bridges/source/cpp_uno/msvc_win32_x86-64/call.asm

   1 ; -*- Mode: text; tab-width: 8; indent-tabs-mode: nil comment-column: 44; comment-start: ";; " comment-start-skip: ";; *" -*-
   2
   3 ;; Version: MPL 1.1 / GPLv3+ / LGPLv3+
   4 ;;
   5 ;; The contents of this file are subject to the Mozilla Public License Version
   6 ;; 1.1 (the "License"); you may not use this file except in compliance with
   7 ;; the License or as specified alternatively below. You may obtain a copy of
   8 ;; the License at http://www.mozilla.org/MPL/
   9 ;;
  10 ;; Software distributed under the License is distributed on an "AS IS" basis,
  11 ;; WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  12 ;; for the specific language governing rights and limitations under the
  13 ;; License.
  14 ;;
  15 ;; The Initial Developer of the Original Code is
  16 ;;       Novell, Inc.
  17 ;; Portions created by the Initial Developer are Copyright (C) 2011
  18 ;; Novell, Inc. All Rights Reserved.
  19 ;;
  20 ;; Major Contributor(s):
  21 ;;       Tor Lillqvist <tml@iki.fi>
  22 ;; Portions created by Tor Lillqvist are Copyright (C) 2011 Tor Lillqvist. All Rights Reserved.
  23 ;;
  24 ;; For minor contributions see the git repository.
  25 ;;
  26 ;; Alternatively, the contents of this file may be used under the terms of
  27 ;; either the GNU General Public License Version 3 or later (the "GPLv3+"), or
  28 ;; the GNU Lesser General Public License Version 3 or later (the "LGPLv3+"),
  29 ;; in which case the provisions of the GPLv3+ or the LGPLv3+ are applicable
  30 ;; instead of those above.
  31
  32 ;; This is the function jumped to from the trampoline generated by
  33 ;; codeSnippet() in cpp2uno.cxx. Here we call cpp_vtable_call() which
  34 ;; then calls the actual UNO function.
  35
  36 ;; The code snippet generated is called from "normal" C++ code which
  37 ;; has no idea that it is calling dynamically generated code.
  38
  39 ;; The generated short code snippet is not covered by any function
  40 ;; table and unwind info, but that doesn't matter, as the instructions
  41 ;; in it are not really going to cause any exception. Once it jumps
  42 ;; here it is covered by a function table, and the calls further down
  43 ;; through cpp_vtable_call() can be unwound cleanly.
  44
  45 ;; This is in a separate file for x86-64 as MSVC doesn't have in-line
  46 ;; assembly for x64.
  47
  48 ;; Random web links and other documentation about low-level
  49 ;; implementation details for the C++/UNO bridge on x64 Windows kept
  50 ;; here:
  51
  52 ;; Caolan's "Lazy Hackers Guide To Porting" is useful:
  53 ;; http://wiki.services.openoffice.org/wiki/Lazy_Hackers_Guide_To_Porting
  54
  55 ;; As for details about the x64 Windows calling convention, register
  56 ;; usage, stack usage, exception handling etc, the official
  57 ;; documentation (?) on MSDN is a bit fragmented and split up into a
  58 ;; needlessly large number of short pages. But still:
  59 ;; http://msdn.microsoft.com/en-us/library/7kcdt6fy%28v=VS.90%29.aspx
  60
  61 ;; Also see Raymond Chen's blog post:
  62 ;; http://blogs.msdn.com/b/oldnewthing/archive/2004/01/14/58579.aspx
  63
  64 ;; This one is actually more readable: "Improving Automated Analysis
  65 ;; of Windows x64 Binaries": http://www.uninformed.org/?v=4&a=1
  66
  67 ;; This one has a mass of information about different architectures
  68 ;; and compilers, and contains some details about the x64 Windows
  69 ;; calling convention in particular that Microsoft doesn't mention
  70 ;; above:
  71 ;; http://www.agner.org/optimize/calling_conventions.pdf
  72
  73 ;; Random interesting discussion threads:
  74 ;; http://social.msdn.microsoft.com/Forums/en/vcgeneral/thread/300bd6d3-9381-4d2d-8129-e48b392c05d8
  75
  76 ;; Ken Johnson's blog http://www.nynaeve.net/ has much interesting
  77 ;; information, for instance:
  78 ;; http://www.nynaeve.net/?p=11
  79
  80 typelib_TypeClass_FLOAT equ 10
  81 typelib_TypeClass_DOUBLE equ 11
  82
  83 extern cpp_vtable_call: proc
  84
  85 .code
  86
  87 privateSnippetExecutor proc frame
  88
  89     ;; Make stack frame. Re-align RSP at 16 bytes. We need just one
  90     ;; qword of stack for our own purposes: Where cpp_vtable_call()
  91     ;; will store the return value of the UNO callee. But we of course
  92     ;; must also allocate space for the functions we call (i.e., just
  93     ;; cpp_vtable_call()) to spill their register parameters.
  94
  95     sub rsp, 40
  96     .allocstack (40)
  97     .endprolog
  98
  99     ;; Call cpp_vtable_call() with 2 parameters:
 100
 101     ;; 1 (rcx): nOffsetAndIndex (already put there in code generated by codeSnippet)
 102     ;; 2 (rdx): pointer to where to store return value, followed by our
 103     ;; return address (uninteresting to cpp_vtable_call()), followed
 104     ;; by our spilled register parameters, as stored above, followed
 105     ;; by the rest of our parameters, if any.
 106
 107     lea rdx, 32[rsp]
 108
 109     call cpp_vtable_call
 110
 111     ;; cpp_vtable_call() returns the typelib_TypeClass type of the
 112     ;; return value of the called UNO function
 113
 114     cmp rax, typelib_TypeClass_FLOAT
 115     je Lfloat
 116
 117     cmp rax, typelib_TypeClass_DOUBLE
 118     je Lfloat
 119
 120     mov rax, qword ptr 32[rsp]
 121     jmp Lepilogue
 122
 123 Lfloat:
 124     movsd xmm0, qword ptr 32[rsp]
 125
 126 Lepilogue:
 127     add rsp, 40
 128     ret
 129 privateSnippetExecutor endp
 130
 131 end
 132
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