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

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

-/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
 

src/backend/utils/adt/jsonpath_scan.l

+%{
 /*-------------------------------------------------------------------------
  *
  * jsonpath_scan.l
@@ -11,12 +12,10 @@
  *-------------------------------------------------------------------------
  */
 
-%{
 #include "postgres.h"
 
 #include "mb/pg_wchar.h"
 #include "nodes/pg_list.h"
-#include "utils/jsonpath_scanner.h"
 
 static JsonPathString scanstring;
 
@@ -46,7 +45,6 @@ fprintf_to_ereport(const char *fmt, const char *msg)
 	ereport(ERROR, (errmsg_internal("%s", msg)));
 }
 
-#define yyerror jsonpath_yyerror
 %}
 
 %option 8bit

src/include/Makefile

@@ -54,7 +54,7 @@ install: all installdirs
 	  cp $(srcdir)/$$dir/*.h '$(DESTDIR)$(includedir_server)'/$$dir/ || exit; \
 	done
 ifeq ($(vpath_build),yes)
-	for file in catalog/schemapg.h catalog/pg_*_d.h parser/gram.h storage/lwlocknames.h utils/probes.h utils/jsonpath_gram.h; do \
+	for file in catalog/schemapg.h catalog/pg_*_d.h parser/gram.h storage/lwlocknames.h utils/probes.h; do \
 	  cp $$file '$(DESTDIR)$(includedir_server)'/$$file || exit; \
 	done
 endif
@@ -78,7 +78,7 @@ uninstall:
 
 clean:
 	rm -f utils/fmgroids.h utils/fmgrprotos.h utils/errcodes.h utils/header-stamp
-	rm -f parser/gram.h storage/lwlocknames.h utils/probes.h utils/jsonpath_gram.h
+	rm -f parser/gram.h storage/lwlocknames.h utils/probes.h
 	rm -f catalog/schemapg.h catalog/pg_*_d.h catalog/header-stamp
 
 distclean maintainer-clean: clean

src/include/utils/.gitignore

@@ -3,4 +3,3 @@
 /probes.h
 /errcodes.h
 /header-stamp
-/jsonpath_gram.h

src/include/utils/jsonpath_scanner.h

-/*-------------------------------------------------------------------------
- *
- * jsonpath_scanner.h
- *	Definitions for jsonpath scanner & parser
- *
- * Portions Copyright (c) 2019, PostgreSQL Global Development Group
- *
- * src/include/utils/jsonpath_scanner.h
- *
- *-------------------------------------------------------------------------
- */
-
-#ifndef JSONPATH_SCANNER_H
-#define JSONPATH_SCANNER_H
-
-/* struct JsonPathString is shared between scan and gram */
-typedef struct JsonPathString
-{
-	char	   *val;
-	int			len;
-	int			total;
-}			JsonPathString;
-
-#include "utils/jsonpath.h"
-#include "utils/jsonpath_gram.h"
-
-/* flex 2.5.4 doesn't bother with a decl for this */
-extern int	jsonpath_yylex(YYSTYPE *yylval_param);
-extern int	jsonpath_yyparse(JsonPathParseResult **result);
-extern void jsonpath_yyerror(JsonPathParseResult **result, const char *message);
-
-#endif

src/tools/msvc/Solution.pm

@@ -327,24 +327,6 @@ sub GenerateFiles
 		);
 	}
 
-	if (IsNewer(
-			'src/backend/utils/adt/jsonpath_gram.h',
-			'src/backend/utils/adt/jsonpath_gram.y'))
-	{
-		print "Generating jsonpath_gram.h...\n";
-		chdir('src/backend/utils/adt');
-		system('perl ../../../tools/msvc/pgbison.pl jsonpath_gram.y');
-		chdir('../../../..');
-	}
-
-	if (IsNewer(
-			'src/include/utils/jsonpath_gram.h',
-			'src/backend/utils/adt/jsonpath_gram.h'))
-	{
-		copyFile('src/backend/utils/adt/jsonpath_gram.h',
-			'src/include/utils/jsonpath_gram.h');
-	}
-
 	if ($self->{options}->{python}
 		&& IsNewer(
 			'src/pl/plpython/spiexceptions.h',