[Boost-build] Why do iostream tests link against static libraries ?

From: Kuhl, Brian (brian.kuhl_at_[hidden])
Date: 2021-04-22 03:35:36

I'm trying to get iostreams working with shared libraries on VxWorks
The tests will compile with clang  if I comment out the forced dependency on static libraries

But I'd like to understand the reason for forcing a link of static libraries with a dynamic executable?

https://github.com/boostorg/iostreams/blob/4d2e763ba8b88f3350fbea29b54507a3f5adf0f0/test/Jamfile.v2#L25

rule test-iostreams ( sources * : requirements * : target-name ? ) {
    return [
            run
                $(sources)
                /boost/test//boost_unit_test_framework # /<link>static
                /boost/filesystem//boost_filesystem    # /<link>static
            : # command
            : # input files
            : # build requirements
                <toolset>msvc:<define>_CRT_SECURE_NO_DEPRECATE
                <toolset>msvc:<define>_SCL_SECURE_NO_DEPRECATE
                <toolset>cw-9.3,<os>darwin:<runtime-link>static
                <define>BOOST_IOSTREAMS_NO_LIB
                <link>shared:<define>BOOST_IOSTREAMS_DYN_LINK=1
                $(requirements)
            : $(target-name)
        ] ;
}

If I don't comments I get a link error.
VxWorks only supports -fpic vs -fPIC

clang-vxworks.compile.c++ ../bin.v2/libs/test/build/clang-vxworks-11.0.0.1/debug/cross-compile-vxworks/link-static/unit_test_parameters.o
    "wr-c++" -x c++ -Wno-c99-extensions -Wno-variadic-macros -O3 -finline-functions -Wno-inline -Wall -pedantic -g -Wno-inline -DBOOST_ALL_NO_LIB=1 -DBOOST_BEAST_ALLOW_DEPRECATED -DBOOST_BEAST_SEPARATE_COMPILATION -I".."  -c -o "../bin.v2/libs/test/build/clang-vxworks-11.0.0.1/debug/cross-compile-vxworks/link-static/unit_test_parameters.o" "../libs/test/src/unit_test_parameters.cpp"
clang-vxworks.archive ../bin.v2/libs/test/build/clang-vxworks-11.0.0.1/debug/cross-compile-vxworks/link-static/libboost_unit_test_framework.a
  "wr-ar"  rcu "../bin.v2/libs/test/build/clang-vxworks-11.0.0.1/debug/cross-compile-vxworks/link-static/libboost_unit_test_framework.a" "../bin.v2/libs/test/build/clang-vxworks-11.0.0.1/debug/cross-compile-vxworks/link-static/compiler_log_formatter.o" "../bin.v2/libs/test/build/clang-vxworks-11.0.0.1/debug/cross-compile-vxworks/link-static/debug.o" "../bin.v2/libs/test/build/clang-vxworks-11.0.0.1/debug/cross-compile-vxworks/link-static/decorator.o" "../bin.v2/libs/test/build/clang-vxworks-11.0.0.1/debug/cross-compile-vxworks/link-static/execution_monitor.o" "../bin.v2/libs/test/build/clang-vxworks-11.0.0.1/debug/cross-compile-vxworks/link-static/framework.o" "../bin.v2/libs/test/build/clang-vxworks-11.0.0.1/debug/cross-compile-vxworks/link-static/plain_report_formatter.o" "../bin.v2/libs/test/build/clang-vxworks-11.0.0.1/debug/cross-compile-vxworks/link-static/progress_monitor.o" "../bin.v2/libs/test/build/clang-vxworks-11.0.0.1/debug/cross-compile-vxworks/link-static/results_collector.o" "../bin.v2/libs/test/build/clang-vxworks-11.0.0.1/debug/cross-compile-vxworks/link-static/results_reporter.o" "../bin.v2/libs/test/build/clang-vxworks-11.0.0.1/debug/cross-compile-vxworks/link-static/test_framework_init_observer.o" "../bin.v2/libs/test/build/clang-vxworks-11.0.0.1/debug/cross-compile-vxworks/link-static/test_tools.o" "../bin.v2/libs/test/build/clang-vxworks-11.0.0.1/debug/cross-compile-vxworks/link-static/test_tree.o" "../bin.v2/libs/test/build/clang-vxworks-11.0.0.1/debug/cross-compile-vxworks/link-static/unit_test_log.o" "../bin.v2/libs/test/build/clang-vxworks-11.0.0.1/debug/cross-compile-vxworks/link-static/unit_test_main.o" "../bin.v2/libs/test/build/clang-vxworks-11.0.0.1/debug/cross-compile-vxworks/link-static/unit_test_monitor.o" "../bin.v2/libs/test/build/clang-vxworks-11.0.0.1/debug/cross-compile-vxworks/link-static/unit_test_parameters.o" "../bin.v2/libs/test/build/clang-vxworks-11.0.0.1/debug/cross-compile-vxworks/link-static/junit_log_formatter.o" "../bin.v2/libs/test/build/clang-vxworks-11.0.0.1/debug/cross-compile-vxworks/link-static/xml_log_formatter.o" "../bin.v2/libs/test/build/clang-vxworks-11.0.0.1/debug/cross-compile-vxworks/link-static/xml_report_formatter.o"
clang-vxworks.link ../bin.v2/libs/iostreams/test/array_test.test/clang-vxworks-11.0.0.1/debug/cross-compile-vxworks/array_test.vxe
    "wr-c++"  -o "../bin.v2/libs/iostreams/test/array_test.test/clang-vxworks-11.0.0.1/debug/cross-compile-vxworks/array_test.vxe"    "../bin.v2/libs/iostreams/test/array_test.test/clang-vxworks-11.0.0.1/debug/cross-compile-vxworks/array_test.o" "../bin.v2/libs/test/build/clang-vxworks-11.0.0.1/debug/cross-compile-vxworks/link-static/libboost_unit_test_framework.a" "../bin.v2/libs/filesystem/build/clang-vxworks-11.0.0.1/debug/cross-compile-vxworks/link-static/libboost_filesystem.a" -shared --start-group      --end-group  -fpic
/opt/git/vx7/compilers/llvm-11.0.0.1/LINUX64/bin/ldarm: ../bin.v2/libs/test/build/clang-vxworks-11.0.0.1/debug/cross-compile-vxworks/link-static/libboost_unit_test_framework.a(test_tools.o): relocation R_ARM_MOVW_ABS_NC against `a local symbol' can not be used when making a shared object; recompile with -fPIC
/opt/git/vx7/compilers/llvm-11.0.0.1/LINUX64/bin/ldarm: ../bin.v2/libs/test/build/clang-vxworks-11.0.0.1/debug/cross-compile-vxworks/link-static/libboost_unit_test_framework.a(test_tree.o): relocation R_ARM_MOVW_ABS_NC against `a local symbol' can not be used when making a shared object; recompile with -fPIC