More precise suggestion for non_upper_case_globals

src/librustc_lint/bad_style.rs

@@ -16,7 +16,7 @@ use lint::{LintPass, LateLintPass};
 use syntax::abi::Abi;
 use syntax::ast;
 use syntax::attr;
-use syntax_pos::Span;
+use syntax_pos::{BytePos, Span};
 
 use rustc::hir::{self, PatKind};
 use rustc::hir::intravisit::FnKind;
@@ -342,6 +342,17 @@ impl NonUpperCaseGlobals {
     fn check_upper_case(cx: &LateContext, sort: &str, name: ast::Name, span: Span) {
         if name.as_str().chars().any(|c| c.is_lowercase()) {
             let uc = NonSnakeCase::to_snake_case(&name.as_str()).to_uppercase();
+
+            let start = cx.tcx.sess.codemap().span_to_snippet(span)
+                .map(|snippet| snippet.find(name.as_str().chars().as_str()).unwrap_or(0))
+                .unwrap_or(0);
+            let end = start + name.as_str().len();
+            let span = Span::new(
+                span.lo() + BytePos(start as u32),
+                span.lo() + BytePos(end as u32),
+                span.ctxt()
+            );
+
             if name != &*uc {
                 cx.span_lint(NON_UPPER_CASE_GLOBALS,
                              span,

src/test/ui/lint/lint-group-style.stderr

@@ -25,10 +25,10 @@ note: lint level defined here
    = note: #[forbid(non_snake_case)] implied by #[forbid(bad_style)]
 
 error: static variable `bad` should have an upper case name such as `BAD`
-  --> $DIR/lint-group-style.rs:24:9
+  --> $DIR/lint-group-style.rs:24:16
    |
 24 |         static bad: isize = 1; //~ ERROR should have an upper
-   |         ^^^^^^^^^^^^^^^^^^^^^^
+   |                ^^^
    |
 note: lint level defined here
   --> $DIR/lint-group-style.rs:20:14

src/test/ui/lint/non-upper-case-globals.rs

@@ -0,0 +1,33 @@
+// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![allow(dead_code)]
+#![deny(non_upper_case_globals)]
+
+static foo: isize = 1;
+//~^ ERROR static variable `foo` should have an upper case name such as `FOO`
+
+static mut bar: isize = 1;
+//~^ ERROR static variable `bar` should have an upper case name such as `BAR`
+
+fn main() {
+    const b: usize = 1;
+    //~^ ERROR constant `b` should have an upper case name such as `B`
+}
+
+trait Foo {
+    const camelCase: usize;
+    //~^ ERROR associated constant `camelCase` should have an upper case name such as `CAMEL_CASE`
+}
+
+impl Foo for i32 {
+    const camelCase: usize = 2;
+    //~^ ERROR associated constant `camelCase` should have an upper case name such as `CAMEL_CASE`
+}

src/test/ui/lint/non-upper-case-globals.stderr

@@ -0,0 +1,38 @@
+error: static variable `foo` should have an upper case name such as `FOO`
+  --> $DIR/non-upper-case-globals.rs:14:8
+   |
+14 | static foo: isize = 1;
+   |        ^^^
+   |
+note: lint level defined here
+  --> $DIR/non-upper-case-globals.rs:12:9
+   |
+12 | #![deny(non_upper_case_globals)]
+   |         ^^^^^^^^^^^^^^^^^^^^^^
+
+error: static variable `bar` should have an upper case name such as `BAR`
+  --> $DIR/non-upper-case-globals.rs:17:12
+   |
+17 | static mut bar: isize = 1;
+   |            ^^^
+
+error: constant `b` should have an upper case name such as `B`
+  --> $DIR/non-upper-case-globals.rs:21:11
+   |
+21 |     const b: usize = 1;
+   |           ^
+
+error: associated constant `camelCase` should have an upper case name such as `CAMEL_CASE`
+  --> $DIR/non-upper-case-globals.rs:26:11
+   |
+26 |     const camelCase: usize;
+   |           ^^^^^^^^^
+
+error: associated constant `camelCase` should have an upper case name such as `CAMEL_CASE`
+  --> $DIR/non-upper-case-globals.rs:31:11
+   |
+31 |     const camelCase: usize = 2;
+   |           ^^^^^^^^^
+
+error: aborting due to 5 previous errors
+