ICU: do not include ICU headers for definitions only

Author: Marina Polyakova

src/backend/access/transam/xlog.c

@@ -22,6 +22,10 @@
 #include <sys/time.h>
 #include <unistd.h>
 
+#ifdef USE_ICU
+#include <unicode/uversion.h>
+#endif
+
 #include "access/clog.h"
 #include "access/commit_ts.h"
 #include "access/multixact.h"

src/bin/initdb/initdb.c

@@ -55,6 +55,10 @@
 #include <signal.h>
 #include <time.h>
 
+#ifdef USE_ICU
+#include <unicode/uloc.h>
+#endif
+
 #ifdef HAVE_SHM_OPEN
 #include "sys/mman.h"
 #endif

src/include/port.h

@@ -485,11 +485,12 @@ extern char *get_collation_actual_version(char collprovider,
 #endif
 
 #ifdef USE_ICU
-#include <unicode/ucol.h>
-
 #define ICU_ROOT_LOCALE "root"
 
-extern UCollator *open_collator(const char *collate);
+/* Users of this must import unicode/ucol.h too. */
+struct UCollator;
+extern struct UCollator *open_collator(const char *collate);
+
 extern char * get_icu_language_tag(const char *localename);
 extern const char *get_icu_collate(const char *locale, const char *langtag);
 #ifdef WIN32

src/port/chklocale.c

@@ -27,6 +27,10 @@
 #include "common/pg_collation_fn_common.h"
 #include "mb/pg_wchar.h"
 
+#ifdef USE_ICU
+#include <unicode/ucol.h>
+#endif
+
 /*
  * In backend, we will use palloc/pfree.  In frontend, use malloc/free.
  */