Place #ifdef's around MSVC #pragma's

Rewrite some signed/unsigned unions to use casts.


Imported-from: https://svn.code.sf.net/p/dosbox/code-0/dosbox/trunk@956

src/dos/dos_execute.cpp

@@ -24,7 +24,9 @@
 #include "callback.h"
 #include "debug.h"
 
+#ifdef _MSC_VER
 #pragma pack(1)
+#endif
 struct EXE_Header {
 	Bit16u signature;					/* EXE Signature MZ or ZM */
 	Bit16u extrabytes;					/* Bytes on the last page */
@@ -41,7 +43,9 @@ struct EXE_Header {
 	Bit16u reloctable;
 	Bit16u overlay;
 } GCC_ATTRIBUTE(packed);
+#ifdef _MSC_VER
 #pragma pack()
+#endif
 
 #define MAGIC1 0x5a4d
 #define MAGIC2 0x4d5a

src/dos/dos_files.cpp

@@ -518,7 +518,9 @@ Bit8u FCB_Parsename(Bit16u seg,Bit16u offset,Bit8u parser ,char *string, Bit8u *
 	hasdrive=hasname=hasext=false;
 	Bitu index;bool finished;Bit8u fill;
 /* First get the old data from the fcb */
+#ifdef _MSC_VER
 #pragma pack (1)
+#endif
 	union {
 		struct {
 			char drive[2];
@@ -527,7 +529,9 @@ Bit8u FCB_Parsename(Bit16u seg,Bit16u offset,Bit8u parser ,char *string, Bit8u *
 		} part GCC_ATTRIBUTE (packed) ;
 		char full[DOS_FCBNAME];
 	} fcb_name;
+#ifdef _MSC_VER
 #pragma pack()
+#endif
 	/* Get the old information from the previous fcb */
 	fcb.GetName(fcb_name.full);fcb_name.part.drive[1]=0;fcb_name.part.name[8]=0;fcb_name.part.ext[3]=0;
 	/* Strip of the leading sepetaror */

src/dos/dos_mscdex.cpp

@@ -61,7 +61,9 @@ public:
 	void	SetStrategy			(Bit16u ofs)	{ sSave(sDeviceHeader,strategy,ofs);			};
 
 public:
+	#ifdef _MSC_VER
 	#pragma pack(1)
+	#endif
 	struct sDeviceHeader{
 		RealPt	nextDeviceHeader;
 		Bit16u	devAttributes;
@@ -72,7 +74,9 @@ public:
 		Bit8u	driveLetter;
 		Bit8u	numSubUnits;
 	} TDeviceHeader;
+	#ifdef _MSC_VER
 	#pragma pack()
+	#endif
 };
 
 class CMscdex

src/dos/dos_tables.cpp

@@ -20,13 +20,17 @@
 #include "mem.h"
 #include "dos_inc.h"
 
+#ifdef _MSC_VER
 #pragma pack(1)
+#endif
 struct DOS_TableCase {	
 	Bit16u size;
 	Bit8u chars[256];
 }
 GCC_ATTRIBUTE (packed);
+#ifdef _MSC_VER
 #pragma pack ()
+#endif
 
 RealPt DOS_TableUpCase;
 RealPt DOS_TableLowCase;