1 This directory contains project files for compiling Protocol Buffers using 2 MSVC. This is not the recommended way to do Protocol Buffer development -- 3 we prefer to develop under a Unix-like environment -- but it may be more 4 accessible to those who primarily work with MSVC. 5 6 Compiling and Installing 7 ======================== 8 9 1) Open protobuf.sln in Microsoft Visual Studio. 10 2) Choose "Debug" or "Release" configuration as desired.* 11 3) From the Build menu, choose "Build Solution". Wait for compiling to finish. 12 4) From a command shell, run tests.exe and lite-test.exe and check that all 13 tests pass. 14 5) Run extract_includes.bat to copy all the public headers into a separate 15 "include" directory (under the top-level package directory). 16 6) Copy the contents of the include directory to wherever you want to put 17 headers. 18 7) Copy protoc.exe wherever you put build tools (probably somewhere in your 19 PATH). 20 8) Copy libprotobuf.lib, libprotobuf-lite.lib, and libprotoc.lib wherever you 21 put libraries. 22 23 * To avoid conflicts between the MSVC debug and release runtime libraries, when 24 compiling a debug build of your application, you may need to link against a 25 debug build of libprotobuf.lib. Similarly, release builds should link against 26 release libs. 27 28 DLLs vs. static linking 29 ======================= 30 31 Static linking is now the default for the Protocol Buffer libraries. Due to 32 issues with Win32's use of a separate heap for each DLL, as well as binary 33 compatibility issues between different versions of MSVC's STL library, it is 34 recommended that you use static linkage only. However, it is possible to 35 build libprotobuf and libprotoc as DLLs if you really want. To do this, 36 do the following: 37 38 1) Open protobuf.sln in MSVC. 39 2) For each of the projects libprotobuf, libprotobuf-lite, and libprotoc, do 40 the following: 41 2a) Right-click the project and choose "properties". 42 2b) From the side bar, choose "General", under "Configuration Properties". 43 2c) Change the "Configuration Type" to "Dynamic Library (.dll)". 44 2d) From the side bar, choose "Preprocessor", under "C/C++". 45 2e) Add PROTOBUF_USE_DLLS to the list of preprocessor defines. 46 3) When compiling your project, make sure to #define PROTOBUF_USE_DLLS. 47 48 When distributing your software to end users, we strongly recommend that you 49 do NOT install libprotobuf.dll or libprotoc.dll to any shared location. 50 Instead, keep these libraries next to your binaries, in your application's 51 own install directory. C++ makes it very difficult to maintain binary 52 compatibility between releases, so it is likely that future versions of these 53 libraries will *not* be usable as drop-in replacements. 54 55 If your project is itself a DLL intended for use by third-party software, we 56 recommend that you do NOT expose protocol buffer objects in your library's 57 public interface, and that you statically link protocol buffers into your 58 library. 59 60 ZLib support 61 ============ 62 63 If you want to include GzipInputStream and GzipOutputStream 64 (google/protobuf/io/gzip_stream.h) in libprotoc, you will need to do a few 65 additional steps: 66 67 1) Obtain a copy of the zlib library. The pre-compiled DLL at zlib.net works. 68 2) Make sure zlib's two headers are in your include path and that the .lib file 69 is in your library path. You could place all three files directly into the 70 vsproject directory to compile libprotobuf, but they need to be visible to 71 your own project as well, so you should probably just put them into the 72 VC shared icnlude and library directories. 73 3) Right-click on the "tests" project and choose "properties". Navigate the 74 sidebar to "Configuration Properties" -> "Linker" -> "Input". 75 4) Under "Additional Dependencies", add the name of the zlib .lib file (e.g. 76 zdll.lib). Make sure to update both the Debug and Release configurations. 77 5) If you are compiling libprotobuf and libprotoc as DLLs (see previous 78 section), repeat steps 2 and 3 for the libprotobuf and libprotoc projects. 79 If you are compiling them as static libraries, then you will need to link 80 against the zlib library directly from your own app. 81 6) Edit config.h (in the vsprojects directory) and un-comment the line that 82 #defines HAVE_ZLIB. (Or, alternatively, define this macro via the project 83 settings.) 84 85 Notes on Compiler Warnings 86 ========================== 87 88 The following warnings have been disabled while building the protobuf libraries 89 and compiler. You may have to disable some of them in your own project as 90 well, or live with them. 91 92 C4018 - 'expression' : signed/unsigned mismatch 93 C4146 - unary minus operator applied to unsigned type, result still unsigned 94 C4244 - Conversion from 'type1' to 'type2', possible loss of data. 95 C4251 - 'identifier' : class 'type' needs to have dll-interface to be used by 96 clients of class 'type2' 97 C4267 - Conversion from 'size_t' to 'type', possible loss of data. 98 C4305 - 'identifier' : truncation from 'type1' to 'type2' 99 C4355 - 'this' : used in base member initializer list 100 C4800 - 'type' : forcing value to bool 'true' or 'false' (performance warning) 101 C4996 - 'function': was declared deprecated 102 103 C4251 is of particular note, if you are compiling the Protocol Buffer library 104 as a DLL (see previous section). The protocol buffer library uses templates in 105 its public interfaces. MSVC does not provide any reasonable way to export 106 template classes from a DLL. However, in practice, it appears that exporting 107 templates is not necessary anyway. Since the complete definition of any 108 template is available in the header files, anyone importing the DLL will just 109 end up compiling instances of the templates into their own binary. The 110 Protocol Buffer implementation does not rely on static template members being 111 unique, so there should be no problem with this, but MSVC prints warning 112 nevertheless. So, we disable it. Unfortunately, this warning will also be 113 produced when compiling code which merely uses protocol buffers, meaning you 114 may have to disable it in your code too. 115
