Add MSVC and MSYS2 UCRT64 Build #6

gailium119 · 2024-02-14T06:47:17Z

No description provided.

pbatard · 2025-04-21T10:55:24Z

include/wimlib/compiler.h

 /* Get the minimum of two variables, without multiple evaluation.  */
 #undef min
+#ifdef _MSC_VER
+#define min(a, b)  ((a < b) ? a : b)


NB: MSVC's stdlib.h provides min() and max() so you can avoid this redef by simply including stdlib.h

pbatard · 2025-04-21T10:55:31Z

include/wimlib/compiler.h

+#  define swap(a, b, type) { type _a = (a); (a) = (b); (b) = _a; }
+#endif
 #ifndef swap
-#  define swap(a, b) ({ typeof(a) _a = (a); (a) = (b); (b) = _a; })


Latest Visual Studio supports typeof() when compiling with the /std:clatest flag, so you can avoid the whole dance around typeof() and keep the swap(a, b) as it is. This also applies to other uses of typeof() in the codebase.

For this specific macro, we can also use the more universally compatible:

# define swap(a, b) do { typeof(a) _a = (a); (a) = (b); (b) = _a; } while(0)

pbatard · 2025-04-21T10:55:37Z

include/wimlib/compiler.h


 /* STATIC_ASSERT() - verify the truth of an expression at compilation time.  */
+#ifdef _MSC_VER
+#define STATIC_ASSERT(expr) assert(expr)


Current Visual Studio (even without /std:clatest) defines an __STDC_VERSION__ that is higher 201112L and it has support for _Static_assert(), so this redef can be avoided (especially as you really do want static asserts to work when introducing support for a new compiler).

pbatard · 2025-04-21T10:55:44Z

include/wimlib/compiler.h

+	return 32;
+}
+#define __builtin_constant_p(x)	 0
+#define __builtin_prefetch(x, y) 0


Prefetch is available for MSVC on x86 (but not on ARM) so you should be able to use:

#if defined(_M_IX86) || defined(_M_X64) #define prefetchr _m_prefetch #define prefetchw _m_prefetchw #else #define prefetchr(x) #define prefetchw(x) #endif

pbatard · 2025-04-21T10:55:50Z

include/wimlib/decompress_common.h

 * DECODE_TABLE_ALIGNMENT-byte aligned boundary as well.
 */
+#ifdef _MSC_VER
+#pragma pack(push, 16)


Maybe better to define PRAGMA_BEGIN_PACKED(x) / PRAGMA_END_PACKED macros, as this could reduce all this 3 line boilerplate to a single less conspicuous line.

pbatard · 2025-04-21T10:55:58Z

include/wimlib/list.h

 * @member:	the name of the list_struct within the struct.
 */
-#define list_next_entry(pos, member) \
+#ifdef _MSC_VER


No need for any of these redefs, except one, if using /std:clatest with VS2022.

pbatard · 2025-04-21T10:56:05Z

include/wimlib/list.h


 #define hlist_entry(ptr, type, member) container_of(ptr,type,member)
-
+#ifdef _MSC_VER


This is the only redef needed if using /std:clatest with VS2022 (since sadly MSVC does not support ({ bunch; of; instructions; }) constructs).

pbatard · 2025-04-21T10:56:37Z

src/dentry.c

 {
 	size_t path_len = tstrlen(path);
-	tchar buf[path_len + 1];
+	smart_array(tchar, buf, path_len + 1);


I'd just drop the smart_array() call altogether and add an explicit alloca(), so that anybody who reads the code realises that this actually issues a memory allocation call, regardless of the compiler, as I think these eventually should be replaced by formal MALLOC()/FREE() calls to actually use the wimlib memory allocation overrides -- but of course that is unrelated to the MSVC porting effort.

pbatard · 2025-04-21T10:56:45Z

src/extract.c


 	while (p != end) {
-		size_t n = min(end - p, SPARSE_UNIT);
+		size_t n = min(POINTER_FIX()end - POINTER_FIX()p, SPARSE_UNIT);


I went for a slightly different macro for the same issue, where I used:

#ifdef _MSC_VER #define _PTR(x) (void*)((uintptr_t)x) #else #define _PTR(x) x #endif

For pointer arithmetic, and then could use a less conspicuous:

size_t n = min(_PTR(end - p), SPARSE_UNIT);

pbatard · 2025-04-21T11:03:46Z

include/wimlib/file_io.h

 struct filedes {
 	int fd;
 	unsigned int is_pipe : 1;
-	off_t offset;


You can avoid this whole patch by adding the following in the MSVC preprocessor definitions:

_OFF_T_DEFINED;_off_t=__int64;off_t=_off_t;_FILE_OFFSET_BITS=64;

If you do just that, then off_t will be 64-bit, even when compiling for x86.

pbatard · 2025-04-21T11:34:59Z

src/header.c

 read_wim_header(WIMStruct *wim, struct wim_header *hdr)
 {
+
+#ifdef _MSC_VER


Alternatively, you could have the following in compiler.h:

#ifdef _MSC_VER #define PRAGMA_ALIGN(x, a) __declspec(align(a)) x #else #define PRAGMA_ALIGN(x, a) x __attribute__((aligned(a))) #endif

And then just simplify to:

PRAGMA_ALIGN(struct wim_header_disk disk_hdr, 8);

pbatard · 2025-04-21T16:20:59Z

src/util.c

 #  include <sys/syscall.h>
 #endif
+#ifdef _MSC_VER
+#include "msvc/unistd.h"


This can probably be avoided by adding include/msvc/ to the include directory search path for MSVC, as #include <unistd.h> will work then.

pbatard · 2025-04-21T17:06:28Z

include/msvc/unistd.h

+#define lseek _lseek
+/* read, write, and close are NOT being #defined here, because while there are file handle specific versions for Windows, they probably don't work for sockets. You need to look at your app and consider whether to call e.g. closesocket(). */
+
+#define ssize_t int


ssize_t should be 64-bit on 64-bit platforms.

You can use the following from MinGW:

#ifndef _SSIZE_T_DEFINED #define _SSIZE_T_DEFINED #undef ssize_t #ifdef _WIN64 typedef __int64 ssize_t; #else typedef int ssize_t; #endif #endif

Maybe typedef ptrdiff_t ssize_t; instead?

pbatard · 2025-04-30T17:15:34Z

include/wimlib/compiler.h

+		return 63 - leading_zero;
+	return 64;
+}
+uint32_t __inline __builtin_ctzll(uint32_t value)


ctzll works on 64-bit so it should be uint64_t value here, not uint32_t value.

* This includes all the changes applied to wimlib for MSVC compilation support. * The vast majority of these changes were original, but a very small set came was lifted from ebiggers/wimlib#6 (which we discovered after we went through this whole exercise on our own...)

Administrator and others added 3 commits February 14, 2024 14:42

Add MSVC and MSYS2 UCRT64 Build

a1ae78e

Fix error on wim files larger than 2GiB

ed821bf

Merge branch 'ebiggers:master' into master

99562d1

pbatard reviewed Apr 21, 2025

View reviewed changes

pbatard reviewed Apr 30, 2025

View reviewed changes


		#define hlist_entry(ptr, type, member) container_of(ptr,type,member)

		#ifdef _MSC_VER

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gailium119 commented Feb 14, 2024

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pbatard Apr 21, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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pbatard Apr 21, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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pbatard Apr 30, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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pbatard Apr 21, 2025 •

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