auto merge of #15773 : P1start/rust/style-lints, r=alexcrichton

This unifies the `non_snake_case_functions` and `uppercase_variables` lints into one lint, `non_snake_case`. It also now checks for non-snake-case modules. This also extends the non-camel-case types lint to check type parameters, and merges the `non_uppercase_pattern_statics` lint into the `non_uppercase_statics` lint.

Because the `uppercase_variables` lint is now part of the `non_snake_case` lint, all non-snake-case variables that start with lowercase characters (such as `fooBar`) will now trigger the `non_snake_case` lint.

New code should be updated to use the new `non_snake_case` lint instead of the previous `non_snake_case_functions` and `uppercase_variables` lints. All use of the `non_uppercase_pattern_statics` should be replaced with the `non_uppercase_statics` lint. Any code that previously contained non-snake-case module or variable names should be updated to use snake case names or disable the `non_snake_case` lint. Any code with non-camel-case type parameters should be changed to use camel case or disable the `non_camel_case_types` lint.

This also adds support for lint groups to the compiler. Lint groups are a way of grouping a number of lints together under one name. For example, this also defines a default lint for naming conventions, named `bad_style`. Writing `#[allow(bad_style)]` is equivalent to writing `#[allow(non_camel_case_types, non_snake_case, non_uppercase_statics)]`. These lint groups can also be defined as a compiler plugin using the new `Registry::register_lint_group` method.

This also adds two built-in lint groups, `bad_style` and `unused`. The contents of these groups can be seen by running `rustc -W help`.

[breaking-change]

src/doc/guide-ffi.md

@@ -477,7 +477,7 @@ extern crate libc;
 
 #[cfg(target_os = "win32", target_arch = "x86")]
 #[link(name = "kernel32")]
-#[allow(non_snake_case_functions)]
+#[allow(non_snake_case)]
 extern "stdcall" {
     fn SetEnvironmentVariableA(n: *const u8, v: *const u8) -> libc::c_int;
 }

src/etc/unicode.py

@@ -34,7 +34,7 @@
 
 // NOTE: The following code was generated by "src/etc/unicode.py", do not edit directly
 
-#![allow(missing_doc, non_uppercase_statics, non_snake_case_functions)]
+#![allow(missing_doc, non_uppercase_statics, non_snake_case)]
 '''
 
 # Mapping taken from Table 12 from:

src/libcollections/hash/mod.rs

@@ -157,8 +157,8 @@ macro_rules! impl_hash_tuple(
 
     ( $($name:ident)+) => (
         impl<S: Writer, $($name: Hash<S>),*> Hash<S> for ($($name,)*) {
-            #[allow(uppercase_variables)]
             #[inline]
+            #[allow(non_snake_case)]
             fn hash(&self, state: &mut S) {
                 match *self {
                     ($(ref $name,)*) => {

src/libcore/char.rs

@@ -12,7 +12,7 @@
 //!
 //! For more details, see ::unicode::char (a.k.a. std::char)
 
-#![allow(non_snake_case_functions)]
+#![allow(non_snake_case)]
 #![doc(primitive = "char")]
 
 use mem::transmute;

src/libcore/fmt/mod.rs

@@ -668,7 +668,7 @@ macro_rules! tuple (
     () => ();
     ( $($name:ident,)+ ) => (
         impl<$($name:Show),*> Show for ($($name,)*) {
-            #[allow(uppercase_variables, dead_assignment)]
+            #[allow(non_snake_case, dead_assignment)]
             fn fmt(&self, f: &mut Formatter) -> Result {
                 try!(write!(f, "("));
                 let ($(ref $name,)*) = *self;

src/libcore/ops.rs

@@ -775,7 +775,7 @@ macro_rules! def_fn_mut(
         FnMut<($($args,)*),Result>
         for extern "Rust" fn($($args: $args,)*) -> Result {
             #[rust_call_abi_hack]
-            #[allow(uppercase_variables)]
+            #[allow(non_snake_case)]
             fn call_mut(&mut self, args: ($($args,)*)) -> Result {
                 let ($($args,)*) = args;
                 (*self)($($args,)*)

src/libcore/str.rs

@@ -394,9 +394,9 @@ impl NaiveSearcher {
     fn next(&mut self, haystack: &[u8], needle: &[u8]) -> Option<(uint, uint)> {
         while self.position + needle.len() <= haystack.len() {
             if haystack.slice(self.position, self.position + needle.len()) == needle {
-                let matchPos = self.position;
+                let match_pos = self.position;
                 self.position += needle.len(); // add 1 for all matches
-                return Some((matchPos, matchPos + needle.len()));
+                return Some((match_pos, match_pos + needle.len()));
             } else {
                 self.position += 1;
             }
@@ -410,7 +410,7 @@ impl NaiveSearcher {
 #[deriving(Clone)]
 struct TwoWaySearcher {
     // constants
-    critPos: uint,
+    crit_pos: uint,
     period: uint,
     byteset: u64,
 
@@ -423,32 +423,31 @@ struct TwoWaySearcher {
 // Crochemore, M., Perrin, D., 1991, Two-way string-matching, Journal of the ACM 38(3):651-675.
 impl TwoWaySearcher {
     fn new(needle: &[u8]) -> TwoWaySearcher {
-        let (critPos1, period1) = TwoWaySearcher::maximal_suffix(needle, false);
-        let (critPos2, period2) = TwoWaySearcher::maximal_suffix(needle, true);
+        let (crit_pos1, period1) = TwoWaySearcher::maximal_suffix(needle, false);
+        let (crit_pos2, period2) = TwoWaySearcher::maximal_suffix(needle, true);
 
-        let critPos;
+        let crit_pos;
         let period;
-        if critPos1 > critPos2 {
-            critPos = critPos1;
+        if crit_pos1 > crit_pos2 {
+            crit_pos = crit_pos1;
             period = period1;
         } else {
-            critPos = critPos2;
+            crit_pos = crit_pos2;
             period = period2;
         }
 
         let byteset = needle.iter()
                             .fold(0, |a, &b| (1 << ((b & 0x3f) as uint)) | a);
 
-
-        // The logic here (calculating critPos and period, the final if statement to see which
+        // The logic here (calculating crit_pos and period, the final if statement to see which
         // period to use for the TwoWaySearcher) is essentially an implementation of the
         // "small-period" function from the paper (p. 670)
         //
-        // In the paper they check whether `needle.slice_to(critPos)` is a suffix of
-        // `needle.slice(critPos, critPos + period)`, which is precisely what this does
-        if needle.slice_to(critPos) == needle.slice(period, period + critPos) {
+        // In the paper they check whether `needle.slice_to(crit_pos)` is a suffix of
+        // `needle.slice(crit_pos, crit_pos + period)`, which is precisely what this does
+        if needle.slice_to(crit_pos) == needle.slice(period, period + crit_pos) {
             TwoWaySearcher {
-                critPos: critPos,
+                crit_pos: crit_pos,
                 period: period,
                 byteset: byteset,
 
@@ -457,8 +456,8 @@ impl TwoWaySearcher {
             }
         } else {
             TwoWaySearcher {
-                critPos: critPos,
-                period: cmp::max(critPos, needle.len() - critPos) + 1,
+                crit_pos: crit_pos,
+                period: cmp::max(crit_pos, needle.len() - crit_pos) + 1,
                 byteset: byteset,
 
                 position: 0,
@@ -468,7 +467,7 @@ impl TwoWaySearcher {
     }
 
     #[inline]
-    fn next(&mut self, haystack: &[u8], needle: &[u8], longPeriod: bool) -> Option<(uint, uint)> {
+    fn next(&mut self, haystack: &[u8], needle: &[u8], long_period: bool) -> Option<(uint, uint)> {
         'search: loop {
             // Check that we have room to search in
             if self.position + needle.len() > haystack.len() {
@@ -484,36 +483,37 @@ impl TwoWaySearcher {
             }
 
             // See if the right part of the needle matches
-            let start = if longPeriod { self.critPos } else { cmp::max(self.critPos, self.memory) };
+            let start = if long_period { self.crit_pos }
+                        else { cmp::max(self.crit_pos, self.memory) };
             for i in range(start, needle.len()) {
                 if needle[i] != haystack[self.position + i] {
-                    self.position += i - self.critPos + 1;
-                    if !longPeriod {
+                    self.position += i - self.crit_pos + 1;
+                    if !long_period {
                         self.memory = 0;
                     }
                     continue 'search;
                 }
             }
 
             // See if the left part of the needle matches
-            let start = if longPeriod { 0 } else { self.memory };
-            for i in range(start, self.critPos).rev() {
+            let start = if long_period { 0 } else { self.memory };
+            for i in range(start, self.crit_pos).rev() {
                 if needle[i] != haystack[self.position + i] {
                     self.position += self.period;
-                    if !longPeriod {
+                    if !long_period {
                         self.memory = needle.len() - self.period;
                     }
                     continue 'search;
                 }
             }
 
             // We have found a match!
-            let matchPos = self.position;
+            let match_pos = self.position;
             self.position += needle.len(); // add self.period for all matches
-            if !longPeriod {
+            if !long_period {
                 self.memory = 0; // set to needle.len() - self.period for all matches
             }
-            return Some((matchPos, matchPos + needle.len()));
+            return Some((match_pos, match_pos + needle.len()));
         }
     }
 

src/liblibc/lib.rs

@@ -74,10 +74,10 @@
 */
 
 #![allow(non_camel_case_types)]
-#![allow(non_snake_case_functions)]
+#![allow(non_snake_case)]
 #![allow(non_uppercase_statics)]
 #![allow(missing_doc)]
-#![allow(uppercase_variables)]
+#![allow(non_snake_case)]
 
 #[cfg(test)] extern crate std;
 #[cfg(test)] extern crate test;

src/libnative/io/mod.rs

@@ -21,7 +21,7 @@
 //! play. The only dependencies of these modules are the normal system libraries
 //! that you would find on the respective platform.
 
-#![allow(non_snake_case_functions)]
+#![allow(non_snake_case)]
 
 use libc::c_int;
 use libc;

src/libnative/io/process.rs

@@ -838,7 +838,7 @@ fn free_handle(_handle: *mut ()) {
 
 #[cfg(unix)]
 fn translate_status(status: c_int) -> rtio::ProcessExit {
-    #![allow(non_snake_case_functions)]
+    #![allow(non_snake_case)]
     #[cfg(target_os = "linux")]
     #[cfg(target_os = "android")]
     mod imp {

src/libnum/bigint.rs

@@ -78,6 +78,7 @@ pub type DoubleBigDigit = u64;
 pub static ZERO_BIG_DIGIT: BigDigit = 0;
 static ZERO_VEC: [BigDigit, ..1] = [ZERO_BIG_DIGIT];
 
+#[allow(non_snake_case)]
 pub mod BigDigit {
     use super::BigDigit;
     use super::DoubleBigDigit;

src/librbml/lib.rs

@@ -1132,7 +1132,7 @@ mod tests {
 
 #[cfg(test)]
 mod bench {
-    #![allow(non_snake_case_functions)]
+    #![allow(non_snake_case)]
     use test::Bencher;
     use super::reader;
 

src/libregex/test/bench.rs

@@ -7,7 +7,7 @@
 // <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(non_snake_case_functions)]
+#![allow(non_snake_case)]
 
 use std::rand::{Rng, task_rng};
 use stdtest::Bencher;

src/librustc/diagnostics.rs

@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![allow(non_snake_case)]
+
 register_diagnostic!(E0001, r##"
     This error suggests that the expression arm corresponding to the noted pattern
     will never be reached as for all possible values of the expression being matched,

src/librustc/driver/driver.rs

@@ -242,13 +242,17 @@ pub fn phase_2_configure_and_expand(sess: &Session,
         }
     });
 
-    let Registry { syntax_exts, lint_passes, .. } = registry;
+    let Registry { syntax_exts, lint_passes, lint_groups, .. } = registry;
 
     {
         let mut ls = sess.lint_store.borrow_mut();
         for pass in lint_passes.move_iter() {
             ls.register_pass(Some(sess), true, pass);
         }
+
+        for (name, to) in lint_groups.move_iter() {
+            ls.register_group(Some(sess), true, name, to);
+        }
     }
 
     // Lint plugins are registered; now we can process command line flags.

src/librustc/driver/mod.rs

@@ -180,14 +180,26 @@ Available lint options:
         lints
     }
 
+    fn sort_lint_groups(lints: Vec<(&'static str, Vec<lint::LintId>, bool)>)
+                     -> Vec<(&'static str, Vec<lint::LintId>)> {
+        let mut lints: Vec<_> = lints.move_iter().map(|(x, y, _)| (x, y)).collect();
+        lints.sort_by(|&(x, _): &(&'static str, Vec<lint::LintId>),
+                       &(y, _): &(&'static str, Vec<lint::LintId>)| {
+            x.cmp(&y)
+        });
+        lints
+    }
+
     let (plugin, builtin) = lint_store.get_lints().partitioned(|&(_, p)| p);
     let plugin = sort_lints(plugin);
     let builtin = sort_lints(builtin);
 
-    // FIXME (#7043): We should use the width in character cells rather than
-    // the number of codepoints.
+    let (plugin_groups, builtin_groups) = lint_store.get_lint_groups().partitioned(|&(_, _, p)| p);
+    let plugin_groups = sort_lint_groups(plugin_groups);
+    let builtin_groups = sort_lint_groups(builtin_groups);
+
     let max_name_len = plugin.iter().chain(builtin.iter())
-        .map(|&s| s.name.char_len())
+        .map(|&s| s.name.width(true))
         .max().unwrap_or(0);
     let padded = |x: &str| {
         " ".repeat(max_name_len - x.char_len()).append(x)
@@ -208,16 +220,48 @@ Available lint options:
 
     print_lints(builtin);
 
-    match (loaded_plugins, plugin.len()) {
-        (false, 0) => {
-            println!("Compiler plugins can provide additional lints. To see a listing of these, \
-                      re-run `rustc -W help` with a crate filename.");
+
+
+    let max_name_len = plugin_groups.iter().chain(builtin_groups.iter())
+        .map(|&(s, _)| s.width(true))
+        .max().unwrap_or(0);
+    let padded = |x: &str| {
+        " ".repeat(max_name_len - x.char_len()).append(x)
+    };
+
+    println!("Lint groups provided by rustc:\n");
+    println!("    {}  {}", padded("name"), "sub-lints");
+    println!("    {}  {}", padded("----"), "---------");
+
+    let print_lint_groups = |lints: Vec<(&'static str, Vec<lint::LintId>)>| {
+        for (name, to) in lints.move_iter() {
+            let name = name.chars().map(|x| x.to_lowercase())
+                           .collect::<String>().replace("_", "-");
+            let desc = to.move_iter().map(|x| x.as_str()).collect::<Vec<String>>().connect(", ");
+            println!("    {}  {}",
+                     padded(name.as_slice()), desc);
         }
-        (false, _) => fail!("didn't load lint plugins but got them anyway!"),
-        (true, 0) => println!("This crate does not load any lint plugins."),
-        (true, _) => {
-            println!("Lint checks provided by plugins loaded by this crate:\n");
-            print_lints(plugin);
+        println!("\n");
+    };
+
+    print_lint_groups(builtin_groups);
+
+    match (loaded_plugins, plugin.len(), plugin_groups.len()) {
+        (false, 0, _) | (false, _, 0) => {
+            println!("Compiler plugins can provide additional lints and lint groups. To see a \
+                      listing of these, re-run `rustc -W help` with a crate filename.");
+        }
+        (false, _, _) => fail!("didn't load lint plugins but got them anyway!"),
+        (true, 0, 0) => println!("This crate does not load any lint plugins or lint groups."),
+        (true, l, g) => {
+            if l > 0 {
+                println!("Lint checks provided by plugins loaded by this crate:\n");
+                print_lints(plugin);
+            }
+            if g > 0 {
+                println!("Lint groups provided by plugins loaded by this crate:\n");
+                print_lint_groups(plugin_groups);
+            }
         }
     }
 }