replace-buffer-contents cleanups
* src/editfns.c (NOTE_DELETE, NOTE_INSERT): Avoid unnecessary parens. (Freplace_buffer_contents): Check args before returning results. Avoid integer overflow when computing too_expensive, and work even if MAX-COSTS is bignum. Call alloca and/or malloc just once, not three times. (set_bit, bit_is_set): Simplify micro-optimization by using eassume.
This commit is contained in:
Paul Eggert
parent
08a6d14e41
commit
e0345b4e86
1 changed files with 47 additions and 45 deletions
|
|
@ -1900,8 +1900,8 @@ determines whether case is significant or ignored. */)
|
|||
sys_jmp_buf jmp; \
|
||||
unsigned short quitcounter;
|
||||
|
||||
#define NOTE_DELETE(ctx, xoff) set_bit ((ctx)->deletions, (xoff))
|
||||
#define NOTE_INSERT(ctx, yoff) set_bit ((ctx)->insertions, (yoff))
|
||||
#define NOTE_DELETE(ctx, xoff) set_bit ((ctx)->deletions, xoff)
|
||||
#define NOTE_INSERT(ctx, yoff) set_bit ((ctx)->insertions, yoff)
|
||||
#define EARLY_ABORT(ctx) compareseq_early_abort (ctx)
|
||||
|
||||
struct context;
|
||||
|
|
@ -1954,6 +1954,28 @@ nil. */)
|
|||
if (a == b)
|
||||
error ("Cannot replace a buffer with itself");
|
||||
|
||||
ptrdiff_t too_expensive;
|
||||
if (NILP (max_costs))
|
||||
too_expensive = 1000000;
|
||||
else if (FIXNUMP (max_costs))
|
||||
too_expensive = clip_to_bounds (0, XFIXNUM (max_costs), PTRDIFF_MAX);
|
||||
else
|
||||
{
|
||||
CHECK_INTEGER (max_costs);
|
||||
too_expensive = NILP (Fnatnump (max_costs)) ? 0 : PTRDIFF_MAX;
|
||||
}
|
||||
|
||||
struct timespec time_limit = make_timespec (0, -1);
|
||||
if (!NILP (max_secs))
|
||||
{
|
||||
struct timespec
|
||||
tlim = timespec_add (current_timespec (),
|
||||
lisp_time_argument (max_secs)),
|
||||
tmax = make_timespec (TYPE_MAXIMUM (time_t), TIMESPEC_HZ - 1);
|
||||
if (timespec_cmp (tlim, tmax) < 0)
|
||||
time_limit = tlim;
|
||||
}
|
||||
|
||||
ptrdiff_t min_a = BEGV;
|
||||
ptrdiff_t min_b = BUF_BEGV (b);
|
||||
ptrdiff_t size_a = ZV - min_a;
|
||||
|
|
@ -1983,36 +2005,24 @@ nil. */)
|
|||
|
||||
ptrdiff_t count = SPECPDL_INDEX ();
|
||||
|
||||
|
||||
ptrdiff_t diags = size_a + size_b + 3;
|
||||
ptrdiff_t del_bytes = size_a / CHAR_BIT + 1;
|
||||
ptrdiff_t ins_bytes = size_b / CHAR_BIT + 1;
|
||||
ptrdiff_t *buffer;
|
||||
ptrdiff_t bytes_needed;
|
||||
if (INT_MULTIPLY_WRAPV (diags, 2 * sizeof *buffer, &bytes_needed)
|
||||
|| INT_ADD_WRAPV (del_bytes + ins_bytes, bytes_needed, &bytes_needed))
|
||||
memory_full (SIZE_MAX);
|
||||
USE_SAFE_ALLOCA;
|
||||
buffer = SAFE_ALLOCA (bytes_needed);
|
||||
unsigned char *deletions_insertions = memset (buffer + 2 * diags, 0,
|
||||
del_bytes + ins_bytes);
|
||||
|
||||
/* FIXME: It is not documented how to initialize the contents of the
|
||||
context structure. This code cargo-cults from the existing
|
||||
caller in src/analyze.c of GNU Diffutils, which appears to
|
||||
work. */
|
||||
|
||||
ptrdiff_t diags = size_a + size_b + 3;
|
||||
ptrdiff_t *buffer;
|
||||
USE_SAFE_ALLOCA;
|
||||
SAFE_NALLOCA (buffer, 2, diags);
|
||||
|
||||
if (NILP (max_costs))
|
||||
XSETFASTINT (max_costs, 1000000);
|
||||
else
|
||||
CHECK_FIXNUM (max_costs);
|
||||
|
||||
struct timespec time_limit = make_timespec (0, -1);
|
||||
if (!NILP (max_secs))
|
||||
{
|
||||
struct timespec
|
||||
tlim = timespec_add (current_timespec (),
|
||||
lisp_time_argument (max_secs)),
|
||||
tmax = make_timespec (TYPE_MAXIMUM (time_t), TIMESPEC_HZ - 1);
|
||||
if (timespec_cmp (tlim, tmax) < 0)
|
||||
time_limit = tlim;
|
||||
}
|
||||
|
||||
/* Micro-optimization: Casting to size_t generates much better
|
||||
code. */
|
||||
ptrdiff_t del_bytes = (size_t) size_a / CHAR_BIT + 1;
|
||||
ptrdiff_t ins_bytes = (size_t) size_b / CHAR_BIT + 1;
|
||||
struct context ctx = {
|
||||
.buffer_a = a,
|
||||
.buffer_b = b,
|
||||
|
|
@ -2020,16 +2030,14 @@ nil. */)
|
|||
.beg_b = min_b,
|
||||
.a_unibyte = BUF_ZV (a) == BUF_ZV_BYTE (a),
|
||||
.b_unibyte = BUF_ZV (b) == BUF_ZV_BYTE (b),
|
||||
.deletions = SAFE_ALLOCA (del_bytes),
|
||||
.insertions = SAFE_ALLOCA (ins_bytes),
|
||||
.deletions = deletions_insertions,
|
||||
.insertions = deletions_insertions + del_bytes,
|
||||
.fdiag = buffer + size_b + 1,
|
||||
.bdiag = buffer + diags + size_b + 1,
|
||||
.heuristic = true,
|
||||
.too_expensive = XFIXNUM (max_costs),
|
||||
.too_expensive = too_expensive,
|
||||
.time_limit = time_limit,
|
||||
};
|
||||
memclear (ctx.deletions, del_bytes);
|
||||
memclear (ctx.insertions, ins_bytes);
|
||||
|
||||
/* compareseq requires indices to be zero-based. We add BEGV back
|
||||
later. */
|
||||
|
|
@ -2074,8 +2082,8 @@ nil. */)
|
|||
|
||||
/* Check whether there is a change (insertion or deletion)
|
||||
before the current position. */
|
||||
if ((i > 0 && bit_is_set (ctx.deletions, i - 1)) ||
|
||||
(j > 0 && bit_is_set (ctx.insertions, j - 1)))
|
||||
if ((i > 0 && bit_is_set (ctx.deletions, i - 1))
|
||||
|| (j > 0 && bit_is_set (ctx.insertions, j - 1)))
|
||||
{
|
||||
ptrdiff_t end_a = min_a + i;
|
||||
ptrdiff_t end_b = min_b + j;
|
||||
|
|
@ -2117,21 +2125,15 @@ nil. */)
|
|||
static void
|
||||
set_bit (unsigned char *a, ptrdiff_t i)
|
||||
{
|
||||
eassert (i >= 0);
|
||||
/* Micro-optimization: Casting to size_t generates much better
|
||||
code. */
|
||||
size_t j = i;
|
||||
a[j / CHAR_BIT] |= (1 << (j % CHAR_BIT));
|
||||
eassume (0 <= i);
|
||||
a[i / CHAR_BIT] |= (1 << (i % CHAR_BIT));
|
||||
}
|
||||
|
||||
static bool
|
||||
bit_is_set (const unsigned char *a, ptrdiff_t i)
|
||||
{
|
||||
eassert (i >= 0);
|
||||
/* Micro-optimization: Casting to size_t generates much better
|
||||
code. */
|
||||
size_t j = i;
|
||||
return a[j / CHAR_BIT] & (1 << (j % CHAR_BIT));
|
||||
eassume (0 <= i);
|
||||
return a[i / CHAR_BIT] & (1 << (i % CHAR_BIT));
|
||||
}
|
||||
|
||||
/* Return true if the characters at position POS_A of buffer
|
||||
|
|
|
|||
Loading…
Add table
Reference in a new issue