Postgres' standard mechanism for reporting errors (ereport() or elog())
is used for all sorts of error conditions. This means that throwing
an exception via ereport(ERROR) requires an expensive transaction or
subtransaction abort and cleanup, since the exception catcher dare not
make many assumptions about what has gone wrong. There are situations
where we would rather have a lighter-weight mechanism for dealing
with errors that are known to be safe to recover from without a full
transaction cleanup. This commit creates infrastructure to let us
adapt existing error-reporting code for that purpose. See the
included documentation changes for details. Follow-on commits will
provide test code and usage examples.
The near-term plan is to convert most if not all datatype input
functions to report invalid input "softly". This will enable
implementing some SQL/JSON features cleanly and without the cost
of subtransactions, and it will also allow creating COPY options
to deal with bad input without cancelling the whole COPY.
This patch is mostly by me, but it owes very substantial debt to
earlier work by Nikita Glukhov, Andrew Dunstan, and Amul Sul.
Thanks also to Andres Freund for review.
Discussion: https://postgr.es/m/3bbbb0df-7382-bf87-9737-340ba096e034@postgrespro.ru
Currently, information about the permissions to be checked on relations
mentioned in a query is stored in their range table entries. So the
executor must scan the entire range table looking for relations that
need to have permissions checked. This can make the permission checking
part of the executor initialization needlessly expensive when many
inheritance children are present in the range range. While the
permissions need not be checked on the individual child relations, the
executor still must visit every range table entry to filter them out.
This commit moves the permission checking information out of the range
table entries into a new plan node called RTEPermissionInfo. Every
top-level (inheritance "root") RTE_RELATION entry in the range table
gets one and a list of those is maintained alongside the range table.
This new list is initialized by the parser when initializing the range
table. The rewriter can add more entries to it as rules/views are
expanded. Finally, the planner combines the lists of the individual
subqueries into one flat list that is passed to the executor for
checking.
To make it quick to find the RTEPermissionInfo entry belonging to a
given relation, RangeTblEntry gets a new Index field 'perminfoindex'
that stores the corresponding RTEPermissionInfo's index in the query's
list of the latter.
ExecutorCheckPerms_hook has gained another List * argument; the
signature is now:
typedef bool (*ExecutorCheckPerms_hook_type) (List *rangeTable,
List *rtePermInfos,
bool ereport_on_violation);
The first argument is no longer used by any in-core uses of the hook,
but we leave it in place because there may be other implementations that
do. Implementations should likely scan the rtePermInfos list to
determine which operations to allow or deny.
Author: Amit Langote <amitlangote09@gmail.com>
Discussion: https://postgr.es/m/CA+HiwqGjJDmUhDSfv-U2qhKJjt9ST7Xh9JXC_irsAQ1TAUsJYg@mail.gmail.com
It seems better to deal with this by explicit annotations on the
fields in question, instead of magic knowledge embedded in the
script. While that creates a risk-of-omission from failing to
annotate fields, the preceding commit should catch any such
oversights.
Discussion: https://postgr.es/m/263413.1669513145@sss.pgh.pa.us
Check that if we generate a call to copy, compare, write, or read
a specific node type, that node type does have the appropriate
support function. (This doesn't protect against trying to invoke
nonexistent code when considering generic field types such as
"Node *", but it seems like a useful check anyway.)
Check that array_size() refers to a field appearing earlier in
the struct. Aside from catching obvious errors like a misspelled
field name, this protects against a more subtle mistake: if the
size field appears later in the struct than the array field, then
compare and read functions would misbehave. There is actually
exactly that situation in PlannerInfo, but it's okay since we
do not need compare or read functionality for that (today anyway).
Discussion: https://postgr.es/m/263413.1669513145@sss.pgh.pa.us
We're running out of bits for new permissions. This change doubles the
number of permissions we can accomodate from 16 to 32, so the
forthcoming new ones for vacuum/analyze don't exhaust the pool.
Nathan Bossart
Reviewed by: Bharath Rupireddy, Kyotaro Horiguchi, Stephen Frost, Robert
Haas, Mark Dilger, Tom Lane, Corey Huinker, David G. Johnston, Michael
Paquier.
Discussion: https://postgr.es/m/20220722203735.GB3996698@nathanxps13
This switch impacts 9 patterns related to a SQL-mandated special syntax
for function calls:
- LOCALTIME [ ( typmod ) ]
- LOCALTIMESTAMP [ ( typmod ) ]
- CURRENT_TIME [ ( typmod ) ]
- CURRENT_TIMESTAMP [ ( typmod ) ]
- CURRENT_DATE
Five new entries are added to pg_proc to compensate the removal of
SQLValueFunction to provide backward-compatibility and making this
change transparent for the end-user (for example for the attribute
generated when a keyword is specified in a SELECT or in a FROM clause
without an alias, or when specifying something else than an Iconst to
the parser).
The parser included a set of checks coming from the files in charge of
holding the C functions used for the SQLValueFunction calls (as of
transformSQLValueFunction()), which are now moved within each function's
execution path, so this reduces the dependencies between the execution
and the parsing steps. As of this change, all the SQL keywords use the
same paths for their work, relying only on COERCE_SQL_SYNTAX. Like
fb32748, no performance difference has been noticed, while the perf
profiles get reduced with ExecEvalSQLValueFunction() gone.
Bump catalog version.
Reviewed-by: Corey Huinker, Ted Yu
Discussion: https://postgr.es/m/YzaG3MoryCguUOym@paquier.xyz
This commit changes six SQL keywords to use COERCE_SQL_SYNTAX rather
than relying on SQLValueFunction:
- CURRENT_ROLE
- CURRENT_USER
- USER
- SESSION_USER
- CURRENT_CATALOG
- CURRENT_SCHEMA
Among the six, "user", "current_role" and "current_catalog" require
specific SQL functions to allow ruleutils.c to map them to the SQL
keywords these require when using COERCE_SQL_SYNTAX. Having
pg_proc.proname match with the keyword ensures that the compatibility
remains the same when projecting any of these keywords in a FROM clause
to an attribute name when an alias is not specified. This is covered by
the tests added in 2e0d80c, making sure that a correct mapping happens
with each SQL keyword. The three others (current_schema, session_user
and current_user) already have pg_proc entries for this job, so this
brings more consistency between the way such keywords are treated in the
parser, the executor and ruleutils.c.
SQLValueFunction is reduced to half its contents after this change,
simplifying its logic a bit as there is no need to enforce a C collation
anymore for the entries returning a name as a result. I have made a few
performance tests, with a million-ish calls to these keywords without
seeing a difference in run-time or in perf profiles
(ExecEvalSQLValueFunction() is removed from the profiles). The
remaining SQLValueFunctions are now related to timestamps and dates.
Bump catalog version.
Reviewed-by: Corey Huinker
Discussion: https://postgr.es/m/YzaG3MoryCguUOym@paquier.xyz
Implement a data structure that is a List of Bitmapsets, which is
essentially a 2-D boolean array except that the rows need not all
be the same width. Operations such as union and intersection are
meaningful for these, just as they are for Bitmapsets. Eventually
we might build many of the same operations that we have written for
Bitmapsets, but for the first use-case we just need a few.
That first use-case is for antijoin detection: reduce_outer_joins
needs to find the set of Vars that are certain to be non-null in a
successfully joined (not null-extended) left join row, and also
find the set of Vars subject to higher-level IS NULL constraints,
and intersect them. We had been doing this by making Lists of
the Var nodes and then using list_intersect, which works but is
pretty inefficient compared to a bitmapset-like intersection.
Potentially it's O(N^2) if there are a lot of Vars involved,
which fortunately there generally aren't; still it's not great.
Moreover, that method requires the Vars of interest to be exactly
equal() in the join condition and the upper IS NULL condition,
which is problematic for my WIP patch that labels Vars according
to which outer joins have possibly nulled them.
Discussion: https://postgr.es/m/892228.1668437838@sss.pgh.pa.us
Discussion: https://postgr.es/m/CAMbWs4-mvPPCJ1W6iK6dD5HiNwoJdi6mZp=-7mE8N9Sh+cd0tQ@mail.gmail.com
Add a NodeTag field to struct Bitmapset. This is free because of
alignment considerations on 64-bit hardware. While it adds some
space on 32-bit machines, we aren't optimizing for that case anymore.
The advantage is that data structures such as Lists of Bitmapsets
are now first-class objects to the Node infrastructure, and don't
require special-case code to handle.
This patch includes removal of one such special case, in indxpath.c:
bms_equal_any() can now be replaced by list_member(). There may be
more existing code that could be simplified, but I didn't look very
hard. We also get to drop the read_write_ignore annotations on a
couple of RelOptInfo fields.
The outfuncs/readfuncs support is arranged so that nothing changes
in the string representation of a Bitmapset field; therefore, this
doesn't need a catversion bump.
Amit Langote and Tom Lane
Discussion: https://postgr.es/m/109089.1668197158@sss.pgh.pa.us
There are still some alignment-related failures in the buildfarm,
which might or might not be able to be fixed quickly, but I've also
just realized that it increased the size of many WAL records by 4 bytes
because a block reference contains a RelFileLocator. The effect of that
hasn't been studied or discussed, so revert for now.
RelFileNumbers are now assigned using a separate counter, instead of
being assigned from the OID counter. This counter never wraps around:
if all 2^56 possible RelFileNumbers are used, an internal error
occurs. As the cluster is limited to 2^64 total bytes of WAL, this
limitation should not cause a problem in practice.
If the counter were 64 bits wide rather than 56 bits wide, we would
need to increase the width of the BufferTag, which might adversely
impact buffer lookup performance. Also, this lets us use bigint for
pg_class.relfilenode and other places where these values are exposed
at the SQL level without worrying about overflow.
This should remove the need to keep "tombstone" files around until
the next checkpoint when relations are removed. We do that to keep
RelFileNumbers from being recycled, but now that won't happen
anyway. However, this patch doesn't actually change anything in
this area; it just makes it possible for a future patch to do so.
Dilip Kumar, based on an idea from Andres Freund, who also reviewed
some earlier versions of the patch. Further review and some
wordsmithing by me. Also reviewed at various points by Ashutosh
Sharma, Vignesh C, Amul Sul, Álvaro Herrera, and Tom Lane.
Discussion: http://postgr.es/m/CA+Tgmobp7+7kmi4gkq7Y+4AM9fTvL+O1oQ4-5gFTT+6Ng-dQ=g@mail.gmail.com
We weren't jumbling the merge action list, so wildly different commands
would be considered to use the same query ID. Add that, mention it in
the docs, and some test lines.
Backpatch to 15.
Author: Tatsu <bt22nakamorit@oss.nttdata.com>
Reviewed-by: Julien Rouhaud <rjuju123@gmail.com>
Discussion: https://postgr.es/m/d87e391694db75a038abc3b2597828e8@oss.nttdata.com
Historically we've been more worried about making the output of
float fields look pretty than whether they'd be read back exactly.
That won't work if we're to compare the read-back nodes for
equality, so switch to using the Ryu code for float output.
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/4159834.1657405226@sss.pgh.pa.us
Historically, outToken has represented both NULL and empty-string
strings as "<>", which readfuncs.c then read as NULL, thus failing
to preserve empty-string fields accurately. Remarkably, this has
not caused any serious problems yet, but let's fix it.
We'll keep the "<>" notation for NULL, and use """" for empty string,
because that matches other notational choices already in use.
An actual input string of """" is converted to "\""" (this was true
already, apparently as a hangover from an ancient time when string
quoting was handled directly by pg_strtok).
CHAR fields also use "<>", but for '\0'.
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/4159834.1657405226@sss.pgh.pa.us
The node types A_Const, Constraint, and A_Expr had custom output
functions, but no read functions were implemented so far.
The A_Expr output format had to be tweaked a bit to make it easier to
parse.
Be a bit more cautious about applying strncmp to unterminated strings.
Also error out if an unrecognized enum value is found in each case,
instead of just printing a placeholder value. That was maybe ok for
debugging but won't work if we want to have robust round-tripping.
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/4159834.1657405226@sss.pgh.pa.us
The node tokenizer went out of its way to store BitString node values
without the leading 'b'. But everything else in the system stores the
leading 'b'. This would break if a BitString node is
read-printed-read.
Also, the node tokenizer didn't know that BitString node tokens could
also start with 'x'.
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/4159834.1657405226@sss.pgh.pa.us
The main parser checks whether a literal fits into an int when
deciding whether it should be put into an Integer or Float node. The
parser processes integer literals without signs. So a most-negative
integer literal will not fit into Integer and will end up as a Float
node.
The node tokenizer did this differently. It included the sign when
checking whether the literal fit into int. So a most-negative integer
would indeed fit that way and end up as an Integer node.
In order to preserve the node structure correctly, we need the node
tokenizer to also analyze integer literals without sign.
There are a number of test cases in the regression tests that have a
most-negative integer argument of some utility statement, so this
issue is easily reproduced under WRITE_READ_PARSE_PLAN_TREES.
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/4159834.1657405226@sss.pgh.pa.us
Autoconf is showing its age, fewer and fewer contributors know how to wrangle
it. Recursive make has a lot of hard to resolve dependency issues and slow
incremental rebuilds. Our home-grown MSVC build system is hard to maintain for
developers not using Windows and runs tests serially. While these and other
issues could individually be addressed with incremental improvements, together
they seem best addressed by moving to a more modern build system.
After evaluating different build system choices, we chose to use meson, to a
good degree based on the adoption by other open source projects.
We decided that it's more realistic to commit a relatively early version of
the new build system and mature it in tree.
This commit adds an initial version of a meson based build system. It supports
building postgres on at least AIX, FreeBSD, Linux, macOS, NetBSD, OpenBSD,
Solaris and Windows (however only gcc is supported on aix, solaris). For
Windows/MSVC postgres can now be built with ninja (faster, particularly for
incremental builds) and msbuild (supporting the visual studio GUI, but
building slower).
Several aspects (e.g. Windows rc file generation, PGXS compatibility, LLVM
bitcode generation, documentation adjustments) are done in subsequent commits
requiring further review. Other aspects (e.g. not installing test-only
extensions) are not yet addressed.
When building on Windows with msbuild, builds are slower when using a visual
studio version older than 2019, because those versions do not support
MultiToolTask, required by meson for intra-target parallelism.
The plan is to remove the MSVC specific build system in src/tools/msvc soon
after reaching feature parity. However, we're not planning to remove the
autoconf/make build system in the near future. Likely we're going to keep at
least the parts required for PGXS to keep working around until all supported
versions build with meson.
Some initial help for postgres developers is at
https://wiki.postgresql.org/wiki/Meson
With contributions from Thomas Munro, John Naylor, Stone Tickle and others.
Author: Andres Freund <andres@anarazel.de>
Author: Nazir Bilal Yavuz <byavuz81@gmail.com>
Author: Peter Eisentraut <peter@eisentraut.org>
Reviewed-By: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
Discussion: https://postgr.es/m/20211012083721.hvixq4pnh2pixr3j@alap3.anarazel.de
expression_tree_walker and allied functions have traditionally
declared their callback functions as, say, "bool (*walker) ()"
to allow for variation in the declared types of the callback
functions' context argument. This is apparently going to be
forbidden by the next version of the C standard, and the latest
version of clang warns about that. In any case it's always
been pretty poor for error-detection purposes, so fixing it is
a good thing to do.
What we want to do is change the callback argument declarations to
be like "bool (*walker) (Node *node, void *context)", which is
correct so far as expression_tree_walker and friends are concerned,
but not change the actual callback functions. Strict compliance with
the C standard would require changing them to declare their arguments
as "void *context" and then cast to the appropriate context struct
type internally. That'd be very invasive and it would also introduce
a bunch of opportunities for future bugs, since we'd no longer have
any check that the correct sort of context object is passed by outside
callers or internal recursion cases. Therefore, we're just going
to ignore the standard's position that "void *" isn't necessarily
compatible with struct pointers. No machine built in the last forty
or so years actually behaves that way, so it's not worth introducing
bug hazards for compatibility with long-dead hardware.
Therefore, to silence these compiler warnings, introduce a layer of
macro wrappers that cast the supplied function name to the official
argument type. Thanks to our use of -Wcast-function-type, this will
still produce a warning if the supplied function is seriously
incompatible with the required signature, without going as far as
the official spec restriction does.
This method fixes the problem without any need for source code changes
outside nodeFuncs.h/.c. However, it is an ABI break because the
physically called functions now have names ending in "_impl". Hence
we can only fix it this way in HEAD. In the back branches, we'll have
to settle for disabling -Wdeprecated-non-prototype.
Discussion: https://postgr.es/m/CA+hUKGKpHPDTv67Y+s6yiC8KH5OXeDg6a-twWo_xznKTcG0kSA@mail.gmail.com
The reverts the following and makes some associated cleanups:
commit f79b803dc: Common SQL/JSON clauses
commit f4fb45d15: SQL/JSON constructors
commit 5f0adec25: Make STRING an unreserved_keyword.
commit 33a377608: IS JSON predicate
commit 1a36bc9db: SQL/JSON query functions
commit 606948b05: SQL JSON functions
commit 49082c2cc: RETURNING clause for JSON() and JSON_SCALAR()
commit 4e34747c8: JSON_TABLE
commit fadb48b00: PLAN clauses for JSON_TABLE
commit 2ef6f11b0: Reduce running time of jsonb_sqljson test
commit 14d3f24fa: Further improve jsonb_sqljson parallel test
commit a6baa4bad: Documentation for SQL/JSON features
commit b46bcf7a4: Improve readability of SQL/JSON documentation.
commit 112fdb352: Fix finalization for json_objectagg and friends
commit fcdb35c32: Fix transformJsonBehavior
commit 4cd8717af: Improve a couple of sql/json error messages
commit f7a605f63: Small cleanups in SQL/JSON code
commit 9c3d25e17: Fix JSON_OBJECTAGG uniquefying bug
commit a79153b7a: Claim SQL standard compliance for SQL/JSON features
commit a1e7616d6: Rework SQL/JSON documentation
commit 8d9f9634e: Fix errors in copyfuncs/equalfuncs support for JSON node types.
commit 3c633f32b: Only allow returning string types or bytea from json_serialize
commit 67b26703b: expression eval: Fix EEOP_JSON_CONSTRUCTOR and EEOP_JSONEXPR size.
The release notes are also adjusted.
Backpatch to release 15.
Discussion: https://postgr.es/m/40d2c882-bcac-19a9-754d-4299e1d87ac7@postgresql.org
Since WRITE_NODE_FIELD() output always starts with a space, we don't
need to go out of our way to print another space right before it.
This change is only for visual appearance; the tokenizer on the
reading side would read it the same way (but there is no read support
for A_Expr at this time anyway).
As of 897795240c, check constraints can
be declared invalid. But that patch didn't update _outConstraint() to
also show the relevant struct fields (which were only applicable to
foreign keys before that). This currently only affects debugging
output, so no impact in practice.
The set of fields printed by _outConstraint() in the CONSTR_IDENTITY
case didn't match the set of fields actually used in that case. (The
code was probably uncarefully copied from the CONSTR_DEFAULT case.)
Fix that by using the right set of fields. Since there is no read
support for this node type, this is really just for debugging output
right now, so it doesn't affect anything important.
Commit 964d01ae9 was a few bricks shy of a load here: the script
checked whether gen_node_support.pl itself had been updated since it
was last run, but not whether any of its input files had been updated.
Fix that. While here, scrape the list of input files from the
Makefiles rather than having a duplicate copy, as we do for most
other lists of source files.
In passing, improve gen_node_support.pl's error report for an
incorrect file list.
Per gripe from Amit Kapila.
Discussion: https://postgr.es/m/CAA4eK1KQk4vP-3mTAz26h-PRUZaGu8Fc=q-ZKSajsAthH0A15w@mail.gmail.com
Commit fac1b470a thought we could check for set-returning functions
by testing only the top-level node in an expression tree. This is
wrong in itself, and to make matters worse it encouraged others
to make the same mistake, by exporting tlist.c's special-purpose
IS_SRF_CALL() as a widely-visible macro. I can't find any evidence
that anyone's taken the bait, but it was only a matter of time.
Use expression_returns_set() instead, and stuff the IS_SRF_CALL()
genie back in its bottle, this time with a warning label. I also
added a couple of cross-reference comments.
After a fair amount of fooling around, I've despaired of making
a robust test case that exposes the bug reliably, so no test case
here. (Note that the test case added by fac1b470a is itself
broken, in that it doesn't notice if you remove the code change.
The repro given by the bug submitter currently doesn't fail either
in v15 or HEAD, though I suspect that may indicate an unrelated bug.)
Per bug #17564 from Martijn van Oosterhout. Back-patch to v13,
as the faulty patch was.
Discussion: https://postgr.es/m/17564-c7472c2f90ef2da3@postgresql.org
Commit 964d01ae9 marked a lot of fields as read_write_ignore
to stay consistent with what was dumped by the manually-maintained
outfuncs.c code. However, it seems that a pretty fair number
of those omissions were either flat-out oversights, or a shortcut
taken because hand-written code seemed like it'd be too much trouble.
Let's upgrade things where it seems to make sense to dump.
To do this, we need to add support to gen_node_support.pl and
outfuncs.c for variable-length arrays of Node pointers. That's
pretty straightforward given the model of the existing code
for arrays of scalars, but I found I needed to tighten the
type-recognizing regexes in gen_node_support.pl. (As they
stood, they mistook "foo **" for "foo *". Make sure they're
all fully anchored to prevent additional problems.)
The main thing left un-done here is that a lot of partitioning-related
structs are still not dumped, because they are bare structs not Nodes.
I'm not sure about the wisdom of that choice ... but changing it would
be fairly invasive, so it probably requires more justification than
just making planner node dumps more complete.
Discussion: https://postgr.es/m/1295668.1658258637@sss.pgh.pa.us
When the ability to print variable-length-array fields was first
added to outfuncs.c, there was no corresponding read capability,
as it was used only for debug dumps of planner-internal Nodes.
Not a lot of thought seems to have been put into the output format:
it's just the space-separated array elements and nothing else.
Later such fields appeared in Plan nodes, and still later we grew
read support so that Plans could be transferred to parallel workers,
but the original text format wasn't rethought. It seems inadequate
to me because (a) no cross-check is possible that we got the right
number of array entries, (b) we can't tell the difference between
a NULL pointer and a zero-length array, and (c) except for
WRITE_INDEX_ARRAY, we'd crash if a non-zero length is specified
when the pointer is NULL, a situation that can arise in some fields
that we currently conveniently avoid printing.
Since we're currently in a campaign to make the Node infrastructure
generally more it-just-works-without-thinking-about-it, now seems
like a good time to improve this.
Let's adopt a format similar to that used for Lists, that is "<>"
for a NULL pointer or "(item item item)" otherwise. Also retool
the code to not have so many copies of the identical logic.
I bumped catversion out of an abundance of caution, although I think
that we don't use any such array fields in Nodes that can get into
the catalogs.
Discussion: https://postgr.es/m/1528424.1658272135@sss.pgh.pa.us
This is in preparation for building postgres with meson / ninja.
When building with meson, commands are run at the root of the build tree. Add
an option to put build output into the appropriate place. This can be utilized
by src/tools/msvc/ for a minor simplification, which also provides some
coverage for the new option.
Reviewed-by: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
Discussion: https://postgr.es/m/5e216522-ba3c-f0e6-7f97-5276d0270029@enterprisedb.com
Teach this script to handle function pointer fields honestly.
Previously they were just silently ignored, but that's not likely to
be a behavior we can accept indefinitely. This mostly entails fixing
it so that a field declaration spanning multiple lines can be parsed,
because we have a bunch of such fields that're laid out that way.
But that's a good improvement in its own right.
With that change and a minor regex adjustment, the only struct it
fails to parse in the node-defining headers is A_Const, because
of the embedded union. The path of least resistance is to move
that union declaration outside the struct.
Having done those things, we can make it error out if it finds
any within-struct syntax it doesn't understand, which seems like
a pretty important property for robustness.
This commit doesn't change the output files at all; it's just in
the way of future-proofing.
Discussion: https://postgr.es/m/2593369.1657759779@sss.pgh.pa.us
The initial version of gen_node_support.pl manually excluded most
utility statement node types from having out/read support, and
also some raw-parse-tree-only node types. That was mostly to keep
the output comparable to the old hand-maintained code. We'd like
to have out/read support for utility statements, for debugging
purposes and so that they can be included in new-style SQL functions;
so it's time to lift that restriction.
Most if not all of the previously-excluded raw-parse-tree-only node
types can appear in expression subtrees of utility statements, so
they have to be handled too.
We don't quite have full read support yet; certain custom_read_write
node types need to have their handwritten read functions implemented
before that will work.
Doing this allows us to drop the previous hack in _outQuery to not
dump the utilityStmt field in most cases, which means we no longer
need manually-maintained out/read functions for Query, so get rid
of those in favor of auto-generating them.
Fix a couple of omissions in gen_node_support.pl that are exposed
through having to handle more node types.
catversion bump forced because somebody was sloppy about the field
order in the manually-maintained Query out/read functions.
(Committers should note that almost all changes in parsenodes.h
are now grounds for a catversion bump.)
Read/out support in 5ca0fe5c8a was missing/incomplete, per Tom Lane.
Again, as far as core is concerned, this is not only dead code but also
untested; however, third parties may come to rely on it, so the standard
features should work.
Discussion: https://postgr.es/m/1548311.1657636605@sss.pgh.pa.us
There are a few things that we could do a little better within
get_cheapest_group_keys_order():
1. We should be using list_free() rather than pfree() on a List.
2. We should use for_each_from() instead of manually coding a for loop to
skip the first n elements of a List
3. list_truncate(list_copy(...), n) is not a great way to copy the first n
elements of a list. Let's invent list_copy_head() for that. That way we
don't need to copy the entire list just to truncate it directly
afterwards.
4. We can simplify finding the cheapest cost by setting the cheapest cost
variable to DBL_MAX. That allows us to skip special-casing the initial
iteration of the loop.
Author: David Rowley
Discussion: https://postgr.es/m/CAApHDvrGyL3ft8waEkncG9y5HDMu5TFFJB1paoTC8zi9YK97Nw@mail.gmail.com
Backpatch-through: 15, where get_cheapest_group_keys_order was added.
Having different build systems producing different contents of the
NodeTag enum would be catastrophic for extension ABI stability.
But that ordering depends on the order in which gen_node_support.pl
processes its input files. It seems too fragile to let the Makefiles,
MSVC build scripts, and soon meson build scripts all set this order
independently. As a klugy but serviceable solution, put a canonical
copy of the file list into gen_node_support.pl itself, and check that
against the files given on the command line.
Also, while it's fine to add and delete node tags during development,
we must not let the assigned NodeTag values change unexpectedly in
stable branches. Add a cross-check that can be enabled when a branch
is forked off (or later, but that is a time when we're unlikely to
miss doing it). It just checks that the last auto-assigned number
doesn't change, which is simplistic but will catch the most likely
sorts of mistakes.
From time to time we do need to add a node tag in a stable branch.
To support doing that without changing the branch's auto-assigned
tag numbers, invent pg_node_attr(nodetag_number(VALUE)) which can
be used to give such a node a hand-assigned tag above the last
auto-assigned one.
Discussion: https://postgr.es/m/1249010.1657574337@sss.pgh.pa.us
This allows explaining gen_node_support.pl's handling of execnodes.h
and some other input files as being a shortcut for explicit marking
of all their node declarations as pg_node_attr(nodetag_only).
I foresee that someday we might need to be more fine-grained about
that, and this change provides the infrastructure needed to do so.
For now, it just allows removal of the script's klugy special case
for CallContext and InlineCodeBlock.
Discussion: https://postgr.es/m/75063.1657410615@sss.pgh.pa.us
Commit f10a025cfe added support for List to store Xids, but didn't
handle the new type in all cases. Add some obviously necessary pieces.
As far as I am aware, this is all dead code as far as core code is
concerned, but it seems unacceptable not to have it in case third-party
code wants to rely on this type of list. (Some parts of the List API
remain unimplemented, but that can be fixed as and when needed -- see
lack of list_intersection_oid, list_deduplicate_int as precedents.)
Discussion: https://postgr.es/m/20220708164534.nbejhgt4ajz35p65@alvherre.pgsql
Fix incorrect reporting of the location of errors (such as bogus
node attributes). Add header comments to the generated files,
containing copyright notices and reminders that they are generated
files, as we do in other file-generating scripts. Arrange to not
leave a clutter of temporary files when the script detects an error.
Discussion: https://postgr.es/m/3843645.1657385930@sss.pgh.pa.us
copyfuncs.c and friends no longer seem like great places to put
high-level remarks about what's covered and what isn't. Move that
material to backend/nodes/README and other more-prominent places.
Add back (versions of) some remarks that disappeared in 2be87f092.
Discussion: https://postgr.es/m/3843645.1657385930@sss.pgh.pa.us
Add a script to automatically generate the node support functions
(copy, equal, out, and read, as well as the node tags enum) from the
struct definitions.
For each of the four node support files, it creates two include files,
e.g., copyfuncs.funcs.c and copyfuncs.switch.c, to include in the main
file. All the scaffolding of the main file stays in place.
I have tried to mostly make the coverage of the output match what is
currently there. For example, one could now do out/read coverage of
utility statement nodes, but I have manually excluded those for now.
The reason is mainly that it's easier to diff the before and after,
and adding a bunch of stuff like this might require a separate
analysis and review.
Subtyping (TidScan -> Scan) is supported.
For the hard cases, you can just write a manual function and exclude
generating one. For the not so hard cases, there is a way of
annotating struct fields to get special behaviors. For example,
pg_node_attr(equal_ignore) has the field ignored in equal functions.
(In this patch, I have only ifdef'ed out the code to could be removed,
mainly so that it won't constantly have merge conflicts. It will be
deleted in a separate patch. All the code comments that are worth
keeping from those sections have already been moved to the header
files where the structs are defined.)
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/c1097590-a6a4-486a-64b1-e1f9cc0533ce%40enterprisedb.com
We hadn't noticed this because it's dead code: there is no
situation where we read raw parse trees from text format.
So maybe the right fix is to remove the function altogether,
but I'll forbear for now; it's not the only dead code in
readfuncs.c, I think.
Noted while comparing existing code to the results of
Peter's auto-generation script.
We have been using the term RelFileNode to refer to either (1) the
integer that is used to name the sequence of files for a certain relation
within the directory set aside for that tablespace/database combination;
or (2) that value plus the OIDs of the tablespace and database; or
occasionally (3) the whole series of files created for a relation
based on those values. Using the same name for more than one thing is
confusing.
Replace RelFileNode with RelFileNumber when we're talking about just the
single number, i.e. (1) from above, and with RelFileLocator when we're
talking about all the things that are needed to locate a relation's files
on disk, i.e. (2) from above. In the places where we refer to (3) as
a relfilenode, instead refer to "relation storage".
Since there is a ton of SQL code in the world that knows about
pg_class.relfilenode, don't change the name of that column, or of other
SQL-facing things that derive their name from it.
On the other hand, do adjust closely-related internal terminology. For
example, the structure member names dbNode and spcNode appear to be
derived from the fact that the structure itself was called RelFileNode,
so change those to dbOid and spcOid. Likewise, various variables with
names like rnode and relnode get renamed appropriately, according to
how they're being used in context.
Hopefully, this is clearer than before. It is also preparation for
future patches that intend to widen the relfilenumber fields from its
current width of 32 bits. Variables that store a relfilenumber are now
declared as type RelFileNumber rather than type Oid; right now, these
are the same, but that can now more easily be changed.
Dilip Kumar, per an idea from me. Reviewed also by Andres Freund.
I fixed some whitespace issues, changed a couple of words in a
comment, and made one other minor correction.
Discussion: http://postgr.es/m/CA+TgmoamOtXbVAQf9hWFzonUo6bhhjS6toZQd7HZ-pmojtAmag@mail.gmail.com
Discussion: http://postgr.es/m/CA+Tgmobp7+7kmi4gkq7Y+4AM9fTvL+O1oQ4-5gFTT+6Ng-dQ=g@mail.gmail.com
Discussion: http://postgr.es/m/CAFiTN-vTe79M8uDH1yprOU64MNFE+R3ODRuA+JWf27JbhY4hJw@mail.gmail.com
Noted while comparing existing code to the output of the proposed
patch to automate creation of these functions. Some of the changes
are just cosmetic, but others represent real bugs. I've not
attempted to analyze the user-visible impact.
Back-patch to v15 where this code came in.
Discussion: https://postgr.es/m/1794155.1656984188@sss.pgh.pa.us
Andrew Dunstan