invalid_value: also detect transmute-from-0 (seen in the wild)

This commit is contained in:
Ralf Jung 2019-08-17 11:48:30 +02:00
parent 9ab1d5c73a
commit a9efa738ab
3 changed files with 110 additions and 45 deletions

View File

@ -1879,12 +1879,38 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for InvalidValue {
#[derive(Debug, Copy, Clone, PartialEq)]
enum InitKind { Zeroed, Uninit };
/// Information about why a type cannot be initialized this way.
/// Contains an error message and optionally a span to point at.
type InitError = (String, Option<Span>);
/// Test if this constant is all-0.
fn is_zero(expr: &hir::Expr) -> bool {
use hir::ExprKind::*;
use syntax::ast::LitKind::*;
match &expr.node {
Lit(lit) =>
if let Int(i, _) = lit.node {
i == 0
} else {
false
},
Tup(tup) =>
tup.iter().all(is_zero),
_ =>
false
}
}
/// Determine if this expression is a "dangerous initialization".
fn is_dangerous_init(cx: &LateContext<'_, '_>, expr: &hir::Expr) -> Option<InitKind> {
const ZEROED_PATH: &[Symbol] = &[sym::core, sym::mem, sym::zeroed];
const UININIT_PATH: &[Symbol] = &[sym::core, sym::mem, sym::uninitialized];
// `transmute` is inside an anonymous module (the `extern` block?);
// `Invalid` represents the empty string and matches that.
const TRANSMUTE_PATH: &[Symbol] =
&[sym::core, sym::intrinsics, kw::Invalid, sym::transmute];
if let hir::ExprKind::Call(ref path_expr, ref _args) = expr.node {
if let hir::ExprKind::Call(ref path_expr, ref args) = expr.node {
if let hir::ExprKind::Path(ref qpath) = path_expr.node {
if let Some(def_id) = cx.tables.qpath_res(qpath, path_expr.hir_id)
.opt_def_id()
@ -1895,9 +1921,13 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for InvalidValue {
if cx.match_def_path(def_id, &UININIT_PATH) {
return Some(InitKind::Uninit);
}
if cx.match_def_path(def_id, &TRANSMUTE_PATH) {
if is_zero(&args[0]) {
return Some(InitKind::Zeroed);
}
}
// FIXME: Also detect `MaybeUninit::zeroed().assume_init()` and
// `MaybeUninit::uninit().assume_init()`.
// FIXME: Also detect `transmute` from 0.
}
}
}
@ -1905,10 +1935,6 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for InvalidValue {
None
}
/// Information about why a type cannot be initialized this way.
/// Contains an error message and optionally a span to point at.
type InitError = (String, Option<Span>);
/// Return `Some` only if we are sure this type does *not*
/// allow zero initialization.
fn ty_find_init_error<'tcx>(

View File

@ -7,6 +7,7 @@
#![deny(invalid_value)]
use std::mem::{self, MaybeUninit};
use std::num::NonZeroU32;
enum Void {}
@ -75,6 +76,11 @@ fn main() {
let _val: NonBig = mem::zeroed();
let _val: NonBig = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized
// Transmute-from-0
let _val: &'static i32 = mem::transmute(0usize); //~ ERROR: does not permit zero-initialization
let _val: &'static [i32] = mem::transmute((0usize, 0usize)); //~ ERROR: does not permit zero-initialization
let _val: NonZeroU32 = mem::transmute(0); //~ ERROR: does not permit zero-initialization
// Some more types that should work just fine.
let _val: Option<&'static i32> = mem::zeroed();
let _val: Option<fn()> = mem::zeroed();

View File

@ -1,5 +1,5 @@
error: the type `&'static T` does not permit zero-initialization
--> $DIR/uninitialized-zeroed.rs:27:32
--> $DIR/uninitialized-zeroed.rs:28:32
|
LL | let _val: &'static T = mem::zeroed();
| ^^^^^^^^^^^^^
@ -15,7 +15,7 @@ LL | #![deny(invalid_value)]
= note: References must be non-null
error: the type `&'static T` does not permit being left uninitialized
--> $DIR/uninitialized-zeroed.rs:28:32
--> $DIR/uninitialized-zeroed.rs:29:32
|
LL | let _val: &'static T = mem::uninitialized();
| ^^^^^^^^^^^^^^^^^^^^
@ -26,7 +26,7 @@ LL | let _val: &'static T = mem::uninitialized();
= note: References must be non-null
error: the type `Wrap<&'static T>` does not permit zero-initialization
--> $DIR/uninitialized-zeroed.rs:30:38
--> $DIR/uninitialized-zeroed.rs:31:38
|
LL | let _val: Wrap<&'static T> = mem::zeroed();
| ^^^^^^^^^^^^^
@ -35,13 +35,13 @@ LL | let _val: Wrap<&'static T> = mem::zeroed();
| help: use `MaybeUninit<T>` instead
|
note: References must be non-null (in this struct field)
--> $DIR/uninitialized-zeroed.rs:16:18
--> $DIR/uninitialized-zeroed.rs:17:18
|
LL | struct Wrap<T> { wrapped: T }
| ^^^^^^^^^^
error: the type `Wrap<&'static T>` does not permit being left uninitialized
--> $DIR/uninitialized-zeroed.rs:31:38
--> $DIR/uninitialized-zeroed.rs:32:38
|
LL | let _val: Wrap<&'static T> = mem::uninitialized();
| ^^^^^^^^^^^^^^^^^^^^
@ -50,13 +50,13 @@ LL | let _val: Wrap<&'static T> = mem::uninitialized();
| help: use `MaybeUninit<T>` instead
|
note: References must be non-null (in this struct field)
--> $DIR/uninitialized-zeroed.rs:16:18
--> $DIR/uninitialized-zeroed.rs:17:18
|
LL | struct Wrap<T> { wrapped: T }
| ^^^^^^^^^^
error: the type `!` does not permit zero-initialization
--> $DIR/uninitialized-zeroed.rs:38:23
--> $DIR/uninitialized-zeroed.rs:39:23
|
LL | let _val: ! = mem::zeroed();
| ^^^^^^^^^^^^^
@ -67,7 +67,7 @@ LL | let _val: ! = mem::zeroed();
= note: The never type (`!`) has no valid value
error: the type `!` does not permit being left uninitialized
--> $DIR/uninitialized-zeroed.rs:39:23
--> $DIR/uninitialized-zeroed.rs:40:23
|
LL | let _val: ! = mem::uninitialized();
| ^^^^^^^^^^^^^^^^^^^^
@ -78,7 +78,7 @@ LL | let _val: ! = mem::uninitialized();
= note: The never type (`!`) has no valid value
error: the type `(i32, !)` does not permit zero-initialization
--> $DIR/uninitialized-zeroed.rs:41:30
--> $DIR/uninitialized-zeroed.rs:42:30
|
LL | let _val: (i32, !) = mem::zeroed();
| ^^^^^^^^^^^^^
@ -89,7 +89,7 @@ LL | let _val: (i32, !) = mem::zeroed();
= note: The never type (`!`) has no valid value
error: the type `(i32, !)` does not permit being left uninitialized
--> $DIR/uninitialized-zeroed.rs:42:30
--> $DIR/uninitialized-zeroed.rs:43:30
|
LL | let _val: (i32, !) = mem::uninitialized();
| ^^^^^^^^^^^^^^^^^^^^
@ -100,7 +100,7 @@ LL | let _val: (i32, !) = mem::uninitialized();
= note: The never type (`!`) has no valid value
error: the type `Void` does not permit zero-initialization
--> $DIR/uninitialized-zeroed.rs:44:26
--> $DIR/uninitialized-zeroed.rs:45:26
|
LL | let _val: Void = mem::zeroed();
| ^^^^^^^^^^^^^
@ -111,7 +111,7 @@ LL | let _val: Void = mem::zeroed();
= note: 0-variant enums have no valid value
error: the type `Void` does not permit being left uninitialized
--> $DIR/uninitialized-zeroed.rs:45:26
--> $DIR/uninitialized-zeroed.rs:46:26
|
LL | let _val: Void = mem::uninitialized();
| ^^^^^^^^^^^^^^^^^^^^
@ -122,7 +122,7 @@ LL | let _val: Void = mem::uninitialized();
= note: 0-variant enums have no valid value
error: the type `&'static i32` does not permit zero-initialization
--> $DIR/uninitialized-zeroed.rs:47:34
--> $DIR/uninitialized-zeroed.rs:48:34
|
LL | let _val: &'static i32 = mem::zeroed();
| ^^^^^^^^^^^^^
@ -133,7 +133,7 @@ LL | let _val: &'static i32 = mem::zeroed();
= note: References must be non-null
error: the type `&'static i32` does not permit being left uninitialized
--> $DIR/uninitialized-zeroed.rs:48:34
--> $DIR/uninitialized-zeroed.rs:49:34
|
LL | let _val: &'static i32 = mem::uninitialized();
| ^^^^^^^^^^^^^^^^^^^^
@ -144,7 +144,7 @@ LL | let _val: &'static i32 = mem::uninitialized();
= note: References must be non-null
error: the type `Ref` does not permit zero-initialization
--> $DIR/uninitialized-zeroed.rs:50:25
--> $DIR/uninitialized-zeroed.rs:51:25
|
LL | let _val: Ref = mem::zeroed();
| ^^^^^^^^^^^^^
@ -153,13 +153,13 @@ LL | let _val: Ref = mem::zeroed();
| help: use `MaybeUninit<T>` instead
|
note: References must be non-null (in this struct field)
--> $DIR/uninitialized-zeroed.rs:13:12
--> $DIR/uninitialized-zeroed.rs:14:12
|
LL | struct Ref(&'static i32);
| ^^^^^^^^^^^^
error: the type `Ref` does not permit being left uninitialized
--> $DIR/uninitialized-zeroed.rs:51:25
--> $DIR/uninitialized-zeroed.rs:52:25
|
LL | let _val: Ref = mem::uninitialized();
| ^^^^^^^^^^^^^^^^^^^^
@ -168,13 +168,13 @@ LL | let _val: Ref = mem::uninitialized();
| help: use `MaybeUninit<T>` instead
|
note: References must be non-null (in this struct field)
--> $DIR/uninitialized-zeroed.rs:13:12
--> $DIR/uninitialized-zeroed.rs:14:12
|
LL | struct Ref(&'static i32);
| ^^^^^^^^^^^^
error: the type `fn()` does not permit zero-initialization
--> $DIR/uninitialized-zeroed.rs:53:26
--> $DIR/uninitialized-zeroed.rs:54:26
|
LL | let _val: fn() = mem::zeroed();
| ^^^^^^^^^^^^^
@ -185,7 +185,7 @@ LL | let _val: fn() = mem::zeroed();
= note: Function pointers must be non-null
error: the type `fn()` does not permit being left uninitialized
--> $DIR/uninitialized-zeroed.rs:54:26
--> $DIR/uninitialized-zeroed.rs:55:26
|
LL | let _val: fn() = mem::uninitialized();
| ^^^^^^^^^^^^^^^^^^^^
@ -196,7 +196,7 @@ LL | let _val: fn() = mem::uninitialized();
= note: Function pointers must be non-null
error: the type `Wrap<fn()>` does not permit zero-initialization
--> $DIR/uninitialized-zeroed.rs:56:32
--> $DIR/uninitialized-zeroed.rs:57:32
|
LL | let _val: Wrap<fn()> = mem::zeroed();
| ^^^^^^^^^^^^^
@ -205,13 +205,13 @@ LL | let _val: Wrap<fn()> = mem::zeroed();
| help: use `MaybeUninit<T>` instead
|
note: Function pointers must be non-null (in this struct field)
--> $DIR/uninitialized-zeroed.rs:16:18
--> $DIR/uninitialized-zeroed.rs:17:18
|
LL | struct Wrap<T> { wrapped: T }
| ^^^^^^^^^^
error: the type `Wrap<fn()>` does not permit being left uninitialized
--> $DIR/uninitialized-zeroed.rs:57:32
--> $DIR/uninitialized-zeroed.rs:58:32
|
LL | let _val: Wrap<fn()> = mem::uninitialized();
| ^^^^^^^^^^^^^^^^^^^^
@ -220,13 +220,13 @@ LL | let _val: Wrap<fn()> = mem::uninitialized();
| help: use `MaybeUninit<T>` instead
|
note: Function pointers must be non-null (in this struct field)
--> $DIR/uninitialized-zeroed.rs:16:18
--> $DIR/uninitialized-zeroed.rs:17:18
|
LL | struct Wrap<T> { wrapped: T }
| ^^^^^^^^^^
error: the type `WrapEnum<fn()>` does not permit zero-initialization
--> $DIR/uninitialized-zeroed.rs:59:36
--> $DIR/uninitialized-zeroed.rs:60:36
|
LL | let _val: WrapEnum<fn()> = mem::zeroed();
| ^^^^^^^^^^^^^
@ -235,13 +235,13 @@ LL | let _val: WrapEnum<fn()> = mem::zeroed();
| help: use `MaybeUninit<T>` instead
|
note: Function pointers must be non-null (in this enum field)
--> $DIR/uninitialized-zeroed.rs:17:28
--> $DIR/uninitialized-zeroed.rs:18:28
|
LL | enum WrapEnum<T> { Wrapped(T) }
| ^
error: the type `WrapEnum<fn()>` does not permit being left uninitialized
--> $DIR/uninitialized-zeroed.rs:60:36
--> $DIR/uninitialized-zeroed.rs:61:36
|
LL | let _val: WrapEnum<fn()> = mem::uninitialized();
| ^^^^^^^^^^^^^^^^^^^^
@ -250,13 +250,13 @@ LL | let _val: WrapEnum<fn()> = mem::uninitialized();
| help: use `MaybeUninit<T>` instead
|
note: Function pointers must be non-null (in this enum field)
--> $DIR/uninitialized-zeroed.rs:17:28
--> $DIR/uninitialized-zeroed.rs:18:28
|
LL | enum WrapEnum<T> { Wrapped(T) }
| ^
error: the type `Wrap<(RefPair, i32)>` does not permit zero-initialization
--> $DIR/uninitialized-zeroed.rs:62:42
--> $DIR/uninitialized-zeroed.rs:63:42
|
LL | let _val: Wrap<(RefPair, i32)> = mem::zeroed();
| ^^^^^^^^^^^^^
@ -265,13 +265,13 @@ LL | let _val: Wrap<(RefPair, i32)> = mem::zeroed();
| help: use `MaybeUninit<T>` instead
|
note: References must be non-null (in this struct field)
--> $DIR/uninitialized-zeroed.rs:14:16
--> $DIR/uninitialized-zeroed.rs:15:16
|
LL | struct RefPair((&'static i32, i32));
| ^^^^^^^^^^^^^^^^^^^
error: the type `Wrap<(RefPair, i32)>` does not permit being left uninitialized
--> $DIR/uninitialized-zeroed.rs:63:42
--> $DIR/uninitialized-zeroed.rs:64:42
|
LL | let _val: Wrap<(RefPair, i32)> = mem::uninitialized();
| ^^^^^^^^^^^^^^^^^^^^
@ -280,13 +280,13 @@ LL | let _val: Wrap<(RefPair, i32)> = mem::uninitialized();
| help: use `MaybeUninit<T>` instead
|
note: References must be non-null (in this struct field)
--> $DIR/uninitialized-zeroed.rs:14:16
--> $DIR/uninitialized-zeroed.rs:15:16
|
LL | struct RefPair((&'static i32, i32));
| ^^^^^^^^^^^^^^^^^^^
error: the type `std::vec::Vec<i32>` does not permit zero-initialization
--> $DIR/uninitialized-zeroed.rs:65:30
--> $DIR/uninitialized-zeroed.rs:66:30
|
LL | let _val: Vec<i32> = mem::zeroed();
| ^^^^^^^^^^^^^
@ -301,7 +301,7 @@ LL | ptr: Unique<T>,
| ^^^^^^^^^^^^^^
error: the type `std::vec::Vec<i32>` does not permit being left uninitialized
--> $DIR/uninitialized-zeroed.rs:66:30
--> $DIR/uninitialized-zeroed.rs:67:30
|
LL | let _val: Vec<i32> = mem::uninitialized();
| ^^^^^^^^^^^^^^^^^^^^
@ -316,7 +316,7 @@ LL | ptr: Unique<T>,
| ^^^^^^^^^^^^^^
error: the type `bool` does not permit being left uninitialized
--> $DIR/uninitialized-zeroed.rs:70:26
--> $DIR/uninitialized-zeroed.rs:71:26
|
LL | let _val: bool = mem::uninitialized();
| ^^^^^^^^^^^^^^^^^^^^
@ -327,7 +327,7 @@ LL | let _val: bool = mem::uninitialized();
= note: Booleans must be `true` or `false`
error: the type `Wrap<char>` does not permit being left uninitialized
--> $DIR/uninitialized-zeroed.rs:73:32
--> $DIR/uninitialized-zeroed.rs:74:32
|
LL | let _val: Wrap<char> = mem::uninitialized();
| ^^^^^^^^^^^^^^^^^^^^
@ -336,13 +336,13 @@ LL | let _val: Wrap<char> = mem::uninitialized();
| help: use `MaybeUninit<T>` instead
|
note: Characters must be a valid unicode codepoint (in this struct field)
--> $DIR/uninitialized-zeroed.rs:16:18
--> $DIR/uninitialized-zeroed.rs:17:18
|
LL | struct Wrap<T> { wrapped: T }
| ^^^^^^^^^^
error: the type `NonBig` does not permit being left uninitialized
--> $DIR/uninitialized-zeroed.rs:76:28
--> $DIR/uninitialized-zeroed.rs:77:28
|
LL | let _val: NonBig = mem::uninitialized();
| ^^^^^^^^^^^^^^^^^^^^
@ -352,5 +352,38 @@ LL | let _val: NonBig = mem::uninitialized();
|
= note: NonBig must be initialized inside its custom valid range
error: aborting due to 27 previous errors
error: the type `&'static i32` does not permit zero-initialization
--> $DIR/uninitialized-zeroed.rs:80:34
|
LL | let _val: &'static i32 = mem::transmute(0usize);
| ^^^^^^^^^^^^^^^^^^^^^^
| |
| this code causes undefined behavior when executed
| help: use `MaybeUninit<T>` instead
|
= note: References must be non-null
error: the type `&'static [i32]` does not permit zero-initialization
--> $DIR/uninitialized-zeroed.rs:81:36
|
LL | let _val: &'static [i32] = mem::transmute((0usize, 0usize));
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
| |
| this code causes undefined behavior when executed
| help: use `MaybeUninit<T>` instead
|
= note: References must be non-null
error: the type `std::num::NonZeroU32` does not permit zero-initialization
--> $DIR/uninitialized-zeroed.rs:82:32
|
LL | let _val: NonZeroU32 = mem::transmute(0);
| ^^^^^^^^^^^^^^^^^
| |
| this code causes undefined behavior when executed
| help: use `MaybeUninit<T>` instead
|
= note: std::num::NonZeroU32 must be non-null
error: aborting due to 30 previous errors