CMake/Modules/CMakeParseImplicitLinkInfo.cmake
Brad King 56d4619984 Remove non-language implicit link dependencies
Some compilers use implicit link options of the form

  -lcrt*.o
  -lgcc*
  -lSystem      (on Mac)
  -lSystemStubs (on Mac)

that provide system-wide symbols not specific to any language.
These need not be listed explicitly for mixed-language linking.

We teach CMake to remove the above items from the implicit library list
of each language.  This change makes it possible to mix GNU compiler
versions in some cases.
2009-11-05 12:17:08 -05:00

122 lines
4.5 KiB
CMake

#=============================================================================
# Copyright 2009 Kitware, Inc.
#
# Distributed under the OSI-approved BSD License (the "License");
# see accompanying file Copyright.txt for details.
#
# This software is distributed WITHOUT ANY WARRANTY; without even the
# implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
# See the License for more information.
#=============================================================================
# (To distributed this file outside of CMake, substitute the full
# License text for the above reference.)
# Function parse implicit linker options.
# This is used internally by CMake and should not be included by user
# code.
function(CMAKE_PARSE_IMPLICIT_LINK_INFO text lib_var dir_var log_var)
set(implicit_libs_tmp "")
set(implicit_dirs_tmp)
set(log "")
# Parse implicit linker arguments.
set(linker "CMAKE_LINKER-NOTFOUND")
if(CMAKE_LINKER)
get_filename_component(linker ${CMAKE_LINKER} NAME)
endif()
# Construct a regex to match linker lines. It must match both the
# whole line and just the command (argv[0]).
set(linker_regex "^( *|.*[/\\])(${linker}|ld|collect2)[^/\\]*( |$)")
set(log "${log} link line regex: [${linker_regex}]\n")
string(REGEX REPLACE "\r?\n" ";" output_lines "${text}")
foreach(line IN LISTS output_lines)
set(cmd)
if("${line}" MATCHES "${linker_regex}")
if(UNIX)
separate_arguments(args UNIX_COMMAND "${line}")
else()
separate_arguments(args WINDOWS_COMMAND "${line}")
endif()
list(GET args 0 cmd)
endif()
if("${cmd}" MATCHES "${linker_regex}")
set(log "${log} link line: [${line}]\n")
string(REGEX REPLACE ";-([LYz]);" ";-\\1" args "${args}")
foreach(arg IN LISTS args)
if("${arg}" MATCHES "^-L(.:)?[/\\]")
# Unix search path.
string(REGEX REPLACE "^-L" "" dir "${arg}")
list(APPEND implicit_dirs_tmp ${dir})
set(log "${log} arg [${arg}] ==> dir [${dir}]\n")
elseif("${arg}" MATCHES "^-l[^:]")
# Unix library.
string(REGEX REPLACE "^-l" "" lib "${arg}")
list(APPEND implicit_libs_tmp ${lib})
set(log "${log} arg [${arg}] ==> lib [${lib}]\n")
elseif("${arg}" MATCHES "^(.:)?[/\\].*\\.a$")
# Unix library full path.
list(APPEND implicit_libs_tmp ${arg})
set(log "${log} arg [${arg}] ==> lib [${arg}]\n")
elseif("${arg}" MATCHES "^-Y(P,)?")
# Sun search path.
string(REGEX REPLACE "^-Y(P,)?" "" dirs "${arg}")
string(REPLACE ":" ";" dirs "${dirs}")
list(APPEND implicit_dirs_tmp ${dirs})
set(log "${log} arg [${arg}] ==> dirs [${dirs}]\n")
elseif("${arg}" MATCHES "^-l:")
# HP named library.
list(APPEND implicit_libs_tmp ${arg})
set(log "${log} arg [${arg}] ==> lib [${arg}]\n")
elseif("${arg}" MATCHES "^-z(all|default|weak)extract")
# Link editor option.
list(APPEND implicit_libs_tmp ${arg})
set(log "${log} arg [${arg}] ==> opt [${arg}]\n")
else()
set(log "${log} arg [${arg}] ==> ignore\n")
endif()
endforeach()
break()
elseif("${line}" MATCHES "LPATH(=| is:? )")
set(log "${log} LPATH line: [${line}]\n")
# HP search path.
string(REGEX REPLACE ".*LPATH(=| is:? *)" "" paths "${line}")
string(REPLACE ":" ";" paths "${paths}")
list(APPEND implicit_dirs_tmp ${paths})
set(log "${log} dirs [${paths}]\n")
else()
set(log "${log} ignore line: [${line}]\n")
endif()
endforeach()
# Cleanup list of libraries and flags.
# We remove items that are not language-specific.
set(implicit_libs "")
foreach(lib IN LISTS implicit_libs_tmp)
if("${lib}" MATCHES "^(crt.*\\.o|gcc.*|System.*)$")
set(log "${log} remove lib [${lib}]\n")
else()
list(APPEND implicit_libs "${lib}")
endif()
endforeach()
# Cleanup list of directories.
set(implicit_dirs "")
foreach(d IN LISTS implicit_dirs_tmp)
get_filename_component(dir "${d}" ABSOLUTE)
list(APPEND implicit_dirs "${dir}")
set(log "${log} collapse dir [${d}] ==> [${dir}]\n")
endforeach()
list(REMOVE_DUPLICATES implicit_dirs)
# Log results.
set(log "${log} implicit libs: [${implicit_libs}]\n")
set(log "${log} implicit dirs: [${implicit_dirs}]\n")
# Return results.
set(${lib_var} "${implicit_libs}" PARENT_SCOPE)
set(${dir_var} "${implicit_dirs}" PARENT_SCOPE)
set(${log_var} "${log}" PARENT_SCOPE)
endfunction()