Disable the type byte

Changelog.md

@@ -15,6 +15,7 @@ Breaking Changes:
  * Standard JSON: Remove the ``legacyAST`` option.
  * Type Checker: Function call options can only be given once.
  * Type System: Declarations with the name ``this``, ``super`` and ``_`` are disallowed, with the exception of public functions and events.
+ * Type System: Disallow the ``byte`` type. It was an alias to ``bytes1``.
  * Type System: Disallow ``msg.data`` in ``receive()`` function.
  * Type System: Disallow ``type(super)``.
  * Type System: Disallow enums with more than 256 members.

docs/080-breaking-changes.rst

@@ -50,6 +50,8 @@ the compiler notifying you about it.
   in all branches of the evaluation tree. Now, if constant variables are used as intermediate expressions,
   their values will be properly rounded in the same way as when they are used in run-time expressions.
 
+* The type ``byte`` has been removed. It was an alias of ``bytes1``.
+
 New Restrictions
 ================
 

docs/assembly.rst

@@ -159,7 +159,7 @@ Local Solidity variables are available for assignments, for example:
 
 .. warning::
     If you access variables of a type that spans less than 256 bits
-    (for example ``uint64``, ``address``, ``bytes16`` or ``byte``),
+    (for example ``uint64``, ``address``, or ``bytes16``),
     you cannot make any assumptions about bits not part of the
     encoding of the type. Especially, do not assume them to be zero.
     To be safe, always clear the data properly before you use it

docs/control-structures.rst

@@ -261,7 +261,7 @@ which only need to be created if there is a dispute.
             // can be pre-computed. It is just there for illustration.
             // You actually only need ``new D{salt: salt}(arg)``.
             address predictedAddress = address(uint160(uint(keccak256(abi.encodePacked(
-                byte(0xff),
+                bytes1(0xff),
                 address(this),
                 salt,
                 keccak256(abi.encodePacked(

docs/grammar/SolidityLexer.g4

@@ -4,7 +4,7 @@ lexer grammar SolidityLexer;
  * Keywords reserved for future use in Solidity.
  */
 ReservedKeywords:
-	'after' | 'alias' | 'apply' | 'auto' | 'case' | 'copyof' | 'default' | 'define' | 'final'
+	'after' | 'alias' | 'apply' | 'auto' | 'byte' | 'case' | 'copyof' | 'default' | 'define' | 'final'
 	| 'implements' | 'in' | 'inline' | 'let' | 'macro' | 'match' | 'mutable' | 'null' | 'of'
 	| 'partial' | 'promise' | 'reference' | 'relocatable' | 'sealed' | 'sizeof' | 'static'
 	| 'supports' | 'switch' | 'typedef' | 'typeof' | 'var';
@@ -37,10 +37,9 @@ Fixed: 'fixed' | ('fixed' [1-9][0-9]* 'x' [1-9][0-9]*);
 From: 'from';
 /**
  * Bytes types of fixed length.
- * byte is an alias of bytes1.
  */
 FixedBytes:
-	'byte' | 'bytes1' | 'bytes2' | 'bytes3' | 'bytes4' | 'bytes5' | 'bytes6' | 'bytes7' | 'bytes8' |
+	'bytes1' | 'bytes2' | 'bytes3' | 'bytes4' | 'bytes5' | 'bytes6' | 'bytes7' | 'bytes8' |
 	'bytes9' | 'bytes10' | 'bytes11' | 'bytes12' | 'bytes13' | 'bytes14' | 'bytes15' | 'bytes16' |
 	'bytes17' | 'bytes18' | 'bytes19' | 'bytes20' | 'bytes21' | 'bytes22' | 'bytes23' | 'bytes24' |
 	'bytes25' | 'bytes26' | 'bytes27' | 'bytes28' | 'bytes29' | 'bytes30' | 'bytes31' | 'bytes32';

docs/types/reference-types.rst

@@ -391,7 +391,7 @@ Array Members
             // Create a dynamic byte array:
             bytes memory b = new bytes(200);
             for (uint i = 0; i < b.length; i++)
-                b[i] = byte(uint8(i));
+                b[i] = bytes1(uint8(i));
             return b;
         }
     }

docs/types/value-types.rst

@@ -369,7 +369,6 @@ Fixed-size byte arrays
 
 The value types ``bytes1``, ``bytes2``, ``bytes3``, ..., ``bytes32``
 hold a sequence of bytes from one to up to 32.
-``byte`` is an alias for ``bytes1``.
 
 Operators:
 
@@ -391,6 +390,9 @@ Members:
     31 bytes of space for each element (except in storage). It is better to use the ``bytes``
     type instead.
 
+.. note::
+    Prior to version 0.8.0, ``byte`` used to be an alias for ``bytes1``.
+
 Dynamically-sized byte array
 ----------------------------
 

liblangutil/Token.h

@@ -212,7 +212,6 @@ namespace solidity::langutil
 	K(Int, "int", 0)                                                   \
 	K(UInt, "uint", 0)                                                 \
 	K(Bytes, "bytes", 0)                                               \
-	K(Byte, "byte", 0)                                                 \
 	K(String, "string", 0)                                             \
 	K(Address, "address", 0)                                           \
 	K(Bool, "bool", 0)                                                 \
@@ -242,6 +241,7 @@ namespace solidity::langutil
 	K(Alias, "alias", 0)                                               \
 	K(Apply, "apply", 0)                                               \
 	K(Auto, "auto", 0)                                                 \
+	K(Byte, "byte", 0)                                                 \
 	K(Case, "case", 0)                                                 \
 	K(CopyOf, "copyof", 0)                                             \
 	K(Default, "default", 0)                                           \