diff options
Diffstat (limited to 'manual/lang.texi')
| -rw-r--r-- | manual/lang.texi | 118 |
1 files changed, 59 insertions, 59 deletions
diff --git a/manual/lang.texi b/manual/lang.texi index 18a1da3b22..39bba83540 100644 --- a/manual/lang.texi +++ b/manual/lang.texi @@ -46,7 +46,7 @@ would rather have a program crash, visibly, than have it return nonsense without indicating anything might be wrong. @comment assert.h -@comment ANSI +@comment ISO @deftypefn Macro void assert (int @var{expression}) Verify the programmer's belief that @var{expression} should be nonzero at this point in the program. @@ -139,7 +139,7 @@ problems that @emph{do not} represent bugs in the program. @cindex variadic functions @cindex optional arguments -ANSI C defines a syntax for declaring a function to take a variable +@w{ISO C} defines a syntax for declaring a function to take a variable number or type of arguments. (Such functions are referred to as @dfn{varargs functions} or @dfn{variadic functions}.) However, the language itself provides no mechanism for such functions to access their @@ -191,7 +191,7 @@ These are good reasons to define a @dfn{variadic} function which can handle as many arguments as the caller chooses to pass. Some functions such as @code{open} take a fixed set of arguments, but -occasionally ignore the last few. Strict adherence to ANSI C requires +occasionally ignore the last few. Strict adherence to @w{ISO C} requires these functions to be defined as variadic; in practice, however, the GNU C compiler and most other C compilers let you define such a function to take a fixed set of arguments---the most it can ever use---and then only @@ -229,7 +229,7 @@ additional variable arguments. @xref{Calling Variadics}. variable arguments functions. * Argument Macros:: Detailed specification of the macros for accessing variable arguments. -* Old Varargs:: The pre-ANSI way of defining variadic functions. +* Old Varargs:: The pre-ISO way of defining variadic functions. @end menu @node Variadic Prototypes @@ -241,7 +241,7 @@ additional variable arguments. @xref{Calling Variadics}. A function that accepts a variable number of arguments must be declared with a prototype that says so. You write the fixed arguments as usual, and then tack on @samp{@dots{}} to indicate the possibility of -additional arguments. The syntax of ANSI C requires at least one fixed +additional arguments. The syntax of @w{ISO C} requires at least one fixed argument before the @samp{@dots{}}. For example, @smallexample @@ -264,7 +264,7 @@ definition. Furthermore, this argument's type must be @dfn{self-promoting}: that is, the default promotions must not change its type. This rules out array and function types, as well as @code{float}, @code{char} (whether signed or not) and @w{@code{short int}} -(whether signed or not). This is actually an ANSI C requirement. +(whether signed or not). This is actually an @w{ISO C} requirement. @node Receiving Arguments @subsubsection Receiving the Argument Values @@ -328,7 +328,7 @@ argument values, but at its own pace. argument pointer value to a subroutine, you must not keep using the same argument pointer value after that subroutine returns. For full portability, you should just pass it to @code{va_end}. This is actually -an ANSI C requirement, but most ANSI C compilers work happily +an @w{ISO C} requirement, but most ANSI C compilers work happily regardless. @node How Many Arguments @@ -419,13 +419,13 @@ These macros are defined in the header file @file{stdarg.h}. @pindex stdarg.h @comment stdarg.h -@comment ANSI +@comment ISO @deftp {Data Type} va_list The type @code{va_list} is used for argument pointer variables. @end deftp @comment stdarg.h -@comment ANSI +@comment ISO @deftypefn {Macro} void va_start (va_list @var{ap}, @var{last-required}) This macro initializes the argument pointer variable @var{ap} to point to the first of the optional arguments of the current function; @@ -436,7 +436,7 @@ found in the header file @file{varargs.h}. @end deftypefn @comment stdarg.h -@comment ANSI +@comment ISO @deftypefn {Macro} @var{type} va_arg (va_list @var{ap}, @var{type}) The @code{va_arg} macro returns the value of the next optional argument, and modifies the value of @var{ap} to point to the subsequent argument. @@ -450,7 +450,7 @@ of the actual argument. @end deftypefn @comment stdarg.h -@comment ANSI +@comment ISO @deftypefn {Macro} void va_end (va_list @var{ap}) This ends the use of @var{ap}. After a @code{va_end} call, further @code{va_arg} calls with the same @var{ap} may not work. You should invoke @@ -480,10 +480,10 @@ arguments facility. @subsubsection Old-Style Variadic Functions @pindex varargs.h -Before ANSI C, programmers used a slightly different facility for +Before @w{ISO C}, programmers used a slightly different facility for writing variadic functions. The GNU C compiler still supports it; -currently, it is more portable than the ANSI C facility, since support -for ANSI C is still not universal. The header file which defines the +currently, it is more portable than the @w{ISO C} facility, since support +for @w{ISO C} is still not universal. The header file which defines the old-fashioned variadic facility is called @file{varargs.h}. Using @file{varargs.h} is almost the same as using @file{stdarg.h}. @@ -548,7 +548,7 @@ You can assign it to any pointer variable since it has type @code{void @code{NULL}. @comment stddef.h -@comment ANSI +@comment ISO @deftypevr Macro {void *} NULL This is a null pointer constant. @end deftypevr @@ -571,13 +571,13 @@ recommend instead adding a prototype for the function you are calling. The result of subtracting two pointers in C is always an integer, but the precise data type varies from C compiler to C compiler. Likewise, the data type of the result of @code{sizeof} also varies between compilers. -ANSI defines standard aliases for these two types, so you can refer to +ISO defines standard aliases for these two types, so you can refer to them in a portable fashion. They are defined in the header file @file{stddef.h}. @pindex stddef.h @comment stddef.h -@comment ANSI +@comment ISO @deftp {Data Type} ptrdiff_t This is the signed integer type of the result of subtracting two pointers. For example, with the declaration @code{char *p1, *p2;}, the @@ -588,7 +588,7 @@ type that exists only for this purpose. @end deftp @comment stddef.h -@comment ANSI +@comment ISO @deftp {Data Type} size_t This is an unsigned integer type used to represent the sizes of objects. The result of the @code{sizeof} operator is of this type, and functions @@ -616,7 +616,7 @@ possibility of error, when a function argument or value is supposed to have type @code{size_t}, never declare its type in any other way. @strong{Compatibility Note:} Implementations of C before the advent of -ANSI C generally used @code{unsigned int} for representing object sizes +@w{ISO C} generally used @code{unsigned int} for representing object sizes and @code{int} for pointer subtraction results. They did not necessarily define either @code{size_t} or @code{ptrdiff_t}. Unix systems did define @code{size_t}, in @file{sys/types.h}, but the @@ -665,7 +665,7 @@ bits in an integer data type. But you can compute it from the macro @table @code @comment limits.h -@comment ANSI +@comment ISO @item CHAR_BIT This is the number of bits in a @code{char}---eight, on most systems. The value has type @code{int}. @@ -705,23 +705,23 @@ described by the macro---thus, @code{ULONG_MAX} has type @comment Extra blank lines make it look better. @table @code @comment limits.h -@comment ANSI +@comment ISO @item SCHAR_MIN This is the minimum value that can be represented by a @w{@code{signed char}}. @comment limits.h -@comment ANSI +@comment ISO @item SCHAR_MAX @comment limits.h -@comment ANSI +@comment ISO @itemx UCHAR_MAX These are the maximum values that can be represented by a @w{@code{signed char}} and @w{@code{unsigned char}}, respectively. @comment limits.h -@comment ANSI +@comment ISO @item CHAR_MIN This is the minimum value that can be represented by a @code{char}. @@ -729,7 +729,7 @@ It's equal to @code{SCHAR_MIN} if @code{char} is signed, or zero otherwise. @comment limits.h -@comment ANSI +@comment ISO @item CHAR_MAX This is the maximum value that can be represented by a @code{char}. @@ -737,7 +737,7 @@ It's equal to @code{SCHAR_MAX} if @code{char} is signed, or @code{UCHAR_MAX} otherwise. @comment limits.h -@comment ANSI +@comment ISO @item SHRT_MIN This is the minimum value that can be represented by a @w{@code{signed @@ -745,10 +745,10 @@ short int}}. On most machines that the GNU C library runs on, @code{short} integers are 16-bit quantities. @comment limits.h -@comment ANSI +@comment ISO @item SHRT_MAX @comment limits.h -@comment ANSI +@comment ISO @itemx USHRT_MAX These are the maximum values that can be represented by a @@ -756,7 +756,7 @@ These are the maximum values that can be represented by a respectively. @comment limits.h -@comment ANSI +@comment ISO @item INT_MIN This is the minimum value that can be represented by a @w{@code{signed @@ -764,17 +764,17 @@ int}}. On most machines that the GNU C system runs on, an @code{int} is a 32-bit quantity. @comment limits.h -@comment ANSI +@comment ISO @item INT_MAX @comment limits.h -@comment ANSI +@comment ISO @itemx UINT_MAX These are the maximum values that can be represented by, respectively, the type @w{@code{signed int}} and the type @w{@code{unsigned int}}. @comment limits.h -@comment ANSI +@comment ISO @item LONG_MIN This is the minimum value that can be represented by a @w{@code{signed @@ -782,10 +782,10 @@ long int}}. On most machines that the GNU C system runs on, @code{long} integers are 32-bit quantities, the same size as @code{int}. @comment limits.h -@comment ANSI +@comment ISO @item LONG_MAX @comment limits.h -@comment ANSI +@comment ISO @itemx ULONG_MAX These are the maximum values that can be represented by a @@ -803,7 +803,7 @@ long long int}}. On most machines that the GNU C system runs on, @comment GNU @item LONG_LONG_MAX @comment limits.h -@comment ANSI +@comment ISO @itemx ULONG_LONG_MAX These are the maximum values that can be represented by a @code{signed @@ -962,16 +962,16 @@ expression. The other macros listed here cannot be reliably used in places that require constant expressions, such as @samp{#if} preprocessing directives or in the dimensions of static arrays. -Although the ANSI C standard specifies minimum and maximum values for +Although the @w{ISO C} standard specifies minimum and maximum values for most of these parameters, the GNU C implementation uses whatever values describe the floating point representation of the target machine. So in -principle GNU C actually satisfies the ANSI C requirements only if the +principle GNU C actually satisfies the @w{ISO C} requirements only if the target machine is suitable. In practice, all the machines currently supported are suitable. @table @code @comment float.h -@comment ANSI +@comment ISO @item FLT_ROUNDS This value characterizes the rounding mode for floating point addition. The following values indicate standard rounding modes: @@ -1011,7 +1011,7 @@ the IEEE single-precision standard. @end smallexample @comment float.h -@comment ANSI +@comment ISO @item FLT_RADIX This is the value of the base, or radix, of exponent representation. This is guaranteed to be a constant expression, unlike the other macros @@ -1019,7 +1019,7 @@ described in this section. The value is 2 on all machines we know of except the IBM 360 and derivatives. @comment float.h -@comment ANSI +@comment ISO @item FLT_MANT_DIG This is the number of base-@code{FLT_RADIX} digits in the floating point mantissa for the @code{float} data type. The following expression @@ -1036,7 +1036,7 @@ float radix = FLT_RADIX; where @code{radix} appears @code{FLT_MANT_DIG} times. @comment float.h -@comment ANSI +@comment ISO @item DBL_MANT_DIG @itemx LDBL_MANT_DIG This is the number of base-@code{FLT_RADIX} digits in the floating point @@ -1045,7 +1045,7 @@ respectively. @comment Extra blank lines make it look better. @comment float.h -@comment ANSI +@comment ISO @item FLT_DIG This is the number of decimal digits of precision for the @code{float} @@ -1057,10 +1057,10 @@ point number with @var{p} base @var{b} digits and back again, without change to the @var{q} decimal digits. The value of this macro is supposed to be at least @code{6}, to satisfy -ANSI C. +@w{ISO C}. @comment float.h -@comment ANSI +@comment ISO @item DBL_DIG @itemx LDBL_DIG @@ -1069,7 +1069,7 @@ These are similar to @code{FLT_DIG}, but for the data types macros are supposed to be at least @code{10}. @comment float.h -@comment ANSI +@comment ISO @item FLT_MIN_EXP This is the smallest possible exponent value for type @code{float}. More precisely, is the minimum negative integer such that the value @@ -1077,7 +1077,7 @@ More precisely, is the minimum negative integer such that the value normalized floating point number of type @code{float}. @comment float.h -@comment ANSI +@comment ISO @item DBL_MIN_EXP @itemx LDBL_MIN_EXP @@ -1085,21 +1085,21 @@ These are similar to @code{FLT_MIN_EXP}, but for the data types @code{double} and @code{long double}, respectively. @comment float.h -@comment ANSI +@comment ISO @item FLT_MIN_10_EXP This is the minimum negative integer such that @code{10} raised to this power minus 1 can be represented as a normalized floating point number of type @code{float}. This is supposed to be @code{-37} or even less. @comment float.h -@comment ANSI +@comment ISO @item DBL_MIN_10_EXP @itemx LDBL_MIN_10_EXP These are similar to @code{FLT_MIN_10_EXP}, but for the data types @code{double} and @code{long double}, respectively. @comment float.h -@comment ANSI +@comment ISO @item FLT_MAX_EXP This is the largest possible exponent value for type @code{float}. More precisely, this is the maximum positive integer such that value @@ -1107,28 +1107,28 @@ precisely, this is the maximum positive integer such that value floating point number of type @code{float}. @comment float.h -@comment ANSI +@comment ISO @item DBL_MAX_EXP @itemx LDBL_MAX_EXP These are similar to @code{FLT_MAX_EXP}, but for the data types @code{double} and @code{long double}, respectively. @comment float.h -@comment ANSI +@comment ISO @item FLT_MAX_10_EXP This is the maximum positive integer such that @code{10} raised to this power minus 1 can be represented as a normalized floating point number of type @code{float}. This is supposed to be at least @code{37}. @comment float.h -@comment ANSI +@comment ISO @item DBL_MAX_10_EXP @itemx LDBL_MAX_10_EXP These are similar to @code{FLT_MAX_10_EXP}, but for the data types @code{double} and @code{long double}, respectively. @comment float.h -@comment ANSI +@comment ISO @item FLT_MAX The value of this macro is the maximum number representable in type @@ -1138,7 +1138,7 @@ has type @code{float}. The smallest representable number is @code{- FLT_MAX}. @comment float.h -@comment ANSI +@comment ISO @item DBL_MAX @itemx LDBL_MAX @@ -1147,7 +1147,7 @@ These are similar to @code{FLT_MAX}, but for the data types macro's value is the same as the type it describes. @comment float.h -@comment ANSI +@comment ISO @item FLT_MIN The value of this macro is the minimum normalized positive floating @@ -1155,7 +1155,7 @@ point number that is representable in type @code{float}. It is supposed to be no more than @code{1E-37}. @comment float.h -@comment ANSI +@comment ISO @item DBL_MIN @itemx LDBL_MIN @@ -1164,7 +1164,7 @@ These are similar to @code{FLT_MIN}, but for the data types macro's value is the same as the type it describes. @comment float.h -@comment ANSI +@comment ISO @item FLT_EPSILON This is the minimum positive floating point number of type @code{float} @@ -1172,7 +1172,7 @@ such that @code{1.0 + FLT_EPSILON != 1.0} is true. It's supposed to be no greater than @code{1E-5}. @comment float.h -@comment ANSI +@comment ISO @item DBL_EPSILON @itemx LDBL_EPSILON @@ -1236,7 +1236,7 @@ You can use @code{offsetof} to measure the location within a structure type of a particular structure member. @comment stddef.h -@comment ANSI +@comment ISO @deftypefn {Macro} size_t offsetof (@var{type}, @var{member}) This expands to a integer constant expression that is the offset of the structure member named @var{member} in a the structure type @var{type}. |