Move keywords.c/kwlookup.c into src/common/.

Now that we have src/common/ for code shared between frontend and backend,
we can get rid of (most of) the klugy ways that the keyword table and
keyword lookup code were formerly shared between different uses.
This is a first step towards a more general plan of getting rid of
special-purpose kluges for sharing code in src/bin/.

I chose to merge kwlookup.c back into keywords.c, as it once was, and
always has been so far as keywords.h is concerned.  We could have
kept them separate, but there is noplace that uses ScanKeywordLookup
without also wanting access to the backend's keyword list, so there
seems little point.

ecpg is still a bit weird, but at least now the trickiness is documented.

I think that the MSVC build script should require no adjustments beyond
what's done here ... but we'll soon find out.

4 files changed, 17 insertions, 10 deletions

diff --git a/src/interfaces/ecpg/preproc/.gitignore b/src/interfaces/ecpg/preproc/.gitignore
index 6fca9aff590..aacfb844bda 100644
--- a/src/interfaces/ecpg/preproc/.gitignore
+++ b/src/interfaces/ecpg/preproc/.gitignore
@@ -4,4 +4,3 @@
 /pgc.c
 
 /ecpg
-/kwlookup.c
diff --git a/src/interfaces/ecpg/preproc/Makefile b/src/interfaces/ecpg/preproc/Makefile
index ee3b13a4afa..30db5a049af 100644
--- a/src/interfaces/ecpg/preproc/Makefile
+++ b/src/interfaces/ecpg/preproc/Makefile
@@ -27,7 +27,7 @@ override CPPFLAGS := -I../include -I$(top_srcdir)/src/interfaces/ecpg/include \
 override CFLAGS += $(PTHREAD_CFLAGS) -DECPG_COMPILE
 
 OBJS=	preproc.o pgc.o type.o ecpg.o output.o parser.o \
-	keywords.o c_keywords.o ecpg_keywords.o kwlookup.o ../ecpglib/typename.o descriptor.o variable.o \
+	keywords.o c_keywords.o ecpg_keywords.o ../ecpglib/typename.o descriptor.o variable.o \
 	$(WIN32RES)
 
 # Suppress parallel build to avoid a bug in GNU make 3.82
@@ -53,9 +53,6 @@ preproc.y: ../../../backend/parser/gram.y parse.pl ecpg.addons ecpg.header ecpg.
 
 ecpg_keywords.o c_keywords.o keywords.o preproc.o pgc.o parser.o: preproc.h
 
-kwlookup.c: % : $(top_srcdir)/src/backend/parser/%
-	rm -f $@ && $(LN_S) $< .
-
 distprep: preproc.y preproc.c preproc.h pgc.c
 
 install: all installdirs
@@ -68,7 +65,7 @@ uninstall:
 	rm -f '$(DESTDIR)$(bindir)/ecpg$(X)'
 
 clean distclean:
-	rm -f kwlookup.c *.o ecpg$(X)
+	rm -f *.o ecpg$(X)
 # garbage from development
 	@rm -f core a.out
 
diff --git a/src/interfaces/ecpg/preproc/extern.h b/src/interfaces/ecpg/preproc/extern.h
index ea8fd8ed98c..f6841726e4a 100644
--- a/src/interfaces/ecpg/preproc/extern.h
+++ b/src/interfaces/ecpg/preproc/extern.h
@@ -4,7 +4,8 @@
 #define _ECPG_PREPROC_EXTERN_H
 
 #include "type.h"
-#include "parser/keywords.h"
+
+#include "common/keywords.h"
 
 #include <errno.h>
 #ifndef CHAR_BIT
diff --git a/src/interfaces/ecpg/preproc/keywords.c b/src/interfaces/ecpg/preproc/keywords.c
index 2f17f0c5c02..cffdaed67b0 100644
--- a/src/interfaces/ecpg/preproc/keywords.c
+++ b/src/interfaces/ecpg/preproc/keywords.c
@@ -15,13 +15,23 @@
  */
 #include "postgres_fe.h"
 
-#include "parser/keywords.h"
-#include "type.h"
+/*
+ * This is much trickier than it looks.  We are #include'ing kwlist.h
+ * but the "value" numbers that go into the table are from preproc.h
+ * not the backend's gram.h.  Therefore this table will recognize all
+ * keywords known to the backend, but will supply the token numbers used
+ * by ecpg's grammar, which is what we need.  The ecpg grammar must
+ * define all the same token names the backend does, else we'll get
+ * undefined-symbol failures in this compile.
+ */
+
+#include "common/keywords.h"
+
 #include "extern.h"
 #include "preproc.h"
 
-#define PG_KEYWORD(a,b,c) {a,b,c},
 
+#define PG_KEYWORD(a,b,c) {a,b,c},
 
 const ScanKeyword SQLScanKeywords[] = {
 #include "parser/kwlist.h"