win32u: Use platform-independent layout for DC_ATTR.

dlls/gdi32/dc.c

@@ -2154,6 +2154,7 @@ BOOL WINAPI CancelDC(HDC hdc)
 INT WINAPI StartDocW( HDC hdc, const DOCINFOW *doc )
 {
     DC_ATTR *dc_attr;
+    ABORTPROC proc;
 
     TRACE("DocName %s, Output %s, Datatype %s, fwType %#lx\n",
           debugstr_w(doc->lpszDocName), debugstr_w(doc->lpszOutput),
@@ -2161,7 +2162,8 @@ INT WINAPI StartDocW( HDC hdc, const DOCINFOW *doc )
 
     if (!(dc_attr = get_dc_attr( hdc ))) return SP_ERROR;
 
-    if (dc_attr->abort_proc && !dc_attr->abort_proc( hdc, 0 )) return 0;
+    proc = (ABORTPROC)(UINT_PTR)dc_attr->abort_proc;
+    if (proc && !proc( hdc, 0 )) return 0;
     return NtGdiStartDoc( hdc, doc, NULL, 0 );
 }
 
@@ -2247,7 +2249,7 @@ INT WINAPI SetAbortProc( HDC hdc, ABORTPROC abrtprc )
     DC_ATTR *dc_attr;
 
     if (!(dc_attr = get_dc_attr( hdc ))) return FALSE;
-    dc_attr->abort_proc = abrtprc;
+    dc_attr->abort_proc = (UINT_PTR)abrtprc;
     return TRUE;
 }
 

dlls/win32u/dc.c

@@ -230,7 +230,8 @@ DC *alloc_dc_ptr( DWORD magic )
         free( dc );
         return NULL;
     }
-    dc->attr->hdc = dc->nulldrv.hdc = dc->hSelf;
+    dc->nulldrv.hdc = dc->hSelf;
+    dc->attr->hdc = HandleToUlong( dc->hSelf );
     set_gdi_client_ptr( dc->hSelf, dc->attr );
 
     if (!font_driver.pCreateDC( &dc->physDev, NULL, NULL, NULL ))

include/ntgdi.h

@@ -165,7 +165,7 @@ enum
 
 typedef struct DC_ATTR
 {
-    HDC       hdc;                 /* handle to self */
+    UINT      hdc;                 /* handle to self */
     LONG      disabled;            /* disabled flag, controlled by DCHF_(DISABLE|ENABLE)DC */
     int       save_level;
     COLORREF  background_color;
@@ -196,8 +196,8 @@ typedef struct DC_ATTR
     SIZE      virtual_size;
     UINT      font_code_page;
     RECTL     emf_bounds;
-    void     *emf;
-    ABORTPROC abort_proc;          /* AbortProc for printing */
+    UINT64    emf;                 /* client EMF record pointer */
+    UINT64    abort_proc;          /* AbortProc for printing */
 } DC_ATTR;
 
 struct font_enum_entry