1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
use syntax::ast;
use llvm::LLVMRustHasFeature;
use rustc::session::Session;
use rustc_trans::back::write::create_target_machine;
use syntax::feature_gate::UnstableFeatures;
use syntax::symbol::Symbol;
use libc::c_char;
const ARM_WHITELIST: &'static [&'static str] = &["neon\0", "vfp2\0", "vfp3\0", "vfp4\0"];
const X86_WHITELIST: &'static [&'static str] = &["avx\0", "avx2\0", "bmi\0", "bmi2\0", "sse\0",
"sse2\0", "sse3\0", "sse4.1\0", "sse4.2\0",
"ssse3\0", "tbm\0", "lzcnt\0", "popcnt\0",
"sse4a\0", "rdrnd\0", "rdseed\0", "fma\0"];
pub fn add_configuration(cfg: &mut ast::CrateConfig, sess: &Session) {
let target_machine = create_target_machine(sess);
let whitelist = match &*sess.target.target.arch {
"arm" => ARM_WHITELIST,
"x86" | "x86_64" => X86_WHITELIST,
_ => &[],
};
let tf = Symbol::intern("target_feature");
for feat in whitelist {
assert_eq!(feat.chars().last(), Some('\0'));
if unsafe { LLVMRustHasFeature(target_machine, feat.as_ptr() as *const c_char) } {
cfg.insert((tf, Some(Symbol::intern(&feat[..feat.len() - 1]))));
}
}
let requested_features = sess.opts.cg.target_feature.split(',');
let unstable_options = sess.opts.debugging_opts.unstable_options;
let is_nightly = UnstableFeatures::from_environment().is_nightly_build();
let found_negative = requested_features.clone().any(|r| r == "-crt-static");
let found_positive = requested_features.clone().any(|r| r == "+crt-static");
let crt_static = if sess.target.target.options.crt_static_default {
!found_negative
} else {
found_positive
};
if (found_positive || found_negative) && (!is_nightly || !unstable_options) {
sess.fatal("specifying the `crt-static` target feature is only allowed \
on the nightly channel with `-Z unstable-options` passed \
as well");
}
if crt_static {
cfg.insert((tf, Some(Symbol::intern("crt-static"))));
}
}