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59 lines
2.9 KiB
C
59 lines
2.9 KiB
C
/* BUMP_ALLOC macro - increase table allocation by one element.
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Copyright (C) 1990, 1991, 1993 Free Software Foundation, Inc.
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Francois Pinard <pinard@iro.umontreal.ca>, 1990.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
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/*-------------------------------------------------------------------------.
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| Bump the allocation of the array pointed to by TABLE whenever required. |
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| The table already has already COUNT elements in it, this macro ensure it |
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| has enough space to accommodate at least one more element. Space is |
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| allocated (2 ^ EXPONENT) elements at a time. Each element of the array |
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| is of type TYPE. |
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`-------------------------------------------------------------------------*/
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/* Routines `xmalloc' and `xrealloc' are called to do the actual memory
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management. This implies that the program will abort with an `Virtual
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Memory exhausted!' error if any problem arise.
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To work correctly, at least EXPONENT and TYPE should always be the
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same for all uses of this macro for any given TABLE. A secure way to
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achieve this is to never use this macro directly, but use it to define
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other macros, which would then be TABLE-specific.
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The first time through, COUNT is usually zero. Note that COUNT is not
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updated by this macro, but it should be update elsewhere, later. This
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is convenient, because it allows TABLE[COUNT] to refer to the new
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element at the end. Once its construction is completed, COUNT++ will
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record it in the table. Calling this macro several times in a row
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without updating COUNT is a bad thing to do. */
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#define BUMP_ALLOC(Table, Count, Exponent, Type) \
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BUMP_ALLOC_WITH_SIZE ((Table), (Count), (Exponent), Type, sizeof (Type))
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/* In cases `sizeof TYPE' would not always yield the correct value for
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the size of each element entry, this macro accepts a supplementary
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SIZE argument. The EXPONENT, TYPE and SIZE parameters should still
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have the same value for all macro calls related to a specific TABLE. */
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#define BUMP_ALLOC_WITH_SIZE(Table, Count, Exponent, Type, Size) \
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if (((Count) & (~(~0 << (Exponent)))) == 0) \
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if ((Count) == 0) \
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(Table) = (Type *) xmalloc ((1 << (Exponent)) * (Size)); \
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else \
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(Table) = (Type *) \
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xrealloc ((Table), ((Count) + (1 << (Exponent))) * (Size)); \
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else
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