Third try. Sorry, I had a wrong path in my copy statement.

src/interfaces/ecpg/preproc/Makefile

@@ -9,6 +9,7 @@ PATCHLEVEL=0
 override CPPFLAGS+=-I$(srcdir)/../include -DMAJOR_VERSION=$(MAJOR_VERSION) \
 	-DMINOR_VERSION=$(MINOR_VERSION) -DPATCHLEVEL=$(PATCHLEVEL) \
 	-DINCLUDE_PATH=\"$(includedir)\" 
+# -DYYDEBUG -g
 
 OBJS=preproc.o pgc.o type.o ecpg.o ecpg_keywords.o output.o\
     keywords.o c_keywords.o ../lib/typename.o descriptor.o variable.o

src/interfaces/ecpg/preproc/ecpg.c

@@ -22,7 +22,11 @@ static void
 usage(char *progname)
 {
 	fprintf(stderr, "ecpg - the postgresql preprocessor, version: %d.%d.%d\n", MAJOR_VERSION, MINOR_VERSION, PATCHLEVEL);
-	fprintf(stderr, "Usage: %s: [-v] [-t] [-I include path] [ -o output file name] [-D define name] file1 [file2] ...\n", progname);
+	fprintf(stderr, "Usage: %s: "
+#ifdef YYDEBUG
+								"[-d]"
+#endif
+									" [-v] [-t] [-I include path] [ -o output file name] [-D define name] file1 [file2] ...\n", progname);
 }
 
 static void
@@ -61,7 +65,7 @@ main(int argc, char *const argv[])
 	add_include_path("/usr/local/include");
 	add_include_path(".");
 
-	while ((c = getopt(argc, argv, "vo:I:tD:")) != EOF)
+	while ((c = getopt(argc, argv, "vo:I:tD:d")) != EOF)
 	{
 		switch (c)
 		{
@@ -84,6 +88,11 @@ main(int argc, char *const argv[])
 			case 'D':
 				add_preprocessor_define(optarg);
 				break;
+#ifdef YYDEBUG				
+			case 'd':
+				yydebug=1;
+				break;
+#endif
 			default:
 				usage(argv[0]);
 				return ILLEGAL_OPTION;

src/interfaces/ecpg/preproc/extern.h

@@ -19,6 +19,9 @@ extern char *connection;
 extern char *input_filename;
 extern char *yytext,
 			errortext[128];
+#ifdef YYDEBUG
+extern int yydebug;
+#endif
 extern int	yylineno,
 			yyleng;
 extern FILE *yyin,

src/interfaces/ecpg/preproc/keywords.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/interfaces/ecpg/preproc/keywords.c,v 1.30 2000/09/26 11:41:44 meskes Exp $
+ *	  $Header: /cvsroot/pgsql/src/interfaces/ecpg/preproc/keywords.c,v 1.31 2000/11/07 08:46:27 meskes Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -191,12 +191,12 @@ static ScanKeyword ScanKeywords[] = {
 	{"only", ONLY},
 	{"operator", OPERATOR},
 	{"option", OPTION},
-	{"overlaps", OVERLAPS},
-	{"owner", OWNER},
 	{"or", OR},
 	{"order", ORDER},
 	{"out", OUT},   
 	{"outer", OUTER_P},
+	{"overlaps", OVERLAPS},
+	{"owner", OWNER},
 	{"partial", PARTIAL},
 	{"password", PASSWORD},
 	{"path", PATH_P}, 

src/interfaces/ecpg/preproc/preproc.y

@@ -375,6 +375,8 @@ make_name(void)
 %type  <index>	opt_array_bounds opt_type_array_bounds
 
 %type  <ival>	Iresult
+
+%token YYERROR_VERBOSE
 %%
 prog: statements;
 
@@ -5272,6 +5274,7 @@ c_anything:  IDENT 	{ $$ = $1; }
 	| S_LSHIFT	{ $$ = make_str("<<"); } 
 	| S_MEMBER	{ $$ = make_str("->"); } 
 	| S_MEMPOINT	{ $$ = make_str("->*"); } 
+	| S_MOD		{ $$ = make_str("%="); }
 	| S_MUL		{ $$ = make_str("*="); } 
 	| S_NEQUAL	{ $$ = make_str("!="); } 
 	| S_OR		{ $$ = make_str("||"); } 
@@ -5311,7 +5314,9 @@ blockend : '}'
 
 %%
 
-void yyerror(char * error)
-{
-	mmerror(ET_ERROR, error);
+void yyerror( char * error)
+{	char buf[1024];
+        snprintf(buf,sizeof buf,"%s at or near \"%s\"",error,yytext);
+        buf[sizeof(buf)-1]=0;
+	mmerror(ET_ERROR, buf);
 }