From ed58a00f9b76d18a6917eaf08585648182f104f7 Mon Sep 17 00:00:00 2001 From: Joseph Myers Date: Mon, 5 Mar 2012 15:03:57 +0000 Subject: Reduce discussion of types to which size_t may be equivalent. --- ChangeLog | 6 ++++++ manual/lang.texi | 18 ++---------------- 2 files changed, 8 insertions(+), 16 deletions(-) diff --git a/ChangeLog b/ChangeLog index 6e4f7c47d2..38772bbbba 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,9 @@ +2012-03-05 Joseph Myers + + * manual/lang.texi (size_t): Note types to which size_t may be + equivalent with the GNU C Library, but do not describe when + differences between them are significant. + 2012-03-05 Andreas Jaeger * sysdeps/i386/fpu/libm-test-ulps: Update. diff --git a/manual/lang.texi b/manual/lang.texi index 2a73c723b4..6cb7371aab 100644 --- a/manual/lang.texi +++ b/manual/lang.texi @@ -629,27 +629,13 @@ 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 such as @code{malloc} (@pxref{Unconstrained Allocation}) and @code{memcpy} (@pxref{Copying and Concatenation}) accept arguments of -this type to specify object sizes. +this type to specify object sizes. On systems using @theglibc{}, this +will be @w{@code{unsigned int}} or @w{@code{unsigned long int}}. @strong{Usage Note:} @code{size_t} is the preferred way to declare any arguments or variables that hold the size of an object. @end deftp -In the GNU system @code{size_t} is equivalent to either -@w{@code{unsigned int}} or @w{@code{unsigned long int}}. These types -have identical properties on the GNU system and, for most purposes, you -can use them interchangeably. However, they are distinct as data types, -which makes a difference in certain contexts. - -For example, when you specify the type of a function argument in a -function prototype, it makes a difference which one you use. If the -system header files declare @code{malloc} with an argument of type -@code{size_t} and you declare @code{malloc} with an argument of type -@code{unsigned int}, you will get a compilation error if @code{size_t} -happens to be @code{unsigned long int} on your system. To avoid any -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 @w{ISO C} generally used @code{unsigned int} for representing object sizes and @code{int} for pointer subtraction results. They did not -- cgit 1.4.1