark_stack_top_reg;
     }
@@ -1927,8 +1928,9 @@ STATIC void GC_push_marked(struct hblk *h, hdr *hhdr)
 
     GC_mark_stack_top_reg = GC_mark_stack_top;
     for (p = h -> hb_body; (word)p <= (word)lim; p += sz)
-        if ((*(word *)p & 0x3) != 0)
-            PUSH_OBJ(p, hhdr, GC_mark_stack_top_reg, mark_stack_limit);
+      if ((*(word *)p & 0x3) != 0)
+        GC_mark_stack_top_reg = GC_push_obj(p, hhdr, GC_mark_stack_top_reg,
+                                            mark_stack_limit);
     GC_mark_stack_top = GC_mark_stack_top_reg;
   }
 #endif /* ENABLE_DISCLAIM */
-- 
2.7.4