Avoid having backend-only code compiled into ecpg. Per Zdenek Kotala

src/interfaces/ecpg/preproc/Makefile

@@ -4,7 +4,7 @@
 #
 # Copyright (c) 1998-2007, PostgreSQL Global Development Group
 #
-# $PostgreSQL: pgsql/src/interfaces/ecpg/preproc/Makefile,v 1.128 2007/08/22 08:20:58 meskes Exp $
+# $PostgreSQL: pgsql/src/interfaces/ecpg/preproc/Makefile,v 1.129 2007/10/26 14:17:53 tgl Exp $
 #
 #-------------------------------------------------------------------------
 
@@ -59,9 +59,6 @@ endif
 
 c_keywords.o keywords.o preproc.o parser.o: preproc.h
 
-parser.c: $(top_srcdir)/src/backend/parser/parser.c
-	rm -f $@ && $(LN_S) $< .
-
 distprep: $(srcdir)/preproc.c $(srcdir)/preproc.h $(srcdir)/pgc.c
 
 install: all installdirs
@@ -74,7 +71,7 @@ uninstall:
 	rm -f '$(DESTDIR)$(bindir)/ecpg$(X)'
 
 clean distclean:
-	rm -f *.o ecpg$(X) parser.c
+	rm -f *.o ecpg$(X)
 # garbage from partial builds
 	@rm -f y.tab.c y.tab.h
 # garbage from development

src/interfaces/ecpg/preproc/parser.c

+/*-------------------------------------------------------------------------
+ *
+ * parser.c
+ *		Main entry point/driver for PostgreSQL grammar
+ *
+ * Note that the grammar is not allowed to perform any table access
+ * (since we need to be able to do basic parsing even while inside an
+ * aborted transaction).  Therefore, the data structures returned by
+ * the grammar are "raw" parsetrees that still need to be analyzed by
+ * analyze.c and related files.
+ *
+ *
+ * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ *	  $PostgreSQL: pgsql/src/interfaces/ecpg/preproc/parser.c,v 1.1 2007/10/26 14:17:53 tgl Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres_fe.h"
+
+#include "extern.h"
+#include "preproc.h"
+
+
+static bool have_lookahead;			/* is lookahead info valid? */
+static int	lookahead_token;		/* one-token lookahead */
+static YYSTYPE lookahead_yylval;	/* yylval for lookahead token */
+static YYLTYPE lookahead_yylloc;	/* yylloc for lookahead token */
+
+
+/*
+ * Intermediate filter between parser and base lexer (base_yylex in scan.l).
+ *
+ * The filter is needed because in some cases the standard SQL grammar
+ * requires more than one token lookahead.	We reduce these cases to one-token
+ * lookahead by combining tokens here, in order to keep the grammar LALR(1).
+ *
+ * Using a filter is simpler than trying to recognize multiword tokens
+ * directly in scan.l, because we'd have to allow for comments between the
+ * words.  Furthermore it's not clear how to do it without re-introducing
+ * scanner backtrack, which would cost more performance than this filter
+ * layer does.
+ */
+int
+filtered_base_yylex(void)
+{
+	int			cur_token;
+	int			next_token;
+	YYSTYPE		cur_yylval;
+	YYLTYPE		cur_yylloc;
+
+	/* Get next token --- we might already have it */
+	if (have_lookahead)
+	{
+		cur_token = lookahead_token;
+		base_yylval = lookahead_yylval;
+		base_yylloc = lookahead_yylloc;
+		have_lookahead = false;
+	}
+	else
+		cur_token = base_yylex();
+
+	/* Do we need to look ahead for a possible multiword token? */
+	switch (cur_token)
+	{
+		case NULLS_P:
+			/*
+			 * NULLS FIRST and NULLS LAST must be reduced to one token
+			 */
+			cur_yylval = base_yylval;
+			cur_yylloc = base_yylloc;
+			next_token = base_yylex();
+			switch (next_token)
+			{
+				case FIRST_P:
+					cur_token = NULLS_FIRST;
+					break;
+				case LAST_P:
+					cur_token = NULLS_LAST;
+					break;
+				default:
+					/* save the lookahead token for next time */
+					lookahead_token = next_token;
+					lookahead_yylval = base_yylval;
+					lookahead_yylloc = base_yylloc;
+					have_lookahead = true;
+					/* and back up the output info to cur_token */
+					base_yylval = cur_yylval;
+					base_yylloc = cur_yylloc;
+					break;
+			}
+			break;
+
+		case WITH:
+			/*
+			 * WITH CASCADED, LOCAL, or CHECK must be reduced to one token
+			 *
+			 * XXX an alternative way is to recognize just WITH_TIME and put
+			 * the ugliness into the datetime datatype productions instead of
+			 * WITH CHECK OPTION.  However that requires promoting WITH to a
+			 * fully reserved word.  If we ever have to do that anyway
+			 * (perhaps for SQL99 recursive queries), come back and simplify
+			 * this code.
+			 */
+			cur_yylval = base_yylval;
+			cur_yylloc = base_yylloc;
+			next_token = base_yylex();
+			switch (next_token)
+			{
+				case CASCADED:
+					cur_token = WITH_CASCADED;
+					break;
+				case LOCAL:
+					cur_token = WITH_LOCAL;
+					break;
+				case CHECK:
+					cur_token = WITH_CHECK;
+					break;
+				default:
+					/* save the lookahead token for next time */
+					lookahead_token = next_token;
+					lookahead_yylval = base_yylval;
+					lookahead_yylloc = base_yylloc;
+					have_lookahead = true;
+					/* and back up the output info to cur_token */
+					base_yylval = cur_yylval;
+					base_yylloc = cur_yylloc;
+					break;
+			}
+			break;
+
+		default:
+			break;
+	}
+
+	return cur_token;
+}

src/interfaces/ecpg/preproc/parser/README

-The parse.h file has to be in this directory to comply with the backend's source tree.

src/interfaces/ecpg/preproc/parser/parse.h

-#include "extern.h"
-#include "preproc.h"
-