site_scons/gem5_scons/defaults.py

# Copyright (c) 2013, 2015-2017 ARM Limited
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#
# The license below extends only to copyright in the software and shall
# not be construed as granting a license to any other intellectual
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# licensed hereunder.  You may use the software subject to the license
# terms below provided that you ensure that this notice is replicated
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# modified or unmodified, in source code or in binary form.
#
# Copyright (c) 2011 Advanced Micro Devices, Inc.
# Copyright (c) 2009 The Hewlett-Packard Development Company
# Copyright (c) 2004-2005 The Regents of The University of Michigan
# All rights reserved.
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# modification, are permitted provided that the following conditions are
# met: redistributions of source code must retain the above copyright
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# neither the name of the copyright holders nor the names of its
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import os

from gem5_python_paths import extra_python_paths


def EnvDefaults(env):
    # export TERM so that clang reports errors in color
    use_vars = set(
        [
            "AS",
            "AR",
            "CC",
            "CXX",
            "HOME",
            "LD_LIBRARY_PATH",
            "LIBRARY_PATH",
            "PATH",
            "PKG_CONFIG_PATH",
            "PROTOC",
            "PYTHONPATH",
            "RANLIB",
            "TERM",
            "PYTHON_CONFIG",
            "CCFLAGS_EXTRA",
            "GEM5PY_CCFLAGS_EXTRA",
            "GEM5PY_LINKFLAGS_EXTRA",
            "LINKFLAGS_EXTRA",
            "LANG",
        ]
    )

    use_prefixes = [
        "ASAN_",  # address sanitizer symbolizer path and settings
        "CCACHE_",  # ccache (caching compiler wrapper) configuration
        "CCC_",  # clang static analyzer configuration
        "DISTCC_",  # distcc (distributed compiler wrapper) config
        "INCLUDE_SERVER_",  # distcc pump server settings
        "M5",  # M5 configuration (e.g., path to kernels)
        "NIX_",  # wrapped binaries if using nix package manager
        "TMPDIR",  # default temporary directory
    ]

    for key, val in sorted(os.environ.items()):
        if key in use_vars or any(
            [key.startswith(prefix) for prefix in use_prefixes]
        ):
            env["ENV"][key] = val

    # These variables from the environment override/become SCons variables,
    # with a default if they weren't in the host environment.
    var_overrides = {
        "CC": env["CC"],
        "CXX": env["CXX"],
        "PROTOC": "protoc",
        "PYTHON_CONFIG": ["python3-config", "python-config"],
        "CCFLAGS_EXTRA": "",
        "GEM5PY_CCFLAGS_EXTRA": "",
        "GEM5PY_LINKFLAGS_EXTRA": "",
        "LINKFLAGS_EXTRA": "",
    }
    for key, default in var_overrides.items():
        env[key] = env["ENV"].get(key, default)

    # Tell scons to avoid implicit command dependencies to avoid issues
    # with the param wrappes being compiled twice (see
    # https://github.com/SCons/scons/issues/2811
    env["IMPLICIT_COMMAND_DEPENDENCIES"] = 0
    env.Decider("MD5-timestamp")

    # add useful python code PYTHONPATH so it can be used by subprocesses
    # as well
    env.AppendENVPath("PYTHONPATH", extra_python_paths)

    # Default duplicate option is to use hard links, but this messes up
    # when you use emacs to edit a file in the target dir, as emacs moves
    # file to file~ then copies to file, breaking the link.  Symbolic
    # (soft) links work better.
    env.SetOption("duplicate", "soft-copy")