Merge pull request #2797 from mipli/2250-unimplemented-macro

Lint for unimplemented!()

Author: oli-obk

CHANGELOG.md

@@ -815,6 +815,7 @@ All notable changes to this project will be documented in this file.
 [`trivial_regex`]: https://rust-lang-nursery.github.io/rust-clippy/master/index.html#trivial_regex
 [`type_complexity`]: https://rust-lang-nursery.github.io/rust-clippy/master/index.html#type_complexity
 [`unicode_not_nfc`]: https://rust-lang-nursery.github.io/rust-clippy/master/index.html#unicode_not_nfc
+[`unimplemented`]: https://rust-lang-nursery.github.io/rust-clippy/master/index.html#unimplemented
 [`unit_arg`]: https://rust-lang-nursery.github.io/rust-clippy/master/index.html#unit_arg
 [`unit_cmp`]: https://rust-lang-nursery.github.io/rust-clippy/master/index.html#unit_cmp
 [`unnecessary_cast`]: https://rust-lang-nursery.github.io/rust-clippy/master/index.html#unnecessary_cast

README.md

@@ -7,7 +7,7 @@
 
 A collection of lints to catch common mistakes and improve your [Rust](https://github.com/rust-lang/rust) code.
 
-[There are 258 lints included in this crate!](https://rust-lang-nursery.github.io/rust-clippy/master/index.html)
+[There are 259 lints included in this crate!](https://rust-lang-nursery.github.io/rust-clippy/master/index.html)
 
 We have a bunch of lint categories to allow you to choose how much clippy is supposed to ~~annoy~~ help you:
 

clippy_lints/src/lib.rs

@@ -177,7 +177,7 @@ pub mod non_expressive_names;
 pub mod ok_if_let;
 pub mod open_options;
 pub mod overflow_check_conditional;
-pub mod panic;
+pub mod panic_unimplemented;
 pub mod partialeq_ne_impl;
 pub mod precedence;
 pub mod ptr;
@@ -352,7 +352,7 @@ pub fn register_plugins(reg: &mut rustc_plugin::Registry) {
     reg.register_late_lint_pass(box escape::Pass{too_large_for_stack: conf.too_large_for_stack});
     reg.register_early_lint_pass(box misc_early::MiscEarly);
     reg.register_late_lint_pass(box array_indexing::ArrayIndexing);
-    reg.register_late_lint_pass(box panic::Pass);
+    reg.register_late_lint_pass(box panic_unimplemented::Pass);
     reg.register_late_lint_pass(box strings::StringLitAsBytes);
     reg.register_late_lint_pass(box derive::Derive);
     reg.register_late_lint_pass(box types::CharLitAsU8);
@@ -434,6 +434,7 @@ pub fn register_plugins(reg: &mut rustc_plugin::Registry) {
         methods::WRONG_PUB_SELF_CONVENTION,
         misc::FLOAT_CMP_CONST,
         missing_doc::MISSING_DOCS_IN_PRIVATE_ITEMS,
+        panic_unimplemented::UNIMPLEMENTED,
         shadow::SHADOW_REUSE,
         shadow::SHADOW_SAME,
         shadow::SHADOW_UNRELATED,
@@ -626,7 +627,7 @@ pub fn register_plugins(reg: &mut rustc_plugin::Registry) {
         ok_if_let::IF_LET_SOME_RESULT,
         open_options::NONSENSICAL_OPEN_OPTIONS,
         overflow_check_conditional::OVERFLOW_CHECK_CONDITIONAL,
-        panic::PANIC_PARAMS,
+        panic_unimplemented::PANIC_PARAMS,
         partialeq_ne_impl::PARTIALEQ_NE_IMPL,
         precedence::PRECEDENCE,
         ptr::CMP_NULL,
@@ -748,7 +749,7 @@ pub fn register_plugins(reg: &mut rustc_plugin::Registry) {
         non_expressive_names::JUST_UNDERSCORES_AND_DIGITS,
         non_expressive_names::MANY_SINGLE_CHAR_NAMES,
         ok_if_let::IF_LET_SOME_RESULT,
-        panic::PANIC_PARAMS,
+        panic_unimplemented::PANIC_PARAMS,
         ptr::CMP_NULL,
         ptr::PTR_ARG,
         question_mark::QUESTION_MARK,

clippy_lints/src/panic.rs

@@ -0,0 +1,102 @@
+use rustc::hir::*;
+use rustc::lint::*;
+use syntax::ast::LitKind;
+use syntax::ptr::P;
+use syntax::ext::quote::rt::Span;
+use utils::{is_direct_expn_of, is_expn_of, match_def_path, opt_def_id, paths, resolve_node, span_lint};
+
+/// **What it does:** Checks for missing parameters in `panic!`.
+///
+/// **Why is this bad?** Contrary to the `format!` family of macros, there are
+/// two forms of `panic!`: if there are no parameters given, the first argument
+/// is not a format string and used literally. So while `format!("{}")` will
+/// fail to compile, `panic!("{}")` will not.
+///
+/// **Known problems:** None.
+///
+/// **Example:**
+/// ```rust
+/// panic!("This `panic!` is probably missing a parameter there: {}");
+/// ```
+declare_clippy_lint! {
+    pub PANIC_PARAMS,
+    style,
+    "missing parameters in `panic!` calls"
+}
+
+/// **What it does:** Checks for usage of `unimplemented!`.
+///
+/// **Why is this bad?** This macro should not be present in production code
+///
+/// **Known problems:** None.
+///
+/// **Example:**
+/// ```rust
+/// unimplemented!();
+/// ```
+declare_clippy_lint! {
+    pub UNIMPLEMENTED,
+    restriction,
+    "`unimplemented!` should not be present in production code"
+}
+
+#[allow(missing_copy_implementations)]
+pub struct Pass;
+
+impl LintPass for Pass {
+    fn get_lints(&self) -> LintArray {
+        lint_array!(PANIC_PARAMS, UNIMPLEMENTED)
+    }
+}
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Pass {
+    fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) {
+        if_chain! {
+            if let ExprBlock(ref block, _) = expr.node;
+            if let Some(ref ex) = block.expr;
+            if let ExprCall(ref fun, ref params) = ex.node;
+            if let ExprPath(ref qpath) = fun.node;
+            if let Some(fun_def_id) = opt_def_id(resolve_node(cx, qpath, fun.hir_id));
+            if match_def_path(cx.tcx, fun_def_id, &paths::BEGIN_PANIC);
+            if params.len() == 2;
+            then {
+                if is_expn_of(expr.span, "unimplemented").is_some() {
+                    let span = get_outer_span(expr);
+                    span_lint(cx, UNIMPLEMENTED, span,
+                              "`unimplemented` should not be present in production code");
+                } else {
+                    match_panic(params, expr, cx);
+                }
+            }
+        }
+    }
+}
+
+fn get_outer_span(expr: &Expr) -> Span {
+    if_chain! {
+        if let Some(first) = expr.span.ctxt().outer().expn_info();
+        if let Some(second) = first.call_site.ctxt().outer().expn_info();
+        then {
+            second.call_site
+        } else {
+            expr.span
+        }
+    }
+}
+
+fn match_panic(params: &P<[Expr]>, expr: &Expr, cx: &LateContext) {
+    if_chain! {
+        if let ExprLit(ref lit) = params[0].node;
+        if is_direct_expn_of(expr.span, "panic").is_some();
+        if let LitKind::Str(ref string, _) = lit.node;
+        let string = string.as_str().replace("{{", "").replace("}}", "");
+        if let Some(par) = string.find('{');
+        if string[par..].contains('}');
+        if params[0].span.source_callee().is_none();
+        if params[0].span.lo() != params[0].span.hi();
+        then {
+            span_lint(cx, PANIC_PARAMS, params[0].span,
+                      "you probably are missing some parameter in your format string");
+        }
+    }
+}

clippy_lints/src/panic_unimplemented.rs

@@ -1,7 +1,7 @@
 
 
 
-#![warn(panic_params)]
+#![warn(panic_params, unimplemented)]
 
 fn missing() {
     if true {
@@ -53,6 +53,12 @@ fn ok_escaped() {
     panic!("{case }}");
 }
 
+fn unimplemented() {
+    let a = 2;
+    unimplemented!();
+    let b = a + 2;
+}
+
 fn main() {
     missing();
     ok_single();
@@ -61,4 +67,5 @@ fn main() {
     ok_inner();
     ok_nomsg();
     ok_escaped();
+    unimplemented();
 }

tests/ui/panic.rs renamed to tests/ui/panic_unimplemented.rs

@@ -1,28 +1,36 @@
 error: you probably are missing some parameter in your format string
- --> $DIR/panic.rs:8:16
+ --> $DIR/panic_unimplemented.rs:8:16
   |
 8 |         panic!("{}");
   |                ^^^^
   |
   = note: `-D panic-params` implied by `-D warnings`
 
 error: you probably are missing some parameter in your format string
-  --> $DIR/panic.rs:10:16
+  --> $DIR/panic_unimplemented.rs:10:16
    |
 10 |         panic!("{:?}");
    |                ^^^^^^
 
 error: you probably are missing some parameter in your format string
-  --> $DIR/panic.rs:12:23
+  --> $DIR/panic_unimplemented.rs:12:23
    |
 12 |         assert!(true, "here be missing values: {}");
    |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: you probably are missing some parameter in your format string
-  --> $DIR/panic.rs:15:12
+  --> $DIR/panic_unimplemented.rs:15:12
    |
 15 |     panic!("{{{this}}}");
    |            ^^^^^^^^^^^^
 
-error: aborting due to 4 previous errors
+error: `unimplemented` should not be present in production code
+  --> $DIR/panic_unimplemented.rs:58:5
+   |
+58 |     unimplemented!();
+   |     ^^^^^^^^^^^^^^^^^
+   |
+   = note: `-D unimplemented` implied by `-D warnings`
+
+error: aborting due to 5 previous errors