Cleanup header files

- All now include maxscale/cdefs.h as the very first file.
- MXS_[BEGIN|END]_DECLS added to all C-headers.
  Strictly speaking not necessary for private headers, but
  does not hurt either.
- Include guards moved to the very top of the file.
- #pragma once added.

server/modules/filter/cache/cache.h

@@ -1,5 +1,6 @@
-#ifndef CACHE_H
-#define CACHE_H
+#pragma once
+#ifndef _MAXSCALE_FILTER_CACHE_CACHE_H
+#define _MAXSCALE_FILTER_CACHE_CACHE_H
 /*
  * Copyright (c) 2016 MariaDB Corporation Ab
  *
@@ -15,6 +16,8 @@
 
 #include <limits.h>
 
+MXS_BEGIN_DECLS
+
 #define CACHE_DEBUG_NONE         0
 #define CACHE_DEBUG_MATCHING     1
 #define CACHE_DEBUG_NON_MATCHING 2
@@ -35,4 +38,6 @@
 // Integer value
 #define CACHE_DEFAULT_DEBUG              0
 
+MXS_END_DECLS
+
 #endif

server/modules/filter/cache/cache_storage_api.h

@@ -1,5 +1,6 @@
-#ifndef _MAXSCALE_FILTER_CACHE_CACHE_H
-#define _MAXSCALE_FILTER_CACHE_CACHE_H
+#pragma once
+#ifndef _MAXSCALE_FILTER_CACHE_CACHE_STORAGE_API_H
+#define _MAXSCALE_FILTER_CACHE_CACHE_STORAGE_API_H
 /*
  * Copyright (c) 2016 MariaDB Corporation Ab
  *
@@ -19,7 +20,7 @@
 #include <maxscale/protocol/mysql.h>
 #include <maxscale/skygw_debug.h>
 
-EXTERN_C_BLOCK_BEGIN
+MXS_BEGIN_DECLS
 
 typedef enum cache_result
 {
@@ -116,6 +117,6 @@ typedef struct cache_storage_api
 #define CACHE_STORAGE_ENTRY_POINT "CacheGetStorageAPI"
 typedef CACHE_STORAGE_API* (*CacheGetStorageAPIFN)();
 
-EXTERN_C_BLOCK_END
+MXS_END_DECLS
 
 #endif

server/modules/filter/cache/rules.h

@@ -1,3 +1,4 @@
+#pragma once
 #ifndef _MAXSCALE_FILTER_CACHE_RULES_H
 #define _MAXSCALE_FILTER_CACHE_RULES_H
 /*
@@ -13,12 +14,14 @@
  * Public License.
  */
 
+#include <maxscale/cdefs.h>
 #include <stdbool.h>
 #include <jansson.h>
 #include <maxscale/buffer.h>
 #include <maxscale/session.h>
 #include <maxscale/pcre2.h>
 
+MXS_BEGIN_DECLS
 
 typedef enum cache_rule_attribute
 {
@@ -71,4 +74,6 @@ CACHE_RULES *cache_rules_parse(const char *json, uint32_t debug);
 bool cache_rules_should_store(CACHE_RULES *rules, const char *default_db, const GWBUF* query);
 bool cache_rules_should_use(CACHE_RULES *rules, const SESSION *session);
 
+MXS_END_DECLS
+
 #endif

server/modules/filter/cache/storage.h

@@ -1,3 +1,4 @@
+#pragma once
 #ifndef _MAXSCALE_FILTER_CACHE_STORAGE_H
 #define _MAXSCALE_FILTER_CACHE_STORAGE_H
 /*
@@ -13,8 +14,11 @@
  * Public License.
  */
 
+#include <maxscale/cdefs.h>
 #include "cache_storage_api.h"
 
+MXS_BEGIN_DECLS
+
 typedef struct cache_storage_module_t
 {
     void* handle;
@@ -24,4 +28,6 @@ typedef struct cache_storage_module_t
 CACHE_STORAGE_MODULE* cache_storage_open(const char *name);
 void cache_storage_close(CACHE_STORAGE_MODULE *module);
 
+MXS_END_DECLS
+
 #endif

server/modules/filter/cache/storage/storage_rocksdb/rocksdbinternals.h

@@ -14,6 +14,7 @@
  * Public License.
  */
 
+#include <maxscale/cdefs.h>
 #include "storage_rocksdb.h"
 #include <rocksdb/env.h>
 #include <rocksdb/version.h>

server/modules/filter/cache/storage/storage_rocksdb/rocksdbstorage.h

@@ -1,3 +1,4 @@
+#pragma once
 #ifndef _ROCKSDBSTORAGE_H
 #define _ROCKSDBSTORAGE_H
 /*
@@ -13,6 +14,7 @@
  * Public License.
  */
 
+#include <maxscale/cdefs.h>
 #include "storage_rocksdb.h"
 #include <memory>
 #include <string>

server/modules/filter/cache/storage/storage_rocksdb/storage_rocksdb.h

@@ -1,3 +1,4 @@
+#pragma once
 #ifndef _STORAGE_ROCKSDB_H
 #define _STORAGE_ROCKSDB_H
 /*
@@ -14,6 +15,7 @@
  */
 
 #define MXS_MODULE_NAME "storage_rocksdb"
+#include <maxscale/cdefs.h>
 #include <maxscale/log_manager.h>
 
 #endif

server/modules/filter/dbfwfilter/dbfwfilter.h

@@ -1,3 +1,4 @@
+#pragma once
 #ifndef _DBFWFILTER_H
 #define _DBFWFILTER_H
 /*
@@ -20,8 +21,11 @@
  * the generater parser which is created from the ruleparser.y and token.l files.
  */
 
+#include <maxscale/cdefs.h>
 #include <stdbool.h>
 
+MXS_BEGIN_DECLS
+
 /** Matching type */
 enum match_type
 {
@@ -49,4 +53,6 @@ bool add_active_rule(void* scanner, const char* name);
 void set_matching_mode(void* scanner, enum match_type mode);
 bool create_user_templates(void* scanner);
 
+MXS_END_DECLS
+
 #endif

server/modules/filter/hintfilter/mysqlhint.h

@@ -1,3 +1,4 @@
+#pragma once
 #ifndef _MYSQLHINT_H
 #define _MYSQLHINT_H
 /*
@@ -19,8 +20,12 @@
  * Date         Who             Description
  * 17-07-2014   Mark Riddoch    Initial implementation
  */
+
+#include <maxscale/cdefs.h>
 #include <maxscale/hint.h>
 
+MXS_BEGIN_DECLS
+
 /* Parser tokens for the hint parser */
 typedef enum
 {
@@ -105,11 +110,10 @@ typedef struct
 #define HS_PVALUE       5
 #define HS_PREPARE      6
 
-
 extern HINT *hint_parser(HINT_SESSION *session, GWBUF *request);
 NAMEDHINTS* free_named_hint(NAMEDHINTS* named_hint);
 HINTSTACK*  free_hint_stack(HINTSTACK* hint_stack);
 
-
+MXS_END_DECLS
 
 #endif