binutils-gdb/gdb/testsuite/gdb.rust/simple.rs
Tom Tromey 77c2dba3e8 Avoid crash on single-field union in Rust
PR rust/24976 points out a crash in gdb when a single-field union is
used in Rust.

The immediate problem was a NULL pointer dereference in
quirk_rust_enum.  However, that code is also erroneously treating a
single-field union as if it were a univariant enum.  Looking at the
output of an older Rust compiler, it turns out that univariant enums
are distinguished by having a single *anonymous* field.  This patch
changes quirk_rust_enum to limit its fixup to this case.

Tested with a new-enough version of the Rust compiler to cause the
crash; plus by using an older executable that uses the old univariant
encoding.

gdb/ChangeLog
2019-10-03  Tom Tromey  <tom@tromey.com>

	PR rust/24976:
	* dwarf2read.c (quirk_rust_enum): Handle single-element unions.

gdb/testsuite/ChangeLog
2019-10-03  Tom Tromey  <tom@tromey.com>

	PR rust/24976:
	* gdb.rust/simple.rs (Union2): New type.
	(main): Use Union2.
	* gdb.rust/simple.exp: Add test.
2019-10-03 20:56:22 -06:00

193 lines
4.1 KiB
Rust

// Copyright (C) 2016-2019 Free Software Foundation, Inc.
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
#![allow(dead_code)]
#![allow(unused_variables)]
#![allow(unused_assignments)]
pub struct HiBob {
pub field1: i32,
field2: u64,
}
struct ByeBob(i32, u64);
enum Something {
One,
Two,
Three
}
enum MoreComplicated {
One,
Two(i32),
Three(HiBob),
Four{this: bool, is: u8, a: char, struct_: u64, variant: u32},
}
// tests the nonzero optimization, but fields are reversed
enum NonZeroOptimized {
Empty,
Value(String),
}
fn diff2(x: i32, y: i32) -> i32 {
x - y
}
// Empty function, should not have "void"
// or "()" in its return type
fn empty() {
}
pub struct Unit;
// This triggers the non-zero optimization that yields a different
// enum representation in the debug info.
enum SpaceSaver {
Thebox(u8, Box<i32>),
Nothing,
}
enum Univariant {
Foo {a: u8}
}
enum UnivariantAnon {
Foo(u8)
}
enum ParametrizedEnum<T> {
Val { val: T },
Empty,
}
struct ParametrizedStruct<T> {
next: ParametrizedEnum<Box<ParametrizedStruct<T>>>,
value: T
}
union Union {
f1: i8,
f2: u8,
}
pub union Union2 {
pub name: [u8; 1],
}
struct StringAtOffset {
pub field1: &'static str,
pub field2: i32,
pub field3: &'static str,
}
// A simple structure whose layout won't be changed by the compiler,
// so that ptype/o testing will work on any platform.
struct SimpleLayout {
f1: u16,
f2: u16
}
enum EmptyEnum {}
fn main () {
let a = ();
let b : [i32; 0] = [];
let mut c = 27;
let d = c = 99;
let e = MoreComplicated::Two(73);
let e2 = MoreComplicated::Four {this: true, is: 8, a: 'm',
struct_: 100, variant: 10};
let f = "hi bob";
let g = b"hi bob";
let h = b'9';
let fslice = &f[3..];
let i = ["whatever"; 8];
let j = Unit;
let j2 = Unit{};
let k = SpaceSaver::Nothing;
let l = SpaceSaver::Thebox(9, Box::new(1729));
let v = Something::Three;
let w = [1,2,3,4];
let w_ptr = &w[0];
let x = (23, 25.5);
let y = HiBob {field1: 7, field2: 8};
let z = ByeBob(7, 8);
let field1 = 77;
let field2 = 88;
let y0 = HiBob { field1, field2 };
let univariant = Univariant::Foo {a : 1};
let univariant_anon = UnivariantAnon::Foo(1);
let slice = &w[2..3];
let fromslice = slice[0];
let slice2 = &slice[0..1];
let all1 = &w[..];
let all2 = &slice[..];
let from1 = &w[1..];
let from2 = &slice[1..];
let to1 = &w[..3];
let to2 = &slice[..1];
let st = StringAtOffset { field1: "hello", field2: 1, field3: "world" };
// tests for enum optimizations
let str_some = Some("hi".to_string());
let str_none = None::<String>;
let box_some = Some(Box::new(1u8));
let box_none = None::<Box<u8>>;
let int_some = Some(1u8);
let int_none = None::<u8>;
let custom_some = NonZeroOptimized::Value("hi".into());
let custom_none = NonZeroOptimized::Empty;
let parametrized = ParametrizedStruct {
next: ParametrizedEnum::Val {
val: Box::new(ParametrizedStruct {
next: ParametrizedEnum::Empty,
value: 1,
})
},
value: 0,
};
let u = Union { f2: 255 };
let simplelayout = SimpleLayout { f1: 8, f2: 9 };
let empty_enum_value: EmptyEnum;
let u2 = Union2 { name: [1] };
println!("{}, {}", x.0, x.1); // set breakpoint here
println!("{}", diff2(92, 45));
empty();
}