Rename ecpg's various "extern.h" files to have distinct names.

This should reduce confusion, and in particular make it safe to
copy typename.c into preproc/ and compile it there.

This doesn't affect anything outside ecpg, and particularly not
end users, because these files don't get installed; they just
exist to share declarations among the .c files of each subdirectory.

Discussion: https://postgr.es/m/31364.1543511708@sss.pgh.pa.us

src/interfaces/ecpg/ecpglib/connect.c

@@ -7,7 +7,7 @@
 #include "ecpgtype.h"
 #include "ecpglib.h"
 #include "ecpgerrno.h"
-#include "extern.h"
+#include "ecpglib_extern.h"
 #include "sqlca.h"
 
 #ifdef ENABLE_THREAD_SAFETY

src/interfaces/ecpg/ecpglib/data.c

@@ -8,7 +8,7 @@
 #include "ecpgtype.h"
 #include "ecpglib.h"
 #include "ecpgerrno.h"
-#include "extern.h"
+#include "ecpglib_extern.h"
 #include "sqlca.h"
 #include "pgtypes_numeric.h"
 #include "pgtypes_date.h"

src/interfaces/ecpg/ecpglib/descriptor.c

@@ -12,7 +12,7 @@
 #include "ecpgtype.h"
 #include "ecpglib.h"
 #include "ecpgerrno.h"
-#include "extern.h"
+#include "ecpglib_extern.h"
 #include "sqlca.h"
 #include "sqlda.h"
 #include "sql3types.h"

src/interfaces/ecpg/ecpglib/ecpglib_extern.h

@@ -1,7 +1,7 @@
-/* src/interfaces/ecpg/ecpglib/extern.h */
+/* src/interfaces/ecpg/ecpglib/ecpglib_extern.h */
 
-#ifndef _ECPG_LIB_EXTERN_H
-#define _ECPG_LIB_EXTERN_H
+#ifndef _ECPG_ECPGLIB_EXTERN_H
+#define _ECPG_ECPGLIB_EXTERN_H
 
 #include "libpq-fe.h"
 #include "sqlca.h"
@@ -221,4 +221,4 @@ void		ecpg_set_native_sqlda(int, struct sqlda_struct **, const PGresult *, int,
 #define ECPG_SQLSTATE_ECPG_INTERNAL_ERROR	"YE000"
 #define ECPG_SQLSTATE_ECPG_OUT_OF_MEMORY	"YE001"
 
-#endif							/* _ECPG_LIB_EXTERN_H */
+#endif							/* _ECPG_ECPGLIB_EXTERN_H */

src/interfaces/ecpg/ecpglib/error.c

@@ -6,7 +6,7 @@
 #include "ecpgerrno.h"
 #include "ecpgtype.h"
 #include "ecpglib.h"
-#include "extern.h"
+#include "ecpglib_extern.h"
 #include "sqlca.h"
 
 void

src/interfaces/ecpg/ecpglib/execute.c

@@ -23,7 +23,7 @@
 #include "ecpgtype.h"
 #include "ecpglib.h"
 #include "ecpgerrno.h"
-#include "extern.h"
+#include "ecpglib_extern.h"
 #include "sqlca.h"
 #include "sqlda-native.h"
 #include "sqlda-compat.h"

src/interfaces/ecpg/ecpglib/memory.c

@@ -7,7 +7,7 @@
 #include "ecpgtype.h"
 #include "ecpglib.h"
 #include "ecpgerrno.h"
-#include "extern.h"
+#include "ecpglib_extern.h"
 
 void
 ecpg_free(void *ptr)

src/interfaces/ecpg/ecpglib/misc.c

@@ -9,7 +9,7 @@
 #include "ecpgtype.h"
 #include "ecpglib.h"
 #include "ecpgerrno.h"
-#include "extern.h"
+#include "ecpglib_extern.h"
 #include "sqlca.h"
 #include "pgtypes_numeric.h"
 #include "pgtypes_date.h"

src/interfaces/ecpg/ecpglib/prepare.c

@@ -8,7 +8,7 @@
 #include "ecpgtype.h"
 #include "ecpglib.h"
 #include "ecpgerrno.h"
-#include "extern.h"
+#include "ecpglib_extern.h"
 #include "sqlca.h"
 
 #define STMTID_SIZE 32

src/interfaces/ecpg/ecpglib/sqlda.c

@@ -16,7 +16,7 @@
 #include "ecpgtype.h"
 #include "ecpglib.h"
 #include "ecpgerrno.h"
-#include "extern.h"
+#include "ecpglib_extern.h"
 #include "sqlca.h"
 #include "sqlda-native.h"
 #include "sqlda-compat.h"

src/interfaces/ecpg/ecpglib/typename.c

@@ -7,7 +7,7 @@
 
 #include "ecpgtype.h"
 #include "ecpglib.h"
-#include "extern.h"
+#include "ecpglib_extern.h"
 #include "sqltypes.h"
 #include "sql3types.h"
 

src/interfaces/ecpg/pgtypeslib/common.c

@@ -2,7 +2,7 @@
 
 #include "postgres_fe.h"
 
-#include "extern.h"
+#include "pgtypeslib_extern.h"
 #include "pgtypes.h"
 
 /* Return value is zero-filled. */

src/interfaces/ecpg/pgtypeslib/datetime.c

@@ -6,7 +6,7 @@
 #include <ctype.h>
 #include <limits.h>
 
-#include "extern.h"
+#include "pgtypeslib_extern.h"
 #include "dt.h"
 #include "pgtypes_error.h"
 #include "pgtypes_date.h"

src/interfaces/ecpg/pgtypeslib/dt_common.c

@@ -6,7 +6,7 @@
 #include <ctype.h>
 #include <math.h>
 
-#include "extern.h"
+#include "pgtypeslib_extern.h"
 #include "dt.h"
 #include "pgtypes_timestamp.h"
 

src/interfaces/ecpg/pgtypeslib/interval.c

@@ -11,7 +11,7 @@
 
 #include "common/string.h"
 
-#include "extern.h"
+#include "pgtypeslib_extern.h"
 #include "dt.h"
 #include "pgtypes_error.h"
 #include "pgtypes_interval.h"

src/interfaces/ecpg/pgtypeslib/numeric.c

@@ -5,7 +5,7 @@
 #include <float.h>
 #include <limits.h>
 
-#include "extern.h"
+#include "pgtypeslib_extern.h"
 #include "pgtypes_error.h"
 
 #define Max(x, y)				((x) > (y) ? (x) : (y))

src/interfaces/ecpg/pgtypeslib/pgtypeslib_extern.h

@@ -1,7 +1,7 @@
-/* src/interfaces/ecpg/pgtypeslib/extern.h */
+/* src/interfaces/ecpg/pgtypeslib/pgtypeslib_extern.h */
 
-#ifndef __PGTYPES_COMMON_H__
-#define __PGTYPES_COMMON_H__
+#ifndef _ECPG_PGTYPESLIB_EXTERN_H
+#define _ECPG_PGTYPESLIB_EXTERN_H
 
 #include "pgtypes_error.h"
 
@@ -50,4 +50,4 @@ char	   *pgtypes_strdup(const char *);
 #define TRUE	   1
 #endif							/* TRUE */
 
-#endif							/* __PGTYPES_COMMON_H__ */
+#endif							/* _ECPG_PGTYPESLIB_EXTERN_H */

src/interfaces/ecpg/pgtypeslib/timestamp.c

@@ -11,7 +11,7 @@
 #error -ffast-math is known to break this code
 #endif
 
-#include "extern.h"
+#include "pgtypeslib_extern.h"
 #include "dt.h"
 #include "pgtypes_timestamp.h"
 #include "pgtypes_date.h"

src/interfaces/ecpg/preproc/c_keywords.c

@@ -11,7 +11,7 @@
 
 #include <ctype.h>
 
-#include "extern.h"
+#include "preproc_extern.h"
 #include "preproc.h"
 
 /*

src/interfaces/ecpg/preproc/descriptor.c

@@ -9,7 +9,7 @@
 
 #include "postgres_fe.h"
 
-#include "extern.h"
+#include "preproc_extern.h"
 
 /*
  * assignment handling function (descriptor)

src/interfaces/ecpg/preproc/ecpg.c

@@ -9,7 +9,7 @@
 
 #include "getopt_long.h"
 
-#include "extern.h"
+#include "preproc_extern.h"
 
 int			ret_value = 0;
 bool		autocommit = false,

src/interfaces/ecpg/preproc/ecpg.header

@@ -4,7 +4,7 @@
 %{
 #include "postgres_fe.h"
 
-#include "extern.h"
+#include "preproc_extern.h"
 #include "ecpg_config.h"
 #include <unistd.h>
 

src/interfaces/ecpg/preproc/ecpg_keywords.c

@@ -13,7 +13,7 @@
 
 #include <ctype.h>
 
-#include "extern.h"
+#include "preproc_extern.h"
 #include "preproc.h"
 
 /*

src/interfaces/ecpg/preproc/keywords.c

@@ -27,7 +27,7 @@
 
 #include "common/keywords.h"
 
-#include "extern.h"
+#include "preproc_extern.h"
 #include "preproc.h"
 
 

src/interfaces/ecpg/preproc/output.c

@@ -2,7 +2,7 @@
 
 #include "postgres_fe.h"
 
-#include "extern.h"
+#include "preproc_extern.h"
 
 static void output_escaped_str(char *cmd, bool quoted);
 

src/interfaces/ecpg/preproc/parser.c

@@ -18,7 +18,7 @@
 
 #include "postgres_fe.h"
 
-#include "extern.h"
+#include "preproc_extern.h"
 #include "preproc.h"
 
 

src/interfaces/ecpg/preproc/pgc.l

@@ -22,7 +22,7 @@
 
 #include "common/string.h"
 
-#include "extern.h"
+#include "preproc_extern.h"
 #include "preproc.h"
 }
 

src/interfaces/ecpg/preproc/preproc_extern.h

@@ -1,4 +1,4 @@
-/* src/interfaces/ecpg/preproc/extern.h */
+/* src/interfaces/ecpg/preproc/preproc_extern.h */
 
 #ifndef _ECPG_PREPROC_EXTERN_H
 #define _ECPG_PREPROC_EXTERN_H
@@ -7,7 +7,6 @@
 
 #include "common/keywords.h"
 
-#include <errno.h>
 #ifndef CHAR_BIT
 #include <limits.h>
 #endif

src/interfaces/ecpg/preproc/type.c

@@ -2,7 +2,7 @@
 
 #include "postgres_fe.h"
 
-#include "extern.h"
+#include "preproc_extern.h"
 
 #define indicator_set ind_type != NULL && ind_type->type != ECPGt_NO_INDICATOR
 

src/interfaces/ecpg/preproc/variable.c

@@ -2,7 +2,7 @@
 
 #include "postgres_fe.h"
 
-#include "extern.h"
+#include "preproc_extern.h"
 
 static struct variable *allvariables = NULL;