Move #includes out of extern "C" blocks

Do some include shuffling for `**.h` files within lib, programs, tests, and zlibWrapper.
`lib/legacy` and `lib/deprecated` are untouched.
`#include`s within `extern "C"` blocks in .cpp files are untouched.

todo: shuffling for `xxhash.h`

programs/benchfn.h

@@ -15,10 +15,6 @@
  * or detecting and returning an error
  */
 
-#if defined (__cplusplus)
-extern "C" {
-#endif
-
 #ifndef BENCH_FN_H_23876
 #define BENCH_FN_H_23876
 
@@ -26,6 +22,10 @@ extern "C" {
 #include <stddef.h>   /* size_t */
 
 
+#if defined (__cplusplus)
+extern "C" {
+#endif
+
 /* ====  Benchmark any function, iterated on a set of blocks  ==== */
 
 /* BMK_runTime_t: valid result return type */

programs/benchzstd.h

@@ -14,10 +14,6 @@
   * and display progress result and final summary
   */
 
-#if defined (__cplusplus)
-extern "C" {
-#endif
-
 #ifndef BENCH_ZSTD_H_3242387
 #define BENCH_ZSTD_H_3242387
 
@@ -27,6 +23,10 @@ extern "C" {
 #include "../lib/zstd.h"     /* ZSTD_compressionParameters */
 
 
+#if defined (__cplusplus)
+extern "C" {
+#endif
+
 /* ===  Constants  === */
 
 #define MB_UNIT 1000000

programs/fileio_asyncio.h

@@ -22,10 +22,6 @@
 #ifndef ZSTD_FILEIO_ASYNCIO_H
 #define ZSTD_FILEIO_ASYNCIO_H
 
-#if defined (__cplusplus)
-extern "C" {
-#endif
-
 #include "../lib/common/mem.h"     /* U32, U64 */
 #include "fileio_types.h"
 #include "platform.h"
@@ -35,6 +31,10 @@ extern "C" {
 
 #define MAX_IO_JOBS          (10)
 
+#if defined (__cplusplus)
+extern "C" {
+#endif
+
 typedef struct {
     /* These struct fields should be set only on creation and not changed afterwards */
     POOL_ctx* threadPool;

programs/fileio_common.h

@@ -11,15 +11,22 @@
 #ifndef ZSTD_FILEIO_COMMON_H
 #define ZSTD_FILEIO_COMMON_H
 
-#if defined (__cplusplus)
-extern "C" {
-#endif
-
 #include "../lib/common/mem.h"     /* U32, U64 */
 #include "fileio_types.h"
 #include "platform.h"
 #include "timefn.h"     /* UTIL_getTime, UTIL_clockSpanMicro */
 
+#if !(defined(_MSC_VER) && _MSC_VER >= 1400) \
+    && !(!defined(__64BIT__) && (PLATFORM_POSIX_VERSION >= 200112L)) \
+    && !(defined(__MINGW32__) && !defined(__STRICT_ANSI__) && !defined(__NO_MINGW_LFS) && defined(__MSVCRT__)) \
+    && (defined(_WIN32) && !defined(__DJGPP__))
+#   include <windows.h>
+#endif
+
+#if defined (__cplusplus)
+extern "C" {
+#endif
+
 /*-*************************************
 *  Macros
 ***************************************/
@@ -89,7 +96,6 @@ extern UTIL_time_t g_displayClock;
 #   define LONG_SEEK fseeko64
 #   define LONG_TELL ftello64
 #elif defined(_WIN32) && !defined(__DJGPP__)
-#   include <windows.h>
     static int LONG_SEEK(FILE* file, __int64 offset, int origin) {
         LARGE_INTEGER off;
         DWORD method;

programs/platform.h

@@ -11,12 +11,6 @@
 #ifndef PLATFORM_H_MODULE
 #define PLATFORM_H_MODULE
 
-#if defined (__cplusplus)
-extern "C" {
-#endif
-
-
-
 /* **************************************
 *  Compiler Options
 ****************************************/
@@ -144,10 +138,20 @@ extern "C" {
 #  include <io.h>      /* _isatty */
 #  include <windows.h> /* DeviceIoControl, HANDLE, FSCTL_SET_SPARSE */
 #  include <stdio.h>   /* FILE */
+
+#if defined (__cplusplus)
+extern "C" {
+#endif
+
 static __inline int IS_CONSOLE(FILE* stdStream) {
     DWORD dummy;
     return _isatty(_fileno(stdStream)) && GetConsoleMode((HANDLE)_get_osfhandle(_fileno(stdStream)), &dummy);
 }
+
+#if defined (__cplusplus)
+}
+#endif
+
 #else
 #  define IS_CONSOLE(stdStream) 0
 #endif
@@ -210,9 +214,4 @@ static __inline int IS_CONSOLE(FILE* stdStream) {
 #  endif
 #endif
 
-
-#if defined (__cplusplus)
-}
-#endif
-
 #endif /* PLATFORM_H_MODULE */

programs/timefn.h

@@ -11,12 +11,6 @@
 #ifndef TIME_FN_H_MODULE_287987
 #define TIME_FN_H_MODULE_287987
 
-#if defined (__cplusplus)
-extern "C" {
-#endif
-
-
-
 /*-****************************************
 *  Types
 ******************************************/
@@ -32,6 +26,11 @@ extern "C" {
   typedef unsigned long long PTime;  /* does not support compilers without long long support */
 #endif
 
+
+#if defined (__cplusplus)
+extern "C" {
+#endif
+
 /* UTIL_time_t contains a nanosecond time counter.
  * The absolute value is not meaningful.
  * It's only valid to compute the difference between 2 measurements. */

programs/util.c

@@ -8,11 +8,6 @@
  * You may select, at your option, one of the above-listed licenses.
  */
 
-#if defined (__cplusplus)
-extern "C" {
-#endif
-
-
 /*-****************************************
 *  Dependencies
 ******************************************/
@@ -1646,7 +1641,3 @@ int UTIL_countLogicalCores(void)
 {
     return UTIL_countCores(1);
 }
-
-#if defined (__cplusplus)
-}
-#endif

programs/util.h

@@ -20,6 +20,9 @@
 #include <sys/types.h>    /* stat, utime */
 #include <sys/stat.h>     /* stat, chmod */
 #include "../lib/common/mem.h"          /* U64 */
+#if not (defined(_MSC_VER) || defined(__MINGW32__) || defined (__MSVCRT__))
+#include <libgen.h>
+#endif
 
 /*-************************************************************
 *  Fix fseek()'s 2GiB barrier with MSVC, macOS, *BSD, MinGW
@@ -116,7 +119,6 @@ int UTIL_requireUserConfirmation(const char* prompt, const char* abortMsg, const
 #define STRDUP(s) _strdup(s)
 #else
 #define PATH_SEP '/'
-#include <libgen.h>
 #define STRDUP(s) strdup(s)
 #endif