annotate zlib/win32/DLL_FAQ.txt @ 51:ae3a4bfb450b

add some files of version 4.4.3 that have been forgotten.
author kent <kent@cr.ie.u-ryukyu.ac.jp>
date Sun, 07 Feb 2010 18:27:48 +0900
parents
children 04ced10e8804
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51
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1
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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2 Frequently Asked Questions about ZLIB1.DLL
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3
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4
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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5 This document describes the design, the rationale, and the usage
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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6 of the official DLL build of zlib, named ZLIB1.DLL. If you have
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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7 general questions about zlib, you should see the file "FAQ" found
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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8 in the zlib distribution, or at the following location:
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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9 http://www.gzip.org/zlib/zlib_faq.html
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10
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11
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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12 1. What is ZLIB1.DLL, and how can I get it?
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13
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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14 - ZLIB1.DLL is the official build of zlib as a DLL.
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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15 (Please remark the character '1' in the name.)
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16
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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17 Pointers to a precompiled ZLIB1.DLL can be found in the zlib
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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18 web site at:
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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19 http://www.zlib.org/
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20
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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21 Applications that link to ZLIB1.DLL can rely on the following
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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22 specification:
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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23
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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24 * The exported symbols are exclusively defined in the source
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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25 files "zlib.h" and "zlib.def", found in an official zlib
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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26 source distribution.
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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27 * The symbols are exported by name, not by ordinal.
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28 * The exported names are undecorated.
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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29 * The calling convention of functions is "C" (CDECL).
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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30 * The ZLIB1.DLL binary is linked to MSVCRT.DLL.
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31
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32 The archive in which ZLIB1.DLL is bundled contains compiled
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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33 test programs that must run with a valid build of ZLIB1.DLL.
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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34 It is recommended to download the prebuilt DLL from the zlib
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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35 web site, instead of building it yourself, to avoid potential
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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36 incompatibilities that could be introduced by your compiler
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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37 and build settings. If you do build the DLL yourself, please
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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38 make sure that it complies with all the above requirements,
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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39 and it runs with the precompiled test programs, bundled with
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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40 the original ZLIB1.DLL distribution.
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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41
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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42 If, for any reason, you need to build an incompatible DLL,
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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43 please use a different file name.
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44
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45
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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46 2. Why did you change the name of the DLL to ZLIB1.DLL?
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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47 What happened to the old ZLIB.DLL?
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48
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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49 - The old ZLIB.DLL, built from zlib-1.1.4 or earlier, required
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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50 compilation settings that were incompatible to those used by
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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51 a static build. The DLL settings were supposed to be enabled
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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52 by defining the macro ZLIB_DLL, before including "zlib.h".
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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53 Incorrect handling of this macro was silently accepted at
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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54 build time, resulting in two major problems:
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55
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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56 * ZLIB_DLL was missing from the old makefile. When building
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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57 the DLL, not all people added it to the build options. In
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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58 consequence, incompatible incarnations of ZLIB.DLL started
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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59 to circulate around the net.
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60
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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61 * When switching from using the static library to using the
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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62 DLL, applications had to define the ZLIB_DLL macro and
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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63 to recompile all the sources that contained calls to zlib
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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64 functions. Failure to do so resulted in creating binaries
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65 that were unable to run with the official ZLIB.DLL build.
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66
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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67 The only possible solution that we could foresee was to make
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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68 a binary-incompatible change in the DLL interface, in order to
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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69 remove the dependency on the ZLIB_DLL macro, and to release
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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70 the new DLL under a different name.
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71
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72 We chose the name ZLIB1.DLL, where '1' indicates the major
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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73 zlib version number. We hope that we will not have to break
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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74 the binary compatibility again, at least not as long as the
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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75 zlib-1.x series will last.
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76
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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77 There is still a ZLIB_DLL macro, that can trigger a more
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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78 efficient build and use of the DLL, but compatibility no
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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79 longer dependents on it.
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80
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81
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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82 3. Can I build ZLIB.DLL from the new zlib sources, and replace
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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83 an old ZLIB.DLL, that was built from zlib-1.1.4 or earlier?
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84
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85 - In principle, you can do it by assigning calling convention
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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86 keywords to the macros ZEXPORT and ZEXPORTVA. In practice,
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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87 it depends on what you mean by "an old ZLIB.DLL", because the
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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88 old DLL exists in several mutually-incompatible versions.
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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89 You have to find out first what kind of calling convention is
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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90 being used in your particular ZLIB.DLL build, and to use the
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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91 same one in the new build. If you don't know what this is all
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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92 about, you might be better off if you would just leave the old
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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93 DLL intact.
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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94
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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95
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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96 4. Can I compile my application using the new zlib interface, and
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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97 link it to an old ZLIB.DLL, that was built from zlib-1.1.4 or
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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98 earlier?
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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99
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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100 - The official answer is "no"; the real answer depends again on
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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101 what kind of ZLIB.DLL you have. Even if you are lucky, this
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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102 course of action is unreliable.
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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103
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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104 If you rebuild your application and you intend to use a newer
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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105 version of zlib (post- 1.1.4), it is strongly recommended to
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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106 link it to the new ZLIB1.DLL.
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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107
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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108
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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109 5. Why are the zlib symbols exported by name, and not by ordinal?
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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110
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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111 - Although exporting symbols by ordinal is a little faster, it
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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112 is risky. Any single glitch in the maintenance or use of the
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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113 DEF file that contains the ordinals can result in incompatible
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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114 builds and frustrating crashes. Simply put, the benefits of
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kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
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115 exporting symbols by ordinal do not justify the risks.
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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116
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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117 Technically, it should be possible to maintain ordinals in
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118 the DEF file, and still export the symbols by name. Ordinals
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119 exist in every DLL, and even if the dynamic linking performed
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120 at the DLL startup is searching for names, ordinals serve as
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parents:
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121 hints, for a faster name lookup. However, if the DEF file
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122 contains ordinals, the Microsoft linker automatically builds
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123 an implib that will cause the executables linked to it to use
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124 those ordinals, and not the names. It is interesting to
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parents:
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125 notice that the GNU linker for Win32 does not suffer from this
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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126 problem.
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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127
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128 It is possible to avoid the DEF file if the exported symbols
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129 are accompanied by a "__declspec(dllexport)" attribute in the
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130 source files. You can do this in zlib by predefining the
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kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
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131 ZLIB_DLL macro.
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132
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133
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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134 6. I see that the ZLIB1.DLL functions use the "C" (CDECL) calling
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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135 convention. Why not use the STDCALL convention?
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136 STDCALL is the standard convention in Win32, and I need it in
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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137 my Visual Basic project!
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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138
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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139 (For readability, we use CDECL to refer to the convention
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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140 triggered by the "__cdecl" keyword, STDCALL to refer to
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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141 the convention triggered by "__stdcall", and FASTCALL to
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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142 refer to the convention triggered by "__fastcall".)
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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143
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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144 - Most of the native Windows API functions (without varargs) use
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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145 indeed the WINAPI convention (which translates to STDCALL in
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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146 Win32), but the standard C functions use CDECL. If a user
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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147 application is intrinsically tied to the Windows API (e.g.
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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148 it calls native Windows API functions such as CreateFile()),
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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149 sometimes it makes sense to decorate its own functions with
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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150 WINAPI. But if ANSI C or POSIX portability is a goal (e.g.
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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151 it calls standard C functions such as fopen()), it is not a
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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152 sound decision to request the inclusion of <windows.h>, or to
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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153 use non-ANSI constructs, for the sole purpose to make the user
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154 functions STDCALL-able.
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155
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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156 The functionality offered by zlib is not in the category of
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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157 "Windows functionality", but is more like "C functionality".
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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158
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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159 Technically, STDCALL is not bad; in fact, it is slightly
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160 faster than CDECL, and it works with variable-argument
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161 functions, just like CDECL. It is unfortunate that, in spite
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162 of using STDCALL in the Windows API, it is not the default
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kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
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163 convention used by the C compilers that run under Windows.
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kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
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164 The roots of the problem reside deep inside the unsafety of
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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165 the K&R-style function prototypes, where the argument types
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kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
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166 are not specified; but that is another story for another day.
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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167
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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168 The remaining fact is that CDECL is the default convention.
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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169 Even if an explicit convention is hard-coded into the function
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170 prototypes inside C headers, problems may appear. The
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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171 necessity to expose the convention in users' callbacks is one
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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172 of these problems.
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173
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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174 The calling convention issues are also important when using
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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175 zlib in other programming languages. Some of them, like Ada
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176 (GNAT) and Fortran (GNU G77), have C bindings implemented
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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177 initially on Unix, and relying on the C calling convention.
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178 On the other hand, the pre- .NET versions of Microsoft Visual
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179 Basic require STDCALL, while Borland Delphi prefers, although
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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180 it does not require, FASTCALL.
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181
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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182 In fairness to all possible uses of zlib outside the C
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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183 programming language, we choose the default "C" convention.
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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184 Anyone interested in different bindings or conventions is
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185 encouraged to maintain specialized projects. The "contrib/"
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186 directory from the zlib distribution already holds a couple
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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187 of foreign bindings, such as Ada, C++, and Delphi.
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188
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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189
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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190 7. I need a DLL for my Visual Basic project. What can I do?
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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191
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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192 - Define the ZLIB_WINAPI macro before including "zlib.h", when
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kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
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193 building both the DLL and the user application (except that
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kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
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194 you don't need to define anything when using the DLL in Visual
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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195 Basic). The ZLIB_WINAPI macro will switch on the WINAPI
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parents:
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196 (STDCALL) convention. The name of this DLL must be different
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kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
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197 than the official ZLIB1.DLL.
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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198
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kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
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199 Gilles Vollant has contributed a build named ZLIBWAPI.DLL,
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kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
200 with the ZLIB_WINAPI macro turned on, and with the minizip
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kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
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201 functionality built in. For more information, please read
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kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
202 the notes inside "contrib/vstudio/readme.txt", found in the
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kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
203 zlib distribution.
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kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
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204
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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205
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kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
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206 8. I need to use zlib in my Microsoft .NET project. What can I
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kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
207 do?
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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diff changeset
208
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kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
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209 - Henrik Ravn has contributed a .NET wrapper around zlib. Look
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kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
210 into contrib/dotzlib/, inside the zlib distribution.
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parents:
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211
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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212
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kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
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213 9. If my application uses ZLIB1.DLL, should I link it to
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kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
214 MSVCRT.DLL? Why?
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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215
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kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
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216 - It is not required, but it is recommended to link your
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kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
217 application to MSVCRT.DLL, if it uses ZLIB1.DLL.
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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218
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kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
219 The executables (.EXE, .DLL, etc.) that are involved in the
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
220 same process and are using the C run-time library (i.e. they
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kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
221 are calling standard C functions), must link to the same
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kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
222 library. There are several libraries in the Win32 system:
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kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
223 CRTDLL.DLL, MSVCRT.DLL, the static C libraries, etc.
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kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
224 Since ZLIB1.DLL is linked to MSVCRT.DLL, the executables that
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kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
225 depend on it should also be linked to MSVCRT.DLL.
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kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
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226
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kent <kent@cr.ie.u-ryukyu.ac.jp>
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227
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kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
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228 10. Why are you saying that ZLIB1.DLL and my application should
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kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
229 be linked to the same C run-time (CRT) library? I linked my
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kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
230 application and my DLLs to different C libraries (e.g. my
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kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
231 application to a static library, and my DLLs to MSVCRT.DLL),
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kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
232 and everything works fine.
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kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
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233
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kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
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234 - If a user library invokes only pure Win32 API (accessible via
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kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
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235 <windows.h> and the related headers), its DLL build will work
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kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
236 in any context. But if this library invokes standard C API,
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
237 things get more complicated.
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
238
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
239 There is a single Win32 library in a Win32 system. Every
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
240 function in this library resides in a single DLL module, that
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
241 is safe to call from anywhere. On the other hand, there are
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
242 multiple versions of the C library, and each of them has its
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
243 own separate internal state. Standalone executables and user
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
244 DLLs that call standard C functions must link to a C run-time
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
245 (CRT) library, be it static or shared (DLL). Intermixing
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
246 occurs when an executable (not necessarily standalone) and a
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
247 DLL are linked to different CRTs, and both are running in the
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
248 same process.
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
249
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
250 Intermixing multiple CRTs is possible, as long as their
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
251 internal states are kept intact. The Microsoft Knowledge Base
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
252 articles KB94248 "HOWTO: Use the C Run-Time" and KB140584
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
253 "HOWTO: Link with the Correct C Run-Time (CRT) Library"
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
254 mention the potential problems raised by intermixing.
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
255
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
256 If intermixing works for you, it's because your application
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
257 and DLLs are avoiding the corruption of each of the CRTs'
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
258 internal states, maybe by careful design, or maybe by fortune.
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
259
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
260 Also note that linking ZLIB1.DLL to non-Microsoft CRTs, such
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
261 as those provided by Borland, raises similar problems.
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
262
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
263
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
264 11. Why are you linking ZLIB1.DLL to MSVCRT.DLL?
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
265
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
266 - MSVCRT.DLL exists on every Windows 95 with a new service pack
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
267 installed, or with Microsoft Internet Explorer 4 or later, and
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
268 on all other Windows 4.x or later (Windows 98, Windows NT 4,
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
269 or later). It is freely distributable; if not present in the
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
270 system, it can be downloaded from Microsoft or from other
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
271 software provider for free.
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
272
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
273 The fact that MSVCRT.DLL does not exist on a virgin Windows 95
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
274 is not so problematic. Windows 95 is scarcely found nowadays,
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
275 Microsoft ended its support a long time ago, and many recent
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
276 applications from various vendors, including Microsoft, do not
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
277 even run on it. Furthermore, no serious user should run
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
278 Windows 95 without a proper update installed.
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
279
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
280
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
281 12. Why are you not linking ZLIB1.DLL to
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
282 <<my favorite C run-time library>> ?
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
283
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
284 - We considered and abandoned the following alternatives:
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
285
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
286 * Linking ZLIB1.DLL to a static C library (LIBC.LIB, or
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
287 LIBCMT.LIB) is not a good option. People are using the DLL
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
288 mainly to save disk space. If you are linking your program
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
289 to a static C library, you may as well consider linking zlib
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
290 in statically, too.
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
291
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
292 * Linking ZLIB1.DLL to CRTDLL.DLL looks appealing, because
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
293 CRTDLL.DLL is present on every Win32 installation.
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
294 Unfortunately, it has a series of problems: it does not
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
295 work properly with Microsoft's C++ libraries, it does not
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
296 provide support for 64-bit file offsets, (and so on...),
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
297 and Microsoft discontinued its support a long time ago.
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
298
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
299 * Linking ZLIB1.DLL to MSVCR70.DLL or MSVCR71.DLL, supplied
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
300 with the Microsoft .NET platform, and Visual C++ 7.0/7.1,
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
301 raises problems related to the status of ZLIB1.DLL as a
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
302 system component. According to the Microsoft Knowledge Base
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
303 article KB326922 "INFO: Redistribution of the Shared C
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
304 Runtime Component in Visual C++ .NET", MSVCR70.DLL and
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
305 MSVCR71.DLL are not supposed to function as system DLLs,
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
306 because they may clash with MSVCRT.DLL. Instead, the
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
307 application's installer is supposed to put these DLLs
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
308 (if needed) in the application's private directory.
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
309 If ZLIB1.DLL depends on a non-system runtime, it cannot
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
310 function as a redistributable system component.
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
311
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
312 * Linking ZLIB1.DLL to non-Microsoft runtimes, such as
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
313 Borland's, or Cygwin's, raises problems related to the
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
314 reliable presence of these runtimes on Win32 systems.
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
315 It's easier to let the DLL build of zlib up to the people
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
316 who distribute these runtimes, and who may proceed as
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
317 explained in the answer to Question 14.
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
318
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
319
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
320 13. If ZLIB1.DLL cannot be linked to MSVCR70.DLL or MSVCR71.DLL,
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
321 how can I build/use ZLIB1.DLL in Microsoft Visual C++ 7.0
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
322 (Visual Studio .NET) or newer?
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
323
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
324 - Due to the problems explained in the Microsoft Knowledge Base
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
325 article KB326922 (see the previous answer), the C runtime that
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
326 comes with the VC7 environment is no longer considered a
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
327 system component. That is, it should not be assumed that this
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
328 runtime exists, or may be installed in a system directory.
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
329 Since ZLIB1.DLL is supposed to be a system component, it may
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
330 not depend on a non-system component.
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
331
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
332 In order to link ZLIB1.DLL and your application to MSVCRT.DLL
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
333 in VC7, you need the library of Visual C++ 6.0 or older. If
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
334 you don't have this library at hand, it's probably best not to
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
335 use ZLIB1.DLL.
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
336
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
337 We are hoping that, in the future, Microsoft will provide a
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
338 way to build applications linked to a proper system runtime,
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
339 from the Visual C++ environment. Until then, you have a
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
340 couple of alternatives, such as linking zlib in statically.
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
341 If your application requires dynamic linking, you may proceed
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
342 as explained in the answer to Question 14.
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
343
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
344
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
345 14. I need to link my own DLL build to a CRT different than
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
346 MSVCRT.DLL. What can I do?
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
347
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
348 - Feel free to rebuild the DLL from the zlib sources, and link
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
349 it the way you want. You should, however, clearly state that
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
350 your build is unofficial. You should give it a different file
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
351 name, and/or install it in a private directory that can be
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
352 accessed by your application only, and is not visible to the
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
353 others (e.g. it's not in the SYSTEM or the SYSTEM32 directory,
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
354 and it's not in the PATH). Otherwise, your build may clash
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
355 with applications that link to the official build.
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
356
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
357 For example, in Cygwin, zlib is linked to the Cygwin runtime
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
358 CYGWIN1.DLL, and it is distributed under the name CYGZ.DLL.
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
359
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
360
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
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361 15. May I include additional pieces of code that I find useful,
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
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362 link them in ZLIB1.DLL, and export them?
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
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363
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
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364 - No. A legitimate build of ZLIB1.DLL must not include code
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
365 that does not originate from the official zlib source code.
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
366 But you can make your own private DLL build, under a different
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
367 file name, as suggested in the previous answer.
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
368
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
369 For example, zlib is a part of the VCL library, distributed
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
370 with Borland Delphi and C++ Builder. The DLL build of VCL
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
371 is a redistributable file, named VCLxx.DLL.
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
372
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
373
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
374 16. May I remove some functionality out of ZLIB1.DLL, by enabling
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
375 macros like NO_GZCOMPRESS or NO_GZIP at compile time?
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
376
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
377 - No. A legitimate build of ZLIB1.DLL must provide the complete
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
378 zlib functionality, as implemented in the official zlib source
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
379 code. But you can make your own private DLL build, under a
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
380 different file name, as suggested in the previous answer.
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
381
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
382
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
383 17. I made my own ZLIB1.DLL build. Can I test it for compliance?
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
384
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
385 - We prefer that you download the official DLL from the zlib
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
386 web site. If you need something peculiar from this DLL, you
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
387 can send your suggestion to the zlib mailing list.
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
388
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
389 However, in case you do rebuild the DLL yourself, you can run
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
390 it with the test programs found in the DLL distribution.
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
391 Running these test programs is not a guarantee of compliance,
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
392 but a failure can imply a detected problem.
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
393
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
394 **
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
395
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
396 This document is written and maintained by
ae3a4bfb450b add some files of version 4.4.3 that have been forgotten.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
397 Cosmin Truta <cosmint@cs.ubbcluj.ro>