/
build.rs
179 lines (158 loc) · 6.28 KB
/
build.rs
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
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
use std::env;
use std::ffi::OsString;
use std::iter;
use std::path::Path;
use std::process::{self, Command, Stdio};
use std::str;
#[cfg(all(feature = "backtrace", not(feature = "std")))]
compile_error! {
"`backtrace` feature without `std` feature is not supported"
}
fn main() {
let mut error_generic_member_access = false;
if cfg!(feature = "std") {
println!("cargo:rerun-if-changed=build/probe.rs");
let consider_rustc_bootstrap;
if compile_probe(false) {
// This is a nightly or dev compiler, so it supports unstable
// features regardless of RUSTC_BOOTSTRAP. No need to rerun build
// script if RUSTC_BOOTSTRAP is changed.
error_generic_member_access = true;
consider_rustc_bootstrap = false;
} else if let Some(rustc_bootstrap) = env::var_os("RUSTC_BOOTSTRAP") {
if compile_probe(true) {
// This is a stable or beta compiler for which the user has set
// RUSTC_BOOTSTRAP to turn on unstable features. Rerun build
// script if they change it.
error_generic_member_access = true;
consider_rustc_bootstrap = true;
} else if rustc_bootstrap == "1" {
// This compiler does not support the generic member access API
// in the form that anyhow expects. No need to pay attention to
// RUSTC_BOOTSTRAP.
error_generic_member_access = false;
consider_rustc_bootstrap = false;
} else {
// This is a stable or beta compiler for which RUSTC_BOOTSTRAP
// is set to restrict the use of unstable features by this
// crate.
error_generic_member_access = false;
consider_rustc_bootstrap = true;
}
} else {
// Without RUSTC_BOOTSTRAP, this compiler does not support the
// generic member access API in the form that anyhow expects, but
// try again if the user turns on unstable features.
error_generic_member_access = false;
consider_rustc_bootstrap = true;
}
if error_generic_member_access {
println!("cargo:rustc-cfg=std_backtrace");
println!("cargo:rustc-cfg=error_generic_member_access");
}
if consider_rustc_bootstrap {
println!("cargo:rerun-if-env-changed=RUSTC_BOOTSTRAP");
}
}
let rustc = match rustc_minor_version() {
Some(rustc) => rustc,
None => return,
};
if rustc >= 80 {
println!("cargo:rustc-check-cfg=cfg(anyhow_nightly_testing)");
println!("cargo:rustc-check-cfg=cfg(anyhow_no_fmt_arguments_as_str)");
println!("cargo:rustc-check-cfg=cfg(anyhow_no_ptr_addr_of)");
println!("cargo:rustc-check-cfg=cfg(anyhow_no_unsafe_op_in_unsafe_fn_lint)");
println!("cargo:rustc-check-cfg=cfg(doc_cfg)");
println!("cargo:rustc-check-cfg=cfg(error_generic_member_access)");
println!("cargo:rustc-check-cfg=cfg(std_backtrace)");
}
if rustc < 51 {
// core::ptr::addr_of
// https://blog.rust-lang.org/2021/03/25/Rust-1.51.0.html#stabilized-apis
println!("cargo:rustc-cfg=anyhow_no_ptr_addr_of");
}
if rustc < 52 {
// core::fmt::Arguments::as_str
// https://blog.rust-lang.org/2021/05/06/Rust-1.52.0.html#stabilized-apis
println!("cargo:rustc-cfg=anyhow_no_fmt_arguments_as_str");
// #![deny(unsafe_op_in_unsafe_fn)]
// https://github.com/rust-lang/rust/issues/71668
println!("cargo:rustc-cfg=anyhow_no_unsafe_op_in_unsafe_fn_lint");
}
if !error_generic_member_access && cfg!(feature = "std") && rustc >= 65 {
// std::backtrace::Backtrace
// https://blog.rust-lang.org/2022/11/03/Rust-1.65.0.html#stabilized-apis
println!("cargo:rustc-cfg=std_backtrace");
}
}
fn compile_probe(rustc_bootstrap: bool) -> bool {
if env::var_os("RUSTC_STAGE").is_some() {
// We are running inside rustc bootstrap. This is a highly non-standard
// environment with issues such as:
//
// https://github.com/rust-lang/cargo/issues/11138
// https://github.com/rust-lang/rust/issues/114839
//
// Let's just not use nightly features here.
return false;
}
let rustc = cargo_env_var("RUSTC");
let out_dir = cargo_env_var("OUT_DIR");
let probefile = Path::new("build").join("probe.rs");
let rustc_wrapper = env::var_os("RUSTC_WRAPPER").filter(|wrapper| !wrapper.is_empty());
let rustc_workspace_wrapper =
env::var_os("RUSTC_WORKSPACE_WRAPPER").filter(|wrapper| !wrapper.is_empty());
let mut rustc = rustc_wrapper
.into_iter()
.chain(rustc_workspace_wrapper)
.chain(iter::once(rustc));
let mut cmd = Command::new(rustc.next().unwrap());
cmd.args(rustc);
if !rustc_bootstrap {
cmd.env_remove("RUSTC_BOOTSTRAP");
}
cmd.stderr(Stdio::null())
.arg("--edition=2018")
.arg("--crate-name=anyhow")
.arg("--crate-type=lib")
.arg("--emit=dep-info,metadata")
.arg("--cap-lints=allow")
.arg("--out-dir")
.arg(out_dir)
.arg(probefile);
if let Some(target) = env::var_os("TARGET") {
cmd.arg("--target").arg(target);
}
// If Cargo wants to set RUSTFLAGS, use that.
if let Ok(rustflags) = env::var("CARGO_ENCODED_RUSTFLAGS") {
if !rustflags.is_empty() {
for arg in rustflags.split('\x1f') {
cmd.arg(arg);
}
}
}
match cmd.status() {
Ok(status) => status.success(),
Err(_) => false,
}
}
fn rustc_minor_version() -> Option<u32> {
let rustc = cargo_env_var("RUSTC");
let output = Command::new(rustc).arg("--version").output().ok()?;
let version = str::from_utf8(&output.stdout).ok()?;
let mut pieces = version.split('.');
if pieces.next() != Some("rustc 1") {
return None;
}
pieces.next()?.parse().ok()
}
fn cargo_env_var(key: &str) -> OsString {
env::var_os(key).unwrap_or_else(|| {
eprintln!(
"Environment variable ${} is not set during execution of build script",
key,
);
process::exit(1);
})
}