Merge branch 'master' into 7594/while_let_some_result

Author: andrewpollack

.cargo/config

@@ -1,8 +1,10 @@
 [alias]
 uitest = "test --test compile-test"
-dev = "run --target-dir clippy_dev/target --package clippy_dev --bin clippy_dev --manifest-path clippy_dev/Cargo.toml --"
-lintcheck = "run --target-dir lintcheck/target --package lintcheck --bin lintcheck --manifest-path lintcheck/Cargo.toml  -- "
+dev = "run --package clippy_dev --bin clippy_dev --manifest-path clippy_dev/Cargo.toml --"
+lintcheck = "run --package lintcheck --bin lintcheck --manifest-path lintcheck/Cargo.toml  -- "
 collect-metadata = "test --test dogfood --features metadata-collector-lint -- run_metadata_collection_lint --ignored"
 
 [build]
-rustflags = ["-Zunstable-options"]
+# -Zbinary-dep-depinfo allows us to track which rlib files to use for compiling UI tests
+rustflags = ["-Zunstable-options", "-Zbinary-dep-depinfo"]
+target-dir = "target"

.github/ISSUE_TEMPLATE/blank_issue.md

@@ -5,9 +5,10 @@ about: Create a blank issue.
 
 
 <!--
-Additional labels can be added to this issue by including the following command:
+Additional labels can be added to this issue by including the following command
+(without the space after the @ symbol):
 
-@rustbot label +<label>
+@ rustbot label +<label>
 
 Common labels for this issue type are:
 * C-an-interesting-project

.github/ISSUE_TEMPLATE/bug_report.md

@@ -33,9 +33,10 @@ LLVM version: 10.0
 ```
 
 <!--
-Additional labels can be added to this issue by including the following command:
+Additional labels can be added to this issue by including the following command
+(without the space after the @ symbol):
 
-@rustbot label +<label>
+@ rustbot label +<label>
 
 Common labels for this issue type are:
 * `I-suggestion-causes-error`

.github/ISSUE_TEMPLATE/false_positive.md

@@ -34,9 +34,10 @@ LLVM version: 10.0
 ```
 
 <!--
-Additional labels can be added to this issue by including the following command:
+Additional labels can be added to this issue by including the following command
+(without the space after the @ symbol):
 
-@rustbot label +<label>
+@ rustbot label +<label>
 
 Common labels for this issue type are:
 * I-suggestion-causes-error

CHANGELOG.md

@@ -968,7 +968,7 @@ Released 2020-11-19
   [#5907](https://github.com/rust-lang/rust-clippy/pull/5907)
 * [`suspicious_arithmetic_impl`]: extend to implementations of `BitAnd`, `BitOr`, `BitXor`, `Rem`, `Shl`, and `Shr`
   [#5884](https://github.com/rust-lang/rust-clippy/pull/5884)
-* [`invalid_atomic_ordering`]: detect misuse of `compare_exchange`, `compare_exchange_weak`, and `fetch_update`
+* `invalid_atomic_ordering`: detect misuse of `compare_exchange`, `compare_exchange_weak`, and `fetch_update`
   [#6025](https://github.com/rust-lang/rust-clippy/pull/6025)
 * Avoid [`redundant_pattern_matching`] triggering in macros
   [#6069](https://github.com/rust-lang/rust-clippy/pull/6069)
@@ -1455,7 +1455,7 @@ Released 2020-03-12
 * [`option_as_ref_deref`] [#4945](https://github.com/rust-lang/rust-clippy/pull/4945)
 * [`wildcard_in_or_patterns`] [#4960](https://github.com/rust-lang/rust-clippy/pull/4960)
 * [`iter_nth_zero`] [#4966](https://github.com/rust-lang/rust-clippy/pull/4966)
-* [`invalid_atomic_ordering`] [#4999](https://github.com/rust-lang/rust-clippy/pull/4999)
+* `invalid_atomic_ordering` [#4999](https://github.com/rust-lang/rust-clippy/pull/4999)
 * [`skip_while_next`] [#5067](https://github.com/rust-lang/rust-clippy/pull/5067)
 
 ### Moves and Deprecations
@@ -2617,6 +2617,7 @@ Released 2018-09-13
 [`deprecated_cfg_attr`]: https://rust-lang.github.io/rust-clippy/master/index.html#deprecated_cfg_attr
 [`deprecated_semver`]: https://rust-lang.github.io/rust-clippy/master/index.html#deprecated_semver
 [`deref_addrof`]: https://rust-lang.github.io/rust-clippy/master/index.html#deref_addrof
+[`derivable_impls`]: https://rust-lang.github.io/rust-clippy/master/index.html#derivable_impls
 [`derive_hash_xor_eq`]: https://rust-lang.github.io/rust-clippy/master/index.html#derive_hash_xor_eq
 [`derive_ord_xor_partial_ord`]: https://rust-lang.github.io/rust-clippy/master/index.html#derive_ord_xor_partial_ord
 [`disallowed_method`]: https://rust-lang.github.io/rust-clippy/master/index.html#disallowed_method
@@ -2715,7 +2716,6 @@ Released 2018-09-13
 [`integer_arithmetic`]: https://rust-lang.github.io/rust-clippy/master/index.html#integer_arithmetic
 [`integer_division`]: https://rust-lang.github.io/rust-clippy/master/index.html#integer_division
 [`into_iter_on_ref`]: https://rust-lang.github.io/rust-clippy/master/index.html#into_iter_on_ref
-[`invalid_atomic_ordering`]: https://rust-lang.github.io/rust-clippy/master/index.html#invalid_atomic_ordering
 [`invalid_null_ptr_usage`]: https://rust-lang.github.io/rust-clippy/master/index.html#invalid_null_ptr_usage
 [`invalid_regex`]: https://rust-lang.github.io/rust-clippy/master/index.html#invalid_regex
 [`invalid_upcast_comparisons`]: https://rust-lang.github.io/rust-clippy/master/index.html#invalid_upcast_comparisons
@@ -2725,6 +2725,7 @@ Released 2018-09-13
 [`iter_count`]: https://rust-lang.github.io/rust-clippy/master/index.html#iter_count
 [`iter_next_loop`]: https://rust-lang.github.io/rust-clippy/master/index.html#iter_next_loop
 [`iter_next_slice`]: https://rust-lang.github.io/rust-clippy/master/index.html#iter_next_slice
+[`iter_not_returning_iterator`]: https://rust-lang.github.io/rust-clippy/master/index.html#iter_not_returning_iterator
 [`iter_nth`]: https://rust-lang.github.io/rust-clippy/master/index.html#iter_nth
 [`iter_nth_zero`]: https://rust-lang.github.io/rust-clippy/master/index.html#iter_nth_zero
 [`iter_skip_next`]: https://rust-lang.github.io/rust-clippy/master/index.html#iter_skip_next
@@ -2827,6 +2828,7 @@ Released 2018-09-13
 [`needless_doctest_main`]: https://rust-lang.github.io/rust-clippy/master/index.html#needless_doctest_main
 [`needless_for_each`]: https://rust-lang.github.io/rust-clippy/master/index.html#needless_for_each
 [`needless_lifetimes`]: https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
+[`needless_option_as_deref`]: https://rust-lang.github.io/rust-clippy/master/index.html#needless_option_as_deref
 [`needless_pass_by_value`]: https://rust-lang.github.io/rust-clippy/master/index.html#needless_pass_by_value
 [`needless_question_mark`]: https://rust-lang.github.io/rust-clippy/master/index.html#needless_question_mark
 [`needless_range_loop`]: https://rust-lang.github.io/rust-clippy/master/index.html#needless_range_loop
@@ -2908,6 +2910,7 @@ Released 2018-09-13
 [`reversed_empty_ranges`]: https://rust-lang.github.io/rust-clippy/master/index.html#reversed_empty_ranges
 [`same_functions_in_if_condition`]: https://rust-lang.github.io/rust-clippy/master/index.html#same_functions_in_if_condition
 [`same_item_push`]: https://rust-lang.github.io/rust-clippy/master/index.html#same_item_push
+[`same_name_method`]: https://rust-lang.github.io/rust-clippy/master/index.html#same_name_method
 [`search_is_some`]: https://rust-lang.github.io/rust-clippy/master/index.html#search_is_some
 [`self_assignment`]: https://rust-lang.github.io/rust-clippy/master/index.html#self_assignment
 [`self_named_constructors`]: https://rust-lang.github.io/rust-clippy/master/index.html#self_named_constructors

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "clippy"
-version = "0.1.56"
+version = "0.1.57"
 description = "A bunch of helpful lints to avoid common pitfalls in Rust"
 repository = "https://github.com/rust-lang/rust-clippy"
 readme = "README.md"
@@ -32,11 +32,7 @@ tempfile = { version = "3.1.0", optional = true }
 cargo_metadata = "0.12"
 compiletest_rs = { version = "0.6.0", features = ["tmp"] }
 tester = "0.9"
-serde = { version = "1.0", features = ["derive"] }
-derive-new = "0.5"
 regex = "1.4"
-quote = "1"
-syn = { version = "1", features = ["full"] }
 # This is used by the `collect-metadata` alias.
 filetime = "0.2"
 
@@ -45,6 +41,15 @@ filetime = "0.2"
 # for more information.
 rustc-workspace-hack = "1.0.0"
 
+# UI test dependencies
+clippy_utils = { path = "clippy_utils" }
+derive-new = "0.5"
+if_chain = "1.0"
+itertools = "0.10.1"
+quote = "1"
+serde = { version = "1.0", features = ["derive"] }
+syn = { version = "1", features = ["full"] }
+
 [build-dependencies]
 rustc_tools_util = { version = "0.2.0", path = "rustc_tools_util" }
 

README.md

@@ -45,13 +45,13 @@ or in Travis CI.
 One way to use Clippy is by installing Clippy through rustup as a cargo
 subcommand.
 
-#### Step 1: Install rustup
+#### Step 1: Install Rustup
 
-You can install [rustup](https://rustup.rs/) on supported platforms. This will help
+You can install [Rustup](https://rustup.rs/) on supported platforms. This will help
 us install Clippy and its dependencies.
 
-If you already have rustup installed, update to ensure you have the latest
-rustup and compiler:
+If you already have Rustup installed, update to ensure you have the latest
+Rustup and compiler:
 
 ```terminal
 rustup update

clippy_dev/src/bless.rs

@@ -1,7 +1,6 @@
 //! `bless` updates the reference files in the repo with changed output files
 //! from the last test run.
 
-use std::env;
 use std::ffi::OsStr;
 use std::fs;
 use std::lazy::SyncLazy;
@@ -10,17 +9,9 @@ use walkdir::WalkDir;
 
 use crate::clippy_project_root;
 
-// NOTE: this is duplicated with tests/cargo/mod.rs What to do?
-pub static CARGO_TARGET_DIR: SyncLazy<PathBuf> = SyncLazy::new(|| match env::var_os("CARGO_TARGET_DIR") {
-    Some(v) => v.into(),
-    None => env::current_dir().unwrap().join("target"),
-});
-
 static CLIPPY_BUILD_TIME: SyncLazy<Option<std::time::SystemTime>> = SyncLazy::new(|| {
-    let profile = env::var("PROFILE").unwrap_or_else(|_| "debug".to_string());
-    let mut path = PathBuf::from(&**CARGO_TARGET_DIR);
-    path.push(profile);
-    path.push("cargo-clippy");
+    let mut path = std::env::current_exe().unwrap();
+    path.set_file_name("cargo-clippy");
     fs::metadata(path).ok()?.modified().ok()
 });
 
@@ -94,10 +85,7 @@ fn updated_since_clippy_build(path: &Path) -> Option<bool> {
 }
 
 fn build_dir() -> PathBuf {
-    let profile = env::var("PROFILE").unwrap_or_else(|_| "debug".to_string());
-    let mut path = PathBuf::new();
-    path.push(CARGO_TARGET_DIR.clone());
-    path.push(profile);
-    path.push("test_build_base");
+    let mut path = std::env::current_exe().unwrap();
+    path.set_file_name("test");
     path
 }

clippy_lints/Cargo.toml

@@ -1,8 +1,6 @@
 [package]
 name = "clippy_lints"
-# begin automatic update
-version = "0.1.56"
-# end automatic update
+version = "0.1.57"
 description = "A bunch of helpful lints to avoid common pitfalls in Rust"
 repository = "https://github.com/rust-lang/rust-clippy"
 readme = "README.md"

clippy_lints/src/approx_const.rs

@@ -1,8 +1,10 @@
-use clippy_utils::diagnostics::span_lint;
+use clippy_utils::diagnostics::span_lint_and_help;
+use clippy_utils::{meets_msrv, msrvs};
 use rustc_ast::ast::{FloatTy, LitFloatType, LitKind};
 use rustc_hir::{Expr, ExprKind};
-use rustc_lint::{LateContext, LateLintPass};
-use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_lint::{LateContext, LateLintPass, LintContext};
+use rustc_semver::RustcVersion;
+use rustc_session::{declare_tool_lint, impl_lint_pass};
 use rustc_span::symbol;
 use std::f64::consts as f64;
 
@@ -36,68 +38,82 @@ declare_clippy_lint! {
     "the approximate of a known float constant (in `std::fXX::consts`)"
 }
 
-// Tuples are of the form (constant, name, min_digits)
-const KNOWN_CONSTS: [(f64, &str, usize); 18] = [
-    (f64::E, "E", 4),
-    (f64::FRAC_1_PI, "FRAC_1_PI", 4),
-    (f64::FRAC_1_SQRT_2, "FRAC_1_SQRT_2", 5),
-    (f64::FRAC_2_PI, "FRAC_2_PI", 5),
-    (f64::FRAC_2_SQRT_PI, "FRAC_2_SQRT_PI", 5),
-    (f64::FRAC_PI_2, "FRAC_PI_2", 5),
-    (f64::FRAC_PI_3, "FRAC_PI_3", 5),
-    (f64::FRAC_PI_4, "FRAC_PI_4", 5),
-    (f64::FRAC_PI_6, "FRAC_PI_6", 5),
-    (f64::FRAC_PI_8, "FRAC_PI_8", 5),
-    (f64::LN_10, "LN_10", 5),
-    (f64::LN_2, "LN_2", 5),
-    (f64::LOG10_E, "LOG10_E", 5),
-    (f64::LOG2_E, "LOG2_E", 5),
-    (f64::LOG2_10, "LOG2_10", 5),
-    (f64::LOG10_2, "LOG10_2", 5),
-    (f64::PI, "PI", 3),
-    (f64::SQRT_2, "SQRT_2", 5),
+// Tuples are of the form (constant, name, min_digits, msrv)
+const KNOWN_CONSTS: [(f64, &str, usize, Option<RustcVersion>); 19] = [
+    (f64::E, "E", 4, None),
+    (f64::FRAC_1_PI, "FRAC_1_PI", 4, None),
+    (f64::FRAC_1_SQRT_2, "FRAC_1_SQRT_2", 5, None),
+    (f64::FRAC_2_PI, "FRAC_2_PI", 5, None),
+    (f64::FRAC_2_SQRT_PI, "FRAC_2_SQRT_PI", 5, None),
+    (f64::FRAC_PI_2, "FRAC_PI_2", 5, None),
+    (f64::FRAC_PI_3, "FRAC_PI_3", 5, None),
+    (f64::FRAC_PI_4, "FRAC_PI_4", 5, None),
+    (f64::FRAC_PI_6, "FRAC_PI_6", 5, None),
+    (f64::FRAC_PI_8, "FRAC_PI_8", 5, None),
+    (f64::LN_2, "LN_2", 5, None),
+    (f64::LN_10, "LN_10", 5, None),
+    (f64::LOG2_10, "LOG2_10", 5, Some(msrvs::LOG2_10)),
+    (f64::LOG2_E, "LOG2_E", 5, None),
+    (f64::LOG10_2, "LOG10_2", 5, Some(msrvs::LOG10_2)),
+    (f64::LOG10_E, "LOG10_E", 5, None),
+    (f64::PI, "PI", 3, None),
+    (f64::SQRT_2, "SQRT_2", 5, None),
+    (f64::TAU, "TAU", 3, Some(msrvs::TAU)),
 ];
 
-declare_lint_pass!(ApproxConstant => [APPROX_CONSTANT]);
+pub struct ApproxConstant {
+    msrv: Option<RustcVersion>,
+}
 
-impl<'tcx> LateLintPass<'tcx> for ApproxConstant {
-    fn check_expr(&mut self, cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) {
-        if let ExprKind::Lit(lit) = &e.kind {
-            check_lit(cx, &lit.node, e);
+impl ApproxConstant {
+    #[must_use]
+    pub fn new(msrv: Option<RustcVersion>) -> Self {
+        Self { msrv }
+    }
+
+    fn check_lit(&self, cx: &LateContext<'_>, lit: &LitKind, e: &Expr<'_>) {
+        match *lit {
+            LitKind::Float(s, LitFloatType::Suffixed(fty)) => match fty {
+                FloatTy::F32 => self.check_known_consts(cx, e, s, "f32"),
+                FloatTy::F64 => self.check_known_consts(cx, e, s, "f64"),
+            },
+            LitKind::Float(s, LitFloatType::Unsuffixed) => self.check_known_consts(cx, e, s, "f{32, 64}"),
+            _ => (),
         }
     }
-}
 
-fn check_lit(cx: &LateContext<'_>, lit: &LitKind, e: &Expr<'_>) {
-    match *lit {
-        LitKind::Float(s, LitFloatType::Suffixed(fty)) => match fty {
-            FloatTy::F32 => check_known_consts(cx, e, s, "f32"),
-            FloatTy::F64 => check_known_consts(cx, e, s, "f64"),
-        },
-        LitKind::Float(s, LitFloatType::Unsuffixed) => check_known_consts(cx, e, s, "f{32, 64}"),
-        _ => (),
+    fn check_known_consts(&self, cx: &LateContext<'_>, e: &Expr<'_>, s: symbol::Symbol, module: &str) {
+        let s = s.as_str();
+        if s.parse::<f64>().is_ok() {
+            for &(constant, name, min_digits, msrv) in &KNOWN_CONSTS {
+                if is_approx_const(constant, &s, min_digits)
+                    && msrv.as_ref().map_or(true, |msrv| meets_msrv(self.msrv.as_ref(), msrv))
+                {
+                    span_lint_and_help(
+                        cx,
+                        APPROX_CONSTANT,
+                        e.span,
+                        &format!("approximate value of `{}::consts::{}` found", module, &name),
+                        None,
+                        "consider using the constant directly",
+                    );
+                    return;
+                }
+            }
+        }
     }
 }
 
-fn check_known_consts(cx: &LateContext<'_>, e: &Expr<'_>, s: symbol::Symbol, module: &str) {
-    let s = s.as_str();
-    if s.parse::<f64>().is_ok() {
-        for &(constant, name, min_digits) in &KNOWN_CONSTS {
-            if is_approx_const(constant, &s, min_digits) {
-                span_lint(
-                    cx,
-                    APPROX_CONSTANT,
-                    e.span,
-                    &format!(
-                        "approximate value of `{}::consts::{}` found. \
-                         Consider using it directly",
-                        module, &name
-                    ),
-                );
-                return;
-            }
+impl_lint_pass!(ApproxConstant => [APPROX_CONSTANT]);
+
+impl<'tcx> LateLintPass<'tcx> for ApproxConstant {
+    fn check_expr(&mut self, cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) {
+        if let ExprKind::Lit(lit) = &e.kind {
+            self.check_lit(cx, &lit.node, e);
         }
     }
+
+    extract_msrv_attr!(LateContext);
 }
 
 /// Returns `false` if the number of significant figures in `value` are

clippy_lints/src/assertions_on_constants.rs

@@ -1,5 +1,6 @@
 use clippy_utils::consts::{constant, Constant};
 use clippy_utils::diagnostics::span_lint_and_help;
+use clippy_utils::higher;
 use clippy_utils::source::snippet_opt;
 use clippy_utils::{is_direct_expn_of, is_expn_of, match_panic_call};
 use if_chain::if_chain;
@@ -116,7 +117,7 @@ enum AssertKind {
 /// where `message` is any expression and `c` is a constant bool.
 fn match_assert_with_message<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) -> Option<AssertKind> {
     if_chain! {
-        if let ExprKind::If(cond, then, _) = expr.kind;
+        if let Some(higher::If { cond, then, .. }) = higher::If::hir(expr);
         if let ExprKind::Unary(UnOp::Not, expr) = cond.kind;
         // bind the first argument of the `assert!` macro
         if let Some((Constant::Bool(is_true), _)) = constant(cx, cx.typeck_results(), expr);