[v3] backport r163282 to 4.5 branch to fix libstdc++/45999

[Jonathan Wakely]

Not a regression, but the python pretty printers are a highly visible
feature of GCC 4.5 and GDB 7 amd I think it's worth backporting this
fairly safe change to support vector<bool>, so checked in to 4.5
branch.

2010-10-18  Jonathan Wakely  <jwakely.gcc@gmail.com>

        Backport from mainline:
        2010-08-16  Chris Moller  <cmoller@redhat.com>

        http://sourceware.org/bugzilla/show_bug.cgi?id=11874
        * python/libstdcxx/v6/printers.py (StdVectorPrinter): Added stuff
        to handle pretty-printing of std::vector<bool>.

Tested x86_64-linux with GDB 7.1-34.fc13
-------------- next part --------------
Index: python/libstdcxx/v6/printers.py
===================================================================
--- python/libstdcxx/v6/printers.py	(revision 165656)
+++ python/libstdcxx/v6/printers.py	(working copy)
@@ -153,37 +153,71 @@ class StdVectorPrinter:
     "Print a std::vector"
 
     class _iterator:
-        def __init__ (self, start, finish):
-            self.item = start
-            self.finish = finish
+        def __init__ (self, start, finish, bitvec):
+            self.bitvec = bitvec
+            if bitvec:
+                self.item   = start['_M_p']
+                self.so     = start['_M_offset']
+                self.finish = finish['_M_p']
+                self.fo     = finish['_M_offset']
+                itype = self.item.dereference().type
+                self.isize = 8 * itype.sizeof
+            else:
+                self.item = start
+                self.finish = finish
             self.count = 0
 
         def __iter__(self):
             return self
 
         def next(self):
-            if self.item == self.finish:
-                raise StopIteration
             count = self.count
             self.count = self.count + 1
-            elt = self.item.dereference()
-            self.item = self.item + 1
-            return ('[%d]' % count, elt)
+            if self.bitvec:
+                if self.item == self.finish and self.so >= self.fo:
+                    raise StopIteration
+                elt = self.item.dereference()
+                obit = 1 if elt & (1 << self.so) else 0
+                self.so = self.so + 1
+                if self.so >= self.isize:
+                    self.item = self.item + 1
+                    self.so = 0
+                return ('[%d]' % count, obit)
+            else:
+                if self.item == self.finish:
+                    raise StopIteration
+                elt = self.item.dereference()
+                self.item = self.item + 1
+                return ('[%d]' % count, elt)
 
     def __init__(self, typename, val):
         self.typename = typename
         self.val = val
+        self.is_bool = val.type.template_argument(0).code  == gdb.TYPE_CODE_BOOL
 
     def children(self):
         return self._iterator(self.val['_M_impl']['_M_start'],
-                              self.val['_M_impl']['_M_finish'])
+                              self.val['_M_impl']['_M_finish'],
+                              self.is_bool)
 
     def to_string(self):
         start = self.val['_M_impl']['_M_start']
         finish = self.val['_M_impl']['_M_finish']
         end = self.val['_M_impl']['_M_end_of_storage']
-        return ('%s of length %d, capacity %d'
-                % (self.typename, int (finish - start), int (end - start)))
+        if self.is_bool:
+            start = self.val['_M_impl']['_M_start']['_M_p']
+            so    = self.val['_M_impl']['_M_start']['_M_offset']
+            finish = self.val['_M_impl']['_M_finish']['_M_p']
+            fo     = self.val['_M_impl']['_M_finish']['_M_offset']
+            itype = start.dereference().type
+            bl = 8 * itype.sizeof
+            length   = (bl - so) + bl * ((finish - start) - 1) + fo
+            capacity = bl * (end - start)
+            return ('%s<bool> of length %d, capacity %d'
+                    % (self.typename, int (length), int (capacity)))
+        else:
+            return ('%s of length %d, capacity %d'
+                    % (self.typename, int (finish - start), int (end - start)))
 
     def display_hint(self):
         return 'array'