Commit Graph

60 Commits

Author SHA1 Message Date
Nathan Bossart 3b42bdb471 Use new overflow-safe integer comparison functions.
Commit 6b80394781 introduced integer comparison functions designed
to be as efficient as possible while avoiding overflow.  This
commit makes use of these functions in many of the in-tree qsort()
comparators to help ensure transitivity.  Many of these comparator
functions should also see a small performance boost.

Author: Mats Kindahl
Reviewed-by: Andres Freund, Fabrízio de Royes Mello
Discussion: https://postgr.es/m/CA%2B14426g2Wa9QuUpmakwPxXFWG_1FaY0AsApkvcTBy-YfS6uaw%40mail.gmail.com
2024-02-16 14:05:36 -06:00
Bruce Momjian 29275b1d17 Update copyright for 2024
Reported-by: Michael Paquier

Discussion: https://postgr.es/m/ZZKTDPxBBMt3C0J9@paquier.xyz

Backpatch-through: 12
2024-01-03 20:49:05 -05:00
Michael Paquier aa0d350456 Improve description of keys in tsvector
If all the bits of a key in a tsvector are true (marked with ALLISTRUE),
gtsvectorout() would show the following description:
"0 true bits, 0 false bits"

This is confusing, as all the bits are true, but this would be
equivalent to the information if siglen is 0.

This commit improves the output so as "all true bits" show instead in
this case.  Alexander has proposed a regression test for pageinspect,
not included here as it is rather expensive compared to its coverage
value.

Author: Alexander Lakhin
Discussion: https://postgr.es/m/17950-6c80a8d2b94ec695@postgresql.org
2023-09-05 13:57:44 +09:00
Michael Paquier ae10dbb0c5 Fix out-of-bound read in gtsvector_picksplit()
This could lead to an imprecise choice when splitting an index page of a
GiST index on a tsvector, deciding which entries should remain on the
old page and which entries should move to a new page.

This is wrong since tsearch2 has been moved into core with commit
140d4ebcb4, so backpatch all the way down.  This error has been
spotted by valgrind.

Author: Alexander Lakhin
Discussion: https://postgr.es/m/17950-6c80a8d2b94ec695@postgresql.org
Backpatch-through: 11
2023-09-04 14:55:37 +09:00
Peter Eisentraut aa69541046 Remove useless casts to (void *) in arguments of some system functions
The affected functions are: bsearch, memcmp, memcpy, memset, memmove,
qsort, repalloc

Reviewed-by: Corey Huinker <corey.huinker@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/fd9adf5d-b1aa-e82f-e4c7-263c30145807%40enterprisedb.com
2023-02-07 06:57:59 +01:00
Bruce Momjian c8e1ba736b Update copyright for 2023
Backpatch-through: 11
2023-01-02 15:00:37 -05:00
Tom Lane d02ef65bce Standardize error reports in unimplemented I/O functions.
We chose a specific wording of the not-implemented errors for
pseudotype I/O functions and other cases where there's little
value in implementing input and/or output.  gtsvectorin never
got that memo though, nor did most of contrib.  Make these all
fall in line, mostly because I'm a neatnik but also to remove
unnecessary translatable strings.

gbtreekey_in needs a bit of extra love since it supports
multiple SQL types.  Sadly, gbtreekey_out doesn't have the
ability to do that, but I think it's unreachable anyway.

Noted while surveying datatype input functions to see what we
have left to fix.
2022-12-10 18:26:43 -05:00
Peter Eisentraut f14aad5169 Remove unnecessary uses of Abs()
Use C standard abs() or fabs() instead.

Reviewed-by: Zhang Mingli <zmlpostgres@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/4beb42b5-216b-bce8-d452-d924d5794c63%40enterprisedb.com
2022-10-07 13:29:33 +02:00
Peter Eisentraut 6bcda4a721 Fix incorrect uses of Datum conversion macros
Since these macros just cast whatever you give them to the designated
output type, and many normal uses also cast the output type further, a
number of incorrect uses go undiscovered.  The fixes in this patch
have been discovered by changing these macros to inline functions,
which is the subject of a future patch.

Reviewed-by: Aleksander Alekseev <aleksander@timescale.com>
Discussion: https://www.postgresql.org/message-id/flat/8528fb7e-0aa2-6b54-85fb-0c0886dbd6ed%40enterprisedb.com
2022-09-05 13:30:44 +02:00
Peter Eisentraut 258f48f858 Change some unnecessary MemSet calls
MemSet() with a value other than 0 just falls back to memset(), so the
indirection is unnecessary if the value is constant and not 0.  Since
there is some interest in getting rid of MemSet(), this gets some easy
cases out of the way.  (There are a few MemSet() calls that I didn't
change to maintain the consistency with their surrounding code.)

Discussion: https://www.postgresql.org/message-id/flat/CAEudQApCeq4JjW1BdnwU=m=-DvG5WyUik0Yfn3p6UNphiHjj+w@mail.gmail.com
2022-07-01 00:16:38 +02:00
Bruce Momjian 27b77ecf9f Update copyright for 2022
Backpatch-through: 10
2022-01-07 19:04:57 -05:00
Bruce Momjian ca3b37487b Update copyright for 2021
Backpatch-through: 9.5
2021-01-02 13:06:25 -05:00
Tom Lane 79d6d1a277 Replace TS_execute's TS_EXEC_CALC_NOT flag with TS_EXEC_SKIP_NOT.
It's fairly silly that ignoring NOT subexpressions is TS_execute's
default behavior.  It's wrong on its face and it encourages errors
of omission.  Moreover, the only two remaining callers that aren't
specifying CALC_NOT are in ts_headline calculations, and it's very
arguable that those are bugs: if you've specified "!foo" in your
query, why would you want to get a headline that includes "foo"?

Hence, rip that out and change the default behavior to be to calculate
NOT accurately.  As a concession to the slim chance that there is still
somebody somewhere who needs the incorrect behavior, provide a new
SKIP_NOT flag to explicitly request that.

Back-patch into v13, mainly because it seems better to change this
at the same time as the previous commit's rejiggering of TS_execute
related APIs.  Any outside callers affected by this change are
probably also affected by that one.

Discussion: https://postgr.es/m/CALT9ZEE-aLotzBg-pOp2GFTesGWVYzXA3=mZKzRDa_OKnLF7Mg@mail.gmail.com
2020-07-24 15:43:56 -04:00
Tom Lane 2f2007fbb2 Fix assorted bugs by changing TS_execute's callback API to ternary logic.
Text search sometimes failed to find valid matches, for instance
'!crew:A'::tsquery might fail to locate 'crew:1B'::tsvector during
an index search.  The root of the issue is that TS_execute's callback
functions were not changed to use ternary (yes/no/maybe) reporting
when we made the search logic itself do so.  It's somewhat annoying
to break that API, but on the other hand we now see that any code
using plain boolean logic is almost certainly broken since the
addition of phrase search.  There seem to be very few outside callers
of this code anyway, so we'll just break them intentionally to get
them to adapt.

This allows removal of tsginidx.c's private re-implementation of
TS_execute, since that's now entirely duplicative.  It's also no
longer necessary to avoid use of CALC_NOT in tsgistidx.c, since
the underlying callbacks can now do something reasonable.

Back-patch into v13.  We can't change this in stable branches,
but it seems not quite too late to fix it in v13.

Tom Lane and Pavel Borisov

Discussion: https://postgr.es/m/CALT9ZEE-aLotzBg-pOp2GFTesGWVYzXA3=mZKzRDa_OKnLF7Mg@mail.gmail.com
2020-07-24 15:26:51 -04:00
Tom Lane 5cbfce562f Initial pgindent and pgperltidy run for v13.
Includes some manual cleanup of places that pgindent messed up,
most of which weren't per project style anyway.

Notably, it seems some people didn't absorb the style rules of
commit c9d297751, because there were a bunch of new occurrences
of function calls with a newline just after the left paren, all
with faulty expectations about how the rest of the call would get
indented.
2020-05-14 13:06:50 -04:00
Alexander Korotkov 911e702077 Implement operator class parameters
PostgreSQL provides set of template index access methods, where opclasses have
much freedom in the semantics of indexing.  These index AMs are GiST, GIN,
SP-GiST and BRIN.  There opclasses define representation of keys, operations on
them and supported search strategies.  So, it's natural that opclasses may be
faced some tradeoffs, which require user-side decision.  This commit implements
opclass parameters allowing users to set some values, which tell opclass how to
index the particular dataset.

This commit doesn't introduce new storage in system catalog.  Instead it uses
pg_attribute.attoptions, which is used for table column storage options but
unused for index attributes.

In order to evade changing signature of each opclass support function, we
implement unified way to pass options to opclass support functions.  Options
are set to fn_expr as the constant bytea expression.  It's possible due to the
fact that opclass support functions are executed outside of expressions, so
fn_expr is unused for them.

This commit comes with some examples of opclass options usage.  We parametrize
signature length in GiST.  That applies to multiple opclasses: tsvector_ops,
gist__intbig_ops, gist_ltree_ops, gist__ltree_ops, gist_trgm_ops and
gist_hstore_ops.  Also we parametrize maximum number of integer ranges for
gist__int_ops.  However, the main future usage of this feature is expected
to be json, where users would be able to specify which way to index particular
json parts.

Catversion is bumped.

Discussion: https://postgr.es/m/d22c3a18-31c7-1879-fc11-4c1ce2f5e5af%40postgrespro.ru
Author: Nikita Glukhov, revised by me
Reviwed-by: Nikolay Shaplov, Robert Haas, Tom Lane, Tomas Vondra, Alvaro Herrera
2020-03-30 19:17:23 +03:00
Alvaro Herrera c9d2977519 Clean up newlines following left parentheses
We used to strategically place newlines after some function call left
parentheses to make pgindent move the argument list a few chars to the
left, so that the whole line would fit under 80 chars.  However,
pgindent no longer does that, so the newlines just made the code
vertically longer for no reason.  Remove those newlines, and reflow some
of those lines for some extra naturality.

Reviewed-by: Michael Paquier, Tom Lane
Discussion: https://postgr.es/m/20200129200401.GA6303@alvherre.pgsql
2020-01-30 13:42:14 -03:00
Bruce Momjian 7559d8ebfa Update copyrights for 2020
Backpatch-through: update all files in master, backpatch legal files through 9.4
2020-01-01 12:21:45 -05:00
Thomas Munro 7815e7efdb Add reusable routine for making arrays unique.
Introduce qunique() and qunique_arg(), which can be used after qsort()
and qsort_arg() respectively to remove duplicate values.  Use it where
appropriate.

Author: Thomas Munro
Reviewed-by: Tom Lane (in an earlier version)
Discussion: https://postgr.es/m/CAEepm%3D2vmFTNpAmwbGGD2WaryM6T3hSDVKQPfUwjdD_5XY6vAA%40mail.gmail.com
2019-11-07 17:00:48 +13:00
Robert Haas 8b94dab066 Split tuptoaster.c into three separate files.
detoast.c/h contain functions required to detoast a datum, partially
or completely, plus a few other utility functions for examining the
size of toasted datums.

toast_internals.c/h contain functions that are used internally to the
TOAST subsystem but which (mostly) do not need to be accessed from
outside.

heaptoast.c/h contains code that is intrinsically specific to the
heap AM, either because it operates on HeapTuples or is based on the
layout of a heap page.

detoast.c and toast_internals.c are placed in
src/backend/access/common rather than src/backend/access/heap.  At
present, both files still have dependencies on the heap, but that will
be improved in a future commit.

Patch by me, reviewed and tested by Prabhat Sabu, Thomas Munro,
Andres Freund, and Álvaro Herrera.

Discussion: http://postgr.es/m/CA+TgmoZv-=2iWM4jcw5ZhJeL18HF96+W1yJeYrnGMYdkFFnEpQ@mail.gmail.com
2019-09-05 13:15:10 -04:00
Tom Lane 02a6a54ecd Make use of compiler builtins and/or assembly for CLZ, CTZ, POPCNT.
Test for the compiler builtins __builtin_clz, __builtin_ctz, and
__builtin_popcount, and make use of these in preference to
handwritten C code if they're available.  Create src/port
infrastructure for "leftmost one", "rightmost one", and "popcount"
so as to centralize these decisions.

On x86_64, __builtin_popcount generally won't make use of the POPCNT
opcode because that's not universally supported yet.  Provide code
that checks CPUID and then calls POPCNT via asm() if available.
This requires indirecting through a function pointer, which is
an annoying amount of overhead for a one-instruction operation,
but it's probably not worth working harder than this for our
current use-cases.

I'm not sure we've found all the existing places that could profit
from this new infrastructure; but we at least touched all the
ones that used copied-and-pasted versions of the bitmapset.c code,
and got rid of multiple copies of the associated constant arrays.

While at it, replace c-compiler.m4's one-per-builtin-function
macros with a single one that can handle all the cases we need
to worry about so far.  Also, because I'm paranoid, make those
checks into AC_LINK checks rather than just AC_COMPILE; the
former coding failed to verify that libgcc has support for the
builtin, in cases where it's not inline code.

David Rowley, Thomas Munro, Alvaro Herrera, Tom Lane

Discussion: https://postgr.es/m/CAKJS1f9WTAGG1tPeJnD18hiQW5gAk59fQ6WK-vfdAKEHyRg2RA@mail.gmail.com
2019-02-15 23:22:33 -05:00
Bruce Momjian 97c39498e5 Update copyright for 2019
Backpatch-through: certain files through 9.4
2019-01-02 12:44:25 -05:00
Bruce Momjian 9d4649ca49 Update copyright for 2018
Backpatch-through: certain files through 9.3
2018-01-02 23:30:12 -05:00
Peter Eisentraut 2eb4a831e5 Change TRUE/FALSE to true/false
The lower case spellings are C and C++ standard and are used in most
parts of the PostgreSQL sources.  The upper case spellings are only used
in some files/modules.  So standardize on the standard spellings.

The APIs for ICU, Perl, and Windows define their own TRUE and FALSE, so
those are left as is when using those APIs.

In code comments, we use the lower-case spelling for the C concepts and
keep the upper-case spelling for the SQL concepts.

Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
2017-11-08 11:37:28 -05:00
Tom Lane 2d484f9b05 Remove no-op GiST support functions in the core GiST opclasses.
The preceding patch allowed us to remove useless GiST support functions.
This patch actually does that for all the no-op cases in the core GiST
code.  This buys us whatever performance gain is to be had, and more
importantly exercises the preceding patch.

There remain no-op functions in the contrib GiST opclasses, but those
will take more work to remove.

Discussion: https://postgr.es/m/CAJEAwVELVx9gYscpE=Be6iJxvdW5unZ_LkcAaVNSeOwvdwtD=A@mail.gmail.com
2017-09-19 23:32:59 -04:00
Tom Lane 4bd1994650 Make DatumGetFoo/PG_GETARG_FOO/PG_RETURN_FOO macro names more consistent.
By project convention, these names should include "P" when dealing with a
pointer type; that is, if the result of a GETARG macro is of type FOO *,
it should be called PG_GETARG_FOO_P not just PG_GETARG_FOO.  Some newer
types such as JSONB and ranges had not followed the convention, and a
number of contrib modules hadn't gotten that memo either.  Rename the
offending macros to improve consistency.

In passing, fix a few places that thought PG_DETOAST_DATUM() returns
a Datum; it does not, it returns "struct varlena *".  Applying
DatumGetPointer to that happens not to cause any bad effects today,
but it's formally wrong.  Also, adjust an ltree macro that was designed
without any thought for what pgindent would do with it.

This is all cosmetic and shouldn't have any impact on generated code.

Mark Dilger, some further tweaks by me

Discussion: https://postgr.es/m/EA5676F4-766F-4F38-8348-ECC7DB427C6A@gmail.com
2017-09-18 15:21:23 -04:00
Peter Eisentraut 17273d059c Remove unnecessary parentheses in return statements
The parenthesized style has only been used in a few modules.  Change
that to use the style that is predominant across the whole tree.

Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
Reviewed-by: Ryan Murphy <ryanfmurphy@gmail.com>
2017-09-05 14:52:55 -04:00
Peter Eisentraut 352a24a1f9 Generate fmgr prototypes automatically
Gen_fmgrtab.pl creates a new file fmgrprotos.h, which contains
prototypes for all functions registered in pg_proc.h.  This avoids
having to manually maintain these prototypes across a random variety of
header files.  It also automatically enforces a correct function
signature, and since there are warnings about missing prototypes, it
will detect functions that are defined but not registered in
pg_proc.h (or otherwise used).

Reviewed-by: Pavel Stehule <pavel.stehule@gmail.com>
2017-01-17 14:06:07 -05:00
Bruce Momjian 1d25779284 Update copyright via script for 2017 2017-01-03 13:48:53 -05:00
Tom Lane 89fcea1ace Fix strange behavior (and possible crashes) in full text phrase search.
In an attempt to simplify the tsquery matching engine, the original
phrase search patch invented rewrite rules that would rearrange a
tsquery so that no AND/OR/NOT operator appeared below a PHRASE operator.
But this approach had numerous problems.  The rearrangement step was
missed by ts_rewrite (and perhaps other places), allowing tsqueries
to be created that would cause Assert failures or perhaps crashes at
execution, as reported by Andreas Seltenreich.  The rewrite rules
effectively defined semantics for operators underneath PHRASE that were
buggy, or at least unintuitive.  And because rewriting was done in
tsqueryin() rather than at execution, the rearrangement was user-visible,
which is not very desirable --- for example, it might cause unexpected
matches or failures to match in ts_rewrite.

As a somewhat independent problem, the behavior of nested PHRASE operators
was only sane for left-deep trees; queries like "x <-> (y <-> z)" did not
behave intuitively at all.

To fix, get rid of the rewrite logic altogether, and instead teach the
tsquery execution engine to manage AND/OR/NOT below a PHRASE operator
by explicitly computing the match location(s) and match widths for these
operators.

This requires introducing some additional fields into the publicly visible
ExecPhraseData struct; but since there's no way for third-party code to
pass such a struct to TS_phrase_execute, it shouldn't create an ABI problem
as long as we don't move the offsets of the existing fields.

Another related problem was that index searches supposed that "!x <-> y"
could be lossily approximated as "!x & y", which isn't correct because
the latter will reject, say, "x q y" which the query itself accepts.
This required some tweaking in TS_execute_ternary along with the main
tsquery engine.

Back-patch to 9.6 where phrase operators were introduced.  While this
could be argued to change behavior more than we'd like in a stable branch,
we have to do something about the crash hazards and index-vs-seqscan
inconsistency, and it doesn't seem desirable to let the unintuitive
behaviors induced by the rewriting implementation stand as precedent.

Discussion: https://postgr.es/m/28215.1481999808@sss.pgh.pa.us
Discussion: https://postgr.es/m/26706.1482087250@sss.pgh.pa.us
2016-12-21 15:18:39 -05:00
Teodor Sigaev 3dbbd0f02a Do not fallback to AND for FTS phrase operator.
If there is no positional information of lexemes then phrase operator will not
fallback to AND operator. This change makes needing to modify TS_execute()
interface, because somewhere (in indexes, for example) positional information
is unaccesible and in this cases we need to force fallback to AND.

Per discussion c19fcfec308e6ccd952cdde9e648b505@mail.gmail.com
2016-06-27 20:47:32 +03:00
Teodor Sigaev bb140506df Phrase full text search.
Patch introduces new text search operator (<-> or <DISTANCE>) into tsquery.
On-disk and binary in/out format of tsquery are backward compatible.
It has two side effect:
- change order for tsquery, so, users, who has a btree index over tsquery,
  should reindex it
- less number of parenthesis in tsquery output, and tsquery becomes more
  readable

Authors: Teodor Sigaev, Oleg Bartunov, Dmitry Ivanov
Reviewers: Alexander Korotkov, Artur Zakirov
2016-04-07 18:44:18 +03:00
Tom Lane eb43e851d6 Create stub functions to support pg_upgrade of old contrib/tsearch2.
Commits 9ff60273e3 and dbe2328959 adjusted the declarations
of some core functions referenced by contrib/tsearch2's install script,
forgetting that in a pg_upgrade situation, we'll be trying to restore
operator class definitions that reference the old signatures.  We've
hit this problem before; solve it in the same way as before, namely by
installing stub functions that have the expected signature and just
invoke the correct function.  Per report from Jeff Janes.

(Someday we ought to stop supporting contrib/tsearch2, but I'm not
sure today is that day.)
2016-03-02 17:37:54 -05:00
Bruce Momjian ee94300446 Update copyright for 2016
Backpatch certain files through 9.1
2016-01-02 13:33:40 -05:00
Heikki Linnakangas 4f700bcd20 Reorganize our CRC source files again.
Now that we use CRC-32C in WAL and the control file, the "traditional" and
"legacy" CRC-32 variants are not used in any frontend programs anymore.
Move the code for those back from src/common to src/backend/utils/hash.

Also move the slicing-by-8 implementation (back) to src/port. This is in
preparation for next patch that will add another implementation that uses
Intel SSE 4.2 instructions to calculate CRC-32C, where available.
2015-04-14 17:03:42 +03:00
Tom Lane 2e211211a7 Use FLEXIBLE_ARRAY_MEMBER in a number of other places.
I think we're about done with this...
2015-02-21 16:12:14 -05:00
Bruce Momjian 4baaf863ec Update copyright for 2015
Backpatch certain files through 9.0
2015-01-06 11:43:47 -05:00
Heikki Linnakangas 5028f22f6e Switch to CRC-32C in WAL and other places.
The old algorithm was found to not be the usual CRC-32 algorithm, used by
Ethernet et al. We were using a non-reflected lookup table with code meant
for a reflected lookup table. That's a strange combination that AFAICS does
not correspond to any bit-wise CRC calculation, which makes it difficult to
reason about its properties. Although it has worked well in practice, seems
safer to use a well-known algorithm.

Since we're changing the algorithm anyway, we might as well choose a
different polynomial. The Castagnoli polynomial has better error-correcting
properties than the traditional CRC-32 polynomial, even if we had
implemented it correctly. Another reason for picking that is that some new
CPUs have hardware support for calculating CRC-32C, but not CRC-32, let
alone our strange variant of it. This patch doesn't add any support for such
hardware, but a future patch could now do that.

The old algorithm is kept around for tsquery and pg_trgm, which use the
values in indexes that need to remain compatible so that pg_upgrade works.
While we're at it, share the old lookup table for CRC-32 calculation
between hstore, ltree and core. They all use the same table, so might as
well.
2014-11-04 11:39:48 +02:00
Robert Haas 0f565c0743 Fix typos.
Etsuro Fujita
2014-10-20 10:23:40 -04:00
Bruce Momjian 7e04792a1c Update copyright for 2014
Update all files in head, and files COPYRIGHT and legal.sgml in all back
branches.
2014-01-07 16:05:30 -05:00
Bruce Momjian bd61a623ac Update copyrights for 2013
Fully update git head, and update back branches in ./COPYRIGHT and
legal.sgml files.
2013-01-01 17:15:01 -05:00
Peter Eisentraut b8b2e3b2de Replace int2/int4 in C code with int16/int32
The latter was already the dominant use, and it's preferable because
in C the convention is that intXX means XX bits.  Therefore, allowing
mixed use of int2, int4, int8, int16, int32 is obviously confusing.

Remove the typedefs for int2 and int4 for now.  They don't seem to be
widely used outside of the PostgreSQL source tree, and the few uses
can probably be cleaned up by the time this ships.
2012-06-25 01:51:46 +03:00
Bruce Momjian 927d61eeff Run pgindent on 9.2 source tree in preparation for first 9.3
commit-fest.
2012-06-10 15:20:04 -04:00
Bruce Momjian e126958c2e Update copyright notices for year 2012. 2012-01-01 18:01:58 -05:00
Peter Eisentraut 1b81c2fe6e Remove many -Wcast-qual warnings
This addresses only those cases that are easy to fix by adding or
moving a const qualifier or removing an unnecessary cast.  There are
many more complicated cases remaining.
2011-09-11 21:54:32 +03:00
Bruce Momjian 6416a82a62 Remove unnecessary #include references, per pgrminclude script. 2011-09-01 10:04:27 -04:00
Bruce Momjian 5d950e3b0c Stamp copyrights for year 2011. 2011-01-01 13:18:15 -05:00
Magnus Hagander 9f2e211386 Remove cvs keywords from all files. 2010-09-20 22:08:53 +02:00
Bruce Momjian 0239800893 Update copyright for the year 2010. 2010-01-02 16:58:17 +00:00
Bruce Momjian d747140279 8.4 pgindent run, with new combined Linux/FreeBSD/MinGW typedef list
provided by Andrew.
2009-06-11 14:49:15 +00:00