fix(sqlite-objstore): provide win32 dirent shim so MSVC builds compile

CMakeLists.txt

@@ -718,6 +718,11 @@ if(CORTEXT_EMBED_OBJSTORE)
       ${CMAKE_CURRENT_SOURCE_DIR}/third_party/sqlite-objstore/src/backend_sqlite.c
     )
   endif()
+  if(WIN32)
+    list(APPEND CORTEXT_OBJSTORE_SRCS
+      ${CMAKE_CURRENT_SOURCE_DIR}/third_party/sqlite-objstore/src/win_dirent.c
+    )
+  endif()
   if(CORTEXT_TARGET_AARCH64)
     list(APPEND CORTEXT_OBJSTORE_SRCS
       ${CMAKE_CURRENT_SOURCE_DIR}/third_party/sqlite-objstore/third_party/blake3/blake3_neon.c

third_party/sqlite-objstore/src/CMakeLists.txt

@@ -79,6 +79,10 @@ if(OBJSTORE_BACKEND_VFS)
     list(APPEND OBJSTORE_SOURCES backend_vfs.c)
 endif()
 
+if(WIN32)
+    list(APPEND OBJSTORE_SOURCES win_dirent.c)
+endif()
+
 function(_objstore_configure_library target)
     target_include_directories(${target}
         PUBLIC

third_party/sqlite-objstore/src/backend_file.c

@@ -13,7 +13,11 @@
 
 #include "backend_fs_common.h"
 
+#if defined(_WIN32)
+#include "win_dirent.h"
+#else
 #include <dirent.h>
+#endif
 #include <errno.h>
 #include <fcntl.h>
 #include <limits.h>

third_party/sqlite-objstore/src/backend_fs_common.c

@@ -1,6 +1,10 @@
 #include "backend_fs_common.h"
 
+#if defined(_WIN32)
+#include "win_dirent.h"
+#else
 #include <dirent.h>
+#endif
 #include <errno.h>
 #include <stdbool.h>
 #include <stdio.h>

third_party/sqlite-objstore/src/backend_portable.c

@@ -1,6 +1,10 @@
 #include "backend_portable.h"
 
+#if defined(_WIN32)
+#include "win_dirent.h"
+#else
 #include <dirent.h>
+#endif
 #include <errno.h>
 #include <limits.h>
 #include <stddef.h>

third_party/sqlite-objstore/src/win_dirent.c

@@ -0,0 +1,85 @@
+#include "win_dirent.h"
+
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define WIN32_LEAN_AND_MEAN 1
+#include <windows.h>
+
+DIR *
+opendir (const char *path)
+{
+  DIR *dir;
+  WIN32_FIND_DATAA find_data;
+  HANDLE handle;
+
+  if (path == NULL)
+    {
+      errno = ENOENT;
+      return NULL;
+    }
+
+  dir = (DIR *) malloc (sizeof (DIR));
+  if (dir == NULL)
+    {
+      errno = ENOMEM;
+      return NULL;
+    }
+
+  handle = FindFirstFileA (path, &find_data);
+  if (handle == INVALID_HANDLE_VALUE)
+    {
+      free (dir);
+      errno = ENOENT;
+      return NULL;
+    }
+
+  dir->handle = (void *) handle;
+  memcpy (dir->entry.d_name, find_data.cFileName,
+          sizeof (find_data.cFileName));
+  dir->entry_valid = 1;
+  return dir;
+}
+
+struct dirent *
+readdir (DIR *dir)
+{
+  WIN32_FIND_DATAA find_data;
+
+  if (dir == NULL)
+    {
+      errno = EBADF;
+      return NULL;
+    }
+
+  if (dir->entry_valid)
+    {
+      dir->entry_valid = 0;
+      return &dir->entry;
+    }
+
+  if (!FindNextFileA ((HANDLE) dir->handle, &find_data))
+    {
+      return NULL;
+    }
+
+  memcpy (dir->entry.d_name, find_data.cFileName,
+          sizeof (find_data.cFileName));
+  dir->entry_valid = 1;
+  return &dir->entry;
+}
+
+int
+closedir (DIR *dir)
+{
+  if (dir == NULL)
+    {
+      errno = EBADF;
+      return -1;
+    }
+
+  FindClose ((HANDLE) dir->handle);
+  free (dir);
+  return 0;
+}

third_party/sqlite-objstore/src/win_dirent.h

@@ -0,0 +1,36 @@
+#ifndef OBJSTORE_WIN_DIRENT_H
+#define OBJSTORE_WIN_DIRENT_H
+
+/*
+ * Minimal POSIX dirent subset for Windows (MSVC and clang-cl).
+ *
+ * sqlite-objstore only needs opendir(), readdir(), closedir(), and
+ * d_name; the system <dirent.h> does not exist on Windows. On other
+ * platforms the real <dirent.h> is used instead.
+ */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct dirent
+{
+  char d_name[260];
+};
+
+typedef struct
+{
+  void *handle;
+  int entry_valid;
+  struct dirent entry;
+} DIR;
+
+DIR *opendir (const char *path);
+struct dirent *readdir (DIR *dir);
+int closedir (DIR *dir);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* OBJSTORE_WIN_DIRENT_H */