Rollup merge of rust-lang#41934 - est31:remove_unused_macros, r=nagisa

Remove unused macros from the codebase

Thanks to the lint I've implemented in rust-lang#41907 I've found some unused macros inside the rustc codebase.

src/libcollections/str.rs

@@ -176,18 +176,6 @@ impl<'a> Iterator for EncodeUtf16<'a> {
 #[unstable(feature = "fused", issue = "35602")]
 impl<'a> FusedIterator for EncodeUtf16<'a> {}
 
-// Return the initial codepoint accumulator for the first byte.
-// The first byte is special, only want bottom 5 bits for width 2, 4 bits
-// for width 3, and 3 bits for width 4
-macro_rules! utf8_first_byte {
-    ($byte:expr, $width:expr) => (($byte & (0x7F >> $width)) as u32)
-}
-
-// return the value of $ch updated with continuation byte $byte
-macro_rules! utf8_acc_cont_byte {
-    ($ch:expr, $byte:expr) => (($ch << 6) | ($byte & 63) as u32)
-}
-
 #[stable(feature = "rust1", since = "1.0.0")]
 impl Borrow<str> for String {
     #[inline]

src/libcore/lib.rs

@@ -104,10 +104,6 @@ mod macros;
 #[macro_use]
 mod internal_macros;
 
-#[path = "num/float_macros.rs"]
-#[macro_use]
-mod float_macros;
-
 #[path = "num/int_macros.rs"]
 #[macro_use]
 mod int_macros;

src/libcore/num/mod.rs

@@ -96,13 +96,6 @@ pub mod dec2flt;
 pub mod bignum;
 pub mod diy_float;
 
-macro_rules! checked_op {
-    ($U:ty, $op:path, $x:expr, $y:expr) => {{
-        let (result, overflowed) = unsafe { $op($x as $U, $y as $U) };
-        if overflowed { None } else { Some(result as Self) }
-    }}
-}
-
 // `Int` + `SignedInt` implemented for signed integers
 macro_rules! int_impl {
     ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr,

src/librustc_errors/emitter.rs

@@ -95,21 +95,6 @@ struct FileWithAnnotatedLines {
     multiline_depth: usize,
 }
 
-
-/// Do not use this for messages that end in `\n` – use `println_maybe_styled` instead. See
-/// `EmitterWriter::print_maybe_styled` for details.
-macro_rules! print_maybe_styled {
-    ($dst: expr, $style: expr, $($arg: tt)*) => {
-        $dst.print_maybe_styled(format_args!($($arg)*), $style, false)
-    }
-}
-
-macro_rules! println_maybe_styled {
-    ($dst: expr, $style: expr, $($arg: tt)*) => {
-        $dst.print_maybe_styled(format_args!($($arg)*), $style, true)
-    }
-}
-
 impl EmitterWriter {
     pub fn stderr(color_config: ColorConfig, code_map: Option<Rc<CodeMapper>>) -> EmitterWriter {
         if color_config.use_color() {

src/librustc_trans/back/msvc/mod.rs

@@ -32,6 +32,7 @@
 //! comments can also be found below leading through the various code paths.
 
 // A simple macro to make this option mess easier to read
+#[cfg(windows)]
 macro_rules! otry {
     ($expr:expr) => (match $expr {
         Some(val) => val,

src/librustc_trans/lib.rs

@@ -86,9 +86,6 @@ pub mod back {
 
 pub mod diagnostics;
 
-#[macro_use]
-mod macros;
-
 mod abi;
 mod adt;
 mod asm;

src/libsyntax_ext/deriving/mod.rs

@@ -25,12 +25,6 @@ macro_rules! pathvec {
     )
 }
 
-macro_rules! path {
-    ($($x:tt)*) => (
-        ::ext::deriving::generic::ty::Path::new( pathvec![ $($x)* ] )
-    )
-}
-
 macro_rules! path_local {
     ($x:ident) => (
         ::deriving::generic::ty::Path::new_local(stringify!($x))