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/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
extern char __HeapBase;
extern char __HeapLimit;
void *
_sbrk(int incr)
{
static char *brk = &__HeapBase;
void *prev_brk;
if (incr < 0) {
/* Returning memory to the heap. */
incr = -incr;
if (brk - incr < &__HeapBase) {
prev_brk = (void *)-1;
} else {
prev_brk = brk;
brk -= incr;
}
} else {
/* Allocating memory from the heap. */
if (&__HeapLimit - brk >= incr) {
prev_brk = brk;
brk += incr;
} else {
prev_brk = (void *)-1;
}
}
return prev_brk;
}
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