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# -*- Mode: python; c-basic-offset: 4; 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
# Generates a test program and attempts to compile it. In case of failure, the
# resulting check will return None. If the test program succeeds, it will return
# the output of the test program.
# - `includes` are the includes (as file names) that will appear at the top of
# the generated test program.
# - `body` is the code that will appear in the main function of the generated
# test program. `return 0;` is appended to the function body automatically.
# - `language` is the language selection, so that the appropriate compiler is
# used.
# - `flags` are the flags to be passed to the compiler, in addition to `-c`.
# - `check_msg` is the message to be printed to accompany compiling the test
# program.
@template
def try_compile(
includes=None,
body="",
language="C++",
flags=None,
check_msg=None,
when=None,
onerror=lambda: None,
):
compiler = {
"C": c_compiler,
"C++": cxx_compiler,
}[language]
return compiler.try_compile(
includes, body, flags, check_msg, when=when, onerror=onerror
)
# Generates a test program and attempts to link it. In case of failure, the
# resulting check will return None. If the link succeeds, it will return
# True
# - `includes` are the includes (as file names) that will appear at the top of
# the generated test program.
# - `body` is the code that will appear in the main function of the generated
# test program. `return 0;` is appended to the function body automatically.
# - `language` is the language selection, so that the appropriate compiler is
# used.
# - `flags` are the flags to be passed to the compiler.
# - `check_msg` is the message to be printed to accompany compiling the test
# program.
@template
def try_link(
includes=None,
body="",
language="C++",
flags=None,
check_msg=None,
when=None,
onerror=lambda: None,
):
compiler = {
"C": c_compiler,
"C++": cxx_compiler,
}[language]
return compiler.try_link(
linker_ldflags,
includes,
body,
flags,
check_msg,
when=when,
onerror=onerror,
)
# Checks for the presence of the given header on the target system by compiling
# a test program including that header. The return value of the template is a
# check function returning True if the header is present, and None if it is not.
# The value of this check function is also used to set a variable (with set_define)
# corresponding to the checked header. For instance, HAVE_MALLOC_H will be set in
# defines if check_header if called with 'malloc.h' as input and malloc.h is
# present on the target.
# - `header` is the header, as a file name, to check for.
# - `language` is the language selection, so that the appropriate compiler is
# used.
# - `flags` are the flags to be passed to the compiler, in addition to `-c`.
# - `includes` are additional includes, as file names, to appear before the
# header checked for.
# - `when` is a depends function that if present will make performing the check
# conditional on the value of that function.
@template
def check_header(
header, language="C++", flags=None, includes=None, when=None, onerror=lambda: None
):
if when is None:
when = always
if includes:
includes = includes[:]
else:
includes = []
includes.append(header)
have_header = try_compile(
includes=includes,
language=language,
flags=flags,
check_msg="for %s" % header,
when=when,
onerror=onerror,
)
header_var = "HAVE_%s" % (
header.upper().replace("-", "_").replace("/", "_").replace(".", "_")
)
set_define(header_var, have_header)
return have_header
# A convenience wrapper for check_header for checking multiple headers.
# returns an array of the resulting checks in order corresponding to the
# provided headers.
# - `headers` are the headers to be checked.
# - `kwargs` are keyword arguments passed verbatim to check_header.
@template
def check_headers(*headers, **kwargs):
checks = []
for header in headers:
checks.append(check_header(header, **kwargs))
return checks
@depends(linker_ldflags, target.kernel)
def check_symbol_flags(linker_ldflags, kernel):
if kernel == "WINNT":
# The build doesn't use the compiler to link things as of writing,
# but some compilation checks do. When using clang-cl, the only
# linker we really support is lld.link, but clang-cl defaults to
# link.exe (even when cross-compiling). So we force the use of
# lld.link for the linkage checks.
return ["-fuse-ld=lld"]
return linker_ldflags
# Checks for the presence of the given symbol on the target system by compiling
# a test program. The return value of the template is a check function
# returning True if the symbol can be found, and None if it is not.
@template
def check_symbol(symbol, language="C", flags=None, when=None, onerror=lambda: None):
if when is None:
when = always
compiler, extern_c = {
"C": (c_compiler, ""),
"C++": (cxx_compiler, 'extern "C" '),
}[language]
# Stolen from autoconf 2.13 ; might be irrelevant now, but it doesn't hurt to
# keep using a char return type.
comment = [
"/* Override any gcc2 internal prototype to avoid an error. */",
"/* We use char because int might match the return type of a gcc2",
" builtin and then its argument prototype would still apply. */",
]
if flags:
@depends(check_symbol_flags, dependable(flags))
def flags(base_flags, extra_flags):
if base_flags and extra_flags:
return base_flags + list(extra_flags)
if extra_flags:
return extra_flags
return base_flags
else:
flags = check_symbol_flags
return compiler.try_run(
header=comment + ["%schar %s();" % (extern_c, symbol)],
body="%s();" % symbol,
flags=flags,
check_msg="for %s" % symbol,
when=when,
onerror=onerror,
)
# Determine whether to add a given flag to the given lists of flags for C or
# C++ compilation.
# - `flag` is the flag to test
# - `flags_collection` is a @depends function for a namespace of lists of
# C/C++ compiler flags to add to.
# - `test_flags` is a list of flags to pass to the compiler instead of merely
# passing `flag`. This is especially useful for checking warning flags. If
# this list is empty, `flag` will be passed on its own.
# - `compiler` (optional) is the compiler to test against (c_compiler or
# cxx_compiler, from toolchain.configure). When omitted, both compilers
# are tested; the list of flags added to is dependent on the compiler tested.
# - `when` (optional) is a @depends function or option name conditioning
# when the warning flag is wanted.
# - `check`, when not set, skips checking whether the flag is supported and
# adds it to the list of flags unconditionally.
# - `mode`, can be "compile", "link" or "assemble"
@template
def check_and_add_flags(
flag,
flags_collection,
test_flags=(),
compiler=None,
when=None,
check=True,
mode="compile",
):
assert mode in ("compile", "link", "assemble")
if compiler is not None:
compilers = (compiler,)
elif mode in ("link", "assemble"):
compilers = (c_compiler,)
else:
compilers = (c_compiler, cxx_compiler)
if when is None:
when = always
results = []
if test_flags:
flags = test_flags
else:
flags = [flag]
for c in compilers:
assert c in {c_compiler, cxx_compiler, host_c_compiler, host_cxx_compiler}
if mode == "compile":
lang, list_of_flags = {
c_compiler: ("C", flags_collection.cflags),
cxx_compiler: ("C++", flags_collection.cxxflags),
host_c_compiler: ("host C", flags_collection.host_cflags),
host_cxx_compiler: ("host C++", flags_collection.host_cxxflags),
}[c]
elif mode == "assemble":
lang, list_of_flags = {
c_compiler: ("C", flags_collection.asflags),
host_c_compiler: ("host C", flags_collection.host_asflags),
}[c]
elif mode == "link":
lang, list_of_flags = {
c_compiler: ("C", flags_collection.ldflags),
cxx_compiler: ("C++", flags_collection.ldflags),
host_c_compiler: ("host C", flags_collection.host_ldflags),
host_cxx_compiler: ("host C++", flags_collection.host_ldflags),
}[c]
result = when
if check:
@depends(c, dependable(flags))
def flags(c, flags):
# Don't error out just because clang complains about other things.
if c.type in ("clang", "clang-cl"):
flags += ["-Wno-error=unused-command-line-argument"]
return flags
if mode == "link":
def runner(*args, **kwargs):
if c in (c_compiler, cxx_compiler):
return c.try_link(linker_ldflags, *args, **kwargs)
else:
return c.try_link(host_linker_ldflags, *args, **kwargs)
tool = "linker"
else:
runner = c.try_compile
tool = "compiler"
result = runner(
flags=flags,
when=result,
check_msg="whether the %s %s supports %s" % (lang, tool, flag),
)
@depends(result, list_of_flags)
def maybe_add_flag(result, list_of_flags):
if result:
list_of_flags.append(flag)
results.append(result)
return tuple(results)
@dependable
def warnings_flags():
return namespace(cflags=[], cxxflags=[], host_cflags=[], host_cxxflags=[])
# Tests whether GCC or clang support the given warning flag, and if it is,
# add it to the list of warning flags for the build.
# - `warning` is the warning flag (e.g. -Wfoo)
# - `compiler` (optional) is the compiler to test against (c_compiler or
# cxx_compiler, from toolchain.configure). When omitted, both compilers
# are tested.
# - `when` (optional) is a @depends function or option name conditioning
# when the warning flag is wanted.
# - `check`, when not set, skips checking whether the flag is supported and
# adds it to the list of warning flags unconditionally. This is only meant
# for add_warning().
@template
def check_and_add_warning(warning, compiler=None, when=None, check=True):
# GCC and clang will fail if given an unknown warning option like
# -Wfoobar. But later versions won't fail if given an unknown negated
# warning option like -Wno-foobar. So when we are checking for support
# of a negated warning option, we actually test the positive form, but
# add the negated form to the flags variable.
if warning.startswith("-Wno-") and not warning.startswith("-Wno-error="):
flags = ["-Werror", "-W" + warning[5:]]
elif warning.startswith("-Werror="):
flags = [warning]
else:
flags = ["-Werror", warning]
return check_and_add_flags(
warning, warnings_flags, flags, compiler=compiler, when=when, check=check
)
# Add the given warning to the list of warning flags for the build.
# - `warning` is the warning flag (e.g. -Wfoo)
# - `compiler` (optional) is the compiler to add the flag for (c_compiler or
# cxx_compiler, from toolchain.configure). When omitted, the warning flag
# is added for both compilers.
# - `when` (optional) is a @depends function or option name conditioning
# when the warning flag is wanted.
@template
def add_warning(warning, compiler=None, when=None):
check_and_add_warning(warning, compiler, when, check=False)
# Like the warning checks above, but for general compilation flags.
@dependable
def compilation_flags():
return namespace(cflags=[], cxxflags=[], host_cflags=[], host_cxxflags=[])
# Tests whether GCC or clang support the given compilation flag; if the flag
# is supported, add it to the list of compilation flags for the build.
# - `flag` is the flag to test
# - `compiler` (optional) is the compiler to test against (c_compiler or
# cxx_compiler, from toolchain.configure). When omitted, both compilers
# are tested.
# - `when` (optional) is a @depends function or option name conditioning
# when the warning flag is wanted.
# - `check`, when not set, skips checking whether the flag is supported and
# adds it to the list of flags unconditionally. This is only meant for
# add_flag().
@template
def check_and_add_flag(flag, compiler=None, when=None, check=True):
flags = ["-Werror", flag]
return check_and_add_flags(
flag, compilation_flags, flags, compiler=compiler, when=when, check=check
)
# Add the given flag to the list of flags for the build.
# - `flag` is the flag (e.g. -fno-sized-deallocation)
# - `compiler` (optional) is the compiler to add the flag for (c_compiler or
# cxx_compiler, from toolchain.configure). When omitted, the flag is added
# for both compilers.
# - `when` (optional) is a @depends function or option name conditioning
# when the flag is wanted.
@template
def add_flag(warning, compiler=None, when=None):
check_and_add_flag(warning, compiler, when, check=False)
# Like the compilation checks above, but for asm flags.
@dependable
def asm_flags():
return namespace(asflags=[], host_asflags=[])
# Tests the given assembler flag is supported; if the flag
# is supported, add it to the list of compilation flags for the build.
# - `flag` is the flag to test
# - `when` (optional) is a @depends function or option name conditioning
# when the warning flag is wanted.
# - `check`, when not set, skips checking whether the flag is supported and
# adds it to the list of flags unconditionally. This is only meant for
# add_flag().
@template
def check_and_add_asm_flag(flag, when=None, check=True):
return check_and_add_flags(
flag,
asm_flags,
[flag],
when=when,
check=check,
mode="assemble",
)
# Like the compilation checks above, but for linker flags.
@dependable
def linker_flags():
return namespace(ldflags=[], host_ldflags=[])
# Tests the given linker flag is supported; if the flag
# is supported, add it to the list of compilation flags for the build.
# - `flag` is the flag to test
# - `when` (optional) is a @depends function or option name conditioning
# when the warning flag is wanted.
# - `check`, when not set, skips checking whether the flag is supported and
# adds it to the list of flags unconditionally. This is only meant for
# add_flag().
@template
def check_and_add_linker_flag(flag, compiler=None, when=None, check=True):
return check_and_add_flags(
flag,
linker_flags,
[flag],
when=when,
check=check,
mode="link",
)
# Like the compilation checks above, but for linker optimization flags.
@dependable
def linker_optimize_flags():
return namespace(ldflags=[])
@template
def check_and_add_linker_optimize_flag(flag, compiler=None, when=None, check=True):
return check_and_add_flags(
flag,
linker_optimize_flags,
[flag],
when=when,
check=check,
mode="link",
)
# Add the given flag to the list of linker flags for the build.
# - `flag` is the flag (e.g. -fno-sized-deallocation)
# - `when` (optional) is a @depends function or option name conditioning
# when the flag is wanted.
@template
def add_linker_flag(flag, compiler=None, when=None):
check_and_add_linker_flag(flag, compiler, when, check=False)