Auto merge of #34639 - dzamlo:master, r=michaelwoerister

Use lazy iterator in vec/slice gdb pretty printers

Author: bors

src/etc/gdb_rust_pretty_printing.py

@@ -211,15 +211,12 @@ def to_string(self):
                 ("(len: %i)" % length))
 
     def children(self):
-        cs = []
         (length, data_ptr) = rustpp.extract_length_and_ptr_from_slice(self.__val)
         assert data_ptr.type.get_dwarf_type_kind() == rustpp.DWARF_TYPE_CODE_PTR
         raw_ptr = data_ptr.get_wrapped_value()
 
         for index in range(0, length):
-            cs.append((str(index), (raw_ptr + index).dereference()))
-
-        return cs
+            yield (str(index), (raw_ptr + index).dereference())
 
 
 class RustStringSlicePrinter:
@@ -245,12 +242,10 @@ def to_string(self):
                 ("(len: %i, cap: %i)" % (length, cap)))
 
     def children(self):
-        cs = []
         (length, data_ptr, cap) = rustpp.extract_length_ptr_and_cap_from_std_vec(self.__val)
         gdb_ptr = data_ptr.get_wrapped_value()
         for index in range(0, length):
-            cs.append((str(index), (gdb_ptr + index).dereference()))
-        return cs
+            yield (str(index), (gdb_ptr + index).dereference())
 
 
 class RustStdStringPrinter:

src/test/debuginfo/pretty-huge-vec.rs

@@ -0,0 +1,41 @@
+// Copyright 2013-2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// ignore-windows failing on win32 bot
+// ignore-freebsd: gdb package too new
+// ignore-android: FIXME(#10381)
+// compile-flags:-g
+// min-gdb-version 7.7
+// min-lldb-version: 310
+
+// === GDB TESTS ===================================================================================
+
+// gdb-command: run
+
+// gdb-command: print vec
+// gdb-check:$1 = Vec<u8>(len: 1000000000, cap: 1000000000) = {[...]...}
+
+// gdb-command: print slice
+// gdb-check:$2 = &[u8](len: 1000000000) = {[...]...}
+
+
+#![allow(unused_variables)]
+
+fn main() {
+
+    // Vec
+    let mut vec: Vec<u8> = Vec::with_capacity(1_000_000_000);
+    unsafe{ vec.set_len(1_000_000_000) }
+    let slice = &vec[..];
+
+    zzz(); // #break
+}
+
+fn zzz() { () }

src/test/debuginfo/pretty-uninitialized-vec.rs

@@ -0,0 +1,36 @@
+// Copyright 2013-2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// ignore-windows failing on win32 bot
+// ignore-freebsd: gdb package too new
+// ignore-android: FIXME(#10381)
+// compile-flags:-g
+// min-gdb-version 7.7
+// min-lldb-version: 310
+
+// === GDB TESTS ===================================================================================
+
+// gdb-command: run
+
+// gdb-command: print vec
+// gdb-check:$1 = Vec<i32>(len: [...], cap: [...])[...]
+
+
+#![allow(unused_variables)]
+
+fn main() {
+
+    let vec;
+    zzz(); // #break
+    vec = vec![0];
+
+}
+
+fn zzz() { () }