Add guards against double inclusion.

src/interfaces/ecpg/include/ecpglib.h

@@ -3,6 +3,9 @@
  * definitions into ecpg programs
  */
 
+#ifndef _ECPGLIB_H
+#define _ECPGLIB_H
+
 #include <stdio.h>
 
 #ifndef __BEOS__
@@ -74,3 +77,5 @@ void		ECPGfree_auto_mem(void);
 }
 
 #endif
+
+#endif /* _ECPGLIB_H */

src/interfaces/ecpg/include/ecpgtype.h

@@ -27,6 +27,10 @@
  * This is a typically recursive definition. A structure of typed list elements
  * would probably work fine:
  */
+
+#ifndef _ECPGTYPE_H
+#define _ECPGTYPE_H
+
 #ifdef __cplusplus
 extern		"C"
 {
@@ -76,5 +80,6 @@ enum ECPGdtype
 
 #ifdef __cplusplus
 }
-
 #endif
+
+#endif /* _ECPGTYPE_H */

src/interfaces/ecpg/lib/extern.h

+#ifndef _ECPG_LIB_EXTERN_H
+#define _ECPG_LIB_EXTERN_H
+
 #include "postgres_fe.h"
 #include "libpq-fe.h"
 
@@ -87,3 +90,5 @@ PGresult  **
 
 bool ECPGstore_result(const PGresult *results, int act_field,
 				 const struct statement * stmt, struct variable * var);
+
+#endif /* _ECPG_LIB_EXTERN_H */

src/interfaces/ecpg/preproc/extern.h

+#ifndef _ECPG_PREPROC_EXTERN_H
+#define _ECPG_PREPROC_EXTERN_H
+
 #include "type.h"
 
 #include <errno.h>
@@ -89,3 +92,5 @@ extern ScanKeyword *ScanKeywordLookup(char *text);
 #define OUT_OF_MEMORY		5
 #define INDICATOR_NOT_STRUCT	6
 #define INDICATOR_NOT_SIMPLE	7
+
+#endif /* _ECPG_PREPROC_EXTERN_H */

src/interfaces/ecpg/preproc/type.h

+#ifndef _ECPG_PREPROC_TYPE_H
+#define _ECPG_PREPROC_TYPE_H
+
 #include "ecpgtype.h"
 
 struct ECPGtype;
@@ -172,3 +175,5 @@ typedef struct ScanKeyword
 	char	   *name;
 	int			value;
 } ScanKeyword;
+
+#endif /* _ECPG_PREPROC_TYPE_H */