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rename rustc_attr to rustc_attr_parsing and create rustc_attr_data_structures

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Jonathan Dönszelmann
2024-12-13 14:47:11 +01:00
parent 1341366af9
commit efb98b6552
103 changed files with 481 additions and 395 deletions
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215
compiler/rustc_attr_parsing/src/attributes/repr.rs Normal file
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//! Parsing and validation of builtin attributes
use rustc_abi::Align;
use rustc_ast::attr::AttributeExt;
use rustc_ast::{self as ast, MetaItemKind};
use rustc_attr_data_structures::IntType;
use rustc_attr_data_structures::ReprAttr::*;
use rustc_session::Session;
use rustc_span::symbol::{Symbol, sym};
use crate::ReprAttr;
use crate::session_diagnostics::{self, IncorrectReprFormatGenericCause};
/// Parse #[repr(...)] forms.
///
/// Valid repr contents: any of the primitive integral type names (see
/// `int_type_of_word`, below) to specify enum discriminant type; `C`, to use
/// the same discriminant size that the corresponding C enum would or C
/// structure layout, `packed` to remove padding, and `transparent` to delegate representation
/// concerns to the only non-ZST field.
pub fn find_repr_attrs(sess: &Session, attr: &impl AttributeExt) -> Vec<ReprAttr> {
if attr.has_name(sym::repr) { parse_repr_attr(sess, attr) } else { Vec::new() }
}
pub fn parse_repr_attr(sess: &Session, attr: &impl AttributeExt) -> Vec<ReprAttr> {
assert!(attr.has_name(sym::repr), "expected `#[repr(..)]`, found: {attr:?}");
let mut acc = Vec::new();
let dcx = sess.dcx();
if let Some(items) = attr.meta_item_list() {
for item in items {
let mut recognised = false;
if item.is_word() {
let hint = match item.name_or_empty() {
sym::Rust => Some(ReprRust),
sym::C => Some(ReprC),
sym::packed => Some(ReprPacked(Align::ONE)),
sym::simd => Some(ReprSimd),
sym::transparent => Some(ReprTransparent),
sym::align => {
sess.dcx().emit_err(session_diagnostics::InvalidReprAlignNeedArg {
span: item.span(),
});
recognised = true;
None
}
name => int_type_of_word(name).map(ReprInt),
};
if let Some(h) = hint {
recognised = true;
acc.push(h);
}
} else if let Some((name, value)) = item.singleton_lit_list() {
let mut literal_error = None;
let mut err_span = item.span();
if name == sym::align {
recognised = true;
match parse_alignment(&value.kind) {
Ok(literal) => acc.push(ReprAlign(literal)),
Err(message) => {
err_span = value.span;
literal_error = Some(message)
}
};
} else if name == sym::packed {
recognised = true;
match parse_alignment(&value.kind) {
Ok(literal) => acc.push(ReprPacked(literal)),
Err(message) => {
err_span = value.span;
literal_error = Some(message)
}
};
} else if matches!(name, sym::Rust | sym::C | sym::simd | sym::transparent)
|| int_type_of_word(name).is_some()
{
recognised = true;
sess.dcx().emit_err(session_diagnostics::InvalidReprHintNoParen {
span: item.span(),
name: name.to_ident_string(),
});
}
if let Some(literal_error) = literal_error {
sess.dcx().emit_err(session_diagnostics::InvalidReprGeneric {
span: err_span,
repr_arg: name.to_ident_string(),
error_part: literal_error,
});
}
} else if let Some(meta_item) = item.meta_item() {
match &meta_item.kind {
MetaItemKind::NameValue(value) => {
if meta_item.has_name(sym::align) || meta_item.has_name(sym::packed) {
let name = meta_item.name_or_empty().to_ident_string();
recognised = true;
sess.dcx().emit_err(session_diagnostics::IncorrectReprFormatGeneric {
span: item.span(),
repr_arg: &name,
cause: IncorrectReprFormatGenericCause::from_lit_kind(
item.span(),
&value.kind,
&name,
),
});
} else if matches!(
meta_item.name_or_empty(),
sym::Rust | sym::C | sym::simd | sym::transparent
) || int_type_of_word(meta_item.name_or_empty()).is_some()
{
recognised = true;
sess.dcx().emit_err(session_diagnostics::InvalidReprHintNoValue {
span: meta_item.span,
name: meta_item.name_or_empty().to_ident_string(),
});
}
}
MetaItemKind::List(nested_items) => {
if meta_item.has_name(sym::align) {
recognised = true;
if let [nested_item] = nested_items.as_slice() {
sess.dcx().emit_err(
session_diagnostics::IncorrectReprFormatExpectInteger {
span: nested_item.span(),
},
);
} else {
sess.dcx().emit_err(
session_diagnostics::IncorrectReprFormatAlignOneArg {
span: meta_item.span,
},
);
}
} else if meta_item.has_name(sym::packed) {
recognised = true;
if let [nested_item] = nested_items.as_slice() {
sess.dcx().emit_err(
session_diagnostics::IncorrectReprFormatPackedExpectInteger {
span: nested_item.span(),
},
);
} else {
sess.dcx().emit_err(
session_diagnostics::IncorrectReprFormatPackedOneOrZeroArg {
span: meta_item.span,
},
);
}
} else if matches!(
meta_item.name_or_empty(),
sym::Rust | sym::C | sym::simd | sym::transparent
) || int_type_of_word(meta_item.name_or_empty()).is_some()
{
recognised = true;
sess.dcx().emit_err(session_diagnostics::InvalidReprHintNoParen {
span: meta_item.span,
name: meta_item.name_or_empty().to_ident_string(),
});
}
}
_ => (),
}
}
if !recognised {
// Not a word we recognize. This will be caught and reported by
// the `check_mod_attrs` pass, but this pass doesn't always run
// (e.g. if we only pretty-print the source), so we have to gate
// the `span_delayed_bug` call as follows:
if sess.opts.pretty.map_or(true, |pp| pp.needs_analysis()) {
dcx.span_delayed_bug(item.span(), "unrecognized representation hint");
}
}
}
}
acc
}
fn int_type_of_word(s: Symbol) -> Option<IntType> {
use rustc_attr_data_structures::IntType::*;
match s {
sym::i8 => Some(SignedInt(ast::IntTy::I8)),
sym::u8 => Some(UnsignedInt(ast::UintTy::U8)),
sym::i16 => Some(SignedInt(ast::IntTy::I16)),
sym::u16 => Some(UnsignedInt(ast::UintTy::U16)),
sym::i32 => Some(SignedInt(ast::IntTy::I32)),
sym::u32 => Some(UnsignedInt(ast::UintTy::U32)),
sym::i64 => Some(SignedInt(ast::IntTy::I64)),
sym::u64 => Some(UnsignedInt(ast::UintTy::U64)),
sym::i128 => Some(SignedInt(ast::IntTy::I128)),
sym::u128 => Some(UnsignedInt(ast::UintTy::U128)),
sym::isize => Some(SignedInt(ast::IntTy::Isize)),
sym::usize => Some(UnsignedInt(ast::UintTy::Usize)),
_ => None,
}
}
pub fn parse_alignment(node: &ast::LitKind) -> Result<Align, &'static str> {
if let ast::LitKind::Int(literal, ast::LitIntType::Unsuffixed) = node {
// `Align::from_bytes` accepts 0 as an input, check is_power_of_two() first
if literal.get().is_power_of_two() {
// Only possible error is larger than 2^29
literal
.get()
.try_into()
.ok()
.and_then(|v| Align::from_bytes(v).ok())
.ok_or("larger than 2^29")
} else {
Err("not a power of two")
}
} else {
Err("not an unsuffixed integer")
}
}