Merge StaticConst and StaticStatic lints into StaticConst.

Author: krk

clippy_lints/src/const_static_lifetime.rs

@@ -1,11 +1,11 @@
-use crate::redundant_static_lifetime::RedundantStaticLifetime;
-use crate::utils::in_macro_or_desugar;
+use crate::utils::{in_macro_or_desugar, snippet, span_lint_and_then};
 use rustc::lint::{EarlyContext, EarlyLintPass, LintArray, LintPass};
 use rustc::{declare_lint_pass, declare_tool_lint};
+use rustc_errors::Applicability;
 use syntax::ast::*;
 
 declare_clippy_lint! {
-    /// **What it does:** Checks for constants with an explicit `'static` lifetime.
+    /// **What it does:** Checks for constants and statics with an explicit `'static` lifetime.
     ///
     /// **Why is this bad?** Adding `'static` to every reference can create very
     /// complicated types.
@@ -16,36 +16,77 @@ declare_clippy_lint! {
     /// ```ignore
     /// const FOO: &'static [(&'static str, &'static str, fn(&Bar) -> bool)] =
     /// &[...]
+    /// static FOO: &'static [(&'static str, &'static str, fn(&Bar) -> bool)] =
+    /// &[...]
     /// ```
     /// This code can be rewritten as
     /// ```ignore
     ///  const FOO: &[(&str, &str, fn(&Bar) -> bool)] = &[...]
+    ///  static FOO: &[(&str, &str, fn(&Bar) -> bool)] = &[...]
     /// ```
     pub CONST_STATIC_LIFETIME,
     style,
-    "Using explicit `'static` lifetime for constants when elision rules would allow omitting them."
+    "Using explicit `'static` lifetime for constants or statics when elision rules would allow omitting them."
 }
 
 declare_lint_pass!(StaticConst => [CONST_STATIC_LIFETIME]);
 
 impl StaticConst {
     // Recursively visit types
-    fn visit_type(&mut self, ty: &Ty, cx: &EarlyContext<'_>) {
-        let mut rsl =
-            RedundantStaticLifetime::new(CONST_STATIC_LIFETIME, "Constants have by default a `'static` lifetime");
-        rsl.visit_type(ty, cx)
+    pub fn visit_type(&mut self, ty: &Ty, cx: &EarlyContext<'_>, reason: &str) {
+        match ty.node {
+            // Be careful of nested structures (arrays and tuples)
+            TyKind::Array(ref ty, _) => {
+                self.visit_type(&*ty, cx, reason);
+            },
+            TyKind::Tup(ref tup) => {
+                for tup_ty in tup {
+                    self.visit_type(&*tup_ty, cx, reason);
+                }
+            },
+            // This is what we are looking for !
+            TyKind::Rptr(ref optional_lifetime, ref borrow_type) => {
+                // Match the 'static lifetime
+                if let Some(lifetime) = *optional_lifetime {
+                    match borrow_type.ty.node {
+                        TyKind::Path(..) | TyKind::Slice(..) | TyKind::Array(..) | TyKind::Tup(..) => {
+                            if lifetime.ident.name == syntax::symbol::kw::StaticLifetime {
+                                let snip = snippet(cx, borrow_type.ty.span, "<type>");
+                                let sugg = format!("&{}", snip);
+                                span_lint_and_then(cx, CONST_STATIC_LIFETIME, lifetime.ident.span, reason, |db| {
+                                    db.span_suggestion(
+                                        ty.span,
+                                        "consider removing `'static`",
+                                        sugg,
+                                        Applicability::MachineApplicable, //snippet
+                                    );
+                                });
+                            }
+                        },
+                        _ => {},
+                    }
+                }
+                self.visit_type(&*borrow_type.ty, cx, reason);
+            },
+            TyKind::Slice(ref ty) => {
+                self.visit_type(ty, cx, reason);
+            },
+            _ => {},
+        }
     }
 }
 
 impl EarlyLintPass for StaticConst {
     fn check_item(&mut self, cx: &EarlyContext<'_>, item: &Item) {
         if !in_macro_or_desugar(item.span) {
-            // Match only constants...
             if let ItemKind::Const(ref var_type, _) = item.node {
-                self.visit_type(var_type, cx);
+                self.visit_type(var_type, cx, "Constants have by default a `'static` lifetime");
+                // Don't check associated consts because `'static` cannot be elided on those (issue #2438)
+            }
+
+            if let ItemKind::Static(ref var_type, _, _) = item.node {
+                self.visit_type(var_type, cx, "Statics have by default a `'static` lifetime");
             }
         }
     }
-
-    // Don't check associated consts because `'static` cannot be elided on those (issue #2438)
 }

clippy_lints/src/lib.rs

@@ -141,7 +141,6 @@ macro_rules! declare_clippy_lint {
 mod consts;
 #[macro_use]
 mod utils;
-mod redundant_static_lifetime;
 
 // begin lints modules, do not remove this comment, it’s used in `update_lints`
 pub mod approx_const;
@@ -257,7 +256,6 @@ pub mod returns;
 pub mod serde_api;
 pub mod shadow;
 pub mod slow_vector_initialization;
-pub mod static_static_lifetime;
 pub mod strings;
 pub mod suspicious_trait_impl;
 pub mod swap;
@@ -556,7 +554,6 @@ pub fn register_plugins(reg: &mut rustc_plugin::Registry<'_>, conf: &Conf) {
     reg.register_late_lint_pass(box identity_conversion::IdentityConversion::default());
     reg.register_late_lint_pass(box types::ImplicitHasher);
     reg.register_early_lint_pass(box const_static_lifetime::StaticConst);
-    reg.register_early_lint_pass(box static_static_lifetime::StaticStatic);
     reg.register_late_lint_pass(box fallible_impl_from::FallibleImplFrom);
     reg.register_late_lint_pass(box replace_consts::ReplaceConsts);
     reg.register_late_lint_pass(box types::UnitArg);
@@ -847,7 +844,6 @@ pub fn register_plugins(reg: &mut rustc_plugin::Registry<'_>, conf: &Conf) {
         returns::UNUSED_UNIT,
         serde_api::SERDE_API_MISUSE,
         slow_vector_initialization::SLOW_VECTOR_INITIALIZATION,
-        static_static_lifetime::STATIC_STATIC_LIFETIME,
         strings::STRING_LIT_AS_BYTES,
         suspicious_trait_impl::SUSPICIOUS_ARITHMETIC_IMPL,
         suspicious_trait_impl::SUSPICIOUS_OP_ASSIGN_IMPL,
@@ -966,7 +962,6 @@ pub fn register_plugins(reg: &mut rustc_plugin::Registry<'_>, conf: &Conf) {
         returns::LET_AND_RETURN,
         returns::NEEDLESS_RETURN,
         returns::UNUSED_UNIT,
-        static_static_lifetime::STATIC_STATIC_LIFETIME,
         strings::STRING_LIT_AS_BYTES,
         types::FN_TO_NUMERIC_CAST,
         types::FN_TO_NUMERIC_CAST_WITH_TRUNCATION,

clippy_lints/src/redundant_static_lifetime.rs

@@ -23,6 +23,28 @@ const VAR_TUPLE: &'static (u8, u8) = &(1, 2); // ERROR Consider removing 'static
 
 const VAR_ARRAY: &'static [u8; 1] = b"T"; // ERROR Consider removing 'static.
 
+static STATIC_VAR_ONE: &'static str = "Test static #1"; // ERROR Consider removing 'static.
+
+static STATIC_VAR_TWO: &str = "Test static #2"; // This line should not raise a warning.
+
+static STATIC_VAR_THREE: &[&'static str] = &["one", "two"]; // ERROR Consider removing 'static
+
+static STATIC_VAR_FOUR: (&str, (&str, &'static str), &'static str) = ("on", ("th", "th"), "on"); // ERROR Consider removing 'static
+
+static STATIC_VAR_FIVE: &'static [&[&'static str]] = &[&["test"], &["other one"]]; // ERROR Consider removing 'static
+
+static STATIC_VAR_SIX: &'static u8 = &5;
+
+static STATIC_VAR_SEVEN: &[&(&str, &'static [&'static str])] = &[&("one", &["other one"])];
+
+static STATIC_VAR_HEIGHT: &'static Foo = &Foo {};
+
+static STATIC_VAR_SLICE: &'static [u8] = b"Test static #3"; // ERROR Consider removing 'static.
+
+static STATIC_VAR_TUPLE: &'static (u8, u8) = &(1, 2); // ERROR Consider removing 'static.
+
+static STATIC_VAR_ARRAY: &'static [u8; 1] = b"T"; // ERROR Consider removing 'static.
+
 fn main() {
     let false_positive: &'static str = "test";
     println!("{}", VAR_ONE);

clippy_lints/src/static_static_lifetime.rs

@@ -78,5 +78,83 @@ error: Constants have by default a `'static` lifetime
 LL | const VAR_ARRAY: &'static [u8; 1] = b"T"; // ERROR Consider removing 'static.
    |                  -^^^^^^^-------- help: consider removing `'static`: `&[u8; 1]`
 
-error: aborting due to 13 previous errors
+error: Statics have by default a `'static` lifetime
+  --> $DIR/const_static_lifetime.rs:26:25
+   |
+LL | static STATIC_VAR_ONE: &'static str = "Test static #1"; // ERROR Consider removing 'static.
+   |                        -^^^^^^^---- help: consider removing `'static`: `&str`
+
+error: Statics have by default a `'static` lifetime
+  --> $DIR/const_static_lifetime.rs:30:29
+   |
+LL | static STATIC_VAR_THREE: &[&'static str] = &["one", "two"]; // ERROR Consider removing 'static
+   |                            -^^^^^^^---- help: consider removing `'static`: `&str`
+
+error: Statics have by default a `'static` lifetime
+  --> $DIR/const_static_lifetime.rs:32:40
+   |
+LL | static STATIC_VAR_FOUR: (&str, (&str, &'static str), &'static str) = ("on", ("th", "th"), "on"); // ERROR Consider removing 'static
+   |                                       -^^^^^^^---- help: consider removing `'static`: `&str`
+
+error: Statics have by default a `'static` lifetime
+  --> $DIR/const_static_lifetime.rs:32:55
+   |
+LL | static STATIC_VAR_FOUR: (&str, (&str, &'static str), &'static str) = ("on", ("th", "th"), "on"); // ERROR Consider removing 'static
+   |                                                      -^^^^^^^---- help: consider removing `'static`: `&str`
+
+error: Statics have by default a `'static` lifetime
+  --> $DIR/const_static_lifetime.rs:34:26
+   |
+LL | static STATIC_VAR_FIVE: &'static [&[&'static str]] = &[&["test"], &["other one"]]; // ERROR Consider removing 'static
+   |                         -^^^^^^^------------------ help: consider removing `'static`: `&[&[&'static str]]`
+
+error: Statics have by default a `'static` lifetime
+  --> $DIR/const_static_lifetime.rs:34:38
+   |
+LL | static STATIC_VAR_FIVE: &'static [&[&'static str]] = &[&["test"], &["other one"]]; // ERROR Consider removing 'static
+   |                                     -^^^^^^^---- help: consider removing `'static`: `&str`
+
+error: Statics have by default a `'static` lifetime
+  --> $DIR/const_static_lifetime.rs:36:25
+   |
+LL | static STATIC_VAR_SIX: &'static u8 = &5;
+   |                        -^^^^^^^--- help: consider removing `'static`: `&u8`
+
+error: Statics have by default a `'static` lifetime
+  --> $DIR/const_static_lifetime.rs:38:37
+   |
+LL | static STATIC_VAR_SEVEN: &[&(&str, &'static [&'static str])] = &[&("one", &["other one"])];
+   |                                    -^^^^^^^--------------- help: consider removing `'static`: `&[&'static str]`
+
+error: Statics have by default a `'static` lifetime
+  --> $DIR/const_static_lifetime.rs:38:47
+   |
+LL | static STATIC_VAR_SEVEN: &[&(&str, &'static [&'static str])] = &[&("one", &["other one"])];
+   |                                              -^^^^^^^---- help: consider removing `'static`: `&str`
+
+error: Statics have by default a `'static` lifetime
+  --> $DIR/const_static_lifetime.rs:40:28
+   |
+LL | static STATIC_VAR_HEIGHT: &'static Foo = &Foo {};
+   |                           -^^^^^^^---- help: consider removing `'static`: `&Foo`
+
+error: Statics have by default a `'static` lifetime
+  --> $DIR/const_static_lifetime.rs:42:27
+   |
+LL | static STATIC_VAR_SLICE: &'static [u8] = b"Test static #3"; // ERROR Consider removing 'static.
+   |                          -^^^^^^^----- help: consider removing `'static`: `&[u8]`
+
+error: Statics have by default a `'static` lifetime
+  --> $DIR/const_static_lifetime.rs:44:27
+   |
+LL | static STATIC_VAR_TUPLE: &'static (u8, u8) = &(1, 2); // ERROR Consider removing 'static.
+   |                          -^^^^^^^--------- help: consider removing `'static`: `&(u8, u8)`
+
+error: Statics have by default a `'static` lifetime
+  --> $DIR/const_static_lifetime.rs:46:27
+   |
+LL | static STATIC_VAR_ARRAY: &'static [u8; 1] = b"T"; // ERROR Consider removing 'static.
+   |                          -^^^^^^^-------- help: consider removing `'static`: `&[u8; 1]`
+
+error: aborting due to 26 previous errors