libcpp

[pf3gnuchains/gcc-fork.git] / gcc / ggc-page.c

diff --git a/gcc/ggc-page.c b/gcc/ggc-page.c
index ea637b1..f22ddf6 100644 (file)
--- a/gcc/ggc-page.c
+++ b/gcc/ggc-page.c
@@ -1,5 +1,5 @@
 /* "Bag-of-pages" garbage collector for the GNU compiler.
 /* "Bag-of-pages" garbage collector for the GNU compiler.

-   Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2007
+   Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2007, 2008

    Free Software Foundation, Inc.
 
 This file is part of GCC.
    Free Software Foundation, Inc.
 
 This file is part of GCC.


@@ -1256,6 +1256,57 @@ ggc_alloc_stat (size_t size MEM_STAT_DECL)
   return result;
 }
 
   return result;
 }
 

+/* Mark function for strings.  */
+
+void
+gt_ggc_m_S (const void *p)
+{
+  page_entry *entry;
+  unsigned bit, word;
+  unsigned long mask;
+  unsigned long offset;
+
+  if (!p || !ggc_allocated_p (p))
+    return;
+
+  /* Look up the page on which the object is alloced.  .  */
+  entry = lookup_page_table_entry (p);
+  gcc_assert (entry);
+
+  /* Calculate the index of the object on the page; this is its bit
+     position in the in_use_p bitmap.  Note that because a char* might
+     point to the middle of an object, we need special code here to
+     make sure P points to the start of an object.  */
+  offset = ((const char *) p - entry->page) % object_size_table[entry->order];
+  if (offset)
+    {
+      /* Here we've seen a char* which does not point to the beginning
+        of an allocated object.  We assume it points to the middle of
+        a STRING_CST.  */
+      gcc_assert (offset == offsetof (struct tree_string, str));
+      p = ((const char *) p) - offset;
+      gt_ggc_mx_lang_tree_node ((void *) p);
+      return;
+    }
+
+  bit = OFFSET_TO_BIT (((const char *) p) - entry->page, entry->order);
+  word = bit / HOST_BITS_PER_LONG;
+  mask = (unsigned long) 1 << (bit % HOST_BITS_PER_LONG);
+
+  /* If the bit was previously set, skip it.  */
+  if (entry->in_use_p[word] & mask)
+    return;
+
+  /* Otherwise set it, and decrement the free object count.  */
+  entry->in_use_p[word] |= mask;
+  entry->num_free_objects -= 1;
+
+  if (GGC_DEBUG_LEVEL >= 4)
+    fprintf (G.debug_file, "Marking %p\n", p);
+
+  return;
+}
+

 /* If P is not marked, marks it and return false.  Otherwise return true.
    P must have been allocated by the GC allocator; it mustn't point to
    static objects, stack variables, or memory allocated with malloc.  */
 /* If P is not marked, marks it and return false.  Otherwise return true.
    P must have been allocated by the GC allocator; it mustn't point to
    static objects, stack variables, or memory allocated with malloc.  */