binutils-gdb/gdb/testsuite/gdb.rust/simple.rs
Tom Tromey 098b2108a2 Fix crash with empty Rust enum
While testing my Rust compiler patch to fix the DWARF representation
of Rust enums (https://github.com/rust-lang/rust/pull/54004), I found
a gdb crash coming from one of the Rust test cases.

The bug here is that the new variant support in gdb does not handle
the case where there are no variants in the enum.

This patch fixes the problem in a straightforward way.  Note that the
new tests are somewhat lax because I did not want to try to fully fix
this corner case for older compilers.  If you think that's
unacceptable, let meknow.

Tested on x86-64 Fedora 28 using several versions of the Rust
compiler.  I intend to push this to the 8.2 branch as well.

gdb/ChangeLog
2018-09-13  Tom Tromey  <tom@tromey.com>

	PR rust/23626:
	* rust-lang.c (rust_enum_variant): Now static.
	(rust_empty_enum_p): New function.
	(rust_print_enum, rust_evaluate_subexp, rust_print_struct_def):
	Handle empty enum.

gdb/testsuite/ChangeLog
2018-09-13  Tom Tromey  <tom@tromey.com>

	PR rust/23626:
	* gdb.rust/simple.rs (EmptyEnum): New type.
	(main): Use it.
	* gdb.rust/simple.exp (test_one_slice): Add empty enum test.
2018-09-13 10:57:39 -06:00

178 lines
3.9 KiB
Rust

// Copyright (C) 2016-2018 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,
}
// 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];
// 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 = unsafe { ::std::mem::zeroed() };
println!("{}, {}", x.0, x.1); // set breakpoint here
println!("{}", diff2(92, 45));
empty();
}