72 lines
1.7 KiB
C
72 lines
1.7 KiB
C
/* go-append.c -- the go builtin append function.
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Copyright 2010 The Go Authors. All rights reserved.
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Use of this source code is governed by a BSD-style
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license that can be found in the LICENSE file. */
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#include "runtime.h"
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#include "go-panic.h"
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#include "go-type.h"
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#include "array.h"
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#include "arch.h"
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#include "malloc.h"
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/* We should be OK if we don't split the stack here, since the only
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libc functions we call are memcpy and memmove. If we don't do
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this, we will always split the stack, because of memcpy and
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memmove. */
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extern struct __go_open_array
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__go_append (struct __go_open_array, void *, uintptr_t, uintptr_t)
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__attribute__ ((no_split_stack));
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struct __go_open_array
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__go_append (struct __go_open_array a, void *bvalues, uintptr_t bcount,
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uintptr_t element_size)
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{
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uintptr_t ucount;
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int count;
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if (bvalues == NULL || bcount == 0)
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return a;
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ucount = (uintptr_t) a.__count + bcount;
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count = (int) ucount;
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if ((uintptr_t) count != ucount || count <= a.__count)
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runtime_panicstring ("append: slice overflow");
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if (count > a.__capacity)
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{
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int m;
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void *n;
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m = a.__capacity;
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if (m == 0)
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m = (int) bcount;
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else
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{
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do
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{
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if (a.__count < 1024)
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m += m;
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else
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m += m / 4;
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}
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while (m < count);
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}
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if ((uintptr) m > MaxMem / element_size)
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runtime_panicstring ("growslice: cap out of range");
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n = __go_alloc (m * element_size);
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__builtin_memcpy (n, a.__values, a.__count * element_size);
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a.__values = n;
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a.__capacity = m;
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}
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__builtin_memmove ((char *) a.__values + a.__count * element_size,
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bvalues, bcount * element_size);
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a.__count = count;
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return a;
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}
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