hashmap - 我如何在 GDB 中漂亮地打印 Rust HashMap？

Question

这是我在 GDB 中运行的带有 Vec 和 HashMap 的简单 Rust 示例:

use std::collections::HashMap;

fn main() {
    let v = vec!["Mon", "Tue", "Wed"];
    println!("{:?}", v);

    let mut h = HashMap::new();
    h.insert(1,"Jan");
    h.insert(2,"Feb");
    h.insert(3,"Mar");
    h.insert(4,"Apr");
    println!("{:?}", h);
}

当我查看 Vec 时，它打印得很漂亮，而 HashMap 不是:

bash$ rust-gdb target/debug/test_hashmap
GNU gdb (GDB) 8.1
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License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
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and "show warranty" for details.
This GDB was configured as "x86_64-pc-linux-gnu".
Type "show configuration" for configuration details.
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<http://www.gnu.org/software/gdb/bugs/>.
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For help, type "help".
Type "apropos word" to search for commands related to "word"...
Reading symbols from target/debug/test_hashmap...done.
(gdb) b 12
Breakpoint 1 at 0xa056: file src/main.rs, line 12.
(gdb) r
Starting program: /home/john/proj/test_hashmap/target/debug/test_hashmap 
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/usr/lib/libthread_db.so.1".
["Mon", "Tue", "Wed"]

Breakpoint 1, test_hashmap::main () at src/main.rs:12
12          println!("{:?}", h);
(gdb) p v
$1 = Vec<&str>(len: 3, cap: 3) = {"Mon", "Tue", "Wed"}
(gdb) p h
$2 = HashMap<i32, &str, std::collections::hash::map::RandomState> = {hash_builder = RandomState = {k0 = 12919411587537124140, 
    k1 = 836420561220520453}, table = RawTable<i32, &str> = {capacity_mask = 31, size = 4, hashes = TaggedHashUintPtr = {
      Unique<usize> = {pointer = NonZero<*const usize> = {0x7ffff6c1c400}, _marker = PhantomData<usize>}}, 
    marker = PhantomData<(i32, &str)>}, resize_policy = DefaultResizePolicy}
(gdb) info pretty-printer
global pretty-printers:
  builtin
    mpx_bound128
  objfile /home/john/proj/test_hashmap/target/debug/test_hashmap pretty-printers:
  rust_pretty_printer_lookup_function
(gdb) n
{1: "Jan", 4: "Apr", 3: "Mar", 2: "Feb"}
13      }
(gdb) 

该程序看到了 HashMap(并正常打印它的值)，但我在 GDB 中看不到那些。 Rust pretty-print 似乎已启用，因为 Vec 打印得很好。

如何在常规 GDB 中获取 HashMap 键和值？

Answer 1

目前无法为 HashMap 漂亮地打印键值项。

有an open issue requesting this feature .