# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
# vim: set filetype=python:
# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.


@depends(target, js_package)
def jemalloc_default(target, js_package):
    if js_package:
        return False
    return target.kernel in ("Darwin", "Linux", "WINNT")


option(
    "--enable-jemalloc",
    env="MOZ_MEMORY",
    default=jemalloc_default,
    help="{Replace|Do not replace} memory allocator with jemalloc",
)


set_config("MOZ_MEMORY", True, when="--enable-jemalloc")
set_define("MOZ_MEMORY", True, when="--enable-jemalloc")
add_old_configure_assignment("MOZ_MEMORY", True, when="--enable-jemalloc")


@depends(milestone, build_project)
def replace_malloc_default(milestone, build_project):
    if build_project == "memory":
        return True
    if milestone.is_early_beta_or_earlier and build_project != "js":
        return True


option(
    "--enable-replace-malloc",
    default=replace_malloc_default,
    when="--enable-jemalloc",
    help="{Enable|Disable} ability to dynamically replace the malloc implementation",
)


set_config("MOZ_REPLACE_MALLOC", True, when="--enable-replace-malloc")
set_define("MOZ_REPLACE_MALLOC", True, when="--enable-replace-malloc")


@depends(build_project, when="--enable-replace-malloc")
def replace_malloc_static(build_project):
    # Default to statically linking replace-malloc libraries that can be
    # statically linked, except when building with --enable-project=memory.
    if build_project != "memory":
        return True


set_config("MOZ_REPLACE_MALLOC_STATIC", replace_malloc_static)

# PHC (Probabilistic Heap Checker)
# ==============================================================


# In general, it only makes sense for PHC to run on the platforms that have a
# crash reporter.
@depends(
    build_project,
    target,
    when="--enable-jemalloc",
)
def phc_default(build_project, target):
    if build_project == "js":
        return False

    # Both Linux32 and Win32 have frequent crashes when stack tracing (for
    # unclear reasons), so PHC is enabled only on 64-bit only in both cases.
    return (target.cpu in ("x86_64", "aarch64")) and (
        (target.os == "GNU" and target.kernel == "Linux")
        or (target.kernel == "WINNT")
        or (target.os == "OSX")
    )


option(
    "--enable-phc",
    env="MOZ_PHC",
    default=phc_default,
    when="--enable-jemalloc",
    help="{Enable|Disable} PHC (Probabilistic Memory Checker). "
    "Also enables frame pointers when needed",
)

set_config("MOZ_PHC", True, when="--enable-phc")


# PHC parses stacks using frame pointers on these systems.
@depends("--enable-phc", target, have_unwind, when="--enable-jemalloc")
def phc_implies_frame_pointers(phc, target, have_unwind):
    if not phc:
        return False

    # This should be kept in sync with the ifdefs in memory/build/PHC.cpp
    # that control stack walking.
    # This is true for the first two options in PHC.cpp
    if (target.os == "WINNT" and target.cpu == "x86") or target.kernel == "Darwin":
        return True

    # This should match the #defines in mozglue/misc/StackWalk.cpp
    if (target.cpu in ("x86", "ppc")) and (target.kernel in ("Darwin", "Linux")):
        return not have_unwind

    return False


imply_option("--enable-frame-pointers", True, when=phc_implies_frame_pointers)


with only_when(depends(target.os)(lambda os: os != "WINNT")):
    set_define("HAVE_STRNDUP", check_symbol("strndup"))
    set_define("HAVE_POSIX_MEMALIGN", check_symbol("posix_memalign"))
    set_define("HAVE_MEMALIGN", check_symbol("memalign"))
    set_define("HAVE_MALLOC_USABLE_SIZE", check_symbol("malloc_usable_size"))