Get rid of jsonpath_gram.h and jsonpath_scanner.h

Jsonpath grammar and scanner are both quite small.  It doesn't worth complexity
to compile them separately.  This commit makes grammar and scanner be compiled
at once.  Therefore, jsonpath_gram.h and jsonpath_gram.h are no longer needed.
This commit also does some reorganization of code in jsonpath_gram.y.

Discussion: https://postgr.es/m/d47b2023-3ecb-5f04-d253-d557547cf74f%402ndQuadrant.com

Author: akorotkov

src/backend/Makefile

@@ -136,9 +136,6 @@ parser/gram.h: parser/gram.y
 storage/lmgr/lwlocknames.h: storage/lmgr/generate-lwlocknames.pl storage/lmgr/lwlocknames.txt
 	$(MAKE) -C storage/lmgr lwlocknames.h lwlocknames.c
 
-utils/adt/jsonpath_gram.h: utils/adt/jsonpath_gram.y
-	$(MAKE) -C utils/adt jsonpath_gram.h
-
 # run this unconditionally to avoid needing to know its dependencies here:
 submake-catalog-headers:
 	$(MAKE) -C catalog distprep generated-header-symlinks
@@ -162,7 +159,7 @@ submake-utils-headers:
 
 .PHONY: generated-headers
 
-generated-headers: $(top_builddir)/src/include/parser/gram.h $(top_builddir)/src/include/storage/lwlocknames.h $(top_builddir)/src/include/utils/jsonpath_gram.h submake-catalog-headers submake-utils-headers
+generated-headers: $(top_builddir)/src/include/parser/gram.h $(top_builddir)/src/include/storage/lwlocknames.h submake-catalog-headers submake-utils-headers
 
 $(top_builddir)/src/include/parser/gram.h: parser/gram.h
 	prereqdir=`cd '$(dir $<)' >/dev/null && pwd` && \
@@ -174,11 +171,6 @@ $(top_builddir)/src/include/storage/lwlocknames.h: storage/lmgr/lwlocknames.h
 	  cd '$(dir $@)' && rm -f $(notdir $@) && \
 	  $(LN_S) "$$prereqdir/$(notdir $<)" .
 
-$(top_builddir)/src/include/utils/jsonpath_gram.h: utils/adt/jsonpath_gram.h
-	prereqdir=`cd '$(dir $<)' >/dev/null && pwd` && \
-	  cd '$(dir $@)' && rm -f $(notdir $@) && \
-	  $(LN_S) "$$prereqdir/$(notdir $<)" .
-
 utils/probes.o: utils/probes.d $(SUBDIROBJS)
 	$(DTRACE) $(DTRACEFLAGS) -C -G -s $(call expand_subsys,$^) -o $@
 
@@ -193,7 +185,7 @@ distprep:
 	$(MAKE) -C replication	repl_gram.c repl_scanner.c syncrep_gram.c syncrep_scanner.c
 	$(MAKE) -C storage/lmgr	lwlocknames.h lwlocknames.c
 	$(MAKE) -C utils	distprep
-	$(MAKE) -C utils/adt	jsonpath_gram.c jsonpath_gram.h jsonpath_scan.c
+	$(MAKE) -C utils/adt	jsonpath_gram.c jsonpath_scan.c
 	$(MAKE) -C utils/misc	guc-file.c
 	$(MAKE) -C utils/sort	qsort_tuple.c
 
@@ -316,7 +308,6 @@ maintainer-clean: distclean
 	      storage/lmgr/lwlocknames.c \
 	      storage/lmgr/lwlocknames.h \
 	      utils/adt/jsonpath_gram.c \
-	      utils/adt/jsonpath_gram.h \
 	      utils/adt/jsonpath_scan.c \
 	      utils/misc/guc-file.c \
 	      utils/sort/qsort_tuple.c

src/backend/utils/adt/.gitignore

@@ -1,3 +1,2 @@
-/jsonpath_gram.h
 /jsonpath_gram.c
 /jsonpath_scan.c

src/backend/utils/adt/Makefile

@@ -17,7 +17,7 @@ OBJS = acl.o amutils.o arrayfuncs.o array_expanded.o array_selfuncs.o \
 	float.o format_type.o formatting.o genfile.o \
 	geo_ops.o geo_selfuncs.o geo_spgist.o inet_cidr_ntop.o inet_net_pton.o \
 	int.o int8.o json.o jsonb.o jsonb_gin.o jsonb_op.o jsonb_util.o \
-	jsonfuncs.o jsonpath_gram.o jsonpath_scan.o jsonpath.o jsonpath_exec.o \
+	jsonfuncs.o jsonpath_gram.o jsonpath.o jsonpath_exec.o \
 	like.o like_support.o lockfuncs.o mac.o mac8.o misc.o name.o \
 	network.o network_gist.o network_selfuncs.o network_spgist.o \
 	numeric.o numutils.o oid.o oracle_compat.o \
@@ -33,26 +33,13 @@ OBJS = acl.o amutils.o arrayfuncs.o array_expanded.o array_selfuncs.o \
 	txid.o uuid.o varbit.o varchar.o varlena.o version.o \
 	windowfuncs.o xid.o xml.o
 
-# There is no correct way to write a rule that generates two files.
-# See comment in src/backend/parser/Makefile for the explanation of
-# the trick used here.
-
-jsonpath_gram.h: jsonpath_gram.c
-	touch $@
-
-jsonpath_gram.c: BISONFLAGS += -d
-
 jsonpath_scan.c: FLEXFLAGS = -CF -p -p
 
-
 # Force these dependencies to be known even without dependency info built:
-jsonpath_gram.o jsonpath_scan.o jsonpath_parser.o: jsonpath_gram.h
-
-# jsonpath_gram.c, jsonpath_gram.h, and jsonpath_scan.c are in the
-# distribution tarball, so they are not cleaned here.
-clean distclean maintainer-clean:
-	rm -f lex.backup
+jsonpath_gram.o: jsonpath_scan.c
 
+# jsonpath_gram.c and jsonpath_scan.c are in the distribution tarball,
+# so they are not cleaned here.
 
 like.o: like.c like_match.c