Libc-997.1.1.tar.gz

[apple/libc.git] / stdlib / FreeBSD / alloca.3

diff --git a/stdlib/FreeBSD/alloca.3 b/stdlib/FreeBSD/alloca.3
index 9866edfb2f0f2290b9a33ed98ea46ea485566846..492100a9e437ab4e70003e097d9f2ec8a96af046 100644 (file)
--- a/stdlib/FreeBSD/alloca.3
+++ b/stdlib/FreeBSD/alloca.3
@@ -34,25 +34,25 @@
 .Sh NAME
 .Nm alloca
 .Nd memory allocator
 .Sh NAME
 .Nm alloca
 .Nd memory allocator

-.Sh LIBRARY
-.Lb libc

 .Sh SYNOPSIS
 .Sh SYNOPSIS

+.In alloca.h
+or
+.br

 .In stdlib.h
 .Ft void *
 .Fn alloca "size_t size"
 .Sh DESCRIPTION
 The
 .Fn alloca
 .In stdlib.h
 .Ft void *
 .Fn alloca "size_t size"
 .Sh DESCRIPTION
 The
 .Fn alloca

-function
+macro

 allocates
 .Fa size
 bytes of space in the stack frame of the caller.
 This temporary space is automatically freed on
 return.
 .Sh RETURN VALUES
 allocates
 .Fa size
 bytes of space in the stack frame of the caller.
 This temporary space is automatically freed on
 return.
 .Sh RETURN VALUES

-The

 .Fn alloca
 .Fn alloca

-function returns a pointer to the beginning of the allocated space.
+returns a pointer to the beginning of the allocated space.

 .Sh SEE ALSO
 .Xr brk 2 ,
 .Xr calloc 3 ,
 .Sh SEE ALSO
 .Xr brk 2 ,
 .Xr calloc 3 ,


@@ -60,24 +60,20 @@ function returns a pointer to the beginning of the allocated space.
 .Xr malloc 3 ,
 .Xr realloc 3
 .Sh HISTORY
 .Xr malloc 3 ,
 .Xr realloc 3
 .Sh HISTORY

-The

 .Fn alloca
 .Fn alloca

-function appeared in
+appeared in

 .At 32v .
 .\" .Bx ?? .
 .\" The function appeared in 32v, pwb and pwb.2 and in 3bsd 4bsd
 .\" The first man page (or link to a man page that I can find at the
 .\" moment is 4.3...
 .Sh BUGS
 .At 32v .
 .\" .Bx ?? .
 .\" The function appeared in 32v, pwb and pwb.2 and in 3bsd 4bsd
 .\" The first man page (or link to a man page that I can find at the
 .\" moment is 4.3...
 .Sh BUGS

-The

 .Fn alloca
 .Fn alloca

-function

 is machine and compiler dependent;
 its use is discouraged.
 .Pp
 is machine and compiler dependent;
 its use is discouraged.
 .Pp

-The

 .Fn alloca
 .Fn alloca

-function is slightly unsafe because it cannot ensure that the pointer
+is slightly unsafe because it cannot ensure that the pointer

 returned points to a valid and usable block of memory.
 The allocation made may exceed the bounds of the stack, or even go
 further into other objects in memory, and
 returned points to a valid and usable block of memory.
 The allocation made may exceed the bounds of the stack, or even go
 further into other objects in memory, and


@@ -86,3 +82,8 @@ cannot determine such an error.
 Avoid
 .Fn alloca
 with large unbounded allocations.
 Avoid
 .Fn alloca
 with large unbounded allocations.

+.Pp
+The use of C99 variable-length arrays and
+.Fn alloca
+in the same function will cause the lifetime of alloca's storage to be limited to the block containing the
+.Fn alloca