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vcs-svn: suppress a -Wtype-limits warning
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On 32-bit architectures with 64-bit file offsets, gcc 4.3 and earlier
produce the following warning:

	    CC vcs-svn/sliding_window.o
	vcs-svn/sliding_window.c: In function `check_overflow':
	vcs-svn/sliding_window.c:36: warning: comparison is always false \
	    due to limited range of data type

The warning appears even when gcc is run without any warning flags
(this is gcc bug 12963).  In later versions the same warning can be
reproduced with -Wtype-limits, which is implied by -Wextra.

On 64-bit architectures it really is possible for a size_t not to be
representable as an off_t so the check this is warning about is not
actually redundant.  But even false positives are distracting.  Avoid
the warning by making the "len" argument to check_overflow a
uintmax_t; no functional change intended.

Reported-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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Jonathan Nieder authored and Junio C Hamano committed Feb 2, 2012
1 parent 150f754 commit 3f79000
Showing 1 changed file with 3 additions and 3 deletions.
6 changes: 3 additions & 3 deletions vcs-svn/sliding_window.c
Original file line number Diff line number Diff line change
Expand Up @@ -31,15 +31,15 @@ static int read_to_fill_or_whine(struct line_buffer *file,
return 0;
}

static int check_offset_overflow(off_t offset, size_t len)
static int check_offset_overflow(off_t offset, uintmax_t len)
{
if (len > maximum_signed_value_of_type(off_t))
return error("unrepresentable length in delta: "
"%"PRIuMAX" > OFF_MAX", (uintmax_t) len);
"%"PRIuMAX" > OFF_MAX", len);
if (signed_add_overflows(offset, (off_t) len))
return error("unrepresentable offset in delta: "
"%"PRIuMAX" + %"PRIuMAX" > OFF_MAX",
(uintmax_t) offset, (uintmax_t) len);
(uintmax_t) offset, len);
return 0;
}

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