LDFLAGS+=$USER_LDFLAGS $_LD_FLAGS

_START_GROUP=
_END_GROUP=
BEFORE_PEERS=
AFTER_PEERS=
START_WHOLE_ARCHIVE_VALUE=
END_WHOLE_ARCHIVE_VALUE=
LD_STRIP_FLAG=
_SONAME_OPTION=
_LD_SRCS_GLOBALS=--start-wa ${rootrel;ext=.a:SRCS_GLOBAL} --end-wa ${rootrel;ext=.o:SRCS_GLOBAL} ${rootrel;ext=.supp:SRCS_GLOBAL}
when ($OS_LINUX == "yes" || $OS_ANDROID == "yes" || $OS_CYGWIN == "yes" || $OS_NONE == "yes") {
    _START_GROUP=-Wl,--start-group
    _END_GROUP=-Wl,--end-group
    START_WHOLE_ARCHIVE_VALUE=-Wl,--whole-archive
    END_WHOLE_ARCHIVE_VALUE=-Wl,--no-whole-archive
    LD_STRIP_FLAG=-s
    _SONAME_OPTION=-soname
    _LD_SRCS_GLOBALS=-Wl,--whole-archive --ya-start-command-file ${rootrel;ext=.a:SRCS_GLOBAL} --ya-end-command-file -Wl,--no-whole-archive ${rootrel;ext=.o:SRCS_GLOBAL} ${rootrel;ext=.supp:SRCS_GLOBAL}
}

when ($_LD_WHOLE_ARCHIVE == "yes") {
}

when ($OS_DARWIN == "yes" || $OS_IOS == "yes") {
    _SONAME_OPTION=-install_name
}

_LD_LINKER_OUTPUT=
_LD_LINKER_OUTPUT_FLAG=--linker-output ${output;pre=$MODULE_PREFIX;suf=$MODULE_SUFFIX$MODULE_VERSION.linker.txt:REALPRJNAME}

# Enable section-level DCE (dead code elimination):
# remove whole unused code and data sections
# (needs `-ffunction-sections` and `-fdata-sections` to be useful)
#
# NOTE: CGO linker doesn't seem to support DCE, but shares common LDFLAGS
_LD_DCE_FLAG_GC_SECTIONS=
_LD_DCE_FLAG_PRINT_SECTIONS=
when ($OS_DARWIN == "yes" || $OS_IOS == "yes" || $OS_IOSSIM == "yes") {
    _LD_DCE_FLAG_GC_SECTIONS=-Wl,-dead_strip
}
elsewhen ($OS_LINUX == "yes" || $OS_ANDROID == "yes" || $OS_NONE == "yes") {
    _LD_DCE_FLAG_GC_SECTIONS=-Wl,--gc-sections
    when ($LINKER_DCE_PRINT_SECTIONS == "yes") {
        _LD_DCE_FLAG_PRINT_SECTIONS=-Wl,--print-gc-sections
        _LD_LINKER_OUTPUT=$_LD_LINKER_OUTPUT_FLAG
    }
}
LD_DCE_FLAG =
LD_DCE_FLAG+=$_LD_DCE_FLAG_GC_SECTIONS
LD_DCE_FLAG+=$_LD_DCE_FLAG_PRINT_SECTIONS
DCE_FLAG=

_LD_ICF_FLAG=
_LD_ICF_FLAG_PRINT_SECTIONS=
when ($_DEFAULT_LINKER_ID == "lld") {
    # Enable ICF (identical code folding pass) in safe mode
    # https://research.google/pubs/pub36912/
    _LD_ICF_FLAG=-Wl,--icf=safe
    when ($LINKER_ICF_PRINT_SECTIONS == "yes") {
        _LD_ICF_FLAG_PRINT_SECTIONS=-Wl,--print-icf-sections
        _LD_LINKER_OUTPUT=$_LD_LINKER_OUTPUT_FLAG
    }
}
LD_ICF_FLAG =
LD_ICF_FLAG+=$_LD_ICF_FLAG
LD_ICF_FLAG+=$_LD_ICF_FLAG_PRINT_SECTIONS
ICF_FLAG=

_LD_NO_PIE_FLAG=
when ($_LINKER_ID == "lld" && $PIE != "yes" && ($PIC != "yes" || $PIC_NO_PIE == "yes")) {
    when ($OS_LINUX == "yes")  {
        _LD_NO_PIE_FLAG=-Wl,-no-pie
    }
}

STRIP_FLAG=

C_LIBRARY_PATH=
C_SYSTEM_LIBRARIES_INTERCEPT=
when ($USEMPROF == "yes" || $USE_MPROF == "yes") {
    C_SYSTEM_LIBRARIES_INTERCEPT+=-ldmalloc
}

_LD_THREAD_LIBRARY=
when ($OS_LINUX == "yes" || $OS_DARWIN == "yes") {
    _LD_THREAD_LIBRARY=-lpthread
}

_LD_USE_STDLIB=
when ($_BUILD_COVERAGE == "yes" || $GCOV_COVERAGE == "yes" || $CLANG_COVERAGE == "yes" || $_BUILD_SANITIZED == "yes") {
    _LD_USE_STDLIB=
}
elsewhen ($OS_ANDROID == "yes") {
    when ($_ANDROID_NDK_VERSION_LESS_THEN_23 == "yes") {
        # Preserve old behaviour: specify runtime libs manually
        _LD_USE_STDLIB=-nodefaultlibs
    }
    otherwise {
        # Use toolchain defaults to link with libunwind/clang_rt.builtins
        _LD_USE_STDLIB=-nostdlib++
    }
}
elsewhen ($OS_LINUX == "yes" || $OS_DARWIN == "yes" || $OS_IOS == "yes") {
    _LD_USE_STDLIB=-nodefaultlibs
}

_C_SYSTEM_LIBRARIES=$_LD_USE_STDLIB $_LD_THREAD_LIBRARY $_LD_SYS_LIB -lc
when ($MUSL == "yes") {
    _C_SYSTEM_LIBRARIES=-nostdlib
}
when ($OS_EMSCRIPTEN == "yes") {
    _C_SYSTEM_LIBRARIES=-nostdlib
}
C_SYSTEM_LIBRARIES=$_C_SYSTEM_LIBRARIES

LD_EXPORT_ALL_DYNAMIC_SYMBOLS_FLAG=
when ($OS_LINUX == "yes" || $OS_ANDROID == "yes") {
    LD_EXPORT_ALL_DYNAMIC_SYMBOLS_FLAG=-rdynamic
}

NO_EXPORT_DYNAMIC_SYMBOLS=
EXPORTS_VALUE=$LD_EXPORT_ALL_DYNAMIC_SYMBOLS_FLAG
when ($EXPORTS_FILE) {
    EXPORTS_VALUE=$LD_EXPORT_ALL_DYNAMIC_SYMBOLS_FLAG -Wl,--version-script=${input:EXPORTS_FILE}
}
when ($NO_EXPORT_DYNAMIC_SYMBOLS == "yes") {
    EXPORTS_VALUE=
}

LINKER_SCRIPT_VALUE=${ext=.ld;pre=-T:SRCS_GLOBAL}

_LINKER_TIME_TRACE_GRANULARITY=500
when ($TIME_TRACE_GRANULARITY && $TIME_TRACE_GRANULARITY != "") {
    _LINKER_TIME_TRACE_GRANULARITY=$TIME_TRACE_GRANULARITY
}

_LINKER_TIME_TRACE_FLAG=
when (($TIME_TRACE == "yes" || $LINKER_TIME_TRACE == "yes") && $_DEFAULT_LINKER_ID == "lld") {
    _LINKER_TIME_TRACE_FLAG=\
        -Wl,--time-trace=${rootrel;output;pre=$MODULE_PREFIX;suf=$MODULE_SUFFIX.time_trace.json:REALPRJNAME} \
        -Wl,--time-trace-granularity=$_LINKER_TIME_TRACE_GRANULARITY
}

_EXE_FLAGS=\
    $C_FLAGS_PLATFORM \
    $BEFORE_PEERS \
    $_START_GROUP \
    ${rootrel:PEERS} \
    $_END_GROUP \
    $AFTER_PEERS \
    $EXPORTS_VALUE \
    $LINKER_SCRIPT_VALUE \
    $LDFLAGS \
    $LDFLAGS_GLOBAL \
    $OBJADDE \
    $OBJADDE_LIB \
    $OBJADDE_LIB_GLOBAL \
    $C_LIBRARY_PATH \
    $C_SYSTEM_LIBRARIES_INTERCEPT \
    $C_SYSTEM_LIBRARIES \
    $STRIP_FLAG \
    $DCE_FLAG \
    $ICF_FLAG \
    $_LD_NO_PIE_FLAG \
    $_LINKER_TIME_TRACE_FLAG

_SONAME_FLAG=-Wl,$_SONAME_OPTION,$_SONAME
when ($OS_EMSCRIPTEN == "yes") {
    _SONAME_FLAG=
}
_SHARED_FLAG=-shared
when ($OS_EMSCRIPTEN == "yes") {
    _SHARED_FLAG=-Wl,-shared -Wl,--no-entry -Wl,--export-all -Wl,--import-memory -Wl,--import-undefined 
}
_EXEC_SHARED_FLAG=
when ($OS_LINUX == "yes") {
    _EXEC_SHARED_FLAG=-pie -fPIE -Wl,--unresolved-symbols=ignore-all -rdynamic
}

_LD_ENV_STYLE=${cwd:ARCADIA_BUILD_ROOT} $TOOLCHAIN_ENV ${hide;kv:"p LD"} ${hide;kv:"pc light-blue"} ${hide;kv:"show_out"}
_ROOT_FLAGS=--source-root $ARCADIA_ROOT --build-root $(BUILD_ROOT)

# Program
GENERATE_MF_CMD=\
    $YMAKE_PYTHON ${input:"build/scripts/generate_mf.py"} ${hide;input:"build/scripts/process_command_files.py"} \
    --build-root $ARCADIA_BUILD_ROOT \
    --module-name $REALPRJNAME \
    -o ${rootrel;output;pre=$MODULE_PREFIX;suf=$MODULE_SUFFIX.mf:REALPRJNAME} \
    -t $MODULE_TYPE \
    --ya-start-command-file \
    -Ya,lics $LICENSE_NAMES \
    -Ya,peers ${rootrel:PEERS} \
    -Ya,credits ${input:CREDITS_TEXTS_FILE} $CREDITS_FLAGS \
    --ya-end-command-file

_LINK_SCRIPT_IMPORTS=\
    ${hide;input:"build/scripts/fix_py2_protobuf.py"} \
    ${hide;input:"build/scripts/thinlto_cache.py"} \
    $_PROCESS_WHOLE_ARCHIVE_SCRIPT

LINK_SCRIPT_EXE_FLAGS=

REAL_LINK_EXE_CMDLINE =\
    $YMAKE_PYTHON ${input:"build/scripts/link_exe.py"} \
REAL_LINK_EXE_CMDLINE+=--clang-ver $CLANG_VER
REAL_LINK_EXE_CMDLINE+=$_LD_LINKER_OUTPUT
REAL_LINK_EXE_CMDLINE+=\
    $_ROOT_FLAGS \
    ${pre=--whole-archive-peers :WHOLE_ARCHIVE_PEERS} \
    ${pre=--whole-archive-libs :_WHOLE_ARCHIVE_LIBS_VALUE_GLOBAL} \
    $_LD_ARCH_FLAG \
    $LINK_SCRIPT_EXE_FLAGS \
    $_THINLTO_CACHE_FLAGS \
    $CXX_COMPILER_OLD \
    $_LD_SRCS_GLOBALS \
    $VCS_C_OBJ $_EXTRA_OBJS $AUTO_INPUT -o $TARGET \
    $_EXE_FLAGS \
    $_LINK_SCRIPT_IMPORTS \
    $_LD_ENV_STYLE

REAL_LINK_EXE_TIDY=\
    $YMAKE_PYTHON ${input:"build/scripts/clang_tidy_arch.py"} \
    --output-file $TARGET \
    $_ROOT_FLAGS \
    $AUTO_INPUT \
    ${ext=.tidyjson:SRCS_GLOBAL} \
    $_LD_ENV_STYLE

# Executable Shared Library

REAL_LINK_EXEC_DYN_LIB_CMDLINE =\
    $YMAKE_PYTHON ${input:"build/scripts/link_dyn_lib.py"} \
    ${hide;input:"build/scripts/link_exe.py"} \
    --target $TARGET
REAL_LINK_EXEC_DYN_LIB_CMDLINE+=$_LD_LINKER_OUTPUT
REAL_LINK_EXEC_DYN_LIB_CMDLINE+=\
    $_ROOT_FLAGS \
    ${pre=--whole-archive-peers :WHOLE_ARCHIVE_PEERS} \
    ${pre=--whole-archive-libs :_WHOLE_ARCHIVE_LIBS_VALUE_GLOBAL} \
    $_LD_ARCH_FLAG \
    $LINK_DYN_LIB_FLAGS \
    $_THINLTO_CACHE_FLAGS \
    $CXX_COMPILER_OLD \
    $_LD_SRCS_GLOBALS \
    $VCS_C_OBJ $_EXTRA_OBJS $AUTO_INPUT -o $TARGET \
    $_EXEC_SHARED_FLAG \
    $_SONAME_FLAG \
    $_EXE_FLAGS \
    $_LINK_SCRIPT_IMPORTS \
    $_LD_ENV_STYLE

REAL_LINK_EXEC_DYN_LIB=$REAL_LINK_EXEC_DYN_LIB_IMPL($_WHOLE_ARCHIVE_PEERS_VALUE)

# Shared Library

LINK_DYN_LIB_FLAGS=

REAL_LINK_DYN_LIB_CMDLINE =\
    $YMAKE_PYTHON ${input:"build/scripts/link_dyn_lib.py"} \
    ${hide;input:"build/scripts/link_exe.py"} \
    --target $TARGET
REAL_LINK_DYN_LIB_CMDLINE+=$_LD_LINKER_OUTPUT
REAL_LINK_DYN_LIB_CMDLINE+=\
    ${pre=--whole-archive-peers :WHOLE_ARCHIVE_PEERS} \
    ${pre=--whole-archive-libs :_WHOLE_ARCHIVE_LIBS_VALUE_GLOBAL} \
    $_ROOT_FLAGS \
    $_LD_ARCH_FLAG \
    $LINK_DYN_LIB_FLAGS \
    $_THINLTO_CACHE_FLAGS \
    $CXX_COMPILER_OLD \
    $_LD_SRCS_GLOBALS \
    $VCS_C_OBJ $_EXTRA_OBJS $AUTO_INPUT -o $TARGET \
    $_SHARED_FLAG \
    $_SONAME_FLAG \
    $_EXE_FLAGS \
    $_LINK_SCRIPT_IMPORTS \
    $_LD_ENV_STYLE

REAL_LINK_DYN_LIB=$REAL_LINK_DYN_LIB_IMPL($_WHOLE_ARCHIVE_PEERS_VALUE)

_DWARF_COMMAND=
when (($OS_DARWIN == "yes" || $OS_IOS || $OS_IOSSIM) && $NO_DEBUGINFO != "yes" && $SPLIT_DWARF_VALUE != "no" && $NO_SPLIT_DWARF != "yes") {
    _DWARF_COMMAND=$DWARF_TOOL $TARGET -o ${output;pre=$MODULE_PREFIX$REALPRJNAME.dSYM/Contents/Resources/DWARF/$MODULE_PREFIX:REALPRJNAME} $_LD_ENV_STYLE
}
elsewhen ($OS_DARWIN == "yes" && $NO_DEBUGINFO != "yes") {
    _EXE_FLAGS+=$DEBUG_INFO_FLAGS
}
otherwise {
    _DWARF_COMMAND=
}
DWARF_COMMAND=$_DWARF_COMMAND

_REAL_LINK_EXE=$REAL_LINK_EXE_IMPL($_WHOLE_ARCHIVE_PEERS_VALUE)
_EXTRA_OBJS=
_GENERATE_EXTRA_OBJS=
_EXTRA_LINK_CMD=

_LINK_EXE=
_LINK_EXE+=$GENERATE_MF
_LINK_EXE+=&& $GENERATE_VCS_C_INFO_NODEP
_LINK_EXE+=&& $_GENERATE_EXTRA_OBJS
_LINK_EXE+=&& $COPY_PROFILE_RUNTIME
_LINK_EXE+=&& $REAL_LINK_EXE
_LINK_EXE+=&& $DWARF_COMMAND
_LINK_EXE+=&& $LINK_ADDITIONAL_SECTIONS_COMMAND
_LINK_EXE+=&& $PACK_IOS_CMD
_LINK_EXE+=&& $_EXTRA_LINK_CMD

_LINK_DYN_LIB=
_LINK_DYN_LIB+=$GENERATE_MF
_LINK_DYN_LIB+=&& $GENERATE_VCS_C_INFO_NODEP
_LINK_DYN_LIB+=&& $_GENERATE_EXTRA_OBJS
_LINK_DYN_LIB+=&& $COPY_PROFILE_RUNTIME
_LINK_DYN_LIB+=&& $REAL_LINK_DYN_LIB
_LINK_DYN_LIB+=&& $DWARF_COMMAND
_LINK_DYN_LIB+=&& $LINK_ADDITIONAL_SECTIONS_COMMAND
_LINK_DYN_LIB+=&& $_EXTRA_LINK_CMD

when ($TIDY == "yes") {
    _REAL_LINK_EXE=$REAL_LINK_EXE_TIDY
    _LINK_EXE=$REAL_LINK_EXE
    _LINK_DYN_LIB=$REAL_LINK_EXE
}
REAL_LINK_EXE=$_REAL_LINK_EXE
LINK_EXE=$_LINK_EXE
LINK_DYN_LIB=$_LINK_DYN_LIB

LINK_EXEC_DYN_LIB=\
    $GENERATE_MF && \
    $GENERATE_VCS_C_INFO_NODEP && \
    $_GENERATE_EXTRA_OBJS && \
    $REAL_LINK_EXEC_DYN_LIB && \
    $DWARF_COMMAND && \
    $LINK_ADDITIONAL_SECTIONS_COMMAND

SWIG_DLL_JAR_CMD=\
    $GENERATE_MF && \
    $GENERATE_VCS_C_INFO_NODEP && \
    $REAL_SWIG_DLL_JAR_CMD && \
    $DWARF_COMMAND

_LD_LINK_LIB_EXTRA_INPUT=
_LD_TAIL_LINK_LIB=$AUTO_INPUT $_LD_LINK_LIB_EXTRA_INPUT ${hide;kv:"p AR"} $TOOLCHAIN_ENV ${hide;kv:"pc light-red"} ${hide;kv:"show_out"}
_LD_ARCHIVER=$YMAKE_PYTHON ${input:"build/scripts/link_lib.py"} ${quo:AR_TOOL} $AR_TYPE $_LD_LLVM_AR_FORMAT $ARCADIA_BUILD_ROOT $_LD_AR_PLUGIN
_LD_LIB_GENERATE_MF=$GENERATE_MF &&
when ($TIDY == "yes") {
    _LD_ARCHIVER=$YMAKE_PYTHON ${input:"build/scripts/clang_tidy_arch.py"} --source-root $ARCADIA_ROOT --build-root $ARCADIA_BUILD_ROOT --output-file
    _LD_LIB_GENERATE_MF=
}
LINK_LIB=$_LD_LIB_GENERATE_MF $_LD_ARCHIVER $TARGET $_LD_TAIL_LINK_LIB
GLOBAL_LINK_LIB=$_LD_ARCHIVER $GLOBAL_TARGET $_LD_TAIL_LINK_LIB

# "Fat Object" : pre-linked global objects and static library with all dependencies
_LD_LINK_FAT_PREFIX=$GENERATE_MF && $GENERATE_VCS_C_INFO_NODEP && $YMAKE_PYTHON ${input:"build/scripts/link_fat_obj.py"} --build-root $ARCADIA_BUILD_ROOT $_PROCESS_WHOLE_ARCHIVE_SCRIPT
_LD_LINK_FAT_SRCS_GLOBALS_WA=$_LD_SRCS_GLOBALS
_LD_LINK_FAT_SRCS_GLOBALS_NO_WA=${rootrel;ext=.a:SRCS_GLOBAL} ${rootrel;ext=.o:SRCS_GLOBAL}

macro _FAT_OBJECT_ARGS_BASE(Flag, Lib) {
    .CMD=$Flag=$Lib
}

# FIXME: pre=lib here is weird legacy
_FAT_OBJECT_ARGS=--obj=${output;pre=lib;suf=.o:REALPRJNAME}
_LD_LINK_FAT_SRCS_GLOBALS=$_LD_LINK_FAT_SRCS_GLOBALS_WA

macro PACK_GLOBALS_IN_LIBRARY() {
     SET(_FAT_OBJECT_ARGS $_FAT_OBJECT_ARGS_BASE(--globals-lib, \${output;pre=$MODULE_PREFIX;suf=.globals.a:REALPRJNAME}))
}

when ($OS_ANDROID == "yes") {
    _FAT_OBJECT_ARGS=
    _LD_LINK_FAT_SRCS_GLOBALS=$_LD_LINK_FAT_SRCS_GLOBALS_NO_WA
}

_LD_LINK_FAT_SUFFIX1=$_LD_ARCH_FLAG \
    -Ya,input $AUTO_INPUT $VCS_C_OBJ \
    -Ya,global_srcs

_LD_LINK_FAT_SUFFIX2=-Ya,peers $PEERS \
    -Ya,linker $CXX_COMPILER_OLD \
    $LDFLAGS_GLOBAL $C_FLAGS_PLATFORM $LD_SDK_VERSION \
    -Ya,archiver $_LD_ARCHIVER \
    $TOOLCHAIN_ENV ${hide;kv:"p LD"} ${hide;kv:"pc light-blue"} ${hide;kv:"show_out"}

LINK_FAT_OBJECT=\
    $_LD_LINK_FAT_PREFIX \
    --lib=$TARGET $_FAT_OBJECT_ARGS \
    $_LD_LINK_FAT_SUFFIX1 \
    $_LD_LINK_FAT_SRCS_GLOBALS \
    $_LD_LINK_FAT_SUFFIX2

LINK_RECURSIVE_LIBRARY=\
    $_LD_LINK_FAT_PREFIX \
    --lib=$TARGET --with-own-obj --with-global-srcs \
    $_LD_LINK_FAT_SUFFIX1 \
    $_LD_LINK_FAT_SRCS_GLOBALS_NO_WA \
    $_LD_LINK_FAT_SUFFIX2

LIBRT=-lrt
LIBRESOLV=
when ($OS_LINUX || $OS_DARWIN || $OS_ANDROID) {
    LIBRESOLV=-lresolv
}
PROFFLAG=-pg

_THINLTO_CACHE_FLAGS=
macro THINLTO_CACHE(file) {
    DEFAULT(THINLTO_CACHE use)
    SET(_THINLTO_FILE $file)

    when ($CLANG && $USE_THINLTO == "yes") {
        select ($THINLTO_CACHE) {
            "gen" ? {
                 _THINLTO_CACHE_FLAGS=--thinlto-cache-write --thinlto-cache=${output;pre=out-:_THINLTO_FILE}
            }
            "use" ? {
                 _THINLTO_CACHE_FLAGS=--thinlto-cache=${input:_THINLTO_FILE}
            }
        }
    }
}