Test pretty printing more and fix overzealous type substitution

Author: ssomers

src/etc/gdb_rust_pretty_printing.py

@@ -333,27 +333,31 @@ def children(self):
 # Yield each key (and optionally value) from a BoxedNode.
 def children_of_node(boxed_node, height, want_values):
     node_ptr = boxed_node['ptr']['pointer']
-    if height > 0:
-        type_name = str(node_ptr.type.target()).replace('LeafNode', 'InternalNode')
-        node_type = gdb.lookup_type(type_name)
-        node_ptr = node_ptr.cast(node_type.pointer())
-        leaf = node_ptr['data']
-    else:
-        leaf = node_ptr.dereference()
-    keys = leaf['keys']
-    if want_values:
-        values = leaf['vals']
-    length = int(leaf['len'])
-    for i in xrange(0, length + 1):
+    head = node_ptr.dereference()
+    length = int(head['len'])
+    if length > 0:
         if height > 0:
-            child_ptr = node_ptr['edges'][i]['value']['value']
-            for child in children_of_node(child_ptr, height - 1, want_values):
-                yield child
-        if i < length:
-            if want_values:
-                yield (keys[i]['value']['value'], values[i]['value']['value'])
-            else:
-                yield keys[i]['value']['value']
+            type_name = str(node_ptr.type.target()).replace('LeafNode', 'InternalNode', 1)
+            node_type = gdb.lookup_type(type_name)
+            node_ptr = node_ptr.cast(node_type.pointer())
+            leaf = node_ptr['data']
+            edges = node_ptr['edges']
+        else:
+            leaf = node_ptr.dereference()
+            edges = None
+        keys = leaf['keys']
+        if want_values:
+            values = leaf['vals']
+        for i in xrange(0, length + 1):
+            if edges:
+                child_ptr = edges[i]['value']['value']
+                for child in children_of_node(child_ptr, height - 1, want_values):
+                    yield child
+            if i < length:
+                if want_values:
+                    yield (keys[i]['value']['value'], values[i]['value']['value'])
+                else:
+                    yield keys[i]['value']['value']
 
 class RustStdBTreeSetPrinter(object):
     def __init__(self, val):

src/test/debuginfo/pretty-std-collections.rs

@@ -20,20 +20,26 @@
 // gdb-command: print btree_map
 // gdb-check:$2 = BTreeMap<i32, i32>(len: 15) = {[0] = 0, [1] = 1, [2] = 2, [3] = 3, [4] = 4, [5] = 5, [6] = 6, [7] = 7, [8] = 8, [9] = 9, [10] = 10, [11] = 11, [12] = 12, [13] = 13, [14] = 14}
 
+// gdb-command: print empty_btree_map
+// gdb-check:$3 = BTreeMap<(), ()>(len: 0)
+
+// gdb-command: print nasty_btree_map
+// gdb-check:$4 = BTreeMap<i32, pretty_std_collections::MyLeafNode>(len: 1) = {[1] = pretty_std_collections::MyLeafNode (11)}
+
 // gdb-command: print vec_deque
-// gdb-check:$3 = VecDeque<i32>(len: 3, cap: 8) = {5, 3, 7}
+// gdb-check:$5 = VecDeque<i32>(len: 3, cap: 8) = {5, 3, 7}
 
 // gdb-command: print vec_deque2
-// gdb-check:$4 = VecDeque<i32>(len: 7, cap: 8) = {2, 3, 4, 5, 6, 7, 8}
+// gdb-check:$6 = VecDeque<i32>(len: 7, cap: 8) = {2, 3, 4, 5, 6, 7, 8}
 
 #![allow(unused_variables)]
-use std::collections::BTreeSet;
 use std::collections::BTreeMap;
+use std::collections::BTreeSet;
 use std::collections::VecDeque;
 
+struct MyLeafNode(i32); // helps to ensure we don't blindly replace substring "LeafNode"
 
 fn main() {
-
     // BTreeSet
     let mut btree_set = BTreeSet::new();
     for i in 0..15 {
@@ -45,6 +51,9 @@ fn main() {
     for i in 0..15 {
         btree_map.insert(i, i);
     }
+    let empty_btree_map: BTreeMap<(), ()> = BTreeMap::new();
+    let mut nasty_btree_map: BTreeMap<i32, MyLeafNode> = BTreeMap::new();
+    nasty_btree_map.insert(1, MyLeafNode(11));
 
     // VecDeque
     let mut vec_deque = VecDeque::new();
@@ -63,4 +72,6 @@ fn main() {
     zzz(); // #break
 }
 
-fn zzz() { () }
+fn zzz() {
+    ()
+}