diff --git a/clippy_lints/src/default_trait_access.rs b/clippy_lints/src/default_trait_access.rs
new file mode 100644
index 00000000000..0222f896e28
--- /dev/null
+++ b/clippy_lints/src/default_trait_access.rs
@@ -0,0 +1,63 @@
+use rustc::hir::*;
+use rustc::lint::*;
+
+use crate::utils::{match_def_path, opt_def_id, paths, span_lint_and_sugg};
+
+
+/// **What it does:** Checks for literal calls to `Default::default()`.
+///
+/// **Why is this bad?** It's more clear to the reader to use the name of the type whose default is
+/// being gotten than the generic `Default`.
+///
+/// **Known problems:** None.
+///
+/// **Example:**
+/// ```rust
+/// // Bad
+/// let s: String = Default::default();
+///
+/// // Good
+/// let s = String::default();
+/// ```
+declare_clippy_lint! {
+ pub DEFAULT_TRAIT_ACCESS,
+ style,
+ "checks for literal calls to Default::default()"
+}
+
+#[derive(Copy, Clone)]
+pub struct DefaultTraitAccess;
+
+impl LintPass for DefaultTraitAccess {
+ fn get_lints(&self) -> LintArray {
+ lint_array!(DEFAULT_TRAIT_ACCESS)
+ }
+}
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for DefaultTraitAccess {
+ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) {
+ if_chain! {
+ if let ExprCall(ref path, ..) = expr.node;
+ if let ExprPath(ref qpath) = path.node;
+ if let Some(def_id) = opt_def_id(cx.tables.qpath_def(qpath, path.hir_id));
+ if match_def_path(cx.tcx, def_id, &paths::DEFAULT_TRAIT_METHOD);
+ then {
+ match qpath {
+ QPath::Resolved(..) => {
+ // TODO: Work out a way to put "whatever the imported way of referencing
+ // this type in this file" rather than a fully-qualified type.
+ let replacement = format!("{}::default()", cx.tables.expr_ty(expr));
+ span_lint_and_sugg(
+ cx,
+ DEFAULT_TRAIT_ACCESS,
+ expr.span,
+ &format!("Calling {} is more clear than this expression", replacement),
+ "try",
+ replacement);
+ },
+ QPath::TypeRelative(..) => {},
+ }
+ }
+ }
+ }
+}
diff --git a/clippy_lints/src/lib.rs b/clippy_lints/src/lib.rs
index 52145341400..80c02db081e 100644
--- a/clippy_lints/src/lib.rs
+++ b/clippy_lints/src/lib.rs
@@ -111,6 +111,7 @@ pub mod collapsible_if;
pub mod const_static_lifetime;
pub mod copies;
pub mod cyclomatic_complexity;
+pub mod default_trait_access;
pub mod derive;
pub mod doc;
pub mod double_comparison;
@@ -425,6 +426,7 @@ pub fn register_plugins(reg: &mut rustc_plugin::Registry) {
reg.register_late_lint_pass(box neg_cmp_op_on_partial_ord::NoNegCompOpForPartialOrd);
reg.register_late_lint_pass(box unwrap::Pass);
reg.register_late_lint_pass(box duration_subsec::DurationSubsec);
+ reg.register_late_lint_pass(box default_trait_access::DefaultTraitAccess);
reg.register_lint_group("clippy_restriction", vec![
@@ -512,6 +514,7 @@ pub fn register_plugins(reg: &mut rustc_plugin::Registry) {
copies::IF_SAME_THEN_ELSE,
copies::IFS_SAME_COND,
cyclomatic_complexity::CYCLOMATIC_COMPLEXITY,
+ default_trait_access::DEFAULT_TRAIT_ACCESS,
derive::DERIVE_HASH_XOR_EQ,
double_comparison::DOUBLE_COMPARISONS,
double_parens::DOUBLE_PARENS,
@@ -709,6 +712,7 @@ pub fn register_plugins(reg: &mut rustc_plugin::Registry) {
block_in_if_condition::BLOCK_IN_IF_CONDITION_STMT,
collapsible_if::COLLAPSIBLE_IF,
const_static_lifetime::CONST_STATIC_LIFETIME,
+ default_trait_access::DEFAULT_TRAIT_ACCESS,
enum_variants::ENUM_VARIANT_NAMES,
enum_variants::MODULE_INCEPTION,
eq_op::OP_REF,
diff --git a/clippy_lints/src/utils/paths.rs b/clippy_lints/src/utils/paths.rs
index 5af1a151c8c..7606f4f8471 100644
--- a/clippy_lints/src/utils/paths.rs
+++ b/clippy_lints/src/utils/paths.rs
@@ -24,6 +24,7 @@ pub const C_VOID: [&str; 4] = ["std", "os", "raw", "c_void"];
pub const C_VOID_LIBC: [&str; 2] = ["libc", "c_void"];
pub const DEBUG_FMT_METHOD: [&str; 4] = ["core", "fmt", "Debug", "fmt"];
pub const DEFAULT_TRAIT: [&str; 3] = ["core", "default", "Default"];
+pub const DEFAULT_TRAIT_METHOD: [&str; 4] = ["core", "default", "Default", "default"];
pub const DISPLAY_FMT_METHOD: [&str; 4] = ["core", "fmt", "Display", "fmt"];
pub const DOUBLE_ENDED_ITERATOR: [&str; 4] = ["core", "iter", "traits", "DoubleEndedIterator"];
pub const DROP: [&str; 3] = ["core", "mem", "drop"];
diff --git a/tests/ui/default_trait_access.rs b/tests/ui/default_trait_access.rs
new file mode 100644
index 00000000000..9db875ee305
--- /dev/null
+++ b/tests/ui/default_trait_access.rs
@@ -0,0 +1,39 @@
+#![warn(default_trait_access)]
+
+use std::default::Default as D2;
+use std::string;
+use std::default;
+
+fn main() {
+ let s1: String = Default::default();
+
+ let s2 = String::default();
+
+ let s3: String = D2::default();
+
+ let s4: String = std::default::Default::default();
+
+ let s5 = string::String::default();
+
+ let s6: String = default::Default::default();
+
+ let s7 = std::string::String::default();
+
+ let s8: String = DefaultFactory::make_t_badly();
+
+ let s9: String = DefaultFactory::make_t_nicely();
+
+ println!("[{}] [{}] [{}] [{}] [{}] [{}] [{}] [{}] [{}]", s1, s2, s3, s4, s5, s6, s7, s8, s9);
+}
+
+struct DefaultFactory;
+
+impl DefaultFactory {
+ pub fn make_t_badly<T: Default>() -> T {
+ Default::default()
+ }
+
+ pub fn make_t_nicely<T: Default>() -> T {
+ T::default()
+ }
+}
diff --git a/tests/ui/default_trait_access.stderr b/tests/ui/default_trait_access.stderr
new file mode 100644
index 00000000000..b2cb49e6c80
--- /dev/null
+++ b/tests/ui/default_trait_access.stderr
@@ -0,0 +1,34 @@
+error: Calling std::string::String::default() is more clear than this expression
+ --> $DIR/default_trait_access.rs:8:22
+ |
+8 | let s1: String = Default::default();
+ | ^^^^^^^^^^^^^^^^^^ help: try: `std::string::String::default()`
+ |
+ = note: `-D default-trait-access` implied by `-D warnings`
+
+error: Calling std::string::String::default() is more clear than this expression
+ --> $DIR/default_trait_access.rs:12:22
+ |
+12 | let s3: String = D2::default();
+ | ^^^^^^^^^^^^^ help: try: `std::string::String::default()`
+
+error: Calling std::string::String::default() is more clear than this expression
+ --> $DIR/default_trait_access.rs:14:22
+ |
+14 | let s4: String = std::default::Default::default();
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `std::string::String::default()`
+
+error: Calling std::string::String::default() is more clear than this expression
+ --> $DIR/default_trait_access.rs:18:22
+ |
+18 | let s6: String = default::Default::default();
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `std::string::String::default()`
+
+error: Calling T::default() is more clear than this expression
+ --> $DIR/default_trait_access.rs:33:9
+ |
+33 | Default::default()
+ | ^^^^^^^^^^^^^^^^^^ help: try: `T::default()`
+
+error: aborting due to 5 previous errors
+
diff --git a/tests/ui/default_trait_access.stdout b/tests/ui/default_trait_access.stdout
new file mode 100644
index 00000000000..e69de29bb2d