Add support for VS2015 (VC++ 14.0)

Due to the rewritten CRT in this version of Visual C++ it is no longer
possible (or at least not at all easy) to make use of the ioinfo struct,
which commit b47a847f62 (re-)introduced in order to fix RT#120091/118059.
Therefore, we effectively revert commit b47a847f62 for VS2015 onwards on
the basis that being able to build with VS2015 onwards is more important
than the RT#120091/118059 bug fix. This does unfortunately mean that perls
built with <=VS2013 will not be compatible with perls built with >=VS2015,
but they may well not have been compatible anyway because of the CRT
rewrite, and certainly wouldn't be compatible if perl builds with VS2015
were not supported!

See RT#125714 for more discussion about this.

8 files changed, 241 insertions, 20 deletions

diff --git a/win32/GNUmakefile b/win32/GNUmakefile
index 5db9ba89ca..7a2e761e93 100644
--- a/win32/GNUmakefile
+++ b/win32/GNUmakefile
@@ -173,6 +173,10 @@ USE_LARGE_FILES	:= define
 #CCTYPE		:= MSVC120
 # Visual C++ 2013 Express Edition (aka Visual C++ 12.0) (free version)
 #CCTYPE		:= MSVC120FREE
+# Visual C++ 2015 (aka Visual C++ 14.0) (full version)
+#CCTYPE		:= MSVC140
+# Visual C++ 2015 Express Edition (aka Visual C++ 14.0) (free version)
+#CCTYPE		:= MSVC140FREE
 # MinGW or mingw-w64 with gcc-3.4.5 or later
 #CCTYPE		:= GCC
 
@@ -619,7 +623,13 @@ DEFINES		= -DWIN32 -D_CONSOLE -DNO_STRICT
 LOCDEFS		= -DPERLDLL -DPERL_CORE
 CXX_FLAG	= -TP -EHsc
 
+ifeq ($(CCTYPE),MSVC140)
+LIBC		= ucrt.lib
+else ifeq ($(CCTYPE),MSVC140FREE)
+LIBC		= ucrt.lib
+else
 LIBC		= msvcrt.lib
+endif
 
 ifeq ($(CFG),Debug)
 OPTIMIZE	= -Od -MD -Zi -DDEBUGGING
@@ -628,7 +638,13 @@ else ifeq ($(CFG),DebugSymbols)
 OPTIMIZE	= -Od -MD -Zi
 LINK_DBG	= -debug
 else ifeq ($(CFG),DebugFull)
+ifeq ($(CCTYPE),MSVC140)
+LIBC		= ucrtd.lib
+else ifeq ($(CCTYPE),MSVC140FREE)
+LIBC		= ucrtd.lib
+else
 LIBC		= msvcrtd.lib
+endif
 OPTIMIZE	= -Od -MDd -Zi -D_DEBUG -DDEBUGGING
 LINK_DBG	= -debug
 else
@@ -661,6 +677,13 @@ ifeq ($(PREMSVC80),undef)
 DEFINES		+= -D_CRT_SECURE_NO_DEPRECATE -D_CRT_NONSTDC_NO_DEPRECATE
 endif
 
+# Likewise for deprecated Winsock APIs in VC++ 14.0 for now.
+ifeq ($(CCTYPE),MSVC140)
+DEFINES		= $(DEFINES) -D_WINSOCK_DEPRECATED_NO_WARNINGS
+else ifeq ($(CCTYPE),MSVC140FREE)
+DEFINES		= $(DEFINES) -D_WINSOCK_DEPRECATED_NO_WARNINGS
+endif
+
 # In VS 2005 (VC++ 8.0) Microsoft changes time_t from 32-bit to
 # 64-bit, even in 32-bit mode.  It also provides the _USE_32BIT_TIME_T
 # preprocessor option to revert back to the old functionality for
@@ -680,6 +703,20 @@ LIBBASEFILES	= oldnames.lib kernel32.lib user32.lib gdi32.lib winspool.lib \
 	netapi32.lib uuid.lib ws2_32.lib mpr.lib winmm.lib version.lib \
 	odbc32.lib odbccp32.lib comctl32.lib
 
+ifeq ($(CCTYPE),MSVC140)
+ifeq ($(CFG),DebugFull)
+LIBBASEFILES	+= msvcrtd.lib vcruntimed.lib
+else
+LIBBASEFILES	+= msvcrt.lib vcruntime.lib
+endif
+else ifeq ($(CCTYPE),MSVC140FREE)
+ifeq ($(CFG),DebugFull)
+LIBBASEFILES	+= msvcrtd.lib vcruntimed.lib
+else
+LIBBASEFILES	+= msvcrt.lib vcruntime.lib
+endif
+endif
+
 # Avoid __intel_new_proc_init link error for libircmt.
 # libmmd is /MD equivelent, other variants exist.
 # libmmd is Intel C's math addon funcs to MS CRT, contains long doubles, C99,
@@ -1240,6 +1277,27 @@ $(MINIDIR)\.exists : $(CFGH_TMPL)
 	echo #undef NVff&& \
 	echo #undef NVgf&& \
 	echo #undef USE_LONG_DOUBLE)>> config.h
+ifeq ($(CCTYPE),MSVC140)
+	@(echo #undef FILE_ptr&& \
+	echo #undef FILE_cnt&& \
+	echo #undef FILE_base&& \
+	echo #undef FILE_bufsiz&& \
+	echo #define FILE_ptr(fp) PERLIO_FILE_ptr(fp)&& \
+	echo #define FILE_cnt(fp) PERLIO_FILE_cnt(fp)&& \
+	echo #define FILE_base(fp) PERLIO_FILE_base(fp)&& \
+	echo #define FILE_bufsiz(fp) (PERLIO_FILE_cnt(fp) + PERLIO_FILE_ptr(fp) - PERLIO_FILE_base(fp))&& \
+	echo #define I_STDBOOL)>> config.h
+else ifeq ($(CCTYPE),MSVC140FREE)
+	@(echo #undef FILE_ptr&& \
+	echo #undef FILE_cnt&& \
+	echo #undef FILE_base&& \
+	echo #undef FILE_bufsiz&& \
+	echo #define FILE_ptr(fp) PERLIO_FILE_ptr(fp)&& \
+	echo #define FILE_cnt(fp) PERLIO_FILE_cnt(fp)&& \
+	echo #define FILE_base(fp) PERLIO_FILE_base(fp)&& \
+	echo #define FILE_bufsiz(fp) (PERLIO_FILE_cnt(fp) + PERLIO_FILE_ptr(fp) - PERLIO_FILE_base(fp))&& \
+	echo #define I_STDBOOL)>> config.h
+endif
 ifeq ($(USE_LARGE_FILES),define)
 	@(echo #define Off_t $(INT64)&& \
 	echo #define LSEEKSIZE ^8&& \
diff --git a/win32/Makefile b/win32/Makefile
index 676e7f6943..6c8f7f6eec 100644
--- a/win32/Makefile
+++ b/win32/Makefile
@@ -133,6 +133,10 @@ CCTYPE		= MSVC60
 #CCTYPE		= MSVC120
 # Visual C++ 2013 Express Edition (aka Visual C++ 12.0) (free version)
 #CCTYPE		= MSVC120FREE
+# Visual C++ 2015 (aka Visual C++ 14.0) (full version)
+#CCTYPE		= MSVC140
+# Visual C++ 2015 Express Edition (aka Visual C++ 14.0) (free version)
+#CCTYPE		= MSVC140FREE
 
 #
 # If you are using Intel C++ Compiler uncomment this
@@ -467,7 +471,11 @@ DEFINES		= -DWIN32 -D_CONSOLE -DNO_STRICT
 LOCDEFS		= -DPERLDLL -DPERL_CORE
 CXX_FLAG	= -TP -EHsc
 
+!IF "$(CCTYPE)" == "MSVC140" || "$(CCTYPE)" == "MSVC140FREE"
+LIBC		= ucrt.lib
+!ELSE
 LIBC		= msvcrt.lib
+!ENDIF
 
 !IF  "$(CFG)" == "Debug"
 OPTIMIZE	= -Od -MD -Zi -DDEBUGGING
@@ -478,7 +486,11 @@ OPTIMIZE	= -Od -MD -Zi
 LINK_DBG	= -debug
 !ELSE
 !IF  "$(CFG)" == "DebugFull"
+!IF "$(CCTYPE)" == "MSVC140" || "$(CCTYPE)" == "MSVC140FREE"
+LIBC		= ucrtd.lib
+!ELSE
 LIBC		= msvcrtd.lib
+!ENDIF
 OPTIMIZE	= -Od -MDd -Zi -D_DEBUG -DDEBUGGING
 LINK_DBG	= -debug
 !ELSE
@@ -513,6 +525,11 @@ OPTIMIZE	= $(OPTIMIZE) -fp:precise
 DEFINES		= $(DEFINES) -D_CRT_SECURE_NO_DEPRECATE -D_CRT_NONSTDC_NO_DEPRECATE
 !ENDIF
 
+# Likewise for deprecated Winsock APIs in VC++ 14.0 for now.
+!IF "$(CCTYPE)" == "MSVC140" || "$(CCTYPE)" == "MSVC140FREE"
+DEFINES		= $(DEFINES) -D_WINSOCK_DEPRECATED_NO_WARNINGS
+!ENDIF
+
 # In VS 2005 (VC++ 8.0) Microsoft changes time_t from 32-bit to
 # 64-bit, even in 32-bit mode.  It also provides the _USE_32BIT_TIME_T
 # preprocessor option to revert back to the old functionality for
@@ -533,6 +550,14 @@ LIBBASEFILES	= \
 		netapi32.lib uuid.lib ws2_32.lib mpr.lib winmm.lib \
 		version.lib odbc32.lib odbccp32.lib comctl32.lib
 
+!IF "$(CCTYPE)" == "MSVC140" || "$(CCTYPE)" == "MSVC140FREE"
+!  IF  "$(CFG)" == "DebugFull"
+LIBBASEFILES	= $(LIBBASEFILES) msvcrtd.lib vcruntimed.lib
+!  ELSE
+LIBBASEFILES	= $(LIBBASEFILES) msvcrt.lib vcruntime.lib
+!  ENDIF
+!ENDIF
+
 # Avoid __intel_new_proc_init link error for libircmt.
 # libmmd is /MD equivelent, other variants exist.
 # libmmd is Intel C's math addon funcs to MS CRT, contains long doubles, C99,
@@ -928,6 +953,17 @@ perlglob$(o)  : perlglob.c
 	@echo.>>$@
 	@echo #ifndef _config_h_footer_>>$@
 	@echo #define _config_h_footer_>>$@
+!IF "$(CCTYPE)" == "MSVC140" || "$(CCTYPE)" == "MSVC140FREE"
+	@echo #undef FILE_ptr>>$@
+	@echo #define FILE_ptr(fp) PERLIO_FILE_ptr(fp)>>$@
+	@echo #undef FILE_cnt>>$@
+	@echo #define FILE_cnt(fp) PERLIO_FILE_cnt(fp)>>$@
+	@echo #undef FILE_base>>$@
+	@echo #define FILE_base(fp) PERLIO_FILE_base(fp)>>$@
+	@echo #undef FILE_bufsiz>>$@
+	@echo #define FILE_bufsiz(fp) (PERLIO_FILE_cnt(fp) + PERLIO_FILE_ptr(fp) - PERLIO_FILE_base(fp))>>$@
+	@echo #define I_STDBOOL>>$@
+!ENDIF
 	@echo #undef Off_t>>$@
 	@echo #undef LSEEKSIZE>>$@
 	@echo #undef Off_t_size>>$@
diff --git a/win32/config_sh.PL b/win32/config_sh.PL
index c4a311266d..8d6f7383fa 100644
--- a/win32/config_sh.PL
+++ b/win32/config_sh.PL
@@ -277,6 +277,13 @@ if ($opt{cc} =~ /\bcl/ and $opt{ccversion} =~ /^(\d+)/) {
     if($ccversion < 13) { #VC6
 	$opt{ar} ='lib';
     }
+    if ($ccversion >= 19) { # VC14
+	$opt{stdio_base} = 'PERLIO_FILE_base(fp)';
+	$opt{stdio_bufsiz} = '(PERLIO_FILE_cnt(fp) + PERLIO_FILE_ptr(fp) - PERLIO_FILE_base(fp))';
+	$opt{stdio_cnt} = 'PERLIO_FILE_cnt(fp)';
+	$opt{stdio_ptr} = 'PERLIO_FILE_ptr(fp)';
+	$opt{i_stdbool} = 'define';
+    }
 }
 #find out which MSVC this ICC is using
 elsif ($opt{cc} =~ /\bicl/) {
@@ -286,6 +293,13 @@ elsif ($opt{cc} =~ /\bicl/) {
 	$opt{sGMTIME_max} = 32535291599;
 	$opt{sLOCALTIME_max} = 32535244799;
     }
+    if ($num_ver =~ /^(\d+)/ && $1 >= 19) { # VC14
+	$opt{stdio_base} = 'PERLIO_FILE_base(fp)';
+	$opt{stdio_bufsiz} = '(PERLIO_FILE_cnt(fp) + PERLIO_FILE_ptr(fp) - PERLIO_FILE_base(fp))';
+	$opt{stdio_cnt} = 'PERLIO_FILE_cnt(fp)';
+	$opt{stdio_ptr} = 'PERLIO_FILE_ptr(fp)';
+	$opt{i_stdbool} = 'define';
+    }
     $opt{ar} ='xilib';
 }
 
diff --git a/win32/makefile.mk b/win32/makefile.mk
index 3864e361ee..318b13f688 100644
--- a/win32/makefile.mk
+++ b/win32/makefile.mk
@@ -145,6 +145,10 @@ USE_LARGE_FILES	*= define
 #CCTYPE		= MSVC120
 # Visual C++ 2013 Express Edition (aka Visual C++ 12.0) (free version)
 #CCTYPE		= MSVC120FREE
+# Visual C++ 2015 (aka Visual C++ 14.0) (full version)
+#CCTYPE		= MSVC140
+# Visual C++ 2015 Express Edition (aka Visual C++ 14.0) (free version)
+#CCTYPE		= MSVC140FREE
 # MinGW or mingw-w64 with gcc-3.4.5 or later
 #CCTYPE		= GCC
 
@@ -606,7 +610,11 @@ DEFINES		= -DWIN32 -D_CONSOLE -DNO_STRICT
 LOCDEFS		= -DPERLDLL -DPERL_CORE
 CXX_FLAG	= -TP -EHsc
 
+.IF "$(CCTYPE)" == "MSVC140" || "$(CCTYPE)" == "MSVC140FREE"
+LIBC		= ucrt.lib
+.ELSE
 LIBC		= msvcrt.lib
+.ENDIF
 
 .IF  "$(CFG)" == "Debug"
 OPTIMIZE	= -Od -MD -Zi -DDEBUGGING
@@ -615,7 +623,11 @@ LINK_DBG	= -debug
 OPTIMIZE	= -Od -MD -Zi
 LINK_DBG	= -debug
 .ELIF  "$(CFG)" == "DebugFull"
+.IF "$(CCTYPE)" == "MSVC140" || "$(CCTYPE)" == "MSVC140FREE"
+LIBC		= ucrtd.lib
+.ELSE
 LIBC		= msvcrtd.lib
+.ENDIF
 OPTIMIZE	= -Od -MDd -Zi -D_DEBUG -DDEBUGGING
 LINK_DBG	= -debug
 .ELSE
@@ -648,6 +660,11 @@ OPTIMIZE	+= -fp:precise
 DEFINES		+= -D_CRT_SECURE_NO_DEPRECATE -D_CRT_NONSTDC_NO_DEPRECATE
 .ENDIF
 
+# Likewise for deprecated Winsock APIs in VC++ 14.0 for now.
+.IF "$(CCTYPE)" == "MSVC140" || "$(CCTYPE)" == "MSVC140FREE"
+DEFINES		= $(DEFINES) -D_WINSOCK_DEPRECATED_NO_WARNINGS
+.ENDIF
+
 # In VS 2005 (VC++ 8.0) Microsoft changes time_t from 32-bit to
 # 64-bit, even in 32-bit mode.  It also provides the _USE_32BIT_TIME_T
 # preprocessor option to revert back to the old functionality for
@@ -667,6 +684,14 @@ LIBBASEFILES	= oldnames.lib kernel32.lib user32.lib gdi32.lib winspool.lib \
 	netapi32.lib uuid.lib ws2_32.lib mpr.lib winmm.lib version.lib \
 	odbc32.lib odbccp32.lib comctl32.lib
 
+.IF "$(CCTYPE)" == "MSVC140" || "$(CCTYPE)" == "MSVC140FREE"
+.IF "$(CFG)" == "DebugFull"
+LIBBASEFILES	+= msvcrtd.lib vcruntimed.lib
+.ELSE
+LIBBASEFILES	+= msvcrt.lib vcruntime.lib
+.ENDIF
+.ENDIF
+
 # Avoid __intel_new_proc_init link error for libircmt.
 # libmmd is /MD equivelent, other variants exist.
 # libmmd is Intel C's math addon funcs to MS CRT, contains long doubles, C99,
@@ -1208,6 +1233,17 @@ $(MINIDIR)\.exists : $(CFGH_TMPL)
 	echo #undef NVgf&& \
 	echo #undef USE_LONG_DOUBLE&& \
 	echo #undef USE_CPLUSPLUS)>> config.h
+.IF "$(CCTYPE)" == "MSVC140" || "$(CCTYPE)" == "MSVC140FREE"
+	@(echo #undef FILE_ptr&& \
+	echo #undef FILE_cnt&& \
+	echo #undef FILE_base&& \
+	echo #undef FILE_bufsiz&& \
+	echo #define FILE_ptr(fp) PERLIO_FILE_ptr(fp)&& \
+	echo #define FILE_cnt(fp) PERLIO_FILE_cnt(fp)&& \
+	echo #define FILE_base(fp) PERLIO_FILE_base(fp)&& \
+	echo #define FILE_bufsiz(fp) (PERLIO_FILE_cnt(fp) + PERLIO_FILE_ptr(fp) - PERLIO_FILE_base(fp))&& \
+	echo #define I_STDBOOL)>> config.h
+.ENDIF
 .IF "$(USE_LARGE_FILES)"=="define"
 	@(echo #define Off_t $(INT64)&& \
 	echo #define LSEEKSIZE ^8&& \
diff --git a/win32/perlhost.h b/win32/perlhost.h
index 9963319a92..84b08c9b90 100644
--- a/win32/perlhost.h
+++ b/win32/perlhost.h
@@ -836,15 +836,15 @@ PerlStdIOFdupopen(struct IPerlStdIO* piPerl, FILE* pf)
     int fileno = win32_dup(win32_fileno(pf));
 
     /* open the file in the same mode */
-    if((pf)->_flag & _IOREAD) {
+    if (PERLIO_FILE_flag(pf) & PERLIO_FILE_flag_RD) {
 	mode[0] = 'r';
 	mode[1] = 0;
     }
-    else if((pf)->_flag & _IOWRT) {
+    else if (PERLIO_FILE_flag(pf) & PERLIO_FILE_flag_WR) {
 	mode[0] = 'a';
 	mode[1] = 0;
     }
-    else if((pf)->_flag & _IORW) {
+    else if (PERLIO_FILE_flag(pf) & PERLIO_FILE_flag_RW) {
 	mode[0] = 'r';
 	mode[1] = '+';
 	mode[2] = 0;
diff --git a/win32/win32.c b/win32/win32.c
index 6ac73e2af0..39819212d2 100644
--- a/win32/win32.c
+++ b/win32/win32.c
@@ -4161,15 +4161,15 @@ win32_fdupopen(FILE *pf)
     int fileno = win32_dup(win32_fileno(pf));
 
     /* open the file in the same mode */
-    if((pf)->_flag & _IOREAD) {
+    if (PERLIO_FILE_flag(pf) & PERLIO_FILE_flag_RD) {
 	mode[0] = 'r';
 	mode[1] = 0;
     }
-    else if((pf)->_flag & _IOWRT) {
+    else if (PERLIO_FILE_flag(pf) & PERLIO_FILE_flag_WR) {
 	mode[0] = 'a';
 	mode[1] = 0;
     }
-    else if((pf)->_flag & _IORW) {
+    else if (PERLIO_FILE_flag(pf) & PERLIO_FILE_flag_RW) {
 	mode[0] = 'r';
 	mode[1] = '+';
 	mode[2] = 0;
diff --git a/win32/win32.h b/win32/win32.h
index 9b79e009f1..6de9c9b726 100644
--- a/win32/win32.h
+++ b/win32/win32.h
@@ -262,13 +262,13 @@ typedef unsigned short	mode_t;
 #define snprintf	_snprintf
 #define vsnprintf	_vsnprintf
 
-/* on VC2003, msvcrt.lib is missing these symbols */
+/* on VS2003, msvcrt.lib is missing these symbols */
 #if _MSC_VER >= 1300 && _MSC_VER < 1400
 #  pragma intrinsic(_rotl64,_rotr64)
 #endif
 
-#  pragma warning(push)
-#  pragma warning(disable:4756;disable:4056)
+#pragma warning(push)
+#pragma warning(disable:4756;disable:4056)
 PERL_STATIC_INLINE
 double S_Infinity() {
     /* this is a real C literal which can get further constant folded
@@ -277,8 +277,8 @@ double S_Infinity() {
        folding INF is creating -INF */
     return (DBL_MAX+DBL_MAX);
 }
-#  pragma warning(pop)
-#  define NV_INF S_Infinity()
+#pragma warning(pop)
+#define NV_INF S_Infinity()
 
 /* selectany allows duplicate and unused data symbols to be removed by
    VC linker, if this were static, each translation unit will have its own,
@@ -290,10 +290,64 @@ double S_Infinity() {
    that DLL actually uses __PL_nan_u */
 extern const __declspec(selectany) union { unsigned __int64 __q; double __d; }
 __PL_nan_u = { 0x7FF8000000000000UI64 };
-#  define NV_NAN ((NV)__PL_nan_u.__d)
+#define NV_NAN ((NV)__PL_nan_u.__d)
+
+/* The CRT was rewritten in VS2015. */
+#if _MSC_VER >= 1900
+
+/* No longer declared in stdio.h */
+char *gets(char* buffer);
+
+#define tzname _tzname
+
+/* From corecrt_internal_stdio.h: */
+typedef struct
+{
+    union
+    {
+        FILE  _public_file;
+        char* _ptr;
+    };
+
+    char*            _base;
+    int              _cnt;
+    long             _flags;
+    long             _file;
+    int              _charbuf;
+    int              _bufsiz;
+    char*            _tmpfname;
+    CRITICAL_SECTION _lock;
+} __crt_stdio_stream_data;
+
+#define PERLIO_FILE_flag_RD 0x0001 /* _IOREAD   */
+#define PERLIO_FILE_flag_WR 0x0002 /* _IOWRITE  */
+#define PERLIO_FILE_flag_RW 0x0004 /* _IOUPDATE */
+#define PERLIO_FILE_ptr(f)  (((__crt_stdio_stream_data*)(f))->_ptr)
+#define PERLIO_FILE_base(f) (((__crt_stdio_stream_data*)(f))->_base)
+#define PERLIO_FILE_cnt(f)  (((__crt_stdio_stream_data*)(f))->_cnt)
+#define PERLIO_FILE_flag(f) ((int)(((__crt_stdio_stream_data*)(f))->_flags))
+#define PERLIO_FILE_file(f) ((int)(((__crt_stdio_stream_data*)(f))->_file))
+
+#endif
 
 #endif /* _MSC_VER */
 
+#if (!defined(_MSC_VER)) || (defined(_MSC_VER) && _MSC_VER < 1900)
+
+/* Note: PERLIO_FILE_ptr/base/cnt are not actually used for GCC or <VS2015
+ * since FILE_ptr/base/cnt do the same thing anyway but it doesn't hurt to
+ * define them all here for completeness. */
+#define PERLIO_FILE_flag_RD _IOREAD /* 0x001 */
+#define PERLIO_FILE_flag_WR _IOWRT  /* 0x002 */
+#define PERLIO_FILE_flag_RW _IORW   /* 0x080 */
+#define PERLIO_FILE_ptr(f)  ((f)->_ptr)
+#define PERLIO_FILE_base(f) ((f)->_base)
+#define PERLIO_FILE_cnt(f)  ((f)->_cnt)
+#define PERLIO_FILE_flag(f) ((f)->_flag)
+#define PERLIO_FILE_file(f) ((f)->_file)
+
+#endif
+
 #ifdef __MINGW32__		/* Minimal Gnu-Win32 */
 
 typedef long		uid_t;
@@ -545,21 +599,31 @@ void win32_wait_for_children(pTHX);
 #  define PERL_WAIT_FOR_CHILDREN win32_wait_for_children(aTHX)
 #endif
 
+/* The following ioinfo struct manipulations had been removed but were
+ * reinstated to fix RT#120091/118059. However, they do not work with
+ * the rewritten CRT in VS2015 so they are removed once again for VS2015
+ * onwards, which will therefore suffer from the reintroduction of the
+ * close socket bug. */
+#if (!defined(_MSC_VER)) || (defined(_MSC_VER) && _MSC_VER < 1900)
+
 #ifdef PERL_CORE
+
 /* C doesn't like repeat struct definitions */
 #if defined(__MINGW32__) && (__MINGW32_MAJOR_VERSION>=3)
-#undef _CRTIMP
+#  undef _CRTIMP
 #endif
 #ifndef _CRTIMP
-#define _CRTIMP __declspec(dllimport)
+#  define _CRTIMP __declspec(dllimport)
 #endif
 
 
-/* VV 2005 has multiple ioinfo struct definitions through VC 2005's release life
- * VC 2008-2012 have been stable but do not assume future VCs will have the
+/* VS2005 has multiple ioinfo struct definitions through VS2005's release life
+ * VS2008-2012 have been stable but do not assume future VSs will have the
  * same ioinfo struct, just because past struct stability. If research is done
- * on the CRTs of future VS, the version check can be bumped up so the newer
- * VC uses a fixed ioinfo size.
+ * on the CRTs of future VSs, the version check can be bumped up so the newer
+ * VS uses a fixed ioinfo size. (Actually, only VS2013 (_MSC_VER 1800) hasn't
+ * been looked at; after that we cannot use the ioinfo struct anyway (see the
+ * #if above).)
  */
 #if ! (_MSC_VER < 1400 || (_MSC_VER >= 1500 && _MSC_VER <= 1700) \
   || defined(__MINGW32__))
@@ -582,7 +646,7 @@ typedef struct {
 #  if _MSC_VER >= 1400 && _MSC_VER < 1500
 #    error "This ioinfo struct is incomplete for Visual C 2005"
 #  endif
-/* VC 2005 CRT has at least 3 different definitions of this struct based on the
+/* VS2005 CRT has at least 3 different definitions of this struct based on the
  * CRT DLL's build number. */
 #  if _MSC_VER >= 1500
 #    ifndef _SAFECRT_IMPL
@@ -636,9 +700,12 @@ EXTERN_C _CRTIMP ioinfo* __pioinfo[];
 #endif
 
 /* since we are not doing a dup2(), this works fine */
-#  define _set_osfhnd(fh, osfh) (void)(_osfhnd(fh) = (intptr_t)osfh)
+#define _set_osfhnd(fh, osfh) (void)(_osfhnd(fh) = (intptr_t)osfh)
+
 #endif /* PERL_CORE */
 
+#endif /* !defined(_MSC_VER) || _MSC_VER<1900 */
+
 /* IO.xs and POSIX.xs define PERLIO_NOT_STDIO to 1 */
 #if defined(PERL_EXT_IO) || defined(PERL_EXT_POSIX)
 #undef  PERLIO_NOT_STDIO
diff --git a/win32/win32sck.c b/win32/win32sck.c
index 8eba4cd186..d9d7f3692b 100644
--- a/win32/win32sck.c
+++ b/win32/win32sck.c
@@ -694,10 +694,15 @@ int my_close(int fd)
 	int err;
 	err = closesocket(osf);
 	if (err == 0) {
+#ifdef _set_osfhnd
 	    assert(_osfhnd(fd) == osf); /* catch a bad ioinfo struct def */
 	    /* don't close freed handle */
 	    _set_osfhnd(fd, INVALID_HANDLE_VALUE);
 	    return close(fd);
+#else
+	    (void)close(fd);    /* handle already closed, ignore error */
+	    return 0;
+#endif
 	}
 	else if (err == SOCKET_ERROR) {
 	    int wsaerr = WSAGetLastError();
@@ -726,10 +731,15 @@ my_fclose (FILE *pf)
 	win32_fflush(pf);
 	err = closesocket(osf);
 	if (err == 0) {
+#ifdef _set_osfhnd
 	    assert(_osfhnd(win32_fileno(pf)) == osf); /* catch a bad ioinfo struct def */
 	    /* don't close freed handle */
 	    _set_osfhnd(win32_fileno(pf), INVALID_HANDLE_VALUE);
 	    return fclose(pf);
+#else
+	    (void)fclose(pf);   /* handle already closed, ignore error */
+	    return 0;
+#endif
 	}
 	else if (err == SOCKET_ERROR) {
 	    int wsaerr = WSAGetLastError();