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Auto merge of #6278 - ThibsG:DerefAddrOf, r=llogiq

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Fix bad suggestions for `deref_addrof` and `try_err` lints

Fix bad suggestions when in macro expansion for `deref_addrof` and `try_err` lints.

Fixes: #6234
Fixes: #6242
Fixes: #6237

changelog: none

r? `@llogiq`
This commit is contained in:
bors 2020-11-09 05:25:04 +00:00
commit d212c382c3
8 changed files with 207 additions and 15 deletions
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37
clippy_lints/src/reference.rs
View file

@ -1,9 +1,10 @@
use crate::utils::{in_macro, snippet_with_applicability, span_lint_and_sugg};
use crate::utils::{in_macro, snippet_opt, snippet_with_applicability, span_lint_and_sugg};
use if_chain::if_chain;
use rustc_ast::ast::{Expr, ExprKind, UnOp};
use rustc_ast::ast::{Expr, ExprKind, Mutability, UnOp};
use rustc_errors::Applicability;
use rustc_lint::{EarlyContext, EarlyLintPass};
use rustc_session::{declare_lint_pass, declare_tool_lint};
use rustc_span::BytePos;
declare_clippy_lint! {
/// **What it does:** Checks for usage of `*&` and `*&mut` in expressions.
@ -42,17 +43,45 @@ impl EarlyLintPass for DerefAddrOf {
fn check_expr(&mut self, cx: &EarlyContext<'_>, e: &Expr) {
if_chain! {
if let ExprKind::Unary(UnOp::Deref, ref deref_target) = e.kind;
if let ExprKind::AddrOf(_, _, ref addrof_target) = without_parens(deref_target).kind;
if let ExprKind::AddrOf(_, ref mutability, ref addrof_target) = without_parens(deref_target).kind;
if !in_macro(addrof_target.span);
then {
let mut applicability = Applicability::MachineApplicable;
let sugg = if e.span.from_expansion() {
if let Ok(macro_source) = cx.sess.source_map().span_to_snippet(e.span) {
// Remove leading whitespace from the given span
// e.g: ` $visitor` turns into `$visitor`
let trim_leading_whitespaces = |span| {
snippet_opt(cx, span).and_then(|snip| {
#[allow(clippy::cast_possible_truncation)]
snip.find(|c: char| !c.is_whitespace()).map(|pos| {
span.lo() + BytePos(pos as u32)
})
}).map_or(span, |start_no_whitespace| e.span.with_lo(start_no_whitespace))
};
let rpos = if *mutability == Mutability::Mut {
macro_source.rfind("mut").expect("already checked this is a mutable reference") + "mut".len()
} else {
macro_source.rfind('&').expect("already checked this is a reference") + "&".len()
};
#[allow(clippy::cast_possible_truncation)]
let span_after_ref = e.span.with_lo(BytePos(e.span.lo().0 + rpos as u32));
let span = trim_leading_whitespaces(span_after_ref);
snippet_with_applicability(cx, span, "_", &mut applicability)
} else {
snippet_with_applicability(cx, e.span, "_", &mut applicability)
}
} else {
snippet_with_applicability(cx, addrof_target.span, "_", &mut applicability)
}.to_string();
span_lint_and_sugg(
cx,
DEREF_ADDROF,
e.span,
"immediately dereferencing a reference",
"try this",
format!("{}", snippet_with_applicability(cx, addrof_target.span, "_", &mut applicability)),
sugg,
applicability,
);
}

9
clippy_lints/src/try_err.rs
View file

@ -1,6 +1,6 @@
use crate::utils::{
is_type_diagnostic_item, match_def_path, match_qpath, paths, snippet, snippet_with_macro_callsite,
span_lint_and_sugg,
differing_macro_contexts, in_macro, is_type_diagnostic_item, match_def_path, match_qpath, paths, snippet,
snippet_with_macro_callsite, span_lint_and_sugg,
};
use if_chain::if_chain;
use rustc_errors::Applicability;
@ -92,8 +92,11 @@ impl<'tcx> LateLintPass<'tcx> for TryErr {
};
let expr_err_ty = cx.typeck_results().expr_ty(err_arg);
let differing_contexts = differing_macro_contexts(expr.span, err_arg.span);
let origin_snippet = if err_arg.span.from_expansion() {
let origin_snippet = if in_macro(expr.span) && in_macro(err_arg.span) && differing_contexts {
snippet(cx, err_arg.span.ctxt().outer_expn_data().call_site, "_")
} else if err_arg.span.from_expansion() && !in_macro(expr.span) {
snippet_with_macro_callsite(cx, err_arg.span, "_")
} else {
snippet(cx, err_arg.span, "_")

26
tests/ui/deref_addrof.fixed
View file

@ -1,4 +1,5 @@
// run-rustfix
#![warn(clippy::deref_addrof)]
fn get_number() -> usize {
10
@ -10,7 +11,6 @@ fn get_reference(n: &usize) -> &usize {
#[allow(clippy::many_single_char_names, clippy::double_parens)]
#[allow(unused_variables, unused_parens)]
#[warn(clippy::deref_addrof)]
fn main() {
let a = 10;
let aref = &a;
@ -37,3 +37,27 @@ fn main() {
let b = *aref;
}
#[rustfmt::skip]
macro_rules! m {
($visitor: expr) => {
$visitor
};
}
#[rustfmt::skip]
macro_rules! m_mut {
($visitor: expr) => {
$visitor
};
}
pub struct S;
impl S {
pub fn f(&self) -> &Self {
m!(self)
}
pub fn f_mut(&self) -> &Self {
m_mut!(self)
}
}

26
tests/ui/deref_addrof.rs
View file

@ -1,4 +1,5 @@
// run-rustfix
#![warn(clippy::deref_addrof)]
fn get_number() -> usize {
10
@ -10,7 +11,6 @@ fn get_reference(n: &usize) -> &usize {
#[allow(clippy::many_single_char_names, clippy::double_parens)]
#[allow(unused_variables, unused_parens)]
#[warn(clippy::deref_addrof)]
fn main() {
let a = 10;
let aref = &a;
@ -37,3 +37,27 @@ fn main() {
let b = **&aref;
}
#[rustfmt::skip]
macro_rules! m {
($visitor: expr) => {
*& $visitor
};
}
#[rustfmt::skip]
macro_rules! m_mut {
($visitor: expr) => {
*& mut $visitor
};
}
pub struct S;
impl S {
pub fn f(&self) -> &Self {
m!(self)
}
pub fn f_mut(&self) -> &Self {
m_mut!(self)
}
}

24
tests/ui/deref_addrof.stderr
View file

@ -48,5 +48,27 @@ error: immediately dereferencing a reference
LL | let b = **&aref;
| ^^^^^^ help: try this: `aref`
error: aborting due to 8 previous errors
error: immediately dereferencing a reference
--> $DIR/deref_addrof.rs:44:9
|
LL | *& $visitor
| ^^^^^^^^^^^ help: try this: `$visitor`
...
LL | m!(self)
| -------- in this macro invocation
|
= note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
error: immediately dereferencing a reference
--> $DIR/deref_addrof.rs:51:9
|
LL | *& mut $visitor
| ^^^^^^^^^^^^^^^ help: try this: `$visitor`
...
LL | m_mut!(self)
| ------------ in this macro invocation
|
= note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
error: aborting due to 10 previous errors

34
tests/ui/try_err.fixed
View file

@ -78,12 +78,46 @@ fn nested_error() -> Result<i32, i32> {
Ok(1)
}
// Bad suggestion when in macro (see #6242)
macro_rules! try_validation {
($e: expr) => {{
match $e {
Ok(_) => 0,
Err(_) => return Err(1),
}
}};
}
macro_rules! ret_one {
() => {
1
};
}
macro_rules! try_validation_in_macro {
($e: expr) => {{
match $e {
Ok(_) => 0,
Err(_) => return Err(ret_one!()),
}
}};
}
fn calling_macro() -> Result<i32, i32> {
// macro
try_validation!(Ok::<_, i32>(5));
// `Err` arg is another macro
try_validation_in_macro!(Ok::<_, i32>(5));
Ok(5)
}
fn main() {
basic_test().unwrap();
into_test().unwrap();
negative_test().unwrap();
closure_matches_test().unwrap();
closure_into_test().unwrap();
calling_macro().unwrap();
// We don't want to lint in external macros
try_err!();

34
tests/ui/try_err.rs
View file

@ -78,12 +78,46 @@ fn nested_error() -> Result<i32, i32> {
Ok(1)
}
// Bad suggestion when in macro (see #6242)
macro_rules! try_validation {
($e: expr) => {{
match $e {
Ok(_) => 0,
Err(_) => Err(1)?,
}
}};
}
macro_rules! ret_one {
() => {
1
};
}
macro_rules! try_validation_in_macro {
($e: expr) => {{
match $e {
Ok(_) => 0,
Err(_) => Err(ret_one!())?,
}
}};
}
fn calling_macro() -> Result<i32, i32> {
// macro
try_validation!(Ok::<_, i32>(5));
// `Err` arg is another macro
try_validation_in_macro!(Ok::<_, i32>(5));
Ok(5)
}
fn main() {
basic_test().unwrap();
into_test().unwrap();
negative_test().unwrap();
closure_matches_test().unwrap();
closure_into_test().unwrap();
calling_macro().unwrap();
// We don't want to lint in external macros
try_err!();

32
tests/ui/try_err.stderr
View file

@ -29,28 +29,50 @@ LL | Err(err)?;
| ^^^^^^^^^ help: try this: `return Err(err.into())`
error: returning an `Err(_)` with the `?` operator
--> $DIR/try_err.rs:106:9
--> $DIR/try_err.rs:86:23
|
LL | Err(_) => Err(1)?,
| ^^^^^^^ help: try this: `return Err(1)`
...
LL | try_validation!(Ok::<_, i32>(5));
| --------------------------------- in this macro invocation
|
= note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
error: returning an `Err(_)` with the `?` operator
--> $DIR/try_err.rs:101:23
|
LL | Err(_) => Err(ret_one!())?,
| ^^^^^^^^^^^^^^^^ help: try this: `return Err(ret_one!())`
...
LL | try_validation_in_macro!(Ok::<_, i32>(5));
| ------------------------------------------ in this macro invocation
|
= note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
error: returning an `Err(_)` with the `?` operator
--> $DIR/try_err.rs:140:9
|
LL | Err(foo!())?;
| ^^^^^^^^^^^^ help: try this: `return Err(foo!())`
error: returning an `Err(_)` with the `?` operator
--> $DIR/try_err.rs:113:9
--> $DIR/try_err.rs:147:9
|
LL | Err(io::ErrorKind::WriteZero)?
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `return Poll::Ready(Err(io::ErrorKind::WriteZero.into()))`
error: returning an `Err(_)` with the `?` operator
--> $DIR/try_err.rs:115:9
--> $DIR/try_err.rs:149:9
|
LL | Err(io::Error::new(io::ErrorKind::InvalidInput, "error"))?
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `return Poll::Ready(Err(io::Error::new(io::ErrorKind::InvalidInput, "error")))`
error: returning an `Err(_)` with the `?` operator
--> $DIR/try_err.rs:123:9
--> $DIR/try_err.rs:157:9
|
LL | Err(io::ErrorKind::NotFound)?
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `return Poll::Ready(Some(Err(io::ErrorKind::NotFound.into())))`
error: aborting due to 8 previous errors
error: aborting due to 10 previous errors