mirror of
https://github.com/rust-lang/rust-clippy
synced 2024-12-29 22:43:41 +00:00
731 lines
24 KiB
Rust
731 lines
24 KiB
Rust
use reexport::*;
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use rustc::hir::*;
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use rustc::hir::def_id::DefId;
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use rustc::hir::map::Node;
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use rustc::lint::{LintContext, LateContext, Level, Lint};
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use rustc::middle::cstore;
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use rustc::session::Session;
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use rustc::traits::ProjectionMode;
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use rustc::traits;
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use rustc::ty::subst::Subst;
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use rustc::ty;
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use rustc_errors;
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use std::borrow::Cow;
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use std::env;
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use std::mem;
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use std::str::FromStr;
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use syntax::ast::{self, LitKind};
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use syntax::codemap::{ExpnFormat, ExpnInfo, MultiSpan, Span, DUMMY_SP};
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use syntax::errors::DiagnosticBuilder;
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use syntax::ptr::P;
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pub mod cargo;
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pub mod comparisons;
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pub mod conf;
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mod hir;
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pub mod paths;
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pub mod sugg;
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pub mod internal_lints;
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pub use self::hir::{SpanlessEq, SpanlessHash};
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pub type MethodArgs = HirVec<P<Expr>>;
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/// Produce a nested chain of if-lets and ifs from the patterns:
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///
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/// if_let_chain! {[
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/// let Some(y) = x,
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/// y.len() == 2,
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/// let Some(z) = y,
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/// ], {
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/// block
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/// }}
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///
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/// becomes
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///
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/// if let Some(y) = x {
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/// if y.len() == 2 {
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/// if let Some(z) = y {
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/// block
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/// }
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/// }
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/// }
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#[macro_export]
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macro_rules! if_let_chain {
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([let $pat:pat = $expr:expr, $($tt:tt)+], $block:block) => {
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if let $pat = $expr {
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if_let_chain!{ [$($tt)+], $block }
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}
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};
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([let $pat:pat = $expr:expr], $block:block) => {
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if let $pat = $expr {
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$block
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}
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};
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([let $pat:pat = $expr:expr,], $block:block) => {
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if let $pat = $expr {
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$block
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}
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};
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([$expr:expr, $($tt:tt)+], $block:block) => {
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if $expr {
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if_let_chain!{ [$($tt)+], $block }
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}
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};
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([$expr:expr], $block:block) => {
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if $expr {
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$block
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}
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};
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([$expr:expr,], $block:block) => {
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if $expr {
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$block
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}
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};
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}
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pub mod higher;
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/// Returns true if the two spans come from differing expansions (i.e. one is from a macro and one
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/// isn't).
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pub fn differing_macro_contexts(lhs: Span, rhs: Span) -> bool {
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rhs.expn_id != lhs.expn_id
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}
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/// Returns true if this `expn_info` was expanded by any macro.
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pub fn in_macro<T: LintContext>(cx: &T, span: Span) -> bool {
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cx.sess().codemap().with_expn_info(span.expn_id, |info| info.is_some())
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}
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/// Returns true if the macro that expanded the crate was outside of the current crate or was a
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/// compiler plugin.
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pub fn in_external_macro<T: LintContext>(cx: &T, span: Span) -> bool {
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/// Invokes `in_macro` with the expansion info of the given span slightly heavy, try to use
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/// this after other checks have already happened.
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fn in_macro_ext<T: LintContext>(cx: &T, opt_info: Option<&ExpnInfo>) -> bool {
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// no ExpnInfo = no macro
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opt_info.map_or(false, |info| {
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if let ExpnFormat::MacroAttribute(..) = info.callee.format {
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// these are all plugins
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return true;
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}
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// no span for the callee = external macro
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info.callee.span.map_or(true, |span| {
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// no snippet = external macro or compiler-builtin expansion
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cx.sess().codemap().span_to_snippet(span).ok().map_or(true, |code| !code.starts_with("macro_rules"))
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})
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})
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}
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cx.sess().codemap().with_expn_info(span.expn_id, |info| in_macro_ext(cx, info))
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}
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/// Check if a `DefId`'s path matches the given absolute type path usage.
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///
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/// # Examples
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/// ```
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/// match_def_path(cx, id, &["core", "option", "Option"])
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/// ```
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///
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/// See also the `paths` module.
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pub fn match_def_path(cx: &LateContext, def_id: DefId, path: &[&str]) -> bool {
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use syntax::parse::token;
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struct AbsolutePathBuffer {
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names: Vec<token::InternedString>,
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}
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impl ty::item_path::ItemPathBuffer for AbsolutePathBuffer {
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fn root_mode(&self) -> &ty::item_path::RootMode {
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const ABSOLUTE: &'static ty::item_path::RootMode = &ty::item_path::RootMode::Absolute;
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ABSOLUTE
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}
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fn push(&mut self, text: &str) {
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self.names.push(token::intern(text).as_str());
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}
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}
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let mut apb = AbsolutePathBuffer { names: vec![] };
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cx.tcx.push_item_path(&mut apb, def_id);
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apb.names == path
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}
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/// Check if type is struct or enum type with given def path.
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pub fn match_type(cx: &LateContext, ty: ty::Ty, path: &[&str]) -> bool {
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match ty.sty {
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ty::TyEnum(adt, _) |
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ty::TyStruct(adt, _) => match_def_path(cx, adt.did, path),
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_ => false,
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}
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}
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/// Check if the method call given in `expr` belongs to given type.
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pub fn match_impl_method(cx: &LateContext, expr: &Expr, path: &[&str]) -> bool {
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let method_call = ty::MethodCall::expr(expr.id);
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let trt_id = cx.tcx
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.tables
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.borrow()
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.method_map
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.get(&method_call)
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.and_then(|callee| cx.tcx.impl_of_method(callee.def_id));
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if let Some(trt_id) = trt_id {
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match_def_path(cx, trt_id, path)
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} else {
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false
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}
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}
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/// Check if the method call given in `expr` belongs to given trait.
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pub fn match_trait_method(cx: &LateContext, expr: &Expr, path: &[&str]) -> bool {
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let method_call = ty::MethodCall::expr(expr.id);
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let trt_id = cx.tcx
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.tables
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.borrow()
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.method_map
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.get(&method_call)
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.and_then(|callee| cx.tcx.trait_of_item(callee.def_id));
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if let Some(trt_id) = trt_id {
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match_def_path(cx, trt_id, path)
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} else {
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false
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}
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}
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/// Match a `Path` against a slice of segment string literals.
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///
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/// # Examples
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/// ```
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/// match_path(path, &["std", "rt", "begin_unwind"])
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/// ```
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pub fn match_path(path: &Path, segments: &[&str]) -> bool {
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path.segments.iter().rev().zip(segments.iter().rev()).all(|(a, b)| a.name.as_str() == *b)
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}
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/// Match a `Path` against a slice of segment string literals, e.g.
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///
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/// # Examples
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/// ```
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/// match_path(path, &["std", "rt", "begin_unwind"])
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/// ```
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pub fn match_path_ast(path: &ast::Path, segments: &[&str]) -> bool {
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path.segments.iter().rev().zip(segments.iter().rev()).all(|(a, b)| a.identifier.name.as_str() == *b)
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}
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/// Get the definition associated to a path.
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/// TODO: investigate if there is something more efficient for that.
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pub fn path_to_def(cx: &LateContext, path: &[&str]) -> Option<cstore::DefLike> {
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let cstore = &cx.tcx.sess.cstore;
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let crates = cstore.crates();
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let krate = crates.iter().find(|&&krate| cstore.crate_name(krate) == path[0]);
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if let Some(krate) = krate {
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let mut items = cstore.crate_top_level_items(*krate);
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let mut path_it = path.iter().skip(1).peekable();
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loop {
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let segment = match path_it.next() {
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Some(segment) => segment,
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None => return None,
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};
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for item in &mem::replace(&mut items, vec![]) {
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if item.name.as_str() == *segment {
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if path_it.peek().is_none() {
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return Some(item.def);
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}
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let def_id = match item.def {
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cstore::DefLike::DlDef(def) => def.def_id(),
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cstore::DefLike::DlImpl(def_id) => def_id,
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_ => panic!("Unexpected {:?}", item.def),
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};
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items = cstore.item_children(def_id);
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break;
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}
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}
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}
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} else {
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None
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}
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}
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/// Convenience function to get the `DefId` of a trait by path.
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pub fn get_trait_def_id(cx: &LateContext, path: &[&str]) -> Option<DefId> {
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let def = match path_to_def(cx, path) {
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Some(def) => def,
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None => return None,
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};
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match def {
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cstore::DlDef(def::Def::Trait(trait_id)) => Some(trait_id),
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_ => None,
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}
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}
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/// Check whether a type implements a trait.
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/// See also `get_trait_def_id`.
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pub fn implements_trait<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, ty: ty::Ty<'tcx>, trait_id: DefId,
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ty_params: Vec<ty::Ty<'tcx>>)
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-> bool {
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cx.tcx.populate_implementations_for_trait_if_necessary(trait_id);
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let ty = cx.tcx.erase_regions(&ty);
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cx.tcx.infer_ctxt(None, None, ProjectionMode::Any).enter(|infcx| {
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let obligation = cx.tcx.predicate_for_trait_def(traits::ObligationCause::dummy(),
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trait_id,
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0,
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ty,
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ty_params);
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traits::SelectionContext::new(&infcx).evaluate_obligation_conservatively(&obligation)
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})
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}
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/// Match an `Expr` against a chain of methods, and return the matched `Expr`s.
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///
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/// For example, if `expr` represents the `.baz()` in `foo.bar().baz()`,
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/// `matched_method_chain(expr, &["bar", "baz"])` will return a `Vec` containing the `Expr`s for
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/// `.bar()` and `.baz()`
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pub fn method_chain_args<'a>(expr: &'a Expr, methods: &[&str]) -> Option<Vec<&'a MethodArgs>> {
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let mut current = expr;
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let mut matched = Vec::with_capacity(methods.len());
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for method_name in methods.iter().rev() {
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// method chains are stored last -> first
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if let ExprMethodCall(ref name, _, ref args) = current.node {
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if name.node.as_str() == *method_name {
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matched.push(args); // build up `matched` backwards
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current = &args[0] // go to parent expression
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} else {
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return None;
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}
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} else {
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return None;
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}
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}
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matched.reverse(); // reverse `matched`, so that it is in the same order as `methods`
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Some(matched)
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}
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/// Get the name of the item the expression is in, if available.
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pub fn get_item_name(cx: &LateContext, expr: &Expr) -> Option<Name> {
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let parent_id = cx.tcx.map.get_parent(expr.id);
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match cx.tcx.map.find(parent_id) {
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Some(Node::NodeItem(&Item { ref name, .. })) |
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Some(Node::NodeTraitItem(&TraitItem { ref name, .. })) |
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Some(Node::NodeImplItem(&ImplItem { ref name, .. })) => Some(*name),
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_ => None,
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}
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}
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/// Convert a span to a code snippet if available, otherwise use default.
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///
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/// # Example
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/// ```
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/// snippet(cx, expr.span, "..")
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/// ```
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pub fn snippet<'a, T: LintContext>(cx: &T, span: Span, default: &'a str) -> Cow<'a, str> {
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cx.sess().codemap().span_to_snippet(span).map(From::from).unwrap_or_else(|_| Cow::Borrowed(default))
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}
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/// Convert a span to a code snippet. Returns `None` if not available.
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pub fn snippet_opt<T: LintContext>(cx: &T, span: Span) -> Option<String> {
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cx.sess().codemap().span_to_snippet(span).ok()
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}
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/// Convert a span (from a block) to a code snippet if available, otherwise use default.
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/// This trims the code of indentation, except for the first line. Use it for blocks or block-like
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/// things which need to be printed as such.
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///
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/// # Example
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/// ```
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/// snippet(cx, expr.span, "..")
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/// ```
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pub fn snippet_block<'a, T: LintContext>(cx: &T, span: Span, default: &'a str) -> Cow<'a, str> {
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let snip = snippet(cx, span, default);
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trim_multiline(snip, true)
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}
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/// Like `snippet_block`, but add braces if the expr is not an `ExprBlock`.
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/// Also takes an `Option<String>` which can be put inside the braces.
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pub fn expr_block<'a, T: LintContext>(cx: &T, expr: &Expr, option: Option<String>, default: &'a str) -> Cow<'a, str> {
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let code = snippet_block(cx, expr.span, default);
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let string = option.unwrap_or_default();
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if let ExprBlock(_) = expr.node {
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Cow::Owned(format!("{}{}", code, string))
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} else if string.is_empty() {
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Cow::Owned(format!("{{ {} }}", code))
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} else {
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Cow::Owned(format!("{{\n{};\n{}\n}}", code, string))
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}
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}
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|
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/// Trim indentation from a multiline string with possibility of ignoring the first line.
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pub fn trim_multiline(s: Cow<str>, ignore_first: bool) -> Cow<str> {
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let s_space = trim_multiline_inner(s, ignore_first, ' ');
|
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let s_tab = trim_multiline_inner(s_space, ignore_first, '\t');
|
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trim_multiline_inner(s_tab, ignore_first, ' ')
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}
|
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|
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fn trim_multiline_inner(s: Cow<str>, ignore_first: bool, ch: char) -> Cow<str> {
|
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let x = s.lines()
|
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.skip(ignore_first as usize)
|
||
.filter_map(|l| {
|
||
if l.is_empty() {
|
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None
|
||
} else {
|
||
// ignore empty lines
|
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Some(l.char_indices()
|
||
.find(|&(_, x)| x != ch)
|
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.unwrap_or((l.len(), ch))
|
||
.0)
|
||
}
|
||
})
|
||
.min()
|
||
.unwrap_or(0);
|
||
if x > 0 {
|
||
Cow::Owned(s.lines()
|
||
.enumerate()
|
||
.map(|(i, l)| {
|
||
if (ignore_first && i == 0) || l.is_empty() {
|
||
l
|
||
} else {
|
||
l.split_at(x).1
|
||
}
|
||
})
|
||
.collect::<Vec<_>>()
|
||
.join("\n"))
|
||
} else {
|
||
s
|
||
}
|
||
}
|
||
|
||
/// Get a parent expressions if any – this is useful to constrain a lint.
|
||
pub fn get_parent_expr<'c>(cx: &'c LateContext, e: &Expr) -> Option<&'c Expr> {
|
||
let map = &cx.tcx.map;
|
||
let node_id: NodeId = e.id;
|
||
let parent_id: NodeId = map.get_parent_node(node_id);
|
||
if node_id == parent_id {
|
||
return None;
|
||
}
|
||
map.find(parent_id).and_then(|node| {
|
||
if let Node::NodeExpr(parent) = node {
|
||
Some(parent)
|
||
} else {
|
||
None
|
||
}
|
||
})
|
||
}
|
||
|
||
pub fn get_enclosing_block<'c>(cx: &'c LateContext, node: NodeId) -> Option<&'c Block> {
|
||
let map = &cx.tcx.map;
|
||
let enclosing_node = map.get_enclosing_scope(node)
|
||
.and_then(|enclosing_id| map.find(enclosing_id));
|
||
if let Some(node) = enclosing_node {
|
||
match node {
|
||
Node::NodeBlock(block) => Some(block),
|
||
Node::NodeItem(&Item { node: ItemFn(_, _, _, _, _, ref block), .. }) => Some(block),
|
||
_ => None,
|
||
}
|
||
} else {
|
||
None
|
||
}
|
||
}
|
||
|
||
pub struct DiagnosticWrapper<'a>(pub DiagnosticBuilder<'a>);
|
||
|
||
impl<'a> Drop for DiagnosticWrapper<'a> {
|
||
fn drop(&mut self) {
|
||
self.0.emit();
|
||
}
|
||
}
|
||
|
||
impl<'a> DiagnosticWrapper<'a> {
|
||
fn wiki_link(&mut self, lint: &'static Lint) {
|
||
if env::var("CLIPPY_DISABLE_WIKI_LINKS").is_err() {
|
||
self.0.help(&format!("for further information visit https://github.com/Manishearth/rust-clippy/wiki#{}",
|
||
lint.name_lower()));
|
||
}
|
||
}
|
||
}
|
||
|
||
pub fn span_lint<T: LintContext>(cx: &T, lint: &'static Lint, sp: Span, msg: &str) {
|
||
let mut db = DiagnosticWrapper(cx.struct_span_lint(lint, sp, msg));
|
||
if cx.current_level(lint) != Level::Allow {
|
||
db.wiki_link(lint);
|
||
}
|
||
}
|
||
|
||
// FIXME: needless lifetime doesn't trigger here
|
||
pub fn span_help_and_lint<'a, T: LintContext>(cx: &'a T, lint: &'static Lint, span: Span, msg: &str, help: &str) {
|
||
let mut db = DiagnosticWrapper(cx.struct_span_lint(lint, span, msg));
|
||
if cx.current_level(lint) != Level::Allow {
|
||
db.0.help(help);
|
||
db.wiki_link(lint);
|
||
}
|
||
}
|
||
|
||
pub fn span_note_and_lint<'a, T: LintContext>(cx: &'a T, lint: &'static Lint, span: Span, msg: &str, note_span: Span,
|
||
note: &str) {
|
||
let mut db = DiagnosticWrapper(cx.struct_span_lint(lint, span, msg));
|
||
if cx.current_level(lint) != Level::Allow {
|
||
if note_span == span {
|
||
db.0.note(note);
|
||
} else {
|
||
db.0.span_note(note_span, note);
|
||
}
|
||
db.wiki_link(lint);
|
||
}
|
||
}
|
||
|
||
pub fn span_lint_and_then<'a, T: LintContext, F>(cx: &'a T, lint: &'static Lint, sp: Span, msg: &str, f: F)
|
||
where F: FnOnce(&mut DiagnosticBuilder<'a>)
|
||
{
|
||
let mut db = DiagnosticWrapper(cx.struct_span_lint(lint, sp, msg));
|
||
if cx.current_level(lint) != Level::Allow {
|
||
f(&mut db.0);
|
||
db.wiki_link(lint);
|
||
}
|
||
}
|
||
|
||
/// Create a suggestion made from several `span → replacement`.
|
||
///
|
||
/// Note: in the JSON format (used by `compiletest_rs`), the help message will appear once per
|
||
/// replacement. In human-readable format though, it only appears once before the whole suggestion.
|
||
pub fn multispan_sugg(db: &mut DiagnosticBuilder, help_msg: String, sugg: &[(Span, &str)]) {
|
||
let sugg = rustc_errors::RenderSpan::Suggestion(rustc_errors::CodeSuggestion {
|
||
msp: MultiSpan::from_spans(sugg.iter().map(|&(span, _)| span).collect()),
|
||
substitutes: sugg.iter().map(|&(_, subs)| subs.to_owned()).collect(),
|
||
});
|
||
|
||
let sub = rustc_errors::SubDiagnostic {
|
||
level: rustc_errors::Level::Help,
|
||
message: help_msg,
|
||
span: MultiSpan::new(),
|
||
render_span: Some(sugg),
|
||
};
|
||
db.children.push(sub);
|
||
}
|
||
|
||
/// Return the base type for references and raw pointers.
|
||
pub fn walk_ptrs_ty(ty: ty::Ty) -> ty::Ty {
|
||
match ty.sty {
|
||
ty::TyRef(_, ref tm) => walk_ptrs_ty(tm.ty),
|
||
_ => ty,
|
||
}
|
||
}
|
||
|
||
/// Return the base type for references and raw pointers, and count reference depth.
|
||
pub fn walk_ptrs_ty_depth(ty: ty::Ty) -> (ty::Ty, usize) {
|
||
fn inner(ty: ty::Ty, depth: usize) -> (ty::Ty, usize) {
|
||
match ty.sty {
|
||
ty::TyRef(_, ref tm) => inner(tm.ty, depth + 1),
|
||
_ => (ty, depth),
|
||
}
|
||
}
|
||
inner(ty, 0)
|
||
}
|
||
|
||
/// Check whether the given expression is a constant literal of the given value.
|
||
pub fn is_integer_literal(expr: &Expr, value: u64) -> bool {
|
||
// FIXME: use constant folding
|
||
if let ExprLit(ref spanned) = expr.node {
|
||
if let LitKind::Int(v, _) = spanned.node {
|
||
return v == value;
|
||
}
|
||
}
|
||
false
|
||
}
|
||
|
||
pub fn is_adjusted(cx: &LateContext, e: &Expr) -> bool {
|
||
cx.tcx.tables.borrow().adjustments.get(&e.id).is_some()
|
||
}
|
||
|
||
pub struct LimitStack {
|
||
stack: Vec<u64>,
|
||
}
|
||
|
||
impl Drop for LimitStack {
|
||
fn drop(&mut self) {
|
||
assert_eq!(self.stack.len(), 1);
|
||
}
|
||
}
|
||
|
||
impl LimitStack {
|
||
pub fn new(limit: u64) -> LimitStack {
|
||
LimitStack { stack: vec![limit] }
|
||
}
|
||
pub fn limit(&self) -> u64 {
|
||
*self.stack.last().expect("there should always be a value in the stack")
|
||
}
|
||
pub fn push_attrs(&mut self, sess: &Session, attrs: &[ast::Attribute], name: &'static str) {
|
||
let stack = &mut self.stack;
|
||
parse_attrs(sess, attrs, name, |val| stack.push(val));
|
||
}
|
||
pub fn pop_attrs(&mut self, sess: &Session, attrs: &[ast::Attribute], name: &'static str) {
|
||
let stack = &mut self.stack;
|
||
parse_attrs(sess, attrs, name, |val| assert_eq!(stack.pop(), Some(val)));
|
||
}
|
||
}
|
||
|
||
fn parse_attrs<F: FnMut(u64)>(sess: &Session, attrs: &[ast::Attribute], name: &'static str, mut f: F) {
|
||
for attr in attrs {
|
||
let attr = &attr.node;
|
||
if attr.is_sugared_doc {
|
||
continue;
|
||
}
|
||
if let ast::MetaItemKind::NameValue(ref key, ref value) = attr.value.node {
|
||
if *key == name {
|
||
if let LitKind::Str(ref s, _) = value.node {
|
||
if let Ok(value) = FromStr::from_str(s) {
|
||
f(value)
|
||
} else {
|
||
sess.span_err(value.span, "not a number");
|
||
}
|
||
} else {
|
||
unreachable!()
|
||
}
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
/// Return the pre-expansion span if is this comes from an expansion of the macro `name`.
|
||
/// See also `is_direct_expn_of`.
|
||
pub fn is_expn_of(cx: &LateContext, mut span: Span, name: &str) -> Option<Span> {
|
||
loop {
|
||
let span_name_span = cx.tcx
|
||
.sess
|
||
.codemap()
|
||
.with_expn_info(span.expn_id, |expn| expn.map(|ei| (ei.callee.name(), ei.call_site)));
|
||
|
||
match span_name_span {
|
||
Some((mac_name, new_span)) if mac_name.as_str() == name => return Some(new_span),
|
||
None => return None,
|
||
Some((_, new_span)) => span = new_span,
|
||
}
|
||
}
|
||
}
|
||
|
||
/// Return the pre-expansion span if is this directly comes from an expansion of the macro `name`.
|
||
/// The difference with `is_expn_of` is that in
|
||
/// ```rust,ignore
|
||
/// foo!(bar!(42));
|
||
/// ```
|
||
/// `42` is considered expanded from `foo!` and `bar!` by `is_expn_of` but only `bar!` by
|
||
/// `is_direct_expn_of`.
|
||
pub fn is_direct_expn_of(cx: &LateContext, span: Span, name: &str) -> Option<Span> {
|
||
let span_name_span = cx.tcx
|
||
.sess
|
||
.codemap()
|
||
.with_expn_info(span.expn_id, |expn| expn.map(|ei| (ei.callee.name(), ei.call_site)));
|
||
|
||
match span_name_span {
|
||
Some((mac_name, new_span)) if mac_name.as_str() == name => Some(new_span),
|
||
_ => None,
|
||
}
|
||
}
|
||
|
||
/// Return the index of the character after the first camel-case component of `s`.
|
||
pub fn camel_case_until(s: &str) -> usize {
|
||
let mut iter = s.char_indices();
|
||
if let Some((_, first)) = iter.next() {
|
||
if !first.is_uppercase() {
|
||
return 0;
|
||
}
|
||
} else {
|
||
return 0;
|
||
}
|
||
let mut up = true;
|
||
let mut last_i = 0;
|
||
for (i, c) in iter {
|
||
if up {
|
||
if c.is_lowercase() {
|
||
up = false;
|
||
} else {
|
||
return last_i;
|
||
}
|
||
} else if c.is_uppercase() {
|
||
up = true;
|
||
last_i = i;
|
||
} else if !c.is_lowercase() {
|
||
return i;
|
||
}
|
||
}
|
||
if up {
|
||
last_i
|
||
} else {
|
||
s.len()
|
||
}
|
||
}
|
||
|
||
/// Return index of the last camel-case component of `s`.
|
||
pub fn camel_case_from(s: &str) -> usize {
|
||
let mut iter = s.char_indices().rev();
|
||
if let Some((_, first)) = iter.next() {
|
||
if !first.is_lowercase() {
|
||
return s.len();
|
||
}
|
||
} else {
|
||
return s.len();
|
||
}
|
||
let mut down = true;
|
||
let mut last_i = s.len();
|
||
for (i, c) in iter {
|
||
if down {
|
||
if c.is_uppercase() {
|
||
down = false;
|
||
last_i = i;
|
||
} else if !c.is_lowercase() {
|
||
return last_i;
|
||
}
|
||
} else if c.is_lowercase() {
|
||
down = true;
|
||
} else {
|
||
return last_i;
|
||
}
|
||
}
|
||
last_i
|
||
}
|
||
|
||
/// Convenience function to get the return type of a function or `None` if the function diverges.
|
||
pub fn return_ty<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, fn_item: NodeId) -> Option<ty::Ty<'tcx>> {
|
||
let parameter_env = ty::ParameterEnvironment::for_item(cx.tcx, fn_item);
|
||
let fn_sig = cx.tcx.node_id_to_type(fn_item).fn_sig().subst(cx.tcx, parameter_env.free_substs);
|
||
let fn_sig = cx.tcx.liberate_late_bound_regions(parameter_env.free_id_outlive, &fn_sig);
|
||
if let ty::FnConverging(ret_ty) = fn_sig.output {
|
||
Some(ret_ty)
|
||
} else {
|
||
None
|
||
}
|
||
}
|
||
|
||
/// Check if two types are the same.
|
||
// FIXME: this works correctly for lifetimes bounds (`for <'a> Foo<'a>` == `for <'b> Foo<'b>` but
|
||
// not for type parameters.
|
||
pub fn same_tys<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, a: ty::Ty<'tcx>, b: ty::Ty<'tcx>, parameter_item: NodeId) -> bool {
|
||
let parameter_env = ty::ParameterEnvironment::for_item(cx.tcx, parameter_item);
|
||
cx.tcx.infer_ctxt(None, Some(parameter_env), ProjectionMode::Any).enter(|infcx| {
|
||
let new_a = a.subst(infcx.tcx, infcx.parameter_environment.free_substs);
|
||
let new_b = b.subst(infcx.tcx, infcx.parameter_environment.free_substs);
|
||
infcx.can_equate(&new_a, &new_b).is_ok()
|
||
})
|
||
}
|
||
|
||
/// Return whether the given type is an `unsafe` function.
|
||
pub fn type_is_unsafe_function(ty: ty::Ty) -> bool {
|
||
match ty.sty {
|
||
ty::TyFnDef(_, _, f) |
|
||
ty::TyFnPtr(f) => f.unsafety == Unsafety::Unsafe,
|
||
_ => false,
|
||
}
|
||
}
|
||
|
||
pub fn is_copy<'a, 'ctx>(cx: &LateContext<'a, 'ctx>, ty: ty::Ty<'ctx>, env: NodeId) -> bool {
|
||
let env = ty::ParameterEnvironment::for_item(cx.tcx, env);
|
||
!ty.subst(cx.tcx, env.free_substs).moves_by_default(cx.tcx.global_tcx(), &env, DUMMY_SP)
|
||
}
|