rustc_target/
lib.rs

1//! Some stuff used by rustc that doesn't have many dependencies
2//!
3//! Originally extracted from rustc::back, which was nominally the
4//! compiler 'backend', though LLVM is rustc's backend, so rustc_target
5//! is really just odds-and-ends relating to code gen and linking.
6//! This crate mostly exists to make rustc smaller, so we might put
7//! more 'stuff' here in the future. It does not have a dependency on
8//! LLVM.
9
10// tidy-alphabetical-start
11#![expect(internal_features)]
12#![feature(iter_intersperse)]
13#![feature(rustc_attrs)]
14// tidy-alphabetical-end
15
16use std::path::{Path, PathBuf};
17
18pub mod asm;
19pub mod callconv;
20pub mod json;
21pub mod spec;
22pub mod target_features;
23
24#[cfg(test)]
25mod tests;
26
27use rustc_abi::HashStableContext;
28
29/// The name of rustc's own place to organize libraries.
30///
31/// Used to be `rustc`, now the default is `rustlib`.
32const RUST_LIB_DIR: &str = "rustlib";
33
34/// Returns a `rustlib` path for this particular target, relative to the provided sysroot.
35///
36/// For example: `target_sysroot_path("/usr", "x86_64-unknown-linux-gnu")` =>
37/// `"lib*/rustlib/x86_64-unknown-linux-gnu"`.
38pub fn relative_target_rustlib_path(sysroot: &Path, target_triple: &str) -> PathBuf {
39    let libdir = find_relative_libdir(sysroot);
40    Path::new(libdir.as_ref()).join(RUST_LIB_DIR).join(target_triple)
41}
42
43/// The name of the directory rustc expects libraries to be located.
44fn find_relative_libdir(sysroot: &Path) -> std::borrow::Cow<'static, str> {
45    // FIXME: This is a quick hack to make the rustc binary able to locate
46    // Rust libraries in Linux environments where libraries might be installed
47    // to lib64/lib32. This would be more foolproof by basing the sysroot off
48    // of the directory where `librustc_driver` is located, rather than
49    // where the rustc binary is.
50    // If --libdir is set during configuration to the value other than
51    // "lib" (i.e., non-default), this value is used (see issue #16552).
52
53    #[cfg(target_pointer_width = "64")]
54    const PRIMARY_LIB_DIR: &str = "lib64";
55
56    #[cfg(target_pointer_width = "32")]
57    const PRIMARY_LIB_DIR: &str = "lib32";
58
59    const SECONDARY_LIB_DIR: &str = "lib";
60
61    match option_env!("CFG_LIBDIR_RELATIVE") {
62        None | Some("lib") => {
63            if sysroot.join(PRIMARY_LIB_DIR).join(RUST_LIB_DIR).exists() {
64                PRIMARY_LIB_DIR.into()
65            } else {
66                SECONDARY_LIB_DIR.into()
67            }
68        }
69        Some(libdir) => libdir.into(),
70    }
71}
72
73macro_rules! target_spec_enum {
74    (
75        $( #[$attr:meta] )*
76        pub enum $Name:ident {
77            $(
78                $( #[$variant_attr:meta] )*
79                $Variant:ident = $string:literal,
80            )*
81        }
82        parse_error_type = $parse_error_type:literal;
83    ) => {
84        $( #[$attr] )*
85        #[derive(Clone, Copy, PartialEq, Eq, Hash, Debug, PartialOrd, Ord)]
86        #[derive(schemars::JsonSchema)]
87        pub enum $Name {
88            $(
89                $( #[$variant_attr] )*
90                #[serde(rename = $string)] // for JSON schema generation only
91                $Variant,
92            )*
93        }
94
95        impl FromStr for $Name {
96            type Err = String;
97
98            fn from_str(s: &str) -> Result<Self, Self::Err> {
99                Ok(match s {
100                    $( $string => Self::$Variant, )*
101                    _ => {
102                        let all = [$( concat!("'", $string, "'") ),*].join(", ");
103                        return Err(format!("invalid {}: '{s}'. allowed values: {all}", $parse_error_type));
104                    }
105                })
106            }
107        }
108
109        impl $Name {
110            pub const ALL: &'static [$Name] = &[ $( $Name::$Variant, )* ];
111            pub fn desc(&self) -> &'static str {
112                match self {
113                    $( Self::$Variant => $string, )*
114                }
115            }
116        }
117
118        crate::target_spec_enum!(@common_impls $Name);
119    };
120
121    (
122        $( #[$attr:meta] )*
123        pub enum $Name:ident {
124            $(
125                $( #[$variant_attr:meta] )*
126                $Variant:ident = $string:literal,
127            )*
128        }
129        $( #[$other_variant_attr:meta] )*
130        other_variant = $OtherVariant:ident;
131    ) => {
132        $( #[$attr] )*
133        #[derive(Clone, PartialEq, Eq, Hash, Debug, PartialOrd, Ord)]
134        pub enum $Name {
135            $(
136                $( #[$variant_attr:meta] )*
137                $Variant,
138            )*
139            /// The vast majority of the time, the compiler deals with a fixed
140            /// set of values, so it is convenient for them to be represented in
141            /// an enum. However, it is possible to have arbitrary values in a
142            /// target JSON file (which can be parsed when `--target` is
143            /// specified). This might occur, for example, for an out-of-tree
144            /// codegen backend that supports a value (e.g. architecture or OS)
145            /// that rustc currently doesn't know about. This variant exists as
146            /// an escape hatch for such cases.
147            $( #[$other_variant_attr] )*
148            $OtherVariant(crate::spec::StaticCow<str>),
149        }
150
151        impl schemars::JsonSchema for $Name {
152            fn schema_name() -> std::borrow::Cow<'static, str> {
153                std::borrow::Cow::Borrowed(stringify!($Name))
154            }
155
156            fn json_schema(_: &mut schemars::SchemaGenerator) -> schemars::Schema {
157                schemars::json_schema!({
158                    "type": "string"
159                })
160            }
161        }
162
163        impl FromStr for $Name {
164            type Err = core::convert::Infallible;
165
166            fn from_str(s: &str) -> Result<Self, Self::Err> {
167                Ok(match s {
168                    $( $string => Self::$Variant, )*
169                    _ => Self::$OtherVariant(s.to_owned().into()),
170                })
171            }
172        }
173
174        impl $Name {
175            pub fn desc(&self) -> &str {
176                match self {
177                    $( Self::$Variant => $string, )*
178                    Self::$OtherVariant(name) => name.as_ref(),
179                }
180            }
181        }
182
183        crate::target_spec_enum!(@common_impls $Name);
184    };
185
186    (@common_impls $Name:ident) => {
187        impl crate::json::ToJson for $Name {
188            fn to_json(&self) -> crate::json::Json {
189                self.desc().to_json()
190            }
191        }
192
193        crate::json::serde_deserialize_from_str!($Name);
194
195
196        impl std::fmt::Display for $Name {
197            fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
198                f.write_str(self.desc())
199            }
200        }
201    };
202}
203use target_spec_enum;
rustc_target/lib.rs

rustc_target/
lib.rs
