diff options
| -rw-r--r-- | clippy_lints/src/macro_metavars_in_unsafe.rs | 21 | ||||
| -rw-r--r-- | tests/ui-toml/macro_metavars_in_unsafe/default/test.rs | 15 | ||||
| -rw-r--r-- | tests/ui-toml/macro_metavars_in_unsafe/default/test.stderr | 16 |
3 files changed, 46 insertions, 6 deletions
diff --git a/clippy_lints/src/macro_metavars_in_unsafe.rs b/clippy_lints/src/macro_metavars_in_unsafe.rs index fed58f7ff14..e215097142b 100644 --- a/clippy_lints/src/macro_metavars_in_unsafe.rs +++ b/clippy_lints/src/macro_metavars_in_unsafe.rs @@ -122,8 +122,23 @@ struct BodyVisitor<'a, 'tcx> { /// within a relevant macro. macro_unsafe_blocks: Vec<HirId>, /// When this is >0, it means that the node currently being visited is "within" a - /// macro definition. This is not necessary for correctness, it merely helps reduce the number - /// of spans we need to insert into the map, since only spans from macros are relevant. + /// macro definition. + /// This is used to detect if an expression represents a metavariable. + /// + /// For example, the following pre-expansion code that we want to lint + /// ```ignore + /// macro_rules! m { ($e:expr) => { unsafe { $e; } } } + /// m!(1); + /// ``` + /// would look like this post-expansion code: + /// ```ignore + /// unsafe { /* macro */ + /// 1 /* root */; /* macro */ + /// } + /// ``` + /// Visiting the block and the statement will increment the `expn_depth` so that it is >0, + /// and visiting the expression with a root context while `expn_depth > 0` tells us + /// that it must be a metavariable. expn_depth: u32, cx: &'a LateContext<'tcx>, lint: &'a mut ExprMetavarsInUnsafe, @@ -157,7 +172,9 @@ impl<'a, 'tcx> Visitor<'tcx> for BodyVisitor<'a, 'tcx> { && (self.lint.warn_unsafe_macro_metavars_in_private_macros || is_public_macro(self.cx, macro_def_id)) { self.macro_unsafe_blocks.push(block.hir_id); + self.expn_depth += 1; walk_block(self, block); + self.expn_depth -= 1; self.macro_unsafe_blocks.pop(); } else if ctxt.is_root() && self.expn_depth > 0 { let unsafe_block = self.macro_unsafe_blocks.last().copied(); diff --git a/tests/ui-toml/macro_metavars_in_unsafe/default/test.rs b/tests/ui-toml/macro_metavars_in_unsafe/default/test.rs index a312df5a43a..3dafea56514 100644 --- a/tests/ui-toml/macro_metavars_in_unsafe/default/test.rs +++ b/tests/ui-toml/macro_metavars_in_unsafe/default/test.rs @@ -1,7 +1,7 @@ //! Tests macro_metavars_in_unsafe with default configuration #![feature(decl_macro)] #![warn(clippy::macro_metavars_in_unsafe)] -#![allow(clippy::no_effect)] +#![allow(clippy::no_effect, clippy::not_unsafe_ptr_arg_deref)] #[macro_export] macro_rules! allow_works { @@ -237,6 +237,19 @@ macro_rules! nested_macros { }}; } +pub mod issue13219 { + #[macro_export] + macro_rules! m { + ($e:expr) => { + // Metavariable in a block tail expression + unsafe { $e } + }; + } + pub fn f(p: *const i32) -> i32 { + m!(*p) + } +} + fn main() { allow_works!(1); simple!(1); diff --git a/tests/ui-toml/macro_metavars_in_unsafe/default/test.stderr b/tests/ui-toml/macro_metavars_in_unsafe/default/test.stderr index d6b97f6fde1..6f0ebcbba02 100644 --- a/tests/ui-toml/macro_metavars_in_unsafe/default/test.stderr +++ b/tests/ui-toml/macro_metavars_in_unsafe/default/test.stderr @@ -1,4 +1,16 @@ error: this macro expands metavariables in an unsafe block + --> tests/ui-toml/macro_metavars_in_unsafe/default/test.rs:245:13 + | +LL | unsafe { $e } + | ^^^^^^^^^^^^^ + | + = note: this allows the user of the macro to write unsafe code outside of an unsafe block + = help: consider expanding any metavariables outside of this block, e.g. by storing them in a variable + = help: ... or also expand referenced metavariables in a safe context to require an unsafe block at callsite + = note: `-D clippy::macro-metavars-in-unsafe` implied by `-D warnings` + = help: to override `-D warnings` add `#[allow(clippy::macro_metavars_in_unsafe)]` + +error: this macro expands metavariables in an unsafe block --> tests/ui-toml/macro_metavars_in_unsafe/default/test.rs:19:9 | LL | / unsafe { @@ -10,8 +22,6 @@ LL | | } = note: this allows the user of the macro to write unsafe code outside of an unsafe block = help: consider expanding any metavariables outside of this block, e.g. by storing them in a variable = help: ... or also expand referenced metavariables in a safe context to require an unsafe block at callsite - = note: `-D clippy::macro-metavars-in-unsafe` implied by `-D warnings` - = help: to override `-D warnings` add `#[allow(clippy::macro_metavars_in_unsafe)]` error: this macro expands metavariables in an unsafe block --> tests/ui-toml/macro_metavars_in_unsafe/default/test.rs:30:9 @@ -183,5 +193,5 @@ LL | | } = help: consider expanding any metavariables outside of this block, e.g. by storing them in a variable = help: ... or also expand referenced metavariables in a safe context to require an unsafe block at callsite -error: aborting due to 14 previous errors +error: aborting due to 15 previous errors |