1 use crate::mir::mono::Linkage;
2 use rustc_attr::{InlineAttr, OptimizeAttr};
3 use rustc_session::config::SanitizerSet;
4 use rustc_span::symbol::Symbol;
6 #[derive(Clone, TyEncodable, TyDecodable, HashStable)]
7 pub struct CodegenFnAttrs {
8 pub flags: CodegenFnAttrFlags,
9 /// Parsed representation of the `#[inline]` attribute
10 pub inline: InlineAttr,
11 /// Parsed representation of the `#[optimize]` attribute
12 pub optimize: OptimizeAttr,
13 /// The `#[export_name = "..."]` attribute, indicating a custom symbol a
14 /// function should be exported under
15 pub export_name: Option<Symbol>,
16 /// The `#[link_name = "..."]` attribute, indicating a custom symbol an
17 /// imported function should be imported as. Note that `export_name`
18 /// probably isn't set when this is set, this is for foreign items while
19 /// `#[export_name]` is for Rust-defined functions.
20 pub link_name: Option<Symbol>,
21 /// The `#[link_ordinal = "..."]` attribute, indicating an ordinal an
22 /// imported function has in the dynamic library. Note that this must not
23 /// be set when `link_name` is set. This is for foreign items with the
25 pub link_ordinal: Option<usize>,
26 /// The `#[target_feature(enable = "...")]` attribute and the enabled
27 /// features (only enabled features are supported right now).
28 pub target_features: Vec<Symbol>,
29 /// The `#[linkage = "..."]` attribute and the value we found.
30 pub linkage: Option<Linkage>,
31 /// The `#[link_section = "..."]` attribute, or what executable section this
32 /// should be placed in.
33 pub link_section: Option<Symbol>,
34 /// The `#[no_sanitize(...)]` attribute. Indicates sanitizers for which
35 /// instrumentation should be disabled inside the annotated function.
36 pub no_sanitize: SanitizerSet,
40 #[derive(TyEncodable, TyDecodable, HashStable)]
41 pub struct CodegenFnAttrFlags: u32 {
42 /// `#[cold]`: a hint to LLVM that this function, when called, is never on
45 /// `#[rustc_allocator]`: a hint to LLVM that the pointer returned from this
46 /// function is never null.
47 const ALLOCATOR = 1 << 1;
48 /// `#[unwind]`: an indicator that this function may unwind despite what
49 /// its ABI signature may otherwise imply.
50 const UNWIND = 1 << 2;
51 /// `#[rust_allocator_nounwind]`, an indicator that an imported FFI
52 /// function will never unwind. Probably obsolete by recent changes with
53 /// #[unwind], but hasn't been removed/migrated yet
54 const RUSTC_ALLOCATOR_NOUNWIND = 1 << 3;
55 /// `#[naked]`: an indicator to LLVM that no function prologue/epilogue
56 /// should be generated.
58 /// `#[no_mangle]`: an indicator that the function's name should be the same
60 const NO_MANGLE = 1 << 5;
61 /// `#[rustc_std_internal_symbol]`: an indicator that this symbol is a
62 /// "weird symbol" for the standard library in that it has slightly
63 /// different linkage, visibility, and reachability rules.
64 const RUSTC_STD_INTERNAL_SYMBOL = 1 << 6;
65 /// `#[thread_local]`: indicates a static is actually a thread local
67 const THREAD_LOCAL = 1 << 8;
68 /// `#[used]`: indicates that LLVM can't eliminate this function (but the
71 /// `#[ffi_returns_twice]`, indicates that an extern function can return
73 const FFI_RETURNS_TWICE = 1 << 10;
74 /// `#[track_caller]`: allow access to the caller location
75 const TRACK_CALLER = 1 << 11;
76 /// #[ffi_pure]: applies clang's `pure` attribute to a foreign function
78 const FFI_PURE = 1 << 12;
79 /// #[ffi_const]: applies clang's `const` attribute to a foreign function
81 const FFI_CONST = 1 << 13;
86 pub fn new() -> CodegenFnAttrs {
88 flags: CodegenFnAttrFlags::empty(),
89 inline: InlineAttr::None,
90 optimize: OptimizeAttr::None,
94 target_features: vec![],
97 no_sanitize: SanitizerSet::empty(),
101 /// Returns `true` if `#[inline]` or `#[inline(always)]` is present.
102 pub fn requests_inline(&self) -> bool {
104 InlineAttr::Hint | InlineAttr::Always => true,
105 InlineAttr::None | InlineAttr::Never => false,
109 /// Returns `true` if it looks like this symbol needs to be exported, for example:
111 /// * `#[no_mangle]` is present
112 /// * `#[export_name(...)]` is present
113 /// * `#[linkage]` is present
114 pub fn contains_extern_indicator(&self) -> bool {
115 self.flags.contains(CodegenFnAttrFlags::NO_MANGLE)
116 || self.export_name.is_some()
117 || match self.linkage {
118 // These are private, so make sure we don't try to consider
120 None | Some(Linkage::Internal | Linkage::Private) => false,