PR59170 make pretty printers check for singular iterators

PR libstdc++/59170
	* python/libstdcxx/v6/printers.py (StdListIteratorPrinter.to_string)
	(StdSlistIteratorPrinter.to_string, StdVectorIteratorPrinter.to_string)
	(StdRbtreeIteratorPrinter.to_string)
	(StdDequeIteratorPrinter.to_string): Add check for value-initialized
	iterators.
	* testsuite/libstdc++-prettyprinters/simple.cc: Test them.
	* testsuite/libstdc++-prettyprinters/simple11.cc: Likewise.

From-SVN: r243692

libstdc++-v3/ChangeLog

@@ -1,5 +1,14 @@
 2016-12-15  Jonathan Wakely  <jwakely@redhat.com>
 
+	PR libstdc++/59170
+	* python/libstdcxx/v6/printers.py (StdListIteratorPrinter.to_string)
+	(StdSlistIteratorPrinter.to_string, StdVectorIteratorPrinter.to_string)
+	(StdRbtreeIteratorPrinter.to_string)
+	(StdDequeIteratorPrinter.to_string): Add check for value-initialized
+	iterators.
+	* testsuite/libstdc++-prettyprinters/simple.cc: Test them.
+	* testsuite/libstdc++-prettyprinters/simple11.cc: Likewise.
+
 	PR libstdc++/59161
 	* python/libstdcxx/v6/printers.py (StdListIteratorPrinter.to_string)
 	(StdSlistIteratorPrinter.to_string, StdVectorIteratorPrinter.to_string)

libstdc++-v3/python/libstdcxx/v6/printers.py

@@ -200,6 +200,8 @@ class StdListIteratorPrinter:
         self.typename = typename
 
     def to_string(self):
+        if not self.val['_M_node']:
+            return 'non-dereferenceable iterator for std::list'
         nodetype = find_type(self.val.type, '_Node')
         nodetype = nodetype.strip_typedefs().pointer()
         node = self.val['_M_node'].cast(nodetype).dereference()
@@ -246,6 +248,8 @@ class StdSlistIteratorPrinter:
         self.val = val
 
     def to_string(self):
+        if not self.val['_M_node']:
+            return 'non-dereferenceable iterator for __gnu_cxx::slist'
         nodetype = find_type(self.val.type, '_Node')
         nodetype = nodetype.strip_typedefs().pointer()
         return str(self.val['_M_node'].cast(nodetype).dereference()['_M_data'])
@@ -333,6 +337,8 @@ class StdVectorIteratorPrinter:
         self.val = val
 
     def to_string(self):
+        if not self.val['_M_current']:
+            return 'non-dereferenceable iterator for std::vector'
         return str(self.val['_M_current'].dereference())
 
 class StdTuplePrinter:
@@ -494,6 +500,8 @@ class StdRbtreeIteratorPrinter:
         self.link_type = nodetype.strip_typedefs().pointer()
 
     def to_string (self):
+        if not self.val['_M_node']:
+            return 'non-dereferenceable iterator for associative container'
         node = self.val['_M_node'].cast(self.link_type).dereference()
         return str(get_value_from_Rb_tree_node(node))
 
@@ -708,6 +716,8 @@ class StdDequeIteratorPrinter:
         self.val = val
 
     def to_string(self):
+        if not self.val['_M_cur']:
+            return 'non-dereferenceable iterator for std::deque'
         return str(self.val['_M_cur'].dereference())
 
 class StdStringPrinter:

libstdc++-v3/testsuite/libstdc++-prettyprinters/simple.cc

@@ -30,6 +30,7 @@
 #include <list>
 #include <map>
 #include <set>
+#include <vector>
 #include <ext/slist>
 
 int
@@ -50,6 +51,9 @@ main()
   deq.push_back("two");
 // { dg-final { note-test deq {std::deque with 2 elements = {"one", "two"}} } }
 
+  std::deque<int>::iterator deqiter0;
+// { dg-final { note-test deqiter0 {non-dereferenceable iterator for std::deque} } }
+
   std::deque<std::string>::iterator deqiter = deq.begin();
 // { dg-final { note-test deqiter {"one"} } }
 
@@ -58,6 +62,9 @@ main()
   lst.push_back("two");
 // { dg-final { note-test lst {std::list = {[0] = "one", [1] = "two"}} } }
 
+  std::list<int>::iterator lstiter0;
+// { dg-final { note-test lstiter0 {non-dereferenceable iterator for std::list} } }
+
   std::list<std::string>::iterator lstiter = lst.begin();
   tem = *lstiter;
 // { dg-final { note-test lstiter {"one"}} }
@@ -73,6 +80,9 @@ main()
   std::map<std::string, int>::iterator mpiter = mp.begin();
 // { dg-final { note-test mpiter {{first = "zardoz", second = 23}} } }
 
+  std::map<std::string, int>::iterator mpiter0;
+// { dg-final { note-test mpiter0 {non-dereferenceable iterator for associative container} } }
+
   // PR 67440
   std::set<int> intset;
   intset.insert(2);
@@ -88,6 +98,20 @@ main()
   std::set<std::string>::const_iterator spciter = sp.begin();
 // { dg-final { note-test spciter {"barrel"} } }
 
+  std::set<int>::iterator spiter0;
+// { dg-final { note-test spiter0 {non-dereferenceable iterator for associative container} } }
+
+  std::vector<int> v;
+  v.push_back(1);
+  v.push_back(2);
+  v.erase(v.begin());
+// { dg-final { note-test v {std::vector of length 1, capacity 2 = {2}} } }
+  std::vector<int>::iterator viter3 = v.begin();
+// { dg-final { note-test viter3 {2} } }
+
+  std::vector<int>::iterator viter0;
+// { dg-final { note-test viter0 {non-dereferenceable iterator for std::vector} } }
+
   __gnu_cxx::slist<int> sll;
   sll.push_front(23);
   sll.push_front(47);
@@ -96,6 +120,9 @@ main()
   __gnu_cxx::slist<int>::iterator slliter = sll.begin();
 // { dg-final { note-test slliter {47} } }
 
+  __gnu_cxx::slist<int>::iterator slliter0;
+// { dg-final { note-test slliter0 {non-dereferenceable iterator for __gnu_cxx::slist} } }
+
   std::cout << "\n";
   return 0;			// Mark SPOT
 }

libstdc++-v3/testsuite/libstdc++-prettyprinters/simple11.cc

@@ -30,6 +30,7 @@
 #include <list>
 #include <map>
 #include <set>
+#include <vector>
 #include <ext/slist>
 
 int
@@ -53,6 +54,9 @@ main()
   std::deque<std::string>::iterator deqiter = deq.begin();
 // { dg-final { note-test deqiter {"one"} } }
 
+  std::deque<int>::iterator deqiter0;
+// { dg-final { note-test deqiter0 {non-dereferenceable iterator for std::deque} } }
+
   std::list<std::string> lst;
   lst.push_back("one");
   lst.push_back("two");
@@ -66,6 +70,9 @@ main()
   tem = *lstciter;
 // { dg-final { note-test lstciter {"one"}} }
 
+  std::list<int>::iterator lstiter0;
+// { dg-final { note-test lstiter0 {non-dereferenceable iterator for std::list} } }
+
   std::map<std::string, int> mp;
   mp["zardoz"] = 23;
 // { dg-final { note-test mp {std::map with 1 element = {["zardoz"] = 23}} } }
@@ -73,6 +80,9 @@ main()
   std::map<std::string, int>::iterator mpiter = mp.begin();
 // { dg-final { note-test mpiter {{first = "zardoz", second = 23}} } }
 
+  std::map<std::string, int>::iterator mpiter0;
+// { dg-final { note-test mpiter0 {non-dereferenceable iterator for associative container} } }
+
   // PR 67440
   const std::set<int> const_intset = {2, 3};
 // { dg-final { note-test const_intset {std::set with 2 elements = {[0] = 2, [1] = 3}} } }
@@ -85,6 +95,20 @@ main()
   std::set<std::string>::const_iterator spciter = sp.begin();
 // { dg-final { note-test spciter {"barrel"} } }
 
+  std::set<int>::iterator spiter0;
+// { dg-final { note-test spiter0 {non-dereferenceable iterator for associative container} } }
+
+  std::vector<int> v;
+  v.push_back(1);
+  v.push_back(2);
+  v.erase(v.begin());
+// { dg-final { note-test v {std::vector of length 1, capacity 2 = {2}} } }
+  std::vector<int>::iterator viter3 = v.begin();
+// { dg-final { note-test viter3 {2} } }
+
+  std::vector<int>::iterator viter0;
+// { dg-final { note-test viter0 {non-dereferenceable iterator for std::vector} } }
+
   __gnu_cxx::slist<int> sll;
   sll.push_front(23);
   sll.push_front(47);
@@ -93,6 +117,9 @@ main()
   __gnu_cxx::slist<int>::iterator slliter = sll.begin();
 // { dg-final { note-test slliter {47} } }
 
+  __gnu_cxx::slist<int>::iterator slliter0;
+// { dg-final { note-test slliter0 {non-dereferenceable iterator for __gnu_cxx::slist} } }
+
   std::cout << "\n";
   return 0;			// Mark SPOT
 }