bjoernager/rust
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Rollup merge of #132246 - workingjubilee:campaign-on-irform, r=compiler-errors

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Rename `rustc_abi::Abi` to `BackendRepr`

Remove the confabulation of `rustc_abi::Abi` with what "ABI" actually means by renaming it to `BackendRepr`, and rename `Abi::Aggregate` to `BackendRepr::Memory`. The type never actually represented how things are passed, as that has to have `PassMode` considered, at minimum, but rather it just is how we represented some things to the backend. This conflation arose because LLVM, the primary backend at the time, would lower certain IR forms using certain ABIs. Even that only somewhat was true, as it broke down when one ventured significantly afield of what is described by the System V AMD64 ABI either by using different architectures, ABI-modifying IR annotations, the same architecture **with different ISA extensions enabled**, or other... unexpected delights.

Unfortunately both names are still somewhat of a misnomer right now, as people have written code for years based on this misunderstanding. Still, their original names are even moreso, and for better or worse, this backend code hasn't received as much maintenance as the rest of the compiler, lately. Actually arriving at a correct end-state will simply require us to disentangle a lot of code in order to fix, much of it pointlessly repeated in several places. Thus this is not an "actual fix", just a way to deflect further misunderstandings.
This commit is contained in:
Jubilee 2024-10-30 14:01:37 -07:00 • committed by GitHub
commit 847b6fe6b0
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98 changed files with 873 additions and 643 deletions
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6
compiler/rustc_lint/src/builtin.rs
View file

@ -16,6 +16,7 @@
use std::fmt::Write;
use ast::token::TokenKind;
use rustc_abi::BackendRepr;
use rustc_ast::tokenstream::{TokenStream, TokenTree};
use rustc_ast::visit::{FnCtxt, FnKind};
use rustc_ast::{self as ast, *};
@ -40,7 +41,6 @@ use rustc_span::edition::Edition;
use rustc_span::source_map::Spanned;
use rustc_span::symbol::{Ident, Symbol, kw, sym};
use rustc_span::{BytePos, InnerSpan, Span};
use rustc_target::abi::Abi;
use rustc_target::asm::InlineAsmArch;
use rustc_trait_selection::infer::{InferCtxtExt, TyCtxtInferExt};
use rustc_trait_selection::traits::misc::type_allowed_to_implement_copy;
@ -2468,7 +2468,9 @@ impl<'tcx> LateLintPass<'tcx> for InvalidValue {
// Check if this ADT has a constrained layout (like `NonNull` and friends).
if let Ok(layout) = cx.tcx.layout_of(cx.param_env.and(ty)) {
if let Abi::Scalar(scalar) | Abi::ScalarPair(scalar, _) = &layout.abi {
if let BackendRepr::Scalar(scalar) | BackendRepr::ScalarPair(scalar, _) =
&layout.backend_repr
{
let range = scalar.valid_range(cx);
let msg = if !range.contains(0) {
"must be non-null"

2
compiler/rustc_lint/src/foreign_modules.rs
View file

@ -217,7 +217,7 @@ fn structurally_same_type<'tcx>(
// `extern` blocks cannot be generic, so we'll always get a layout here.
let a_layout = tcx.layout_of(param_env.and(a)).unwrap();
let b_layout = tcx.layout_of(param_env.and(b)).unwrap();
assert_eq!(a_layout.abi, b_layout.abi);
assert_eq!(a_layout.backend_repr, b_layout.backend_repr);
assert_eq!(a_layout.size, b_layout.size);
assert_eq!(a_layout.align, b_layout.align);
}

6
compiler/rustc_lint/src/types.rs
View file

@ -1,6 +1,7 @@
use std::iter;
use std::ops::ControlFlow;
use rustc_abi::{BackendRepr, TagEncoding, Variants, WrappingRange};
use rustc_data_structures::fx::FxHashSet;
use rustc_errors::DiagMessage;
use rustc_hir::{Expr, ExprKind};
@ -13,7 +14,6 @@ use rustc_session::{declare_lint, declare_lint_pass, impl_lint_pass};
use rustc_span::def_id::LocalDefId;
use rustc_span::symbol::sym;
use rustc_span::{Span, Symbol, source_map};
use rustc_target::abi::{Abi, TagEncoding, Variants, WrappingRange};
use rustc_target::spec::abi::Abi as SpecAbi;
use tracing::debug;
use {rustc_ast as ast, rustc_hir as hir};
@ -776,8 +776,8 @@ pub(crate) fn repr_nullable_ptr<'tcx>(
bug!("should be able to compute the layout of non-polymorphic type");
}
let field_ty_abi = &field_ty_layout.ok()?.abi;
if let Abi::Scalar(field_ty_scalar) = field_ty_abi {
let field_ty_abi = &field_ty_layout.ok()?.backend_repr;
if let BackendRepr::Scalar(field_ty_scalar) = field_ty_abi {
match field_ty_scalar.valid_range(&tcx) {
WrappingRange { start: 0, end }
if end == field_ty_scalar.size(&tcx).unsigned_int_max() - 1 =>