721856ff24
A PostgreSQL release tarball contains a number of prebuilt files, in particular files produced by bison, flex, perl, and well as html and man documentation. We have done this consistent with established practice at the time to not require these tools for building from a tarball. Some of these tools were hard to get, or get the right version of, from time to time, and shipping the prebuilt output was a convenience to users. Now this has at least two problems: One, we have to make the build system(s) work in two modes: Building from a git checkout and building from a tarball. This is pretty complicated, but it works so far for autoconf/make. It does not currently work for meson; you can currently only build with meson from a git checkout. Making meson builds work from a tarball seems very difficult or impossible. One particular problem is that since meson requires a separate build directory, we cannot make the build update files like gram.h in the source tree. So if you were to build from a tarball and update gram.y, you will have a gram.h in the source tree and one in the build tree, but the way things work is that the compiler will always use the one in the source tree. So you cannot, for example, make any gram.y changes when building from a tarball. This seems impossible to fix in a non-horrible way. Second, there is increased interest nowadays in precisely tracking the origin of software. We can reasonably track contributions into the git tree, and users can reasonably track the path from a tarball to packages and downloads and installs. But what happens between the git tree and the tarball is obscure and in some cases non-reproducible. The solution for both of these issues is to get rid of the step that adds prebuilt files to the tarball. The tarball now only contains what is in the git tree (*). Getting the additional build dependencies is no longer a problem nowadays, and the complications to keep these dual build modes working are significant. And of course we want to get the meson build system working universally. This commit removes the make distprep target altogether. The make dist target continues to do its job, it just doesn't call distprep anymore. (*) - The tarball also contains the INSTALL file that is built at make dist time, but not by distprep. This is unchanged for now. The make maintainer-clean target, whose job it is to remove the prebuilt files in addition to what make distclean does, is now just an alias to make distprep. (In practice, it is probably obsolete given that git clean is available.) The following programs are now hard build requirements in configure (they were already required by meson.build): - bison - flex - perl Reviewed-by: Michael Paquier <michael@paquier.xyz> Reviewed-by: Andres Freund <andres@anarazel.de> Discussion: https://www.postgresql.org/message-id/flat/e07408d9-e5f2-d9fd-5672-f53354e9305e@eisentraut.org |
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.. | ||
po | ||
.gitignore | ||
Makefile | ||
README.parser | ||
c_keywords.c | ||
c_kwlist.h | ||
check_rules.pl | ||
descriptor.c | ||
ecpg.addons | ||
ecpg.c | ||
ecpg.header | ||
ecpg.tokens | ||
ecpg.trailer | ||
ecpg.type | ||
ecpg_keywords.c | ||
ecpg_kwlist.h | ||
keywords.c | ||
meson.build | ||
nls.mk | ||
output.c | ||
parse.pl | ||
parser.c | ||
pgc.l | ||
preproc_extern.h | ||
type.c | ||
type.h | ||
variable.c |
README.parser
ECPG modifies and extends the core grammar in a way that 1) every token in ECPG is <str> type. New tokens are defined in ecpg.tokens, types are defined in ecpg.type 2) most tokens from the core grammar are simply converted to literals concatenated together to form the SQL string passed to the server, this is done by parse.pl. 3) some rules need side-effects, actions are either added or completely overridden (compared to the basic token concatenation) for them, these are defined in ecpg.addons, the rules for ecpg.addons are explained below. 4) new grammar rules are needed for ECPG metacommands. These are in ecpg.trailer. 5) ecpg.header contains common functions, etc. used by actions for grammar rules. In "ecpg.addons", every modified rule follows this pattern: ECPG: dumpedtokens postfix where "dumpedtokens" is simply tokens from core gram.y's rules concatenated together. e.g. if gram.y has this: ruleA: tokenA tokenB tokenC {...} then "dumpedtokens" is "ruleAtokenAtokenBtokenC". "postfix" above can be: a) "block" - the automatic rule created by parse.pl is completely overridden, the code block has to be written completely as it were in a plain bison grammar b) "rule" - the automatic rule is extended on, so new syntaxes are accepted for "ruleA". E.g.: ECPG: ruleAtokenAtokenBtokenC rule | tokenD tokenE { action_code; } ... It will be substituted with: ruleA: <original syntax forms and actions up to and including "tokenA tokenB tokenC"> | tokenD tokenE { action_code; } ... c) "addon" - the automatic action for the rule (SQL syntax constructed from the tokens concatenated together) is prepended with a new action code part. This code part is written as is's already inside the { ... } Multiple "addon" or "block" lines may appear together with the new code block if the code block is common for those rules.