Split lint into slow and unsafe vector initalization

This commit is contained in:
Guillem Nieto 2018-10-30 00:25:05 +01:00 committed by Guillem Nieto
parent 9b4bc3b6ef
commit 2753f1cbd4
2 changed files with 96 additions and 94 deletions

View File

@ -37,7 +37,25 @@ use crate::rustc_errors::{Applicability};
declare_clippy_lint! {
pub SLOW_VECTOR_INITIALIZATION,
perf,
"slow or unsafe vector initialization"
"slow vector initialization"
}
/// **What it does:** Checks unsafe vector initialization
///
/// **Why is this bad?** Changing the length of a vector may expose uninitialized memory, which
/// can lead to memory safety issues
///
/// **Known problems:** None.
///
/// **Example:**
/// ```rust
/// let mut vec1 = Vec::with_capacity(len);
/// unsafe { vec1.set_len(len); }
/// ```
declare_clippy_lint! {
pub UNSAFE_VECTOR_INITIALIZATION,
correctness,
"unsafe vector initialization"
}
#[derive(Copy, Clone, Default)]
@ -45,7 +63,10 @@ pub struct Pass;
impl LintPass for Pass {
fn get_lints(&self) -> LintArray {
lint_array!(SLOW_VECTOR_INITIALIZATION)
lint_array!(
SLOW_VECTOR_INITIALIZATION,
UNSAFE_VECTOR_INITIALIZATION,
)
}
}
@ -96,7 +117,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Pass {
len_expr: len_arg,
};
Pass::search_slow_initialization(cx, vi, expr.id, expr.span);
Pass::search_slow_initialization(cx, vi, expr.id);
}
}
}
@ -117,7 +138,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Pass {
len_expr: len_arg,
};
Pass::search_slow_initialization(cx, vi, stmt.node.id(), stmt.span);
Pass::search_slow_initialization(cx, vi, stmt.node.id());
}
}
}
@ -145,8 +166,7 @@ impl Pass {
fn search_slow_initialization<'tcx>(
cx: &LateContext<'_, 'tcx>,
vec_initialization: VecInitialization<'tcx>,
parent_node: NodeId,
parent_span: Span
parent_node: NodeId
) {
let enclosing_body = get_enclosing_block(cx, parent_node);
@ -163,30 +183,54 @@ impl Pass {
v.visit_block(enclosing_body.unwrap());
if let Some(ref repeat_expr) = v.slow_expression {
span_lint_and_then(
cx,
SLOW_VECTOR_INITIALIZATION,
parent_span,
"detected slow zero-filling initialization",
|db| {
db.span_suggestion_with_applicability(v.vec_ini.initialization_expr.span, "consider replacing with", "vec![0; ..]".to_string(), Applicability::Unspecified);
match repeat_expr {
InitializationType::Extend(e) => {
db.span_note(e.span, "extended at");
},
InitializationType::Resize(e) => {
db.span_note(e.span, "resized at");
},
InitializationType::UnsafeSetLen(e) => {
db.span_note(e.span, "changed len at");
},
}
}
);
if let Some(ref initialization_expr) = v.slow_expression {
let alloc_span = v.vec_ini.initialization_expr.span;
Pass::lint_initialization(cx, initialization_expr, alloc_span);
}
}
fn lint_initialization<'tcx>(cx: &LateContext<'_, 'tcx>, initialization: &InitializationType<'tcx>, alloc_span: Span) {
match initialization {
InitializationType::UnsafeSetLen(e) =>
Pass::lint_unsafe_initialization(cx, e, alloc_span),
InitializationType::Extend(e) |
InitializationType::Resize(e) =>
Pass::lint_slow_initialization(cx, e, alloc_span),
};
}
fn lint_slow_initialization<'tcx>(
cx: &LateContext<'_, 'tcx>,
slow_fill: &Expr,
alloc_span: Span,
) {
span_lint_and_then(
cx,
SLOW_VECTOR_INITIALIZATION,
slow_fill.span,
"detected slow zero-filling initialization",
|db| {
db.span_suggestion_with_applicability(alloc_span, "consider replacing with", "vec![0; ..]".to_string(), Applicability::Unspecified);
}
);
}
fn lint_unsafe_initialization<'tcx>(
cx: &LateContext<'_, 'tcx>,
slow_fill: &Expr,
alloc_span: Span,
) {
span_lint_and_then(
cx,
UNSAFE_VECTOR_INITIALIZATION,
slow_fill.span,
"detected unsafe vector initialization",
|db| {
db.span_suggestion_with_applicability(alloc_span, "consider replacing with", "vec![0; ..]".to_string(), Applicability::Unspecified);
}
);
}
}
/// SlowInitializationVisitor searches for slow zero filling vector initialization, for the given

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@ -1,115 +1,73 @@
error: detected slow zero-filling initialization
--> $DIR/slow_vector_initialization.rs:22:5
|
22 | let mut vec1 = Vec::with_capacity(len);
| ^^^^^^^^^^^^^^^-----------------------^
| |
| help: consider replacing with: `vec![0; ..]`
|
= note: `-D clippy::slow-vector-initialization` implied by `-D warnings`
note: extended at
--> $DIR/slow_vector_initialization.rs:23:5
|
22 | let mut vec1 = Vec::with_capacity(len);
| ----------------------- help: consider replacing with: `vec![0; ..]`
23 | vec1.extend(repeat(0).take(len));
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: `-D clippy::slow-vector-initialization` implied by `-D warnings`
error: detected slow zero-filling initialization
--> $DIR/slow_vector_initialization.rs:26:5
|
26 | let mut vec2 = Vec::with_capacity(len - 10);
| ^^^^^^^^^^^^^^^----------------------------^
| |
| help: consider replacing with: `vec![0; ..]`
|
note: extended at
--> $DIR/slow_vector_initialization.rs:27:5
|
26 | let mut vec2 = Vec::with_capacity(len - 10);
| ---------------------------- help: consider replacing with: `vec![0; ..]`
27 | vec2.extend(repeat(0).take(len - 10));
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
error: detected slow zero-filling initialization
--> $DIR/slow_vector_initialization.rs:39:5
|
39 | let mut resized_vec = Vec::with_capacity(30);
| ^^^^^^^^^^^^^^^^^^^^^^----------------------^
| |
| help: consider replacing with: `vec![0; ..]`
|
note: resized at
--> $DIR/slow_vector_initialization.rs:42:5
|
39 | let mut resized_vec = Vec::with_capacity(30);
| ---------------------- help: consider replacing with: `vec![0; ..]`
...
42 | resized_vec.resize(30, 0);
| ^^^^^^^^^^^^^^^^^^^^^^^^^
error: detected slow zero-filling initialization
--> $DIR/slow_vector_initialization.rs:40:5
|
40 | let mut extend_vec = Vec::with_capacity(30);
| ^^^^^^^^^^^^^^^^^^^^^----------------------^
| |
| help: consider replacing with: `vec![0; ..]`
|
note: extended at
--> $DIR/slow_vector_initialization.rs:44:5
|
40 | let mut extend_vec = Vec::with_capacity(30);
| ---------------------- help: consider replacing with: `vec![0; ..]`
...
44 | extend_vec.extend(repeat(0).take(30));
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
error: detected slow zero-filling initialization
--> $DIR/slow_vector_initialization.rs:50:5
|
50 | let mut vec1 = Vec::with_capacity(len);
| ^^^^^^^^^^^^^^^-----------------------^
| |
| help: consider replacing with: `vec![0; ..]`
|
note: resized at
--> $DIR/slow_vector_initialization.rs:51:5
|
50 | let mut vec1 = Vec::with_capacity(len);
| ----------------------- help: consider replacing with: `vec![0; ..]`
51 | vec1.resize(len, 0);
| ^^^^^^^^^^^^^^^^^^^
error: detected slow zero-filling initialization
--> $DIR/slow_vector_initialization.rs:58:5
|
58 | let mut vec3 = Vec::with_capacity(len - 10);
| ^^^^^^^^^^^^^^^----------------------------^
| |
| help: consider replacing with: `vec![0; ..]`
|
note: resized at
--> $DIR/slow_vector_initialization.rs:59:5
|
58 | let mut vec3 = Vec::with_capacity(len - 10);
| ---------------------------- help: consider replacing with: `vec![0; ..]`
59 | vec3.resize(len - 10, 0);
| ^^^^^^^^^^^^^^^^^^^^^^^^
error: detected slow zero-filling initialization
--> $DIR/slow_vector_initialization.rs:62:5
|
62 | vec1 = Vec::with_capacity(10);
| ^^^^^^^----------------------
| |
| help: consider replacing with: `vec![0; ..]`
|
note: resized at
--> $DIR/slow_vector_initialization.rs:63:5
|
62 | vec1 = Vec::with_capacity(10);
| ---------------------- help: consider replacing with: `vec![0; ..]`
63 | vec1.resize(10, 0);
| ^^^^^^^^^^^^^^^^^^
error: detected slow zero-filling initialization
--> $DIR/slow_vector_initialization.rs:67:5
|
67 | let mut unsafe_vec: Vec<u8> = Vec::with_capacity(200);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^-----------------------^
| |
| help: consider replacing with: `vec![0; ..]`
|
note: changed len at
error: detected unsafe vector initialization
--> $DIR/slow_vector_initialization.rs:70:9
|
67 | let mut unsafe_vec: Vec<u8> = Vec::with_capacity(200);
| ----------------------- help: consider replacing with: `vec![0; ..]`
...
70 | unsafe_vec.set_len(200);
| ^^^^^^^^^^^^^^^^^^^^^^^
|
= note: #[deny(clippy::unsafe_vector_initialization)] on by default
error: aborting due to 8 previous errors