From 003a2119e7ffe70ee341ebc2bde3866783db8d9d Mon Sep 17 00:00:00 2001 From: Jason Newcomb Date: Mon, 27 Feb 2023 22:01:12 -0500 Subject: [PATCH] Improve diagnostic of `no_mangle_with_rust_abi` --- clippy_lints/src/no_mangle_with_rust_abi.rs | 28 ++++---- tests/ui/no_mangle_with_rust_abi.fixed | 48 ------------- tests/ui/no_mangle_with_rust_abi.rs | 2 - tests/ui/no_mangle_with_rust_abi.stderr | 74 +++++++++++++++------ 4 files changed, 71 insertions(+), 81 deletions(-) delete mode 100644 tests/ui/no_mangle_with_rust_abi.fixed diff --git a/clippy_lints/src/no_mangle_with_rust_abi.rs b/clippy_lints/src/no_mangle_with_rust_abi.rs index bc64ccb295cb..8fd9ae351a0d 100644 --- a/clippy_lints/src/no_mangle_with_rust_abi.rs +++ b/clippy_lints/src/no_mangle_with_rust_abi.rs @@ -1,9 +1,10 @@ -use clippy_utils::diagnostics::span_lint_and_sugg; +use clippy_utils::diagnostics::span_lint_and_then; use clippy_utils::source::snippet_with_applicability; use rustc_errors::Applicability; use rustc_hir::{Item, ItemKind}; use rustc_lint::{LateContext, LateLintPass}; use rustc_session::{declare_lint_pass, declare_tool_lint}; +use rustc_span::{BytePos, Pos}; use rustc_target::spec::abi::Abi; declare_clippy_lint! { @@ -38,25 +39,28 @@ impl<'tcx> LateLintPass<'tcx> for NoMangleWithRustAbi { fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx Item<'tcx>) { if let ItemKind::Fn(fn_sig, _, _) = &item.kind { let attrs = cx.tcx.hir().attrs(item.hir_id()); - let mut applicability = Applicability::MachineApplicable; - let snippet = snippet_with_applicability(cx, fn_sig.span, "..", &mut applicability); + let mut app = Applicability::MaybeIncorrect; + let snippet = snippet_with_applicability(cx, fn_sig.span, "..", &mut app); for attr in attrs { if let Some(ident) = attr.ident() && ident.name == rustc_span::sym::no_mangle && fn_sig.header.abi == Abi::Rust - && !snippet.contains("extern") { + && let Some((fn_attrs, _)) = snippet.split_once("fn") + && !fn_attrs.contains("extern") + { + let sugg_span = fn_sig.span + .with_lo(fn_sig.span.lo() + BytePos::from_usize(fn_attrs.len())) + .shrink_to_lo(); - let suggestion = snippet.split_once("fn") - .map_or(String::new(), |(first, second)| format!(r#"{first}extern "C" fn{second}"#)); - - span_lint_and_sugg( + span_lint_and_then( cx, NO_MANGLE_WITH_RUST_ABI, fn_sig.span, - "attribute #[no_mangle] set on a Rust ABI function", - "try", - suggestion, - applicability + "`#[no_mangle]` set on a function with the default (`Rust`) ABI", + |diag| { + diag.span_suggestion(sugg_span, "set an ABI", "extern \"C\" ", app) + .span_suggestion(sugg_span, "or explicitly set the default", "extern \"Rust\" ", app); + }, ); } } diff --git a/tests/ui/no_mangle_with_rust_abi.fixed b/tests/ui/no_mangle_with_rust_abi.fixed deleted file mode 100644 index d18dec22a8bb..000000000000 --- a/tests/ui/no_mangle_with_rust_abi.fixed +++ /dev/null @@ -1,48 +0,0 @@ -// run-rustfix - -#![allow(unused)] -#![warn(clippy::no_mangle_with_rust_abi)] - -#[no_mangle] -extern "C" fn rust_abi_fn_one(arg_one: u32, arg_two: usize) {} - -#[no_mangle] -pub extern "C" fn rust_abi_fn_two(arg_one: u32, arg_two: usize) {} - -/// # Safety -/// This function shouldn't be called unless the horsemen are ready -#[no_mangle] -pub unsafe extern "C" fn rust_abi_fn_three(arg_one: u32, arg_two: usize) {} - -/// # Safety -/// This function shouldn't be called unless the horsemen are ready -#[no_mangle] -unsafe extern "C" fn rust_abi_fn_four(arg_one: u32, arg_two: usize) {} - -#[no_mangle] -extern "C" fn rust_abi_multiline_function_really_long_name_to_overflow_args_to_multiple_lines( - arg_one: u32, - arg_two: usize, -) -> u32 { - 0 -} - -// Must not run on functions that explicitly opt in to Rust ABI with `extern "Rust"` -#[no_mangle] -#[rustfmt::skip] -extern "Rust" fn rust_abi_fn_explicit_opt_in(arg_one: u32, arg_two: usize) {} - -fn rust_abi_fn_again(arg_one: u32, arg_two: usize) {} - -#[no_mangle] -extern "C" fn c_abi_fn(arg_one: u32, arg_two: usize) {} - -extern "C" fn c_abi_fn_again(arg_one: u32, arg_two: usize) {} - -extern "C" { - fn c_abi_in_block(arg_one: u32, arg_two: usize); -} - -fn main() { - // test code goes here -} diff --git a/tests/ui/no_mangle_with_rust_abi.rs b/tests/ui/no_mangle_with_rust_abi.rs index 481e1b6d9619..b32e721110e0 100644 --- a/tests/ui/no_mangle_with_rust_abi.rs +++ b/tests/ui/no_mangle_with_rust_abi.rs @@ -1,5 +1,3 @@ -// run-rustfix - #![allow(unused)] #![warn(clippy::no_mangle_with_rust_abi)] diff --git a/tests/ui/no_mangle_with_rust_abi.stderr b/tests/ui/no_mangle_with_rust_abi.stderr index 71517d318095..da5d31d8f2d4 100644 --- a/tests/ui/no_mangle_with_rust_abi.stderr +++ b/tests/ui/no_mangle_with_rust_abi.stderr @@ -1,31 +1,66 @@ -error: attribute #[no_mangle] set on a Rust ABI function - --> $DIR/no_mangle_with_rust_abi.rs:7:1 +error: `#[no_mangle]` set on a function with the default (`Rust`) ABI + --> $DIR/no_mangle_with_rust_abi.rs:5:1 | LL | fn rust_abi_fn_one(arg_one: u32, arg_two: usize) {} - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `extern "C" fn rust_abi_fn_one(arg_one: u32, arg_two: usize)` + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | = note: `-D clippy::no-mangle-with-rust-abi` implied by `-D warnings` +help: set an ABI + | +LL | extern "C" fn rust_abi_fn_one(arg_one: u32, arg_two: usize) {} + | ++++++++++ +help: or explicitly set the default + | +LL | extern "Rust" fn rust_abi_fn_one(arg_one: u32, arg_two: usize) {} + | +++++++++++++ -error: attribute #[no_mangle] set on a Rust ABI function - --> $DIR/no_mangle_with_rust_abi.rs:10:1 +error: `#[no_mangle]` set on a function with the default (`Rust`) ABI + --> $DIR/no_mangle_with_rust_abi.rs:8:1 | LL | pub fn rust_abi_fn_two(arg_one: u32, arg_two: usize) {} - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `pub extern "C" fn rust_abi_fn_two(arg_one: u32, arg_two: usize)` + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | +help: set an ABI + | +LL | pub extern "C" fn rust_abi_fn_two(arg_one: u32, arg_two: usize) {} + | ++++++++++ +help: or explicitly set the default + | +LL | pub extern "Rust" fn rust_abi_fn_two(arg_one: u32, arg_two: usize) {} + | +++++++++++++ -error: attribute #[no_mangle] set on a Rust ABI function - --> $DIR/no_mangle_with_rust_abi.rs:15:1 +error: `#[no_mangle]` set on a function with the default (`Rust`) ABI + --> $DIR/no_mangle_with_rust_abi.rs:13:1 | LL | pub unsafe fn rust_abi_fn_three(arg_one: u32, arg_two: usize) {} - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `pub unsafe extern "C" fn rust_abi_fn_three(arg_one: u32, arg_two: usize)` + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | +help: set an ABI + | +LL | pub unsafe extern "C" fn rust_abi_fn_three(arg_one: u32, arg_two: usize) {} + | ++++++++++ +help: or explicitly set the default + | +LL | pub unsafe extern "Rust" fn rust_abi_fn_three(arg_one: u32, arg_two: usize) {} + | +++++++++++++ -error: attribute #[no_mangle] set on a Rust ABI function - --> $DIR/no_mangle_with_rust_abi.rs:20:1 +error: `#[no_mangle]` set on a function with the default (`Rust`) ABI + --> $DIR/no_mangle_with_rust_abi.rs:18:1 | LL | unsafe fn rust_abi_fn_four(arg_one: u32, arg_two: usize) {} - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `unsafe extern "C" fn rust_abi_fn_four(arg_one: u32, arg_two: usize)` + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | +help: set an ABI + | +LL | unsafe extern "C" fn rust_abi_fn_four(arg_one: u32, arg_two: usize) {} + | ++++++++++ +help: or explicitly set the default + | +LL | unsafe extern "Rust" fn rust_abi_fn_four(arg_one: u32, arg_two: usize) {} + | +++++++++++++ -error: attribute #[no_mangle] set on a Rust ABI function - --> $DIR/no_mangle_with_rust_abi.rs:23:1 +error: `#[no_mangle]` set on a function with the default (`Rust`) ABI + --> $DIR/no_mangle_with_rust_abi.rs:21:1 | LL | / fn rust_abi_multiline_function_really_long_name_to_overflow_args_to_multiple_lines( LL | | arg_one: u32, @@ -33,13 +68,14 @@ LL | | arg_two: usize, LL | | ) -> u32 { | |________^ | -help: try +help: set an ABI | -LL + extern "C" fn rust_abi_multiline_function_really_long_name_to_overflow_args_to_multiple_lines( -LL + arg_one: u32, -LL + arg_two: usize, -LL ~ ) -> u32 { +LL | extern "C" fn rust_abi_multiline_function_really_long_name_to_overflow_args_to_multiple_lines( + | ++++++++++ +help: or explicitly set the default | +LL | extern "Rust" fn rust_abi_multiline_function_really_long_name_to_overflow_args_to_multiple_lines( + | +++++++++++++ error: aborting due to 5 previous errors