1# SPDX-License-Identifier: Apache-2.0
2#
3# Copyright (c) 2022, Nordic Semiconductor ASA
4# Copyright (c) 2023, Intel Corporation
5
6# FindGnuLd module for locating LLVM lld linker.
7#
8# The module defines the following variables:
9#
10# 'LLVMLLD_LINKER'
11# Path to LLVM lld linker
12# Set to 'LLVMLLD_LINKER-NOTFOUND' if ld was not found.
13#
14# 'LlvmLld_FOUND', 'LLVMLLD_FOUND'
15# True if LLVM lld was found.
16#
17# 'LLVMLLD_VERSION_STRING'
18# The version of LLVM lld.
19
20include(FindPackageHandleStandardArgs)
21
22# See if the compiler has a preferred linker
23execute_process(COMMAND ${CMAKE_C_COMPILER} --print-prog-name=ld.lld
24                OUTPUT_VARIABLE LLVMLLD_LINKER
25                OUTPUT_STRIP_TRAILING_WHITESPACE)
26
27if(NOT EXISTS "${LLVMLLD_LINKER}")
28  # Need to clear it or else find_program() won't replace the value.
29  set(LLVMLLD_LINKER)
30
31  if(DEFINED TOOLCHAIN_HOME)
32    # Search for linker under TOOLCHAIN_HOME if it is defined
33    # to limit which linker to use, or else we would be using
34    # host tools.
35    set(LLD_SEARCH_PATH PATHS ${TOOLCHAIN_HOME} NO_DEFAULT_PATH)
36  endif()
37
38  # Note that, although there is lld, it cannot be used directly
39  # as it would complain about it not being a generic linker,
40  # and asks you to use ld.lld instead. So do not search for lld.
41  find_program(LLVMLLD_LINKER ld.lld ${LLD_SEARCH_PATH})
42endif()
43
44if(LLVMLLD_LINKER)
45  # Parse the 'ld.lld --version' output to find the installed version.
46  execute_process(
47    COMMAND
48    ${LLVMLLD_LINKER} --version
49    OUTPUT_VARIABLE llvmlld_version_output
50    ERROR_VARIABLE  llvmlld_error_output
51    RESULT_VARIABLE llvmlld_status
52    )
53
54  set(LLVMLLD_VERSION_STRING)
55  if(${llvmlld_status} EQUAL 0)
56    # Extract GNU ld version. Different distros have their
57    # own version scheme so we need to account for that.
58    # Examples:
59    # - "GNU ld (GNU Binutils for Ubuntu) 2.34"
60    # - "GNU ld (Zephyr SDK 0.15.2) 2.38"
61    # - "GNU ld (Gentoo 2.39 p5) 2.39.0"
62    string(REGEX MATCH
63           "LLD ([0-9]+[.][0-9]+[.]?[0-9]*).*"
64           out_var ${llvmlld_version_output})
65    set(LLVMLLD_VERSION_STRING ${CMAKE_MATCH_1})
66  endif()
67endif()
68
69find_package_handle_standard_args(LlvmLld
70                                  REQUIRED_VARS LLVMLLD_LINKER
71                                  VERSION_VAR LLVMLLD_VERSION_STRING
72)
73