Hello Roger,
On Sat, 26 Dec 2020 09:28:16 +0000 Roger Leigh <rle...@codelibre.net> wrote: > On 22 Dec 2020, at 08:27, wwp <subscr...@free.fr> wrote: > > > > I'm attempting to build Xalan-C++ 1.12 following the build steps found at: > > https://apache.github.io/xalan-c/build.html > > > > Build environment: > > CentOS 7 (up-to-date), cmake3 version 3.17.3, gcc 8.2.0 > > Xerces-C++ 3.2.3 build from the sources, using autotools and these > > configure options: > > ./configure --disable-rpath --disable-network --without-icu > > --prefix=/mypath/xerces/3.2.3 > > > > 1. cmake won't detect the C compiler properly (but do we care?): > > > > $ mkdir build && cd build > > $ cmake3 -DCMAKE_INSTALL_PREFIX=$TOOLS/xalan-c-1.12 -Dtranscoder=default .. > > > > [snip] > > -- The C compiler identification is GNU 4.8.5 > > -- The CXX compiler identification is GNU 8.2.0 > > [snip] > > > > The system C compiler *is* gcc 4.8.5, but the one first found on the PATH > > is gcc 8.2.0. > > What wrong magics is performed there? Do we care anyway? > > > > Check your PATH, it should be picking up 8.2.0 if it’s first in the search > path. Otherwise set CMAKE_XXX_COMPILER to override the defaults. > > This isn’t Xerces/Xalan-specific, and I’ve used GCC on CentOS without trouble > for years using the devtoolset toolchains. CMake always detected the > compiler perfectly, but it will depend upon it being able to find it. Maybe > you don’t have a C++ compiler installed on the main system, so 8.2.0 was the > only possibility? I just need gcc 8.2.0 in my build env, the reasons why I need it are off-topic here. But see: $ type gcc gcc is /mypath/gcc/8.2.0/bin/gcc $ type g++ g++ is /mypath/gcc/8.2.0/bin/g++ cmake will display this: -- The C compiler identification is GNU 4.8.5 (<- that's the system one, not the one found first on PATH) -- The CXX compiler identification is GNU 8.2.0 (<- that's OK and expected) With -DCMAKE_C_COMPILER=/mypath/gcc/8.2.0/bin/gcc, it works like I want (I don't need CMAKE_CXX_COMPILER): -- The C compiler identification is GNU 8.2.0 -- The CXX compiler identification is GNU 8.2.0 But something seems wrong in the C compiler identification performed by cmake3. > > 2. cmake won't detect Xerces-C++ 3.2.3: > > > > [snip] > > CMake Error at > > /usr/share/cmake3/Modules/FindPackageHandleStandardArgs.cmake:164 (message): > > Failed to find XercesC (missing: XercesC_LIBRARY XercesC_INCLUDE_DIR > > XercesC_VERSION) (Required is at least version "3.1") > > [snip] > > > > Obviously it doesn't use PKG_CONFIG_PATH to find it, which is wrong if > > xerces-C++ has been built using autotools (this is the recommended method > > on GNU/Linux). > > pkg-config and the build method used for Xerces-C++ are irrelevant. Xalan is > using FindXercesC > (https://cmake.org/cmake/help/latest/module/FindXercesC.html > <https://cmake.org/cmake/help/latest/module/FindXercesC.html>) and will will > detect it if it can find it. > > Did you set CMAKE_PREFIX_PATH to include /mypath/xerces/3.2.3? If not, add > that to the cmake command-line and it should detect it without trouble. Using CMAKE_PREFIX_PATH did it! > > I solved it using: > > $ cmake3 -DCMAKE_INSTALL_PREFIX=$TOOLS/xalan-c-1.12 -Dtranscoder=default > > -DXercesC_VERSION=3.2.3 -DXercesC_LIBRARY="-L/mypath/xerces/3.2.3/lib" > > -DXercesC_INCLUDE_DIR=$TOOLS/xerces/3.2.3/include .. > > > > But I'm not sure this will work, probably missing a -lxerces-c in > > XercesC_LIBRARY. > > None of this should be necessary. Though if you do go this way (not > recommended) the _LIBRARY setting should be the full path to the library, > rather than the directory containing the library. OK. > > 3. ICU seems required or checked whereas I explicitly want the built-in > > transcoder (default). > > > > Does this mean that the ICU libraries are mandatory? The build doc page > > says "ICU C++ libraries and headers (optional)". Why does cmake check > > for ICU libraries if they are optional and the transcoder explicitely > > set NOT to use ICU? > > ICU is optional. Good! > But it will be used if available because it offers more functionality and > provides better behaviour than without. That's up to the one who build to decide, or it should be made mandatory. > > Note that if I remove the system ICU dev files, I'll get: > > > > -- The following ICU libraries were not found: > > -- uc (required) > > -- data (required) > > -- i18n (required) > > -- Failed to find all ICU components (missing: ICU_INCLUDE_DIR > > ICU_LIBRARY _ICU_REQUIRED_LIBS_FOUND) > > > > Anyway, the cmake configure step does not fail. > > That’s expected. OK. > Look at cmake/XalanTranscoderSelection.cmake. “icu" is first in the > list, followed by “default”. If ICU is autodetected, it will take > precedence. To be fair “default” is a misnomer; it should probably > be “internal” or something else which better describes it. > > Use “-Dtranscoder=default” to explicitly set what you want. I use that, this is well documented. > > 4. is there a way NOT to build the docs? > > > > I could not find such a way. I don't need them, doc build > > requirements are not clear or even specified anywhere I could find, > > and it fails here anyway (rule xalan-c-doc-check). > > > > [skipping a huge UNDOCUMENTED CODE section] > > [ 0%] Built target xalan-c-doc-check > > make: *** [all] Error 2 > > > This is the Doxygen API reference. Use "-DBUILD_DOXYGEN=OFF” to > disable. > > The doc check is a warning only; this wasn’t necessarily the direct > cause of the failure—I’d need to see more context here to see exactly > what caused the failure. Using "-DBUILD_DOXYGEN=OFF” did it, probably because my doxygen version is outdated (doxygen-1.8.5-4.el7.x86_64). Roger, thanks a bunch for your precise and detailed help, I really appreciate. Regards, -- wwp https://useplaintext.email/
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