From: Dale Weiler Date: Thu, 7 Mar 2013 15:19:00 +0000 (-0500) Subject: Update specification.tex X-Git-Tag: before-library~26^2~4 X-Git-Url: https://git.xonotic.org/?p=xonotic%2Fgmqcc.git;a=commitdiff_plain;h=bedfee1fae30e47e13013d197b69e15534767b05 Update specification.tex --- diff --git a/doc/specification.tex b/doc/specification.tex index e41a14a..2687946 100644 --- a/doc/specification.tex +++ b/doc/specification.tex @@ -132,7 +132,7 @@ Region of data storage in the execution environment, the contents of which can r values. \subsection*{parameter} -Object declare as part of a function declaration or definition that acquires a value on +Object declared as part of a function declaration or definition that acquires a value on entry to the function, or an identifier from the comma-separated list bounded by the parentheses immediately following the macro name in a function-like macro definition. @@ -189,7 +189,7 @@ The precedence among the syntax rules of translation is specified by the followi by one space character is implementation-defined. \item Preprocessing directives are executed, macro invocations are expanded recursively. A \#include preprocessing directive causes the named header or - source file to be processes from step one through step three, recursively. All + source file to be processed from step one through step three, recursively. All preprocessing directives are then deleted. \item Each source character set member and escape sequence in character constants and string literals is converted to the corresponding member of the execution @@ -201,7 +201,7 @@ The precedence among the syntax rules of translation is specified by the followi syntactically and semantically analyzed and translated. \end{enumerate} \subparagraph*{Footnotes} -Implementations shall behave as if these separate steps occur, even though many are likely +Implementations shall behave as if these steps occur separately, even though many are likely to be folded together in practice. Source files need not be stored as file, nor need there be any one-to-one correspondence between these items and any external representation. The description is conceptual only, and does not specify any particular implementation. @@ -263,8 +263,8 @@ annex A. %% ->-> Scopes of identifiers %% \subsubsection{Scopes of identifiers} An identifier can denote an object; a function, or enumeration; a label name; a macro -name; or a macro parameter. The same identifier can denote difference items at different -point in the program. A member of an enumeration is called an enumeration constant. +name; or a macro parameter. The same identifier can denote different items at different +points in the program. A member of an enumeration is called an enumeration constant. Macro names and macro parameters are not considered further here, because prior to the semantic phase of program translation any occurrences of macro names in the source file are replaced by the preprocessing token sequences that constitute their macro definitions. @@ -280,11 +280,12 @@ parameters.) A label name is the only kind of identifier that has function scope. It can be used (in a goto statement) anywhere in the function in which it appears, and is declared -implicitly by its syntactic appearance (prefixed by a : and a statement). +implicitly by its syntactic appearance (prefixed by a colon :, and suffixed with a +statement). \linebreak Every other identifier has scope determined by the placement of its declaration (in a -declarator or type specifier). If the declarator or types specifier that declares the +declarator or type specifier). If the declarator or type specifier that declares the identifier appears outside any block or list of parameters, the identifier has file scope, which terminates at the end of the file. If the declartor or type specifier that declares the identifier appears inside a block or within the list of parameter @@ -305,7 +306,7 @@ refer to some item (as opposed to the syntactic construct), it refers to the ite relevant name space whose declaration is visible at the point the identifier occurs. \linebreak -Two identifiers have the same scope it and only if their scopes terminate at the same +Two identifiers have the same scope if and only if their scopes terminate at the same point. \linebreak @@ -362,12 +363,12 @@ types, as follows: \begin{itemize} \item An array type describes a contiguously allocated nonempty set of objects with a - particular object types, called the element type. Array types are characterized + particular object type, called the element type. Array types are characterized by their element type and by the number of elements in the array. An array type is said to be derived from its element type, and if its element is type T, the array type is sometimes called "array of T". The construction of an array type from an element type is called "array type derivation". - \item A function type described a function with a specified return type. A function + \item A function type describes a function with a specified return type. A function type is characterized by its return type and the number and types of its parameters. A function type is said to be derived from its return type, and if its return type is T, the function type is sometimes called "function returning @@ -380,7 +381,7 @@ collectively called aggregate types. \linebreak An array of unknown size is an incomplete type. It is completed, for an identifier of -that byte, by specifying the size in a later declaration. Arrays are required to have +that type, by specifying the size in a later declaration. Arrays are required to have known constant size. \linebreak @@ -390,7 +391,7 @@ itself if the type consists of no derived types. \linebreak Any type so far mentioned is an unqualified type. Each unqualified type has several -qualified version of its type, corresponding to the combinations of one, two, or all +qualified versions of its type, corresponding to the combinations of one, two, or all two of const and volatile qualifiers. The qualified or unqualified versions of a type are distinct types that belong to the same type category and have the same representation. A derived type is not qualified by the qualifiers (if any) of the type from which it @@ -417,19 +418,21 @@ is compatible with both of the two types and satisfies the following conditions: parameter in the composite parameter type list is the composite type of the corresponding parameters. \end{itemize} -These rules apply recursively to types from which the twp types are derived. +These rules apply recursively to types from which the two types are derived. \linebreak %% ->Conversions %% \subsection{Conversions} Several operators convert operand values from one type to another automatically. This -sub-clause specified the result required from such an implicit conversion. +sub-clause specifies the result required from such an implicit conversion. \linebreak Conversion from an operand value to a compatible type causes no change to the value or the representation. \linebreak +TODO: Specify all implicit conversions. + %% ->->Aritmetic operands %% \subsubsection{Arithmetic operands} \paragraph*{Boolean type} @@ -443,7 +446,7 @@ An lvalue is an expression with an object type or an incomplete type other than if an lvalue does not designate an object when it is evaluated, the behavior is undefined. When an object is said to have a particular type, the type is specified by the lvalue used to designate the object. A modifiable lvalue is an lvalue that does not have an -array type, does not have an incomplete type, does not have a const-qualified type. +array type, does not have an incomplete type, and does not have a const-qualified type. \linebreak Except when it is the operand of the unary \& operator, the ++ operator, the -- operator, @@ -455,13 +458,12 @@ the lvalue has an incomplete type and does not have array type, the behavior is \linebreak A function designator is an expression that has function type. -\linebreak \paragraph*{void} The (nonexistent) value of a void expression (an expression that has type void) shall not be used in any way, and implicit conversions (except to void) shall not be applied to -such an expression. If an expression of any other type is evaluated as a void expression -, its value or designator is discarded. (A void expression is only evaluated for its +such an expression. If an expression of any other type is evaluated as a void expression, +its value or designator is discarded. (A void expression is only evaluated for its side effects.) \pagebreak @@ -490,11 +492,11 @@ punctuators. A preprocessing token is the minimal lexical element of the languag translation steps three through five. The categories of preprocessing tokens are: header names, identifiers, preprocessing numbers, string literals, punctuators and other single non-white-space characters that do not lexically match the other preprocessing token -categories. If a \' or a \" character matches the last category, the behavior is undefined. +categories. If a ' or a " character matches the last category, the behavior is undefined. Preprocessing tokens can be separated by white space; this consists of comments (described later), or white-space characters (space, horizontal tab, new-line, vertical tab, and form -feed), or both. In certain circumstances during translation step four, white space (or -the absence thereof) serves as more than preprocessing token separation. Whit space may +the absence thereof) serves as more than preprocessing token separation. White space may appear within a preprocessing token only as part of a header name or between the quotation characters in a string literal. \linebreak @@ -510,16 +512,11 @@ could be either a header name or string literal is recognized as the former. \subsubsection{Keywords} \paragraph*{Syntax} \begin{lstlisting}[language=bnf] -keyword ::= enum | break - | return | void - | case | float - | volatile | for - | while | const - | goto | bool - | continue | if - | static | default - | inline | do - | switch | else +keyword ::= enum | break | return | void + | case | float | volatile | for + | while | const | goto | bool + | continue | if | static | default + | inline | do | switch | else | vector | entity \end{lstlisting} \paragraph*{Semantics} @@ -528,21 +525,34 @@ use as keywords, and shall not be used otherwise. %% ->->Identifiers %% \subsubsection{Identifiers} -\paragraph*{Syntax} \begin{lstlisting}[language=bnf] identifier ::= nondigit | identifier nondigit | identifier digit -nondigit ::= _ | a | b | c | d | e | f | g | h | i - | j | k | l | m | n | o | p | q | r | s - | t | u | v | w | x | y | z | A | B | C - | D | E | F | G | H | I | J | K | L | M - | N | P | Q | R | S | T | U | V | W | X - | Y | Z - -digit ::= 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 +nondigit ::= _ | a | b | c | d | e | f | g | h | i + | j | k | l | m | n | o | p | q | r | s + | t | u | v | w | x | y | z | A | B | C + | D | E | F | G | H | I | J | K | L | M + | N | P | Q | R | S | T | U | V | W | X + | Y | Z + +digit ::= 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 \end{lstlisting} +\paragraph*{Semantics} +An identifier is a sequence of nondigit characters (including the underscore \_, the lower +case and upper case Latin letters, and other characters) and digits, which designates one +or more items. Lowercase and uppercase letters are distinct. There is a specific limit of +65535 characters for an identifier. +\linebreak + +When preprocessing tokens are converted to tokens during translation step six, if a +preprocessing token could not be converted to either a keyword or an identifier, it is +converted to a keyword. + +\paragraph*{Predefined identifiers} +Any identifiers that begin with the prefix \_\_builtin, or are within the reserved name +space are reserved by the implementation. %% ->->Constants %% \subsubsection{Constants} @@ -634,13 +644,13 @@ TODO \subsubsection{Comments} Except within a character constant, a string literal, or a comment, the characters /* introduce a comment. The contents of such a comment are examined only to identify -characters and to find the characters /* that terminate it. +characters and to find the characters */ that terminate it. \linebreak Except within a character constant, a string literal, or a comment, the characters // introduce a comment that includes all characters up to, but not including, the next new-line character. The contents of such a comment are examined only to identify -characters and to find the terminating new-line characters. +characters and to find the terminating new-line character. \linebreak %% -> Expressions %% @@ -675,10 +685,10 @@ its type), the behavior is undefined. \subsubsection{Primary expressions} \paragraph*{Syntax} \begin{lstlisting}[language=bnf] -primary-expression := identifier - | constant - | string-literal - ( expression ) +primary-expression ::= identifier + | constant + | string-literal + ( expression ) \end{lstlisting} \paragraph*{Semantics} An identifier is a primary expression, provided it has been declared as designating an