Rollup merge of #111173 - nnethercote:still-more-Encoder-cleanups, r=cjgillot

Still more encoder cleanups

r? ``@cjgillot``

5 files changed, 59 insertions, 127 deletions

diff --git a/compiler/rustc_metadata/src/rmeta/encoder.rs b/compiler/rustc_metadata/src/rmeta/encoder.rs
index 32f9e883fd6..82c66b9dfb9 100644
--- a/compiler/rustc_metadata/src/rmeta/encoder.rs
+++ b/compiler/rustc_metadata/src/rmeta/encoder.rs
@@ -108,11 +108,7 @@ impl<'a, 'tcx> Encoder for EncodeContext<'a, 'tcx> {
         emit_i64(i64);
         emit_i32(i32);
         emit_i16(i16);
-        emit_i8(i8);
 
-        emit_bool(bool);
-        emit_char(char);
-        emit_str(&str);
         emit_raw_bytes(&[u8]);
     }
 }
diff --git a/compiler/rustc_middle/src/query/on_disk_cache.rs b/compiler/rustc_middle/src/query/on_disk_cache.rs
index e56faff5ed4..220118ae5cc 100644
--- a/compiler/rustc_middle/src/query/on_disk_cache.rs
+++ b/compiler/rustc_middle/src/query/on_disk_cache.rs
@@ -1026,11 +1026,7 @@ impl<'a, 'tcx> Encoder for CacheEncoder<'a, 'tcx> {
         emit_i64(i64);
         emit_i32(i32);
         emit_i16(i16);
-        emit_i8(i8);
 
-        emit_bool(bool);
-        emit_char(char);
-        emit_str(&str);
         emit_raw_bytes(&[u8]);
     }
 }
diff --git a/compiler/rustc_middle/src/ty/codec.rs b/compiler/rustc_middle/src/ty/codec.rs
index 7536903ef96..7fc75674da5 100644
--- a/compiler/rustc_middle/src/ty/codec.rs
+++ b/compiler/rustc_middle/src/ty/codec.rs
@@ -506,23 +506,18 @@ macro_rules! implement_ty_decoder {
 
             impl<$($typaram ),*> Decoder for $DecoderName<$($typaram),*> {
                 $crate::__impl_decoder_methods! {
+                    read_usize -> usize;
                     read_u128 -> u128;
                     read_u64 -> u64;
                     read_u32 -> u32;
                     read_u16 -> u16;
                     read_u8 -> u8;
-                    read_usize -> usize;
 
+                    read_isize -> isize;
                     read_i128 -> i128;
                     read_i64 -> i64;
                     read_i32 -> i32;
                     read_i16 -> i16;
-                    read_i8 -> i8;
-                    read_isize -> isize;
-
-                    read_bool -> bool;
-                    read_char -> char;
-                    read_str -> &str;
                 }
 
                 #[inline]
@@ -531,13 +526,13 @@ macro_rules! implement_ty_decoder {
                 }
 
                 #[inline]
-                fn position(&self) -> usize {
-                    self.opaque.position()
+                fn peek_byte(&self) -> u8 {
+                    self.opaque.peek_byte()
                 }
 
                 #[inline]
-                fn peek_byte(&self) -> u8 {
-                    self.opaque.peek_byte()
+                fn position(&self) -> usize {
+                    self.opaque.position()
                 }
             }
         }
diff --git a/compiler/rustc_serialize/src/opaque.rs b/compiler/rustc_serialize/src/opaque.rs
index a2ec318df6d..6b559cb5b2f 100644
--- a/compiler/rustc_serialize/src/opaque.rs
+++ b/compiler/rustc_serialize/src/opaque.rs
@@ -265,52 +265,41 @@ impl Drop for FileEncoder {
     }
 }
 
-macro_rules! file_encoder_write_leb128 {
-    ($enc:expr, $value:expr, $int_ty:ty, $fun:ident) => {{
-        const MAX_ENCODED_LEN: usize = $crate::leb128::max_leb128_len::<$int_ty>();
+macro_rules! write_leb128 {
+    ($this_fn:ident, $int_ty:ty, $write_leb_fn:ident) => {
+        #[inline]
+        fn $this_fn(&mut self, v: $int_ty) {
+            const MAX_ENCODED_LEN: usize = $crate::leb128::max_leb128_len::<$int_ty>();
 
-        // We ensure this during `FileEncoder` construction.
-        debug_assert!($enc.capacity() >= MAX_ENCODED_LEN);
+            // We ensure this during `FileEncoder` construction.
+            debug_assert!(self.capacity() >= MAX_ENCODED_LEN);
 
-        let mut buffered = $enc.buffered;
+            let mut buffered = self.buffered;
 
-        // This can't overflow. See assertion in `FileEncoder::with_capacity`.
-        if std::intrinsics::unlikely(buffered + MAX_ENCODED_LEN > $enc.capacity()) {
-            $enc.flush();
-            buffered = 0;
-        }
+            // This can't overflow. See assertion in `FileEncoder::with_capacity`.
+            if std::intrinsics::unlikely(buffered + MAX_ENCODED_LEN > self.capacity()) {
+                self.flush();
+                buffered = 0;
+            }
 
-        // SAFETY: The above check and flush ensures that there is enough
-        // room to write the encoded value to the buffer.
-        let buf = unsafe {
-            &mut *($enc.buf.as_mut_ptr().add(buffered) as *mut [MaybeUninit<u8>; MAX_ENCODED_LEN])
-        };
+            // SAFETY: The above check and flush ensures that there is enough
+            // room to write the encoded value to the buffer.
+            let buf = unsafe {
+                &mut *(self.buf.as_mut_ptr().add(buffered)
+                    as *mut [MaybeUninit<u8>; MAX_ENCODED_LEN])
+            };
 
-        let encoded = leb128::$fun(buf, $value);
-        $enc.buffered = buffered + encoded.len();
-    }};
+            let encoded = leb128::$write_leb_fn(buf, v);
+            self.buffered = buffered + encoded.len();
+        }
+    };
 }
 
 impl Encoder for FileEncoder {
-    #[inline]
-    fn emit_usize(&mut self, v: usize) {
-        file_encoder_write_leb128!(self, v, usize, write_usize_leb128)
-    }
-
-    #[inline]
-    fn emit_u128(&mut self, v: u128) {
-        file_encoder_write_leb128!(self, v, u128, write_u128_leb128)
-    }
-
-    #[inline]
-    fn emit_u64(&mut self, v: u64) {
-        file_encoder_write_leb128!(self, v, u64, write_u64_leb128)
-    }
-
-    #[inline]
-    fn emit_u32(&mut self, v: u32) {
-        file_encoder_write_leb128!(self, v, u32, write_u32_leb128)
-    }
+    write_leb128!(emit_usize, usize, write_usize_leb128);
+    write_leb128!(emit_u128, u128, write_u128_leb128);
+    write_leb128!(emit_u64, u64, write_u64_leb128);
+    write_leb128!(emit_u32, u32, write_u32_leb128);
 
     #[inline]
     fn emit_u16(&mut self, v: u16) {
@@ -322,25 +311,10 @@ impl Encoder for FileEncoder {
         self.write_one(v);
     }
 
-    #[inline]
-    fn emit_isize(&mut self, v: isize) {
-        file_encoder_write_leb128!(self, v, isize, write_isize_leb128)
-    }
-
-    #[inline]
-    fn emit_i128(&mut self, v: i128) {
-        file_encoder_write_leb128!(self, v, i128, write_i128_leb128)
-    }
-
-    #[inline]
-    fn emit_i64(&mut self, v: i64) {
-        file_encoder_write_leb128!(self, v, i64, write_i64_leb128)
-    }
-
-    #[inline]
-    fn emit_i32(&mut self, v: i32) {
-        file_encoder_write_leb128!(self, v, i32, write_i32_leb128)
-    }
+    write_leb128!(emit_isize, isize, write_isize_leb128);
+    write_leb128!(emit_i128, i128, write_i128_leb128);
+    write_leb128!(emit_i64, i64, write_i64_leb128);
+    write_leb128!(emit_i32, i32, write_i32_leb128);
 
     #[inline]
     fn emit_i16(&mut self, v: i16) {
@@ -437,30 +411,19 @@ impl<'a> MemDecoder<'a> {
 }
 
 macro_rules! read_leb128 {
-    ($dec:expr, $fun:ident) => {{ leb128::$fun($dec) }};
+    ($this_fn:ident, $int_ty:ty, $read_leb_fn:ident) => {
+        #[inline]
+        fn $this_fn(&mut self) -> $int_ty {
+            leb128::$read_leb_fn(self)
+        }
+    };
 }
 
 impl<'a> Decoder for MemDecoder<'a> {
-    #[inline]
-    fn position(&self) -> usize {
-        // SAFETY: This type guarantees start <= current
-        unsafe { self.current.sub_ptr(self.start) }
-    }
-
-    #[inline]
-    fn read_u128(&mut self) -> u128 {
-        read_leb128!(self, read_u128_leb128)
-    }
-
-    #[inline]
-    fn read_u64(&mut self) -> u64 {
-        read_leb128!(self, read_u64_leb128)
-    }
-
-    #[inline]
-    fn read_u32(&mut self) -> u32 {
-        read_leb128!(self, read_u32_leb128)
-    }
+    read_leb128!(read_usize, usize, read_usize_leb128);
+    read_leb128!(read_u128, u128, read_u128_leb128);
+    read_leb128!(read_u64, u64, read_u64_leb128);
+    read_leb128!(read_u32, u32, read_u32_leb128);
 
     #[inline]
     fn read_u16(&mut self) -> u16 {
@@ -480,25 +443,10 @@ impl<'a> Decoder for MemDecoder<'a> {
         }
     }
 
-    #[inline]
-    fn read_usize(&mut self) -> usize {
-        read_leb128!(self, read_usize_leb128)
-    }
-
-    #[inline]
-    fn read_i128(&mut self) -> i128 {
-        read_leb128!(self, read_i128_leb128)
-    }
-
-    #[inline]
-    fn read_i64(&mut self) -> i64 {
-        read_leb128!(self, read_i64_leb128)
-    }
-
-    #[inline]
-    fn read_i32(&mut self) -> i32 {
-        read_leb128!(self, read_i32_leb128)
-    }
+    read_leb128!(read_isize, isize, read_isize_leb128);
+    read_leb128!(read_i128, i128, read_i128_leb128);
+    read_leb128!(read_i64, i64, read_i64_leb128);
+    read_leb128!(read_i32, i32, read_i32_leb128);
 
     #[inline]
     fn read_i16(&mut self) -> i16 {
@@ -506,11 +454,6 @@ impl<'a> Decoder for MemDecoder<'a> {
     }
 
     #[inline]
-    fn read_isize(&mut self) -> isize {
-        read_leb128!(self, read_isize_leb128)
-    }
-
-    #[inline]
     fn read_raw_bytes(&mut self, bytes: usize) -> &'a [u8] {
         if bytes > self.remaining() {
             Self::decoder_exhausted();
@@ -532,6 +475,12 @@ impl<'a> Decoder for MemDecoder<'a> {
         // Since we just checked current == end, the current pointer must be inbounds.
         unsafe { *self.current }
     }
+
+    #[inline]
+    fn position(&self) -> usize {
+        // SAFETY: This type guarantees start <= current
+        unsafe { self.current.sub_ptr(self.start) }
+    }
 }
 
 // Specializations for contiguous byte sequences follow. The default implementations for slices
diff --git a/compiler/rustc_serialize/src/serialize.rs b/compiler/rustc_serialize/src/serialize.rs
index e1bc598736f..06166cabc18 100644
--- a/compiler/rustc_serialize/src/serialize.rs
+++ b/compiler/rustc_serialize/src/serialize.rs
@@ -1,9 +1,5 @@
 //! Support code for encoding and decoding types.
 
-/*
-Core encoding and decoding interfaces.
-*/
-
 use std::alloc::Allocator;
 use std::borrow::Cow;
 use std::cell::{Cell, RefCell};
@@ -35,13 +31,13 @@ const STR_SENTINEL: u8 = 0xC1;
 /// really makes sense to store floating-point values at all.
 /// (If you need it, revert <https://github.com/rust-lang/rust/pull/109984>.)
 pub trait Encoder {
-    // Primitive types:
     fn emit_usize(&mut self, v: usize);
     fn emit_u128(&mut self, v: u128);
     fn emit_u64(&mut self, v: u64);
     fn emit_u32(&mut self, v: u32);
     fn emit_u16(&mut self, v: u16);
     fn emit_u8(&mut self, v: u8);
+
     fn emit_isize(&mut self, v: isize);
     fn emit_i128(&mut self, v: i128);
     fn emit_i64(&mut self, v: i64);
@@ -93,13 +89,13 @@ pub trait Encoder {
 /// really makes sense to store floating-point values at all.
 /// (If you need it, revert <https://github.com/rust-lang/rust/pull/109984>.)
 pub trait Decoder {
-    // Primitive types:
     fn read_usize(&mut self) -> usize;
     fn read_u128(&mut self) -> u128;
     fn read_u64(&mut self) -> u64;
     fn read_u32(&mut self) -> u32;
     fn read_u16(&mut self) -> u16;
     fn read_u8(&mut self) -> u8;
+
     fn read_isize(&mut self) -> isize;
     fn read_i128(&mut self) -> i128;
     fn read_i64(&mut self) -> i64;