From: David Faure <[email protected]>
StdMapPrinter and Tr1UnorderedMapPrinter yield a separate child for the
key and for the value of every element, as their 'map' display hint
requires, but their num_children methods return the number of elements,
i.e. half of what children() produces.
GDB counts the children itself where it does not use num_children, so
the two disagree about the same map. For a std::map with 2 elements:
(gdb) interpreter-exec mi "-enable-pretty-printing"
(gdb) interpreter-exec mi "-var-create v * m"
(gdb) interpreter-exec mi "-var-list-children v"
^done,numchild="4",displayhint="map",children=[...]
while num_children() returns 2. The DAP code in gdb treats the two as
interchangeable: gdb/python/lib/gdb/dap/varref.py calls num_children()
when the printer has one, and falls back to len(list(children())) when
it does not, so a DAP client sees half the children of a std::map,
std::multimap or std::unordered_map.
StdSetPrinter and the sequence container printers yield one child per
element, so they are correct as they are.
libstdc++-v3/ChangeLog
* python/libstdcxx/v6/printers.py (StdMapPrinter.num_children):
Count two children per element.
(Tr1UnorderedMapPrinter.num_children): Likewise.
Signed-off-by: David Faure <[email protected]>
---
libstdc++-v3/python/libstdcxx/v6/printers.py | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/libstdc++-v3/python/libstdcxx/v6/printers.py
b/libstdc++-v3/python/libstdcxx/v6/printers.py
index eff4b72..1bba377 100644
--- a/libstdc++-v3/python/libstdcxx/v6/printers.py
+++ b/libstdc++-v3/python/libstdcxx/v6/printers.py
@@ -909,7 +909,8 @@ class StdMapPrinter(printer_base):
return self._iter(RbtreeIterator(self._val), node)
def num_children(self):
- return len(RbtreeIterator(self._val))
+ # Each element produces two children, the key and the value.
+ return 2 * len(RbtreeIterator(self._val))
def display_hint(self):
return 'map'
@@ -1301,7 +1302,8 @@ class Tr1UnorderedMapPrinter(printer_base):
return izip(counter, data)
def num_children(self):
- return int(self._hashtable()['_M_element_count'])
+ # Each element produces two children, the key and the value.
+ return 2 * int(self._hashtable()['_M_element_count'])
def display_hint(self):
return 'map'
--
2.55.0
