Fix parallel build

[anthonyroussel]

Added BUILT_SOURCES for gram.c, gram.h, gram_minimal.c, gram_minimal.h and scan.c to ensure that bison generated files are built before compilation of dependent C files (when parallelisation is enabled using make -j).

[anthonyroussel]

Without BUILT_SOURCES, the pgpool2 build can fail with this error when parallelisation is enabled:

Running phase: buildPhase
build flags: -j8 SHELL=/nix/store/rlq03x4cwf8zn73hxaxnx0zn5q9kifls-bash-5.3p3/bin/bash
Making all in src
make[1]: Entering directory '/build/source/src'
Making all in parser
make[2]: Entering directory '/build/source/src/parser'
gcc -DHAVE_CONFIG_H -I. -I../../src/include  -D_GNU_SOURCE -I ../../src/include/parser -I /usr/local/pgsql/include   -g -O2 -Wall -Wmissing-prototypes -Wmissing-declarations -Wno-format-truncation -Wno-stringop-truncation -fno-strict-aliasing -c -o copyfuncs.o copyfuncs.c
flex -o'scan.c' scan.l
gcc -DHAVE_CONFIG_H -I. -I../../src/include  -D_GNU_SOURCE -I ../../src/include/parser -I /usr/local/pgsql/include   -g -O2 -Wall -Wmissing-prototypes -Wmissing-declarations -Wno-format-truncation -Wno-stringop-truncation -fno-strict-aliasing -c -o keywords.o keywords.c
gcc -DHAVE_CONFIG_H -I. -I../../src/include  -D_GNU_SOURCE -I ../../src/include/parser -I /usr/local/pgsql/include   -g -O2 -Wall -Wmissing-prototypes -Wmissing-declarations -Wno-format-truncation -Wno-stringop-truncation -fno-strict-aliasing -c -o kwlookup.o kwlookup.c
gcc -DHAVE_CONFIG_H -I. -I../../src/include  -D_GNU_SOURCE -I ../../src/include/parser -I /usr/local/pgsql/include   -g -O2 -Wall -Wmissing-prototypes -Wmissing-declarations -Wno-format-truncation -Wno-stringop-truncation -fno-strict-aliasing -c -o list.o list.c
gcc -DHAVE_CONFIG_H -I. -I../../src/include  -D_GNU_SOURCE -I ../../src/include/parser -I /usr/local/pgsql/include   -g -O2 -Wall -Wmissing-prototypes -Wmissing-declarations -Wno-format-truncation -Wno-stringop-truncation -fno-strict-aliasing -c -o makefuncs.o makefuncs.c
gcc -DHAVE_CONFIG_H -I. -I../../src/include  -D_GNU_SOURCE -I ../../src/include/parser -I /usr/local/pgsql/include   -g -O2 -Wall -Wmissing-prototypes -Wmissing-declarations -Wno-format-truncation -Wno-stringop-truncation -fno-strict-aliasing -c -o nodes.o nodes.c
gcc -DHAVE_CONFIG_H -I. -I../../src/include  -D_GNU_SOURCE -I ../../src/include/parser -I /usr/local/pgsql/include   -g -O2 -Wall -Wmissing-prototypes -Wmissing-declarations -Wno-format-truncation -Wno-stringop-truncation -fno-strict-aliasing -c -o outfuncs.o outfuncs.c
gcc -DHAVE_CONFIG_H -I. -I../../src/include  -D_GNU_SOURCE -I ../../src/include/parser -I /usr/local/pgsql/include   -g -O2 -Wall -Wmissing-prototypes -Wmissing-declarations -Wno-format-truncation -Wno-stringop-truncation -fno-strict-aliasing -c -o parser.o parser.c
gcc -DHAVE_CONFIG_H -I. -I../../src/include  -D_GNU_SOURCE -I ../../src/include/parser -I /usr/local/pgsql/include   -g -O2 -Wall -Wmissing-prototypes -Wmissing-declarations -Wno-format-truncation -Wno-stringop-truncation -fno-strict-aliasing -c -o scansup.o scansup.c
gcc -DHAVE_CONFIG_H -I. -I../../src/include  -D_GNU_SOURCE -I ../../src/include/parser -I /usr/local/pgsql/include   -g -O2 -Wall -Wmissing-prototypes -Wmissing-declarations -Wno-format-truncation -Wno-stringop-truncation -fno-strict-aliasing -c -o stringinfo.o stringinfo.c
gcc -DHAVE_CONFIG_H -I. -I../../src/include  -D_GNU_SOURCE -I ../../src/include/parser -I /usr/local/pgsql/include   -g -O2 -Wall -Wmissing-prototypes -Wmissing-declarations -Wno-format-truncation -Wno-stringop-truncation -fno-strict-aliasing -c -o value.o value.c
In file included from parser.c:27:
../../src/include/parser/gramparse.h:33:10: fatal error: gram.h: No such file or directory
   33 | #include "gram.h"
      |          ^~~~~~~~
compilation terminated.
make[2]: *** [Makefile:439: parser.o] Error 1
make[2]: *** Waiting for unfinished jobs....
make[2]: Leaving directory '/build/source/src/parser'
make[1]: *** [Makefile:948: all-recursive] Error 1
make[1]: Leaving directory '/build/source/src'
make: *** [Makefile:421: all-recursive] Error 1

Issue encountered while trying to migrate pgpool-II Nixpkgs package from tarball to Git fetch: NixOS/nixpkgs#484902

[tatsuo-ishii]

Thanks for the pull request. I think your fix is useful but since we do not accept pull requests, I have applied your patch to the original repository.
https://git.postgresql.org/gitweb/?p=pgpool2.git;a=summary