rustdoc: factor document_type_layout into its own module

This commit is contained in:
Michael Howell 2023-04-21 10:06:31 -07:00
parent 99e1cdb46f
commit 2b728c1f85
3 changed files with 90 additions and 77 deletions

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@ -32,6 +32,7 @@
mod print_item;
mod sidebar;
mod span_map;
mod type_layout;
mod write_shared;
pub(crate) use self::context::*;

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@ -6,16 +6,14 @@
use rustc_hir::def::CtorKind;
use rustc_hir::def_id::DefId;
use rustc_middle::middle::stability;
use rustc_middle::span_bug;
use rustc_middle::ty::layout::LayoutError;
use rustc_middle::ty::{self, Adt, TyCtxt};
use rustc_middle::ty::{self, TyCtxt};
use rustc_span::hygiene::MacroKind;
use rustc_span::symbol::{kw, sym, Symbol};
use rustc_target::abi::{Primitive, TagEncoding, Variants};
use std::cmp::Ordering;
use std::fmt;
use std::rc::Rc;
use super::type_layout::document_type_layout;
use super::{
collect_paths_for_type, document, ensure_trailing_slash, get_filtered_impls_for_reference,
item_ty_to_section, notable_traits_button, notable_traits_json, render_all_impls,
@ -1932,79 +1930,6 @@ struct update syntax will not work.",
})
}
fn document_type_layout<'a, 'cx: 'a>(
cx: &'a Context<'cx>,
ty_def_id: DefId,
) -> impl fmt::Display + 'a + Captures<'cx> {
#[derive(Template)]
#[template(path = "type_layout.html")]
struct TypeLayout<'cx> {
variants: Vec<(Symbol, TypeLayoutSize)>,
type_layout_size: Result<TypeLayoutSize, LayoutError<'cx>>,
}
#[derive(Template)]
#[template(path = "type_layout_size.html")]
struct TypeLayoutSize {
is_unsized: bool,
is_uninhabited: bool,
size: u64,
}
display_fn(move |f| {
if !cx.shared.show_type_layout {
return Ok(());
}
let tcx = cx.tcx();
let param_env = tcx.param_env(ty_def_id);
let ty = tcx.type_of(ty_def_id).subst_identity();
let type_layout = tcx.layout_of(param_env.and(ty));
let variants =
if let Ok(type_layout) = type_layout &&
let Variants::Multiple { variants, tag, tag_encoding, .. } =
type_layout.layout.variants() &&
!variants.is_empty()
{
let tag_size =
if let TagEncoding::Niche { .. } = tag_encoding {
0
} else if let Primitive::Int(i, _) = tag.primitive() {
i.size().bytes()
} else {
span_bug!(cx.tcx().def_span(ty_def_id), "tag is neither niche nor int")
};
let variants = variants
.iter_enumerated()
.map(|(variant_idx, variant_layout)| {
let Adt(adt, _) = type_layout.ty.kind() else {
span_bug!(cx.tcx().def_span(ty_def_id), "not an adt")
};
let name = adt.variant(variant_idx).name;
let is_unsized = variant_layout.abi.is_unsized();
let is_uninhabited = variant_layout.abi.is_uninhabited();
let size = variant_layout.size.bytes() - tag_size;
let type_layout_size = TypeLayoutSize { is_unsized, is_uninhabited, size };
(name, type_layout_size)
}).collect();
variants
} else {
Vec::new()
}
;
let type_layout_size = tcx.layout_of(param_env.and(ty)).map(|layout| {
let is_unsized = layout.abi.is_unsized();
let is_uninhabited = layout.abi.is_uninhabited();
let size = layout.size.bytes();
TypeLayoutSize { is_unsized, is_uninhabited, size }
});
Ok(TypeLayout { variants, type_layout_size }.render_into(f).unwrap())
})
}
fn pluralize(count: usize) -> &'static str {
if count > 1 { "s" } else { "" }
}

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@ -0,0 +1,87 @@
use askama::Template;
use rustc_data_structures::captures::Captures;
use rustc_hir::def_id::DefId;
use rustc_middle::span_bug;
use rustc_middle::ty::layout::LayoutError;
use rustc_middle::ty::Adt;
use rustc_span::symbol::Symbol;
use rustc_target::abi::{Primitive, TagEncoding, Variants};
use std::fmt;
use crate::html::format::display_fn;
use crate::html::render::Context;
#[derive(Template)]
#[template(path = "type_layout.html")]
struct TypeLayout<'cx> {
variants: Vec<(Symbol, TypeLayoutSize)>,
type_layout_size: Result<TypeLayoutSize, LayoutError<'cx>>,
}
#[derive(Template)]
#[template(path = "type_layout_size.html")]
struct TypeLayoutSize {
is_unsized: bool,
is_uninhabited: bool,
size: u64,
}
pub(crate) fn document_type_layout<'a, 'cx: 'a>(
cx: &'a Context<'cx>,
ty_def_id: DefId,
) -> impl fmt::Display + 'a + Captures<'cx> {
display_fn(move |f| {
if !cx.shared.show_type_layout {
return Ok(());
}
let tcx = cx.tcx();
let param_env = tcx.param_env(ty_def_id);
let ty = tcx.type_of(ty_def_id).subst_identity();
let type_layout = tcx.layout_of(param_env.and(ty));
let variants =
if let Ok(type_layout) = type_layout &&
let Variants::Multiple { variants, tag, tag_encoding, .. } =
type_layout.layout.variants() &&
!variants.is_empty()
{
let tag_size =
if let TagEncoding::Niche { .. } = tag_encoding {
0
} else if let Primitive::Int(i, _) = tag.primitive() {
i.size().bytes()
} else {
span_bug!(cx.tcx().def_span(ty_def_id), "tag is neither niche nor int")
};
let variants = variants
.iter_enumerated()
.map(|(variant_idx, variant_layout)| {
let Adt(adt, _) = type_layout.ty.kind() else {
span_bug!(cx.tcx().def_span(ty_def_id), "not an adt")
};
let name = adt.variant(variant_idx).name;
let is_unsized = variant_layout.abi.is_unsized();
let is_uninhabited = variant_layout.abi.is_uninhabited();
let size = variant_layout.size.bytes() - tag_size;
let type_layout_size = TypeLayoutSize { is_unsized, is_uninhabited, size };
(name, type_layout_size)
}).collect();
variants
} else {
Vec::new()
}
;
let type_layout_size = tcx.layout_of(param_env.and(ty)).map(|layout| {
let is_unsized = layout.abi.is_unsized();
let is_uninhabited = layout.abi.is_uninhabited();
let size = layout.size.bytes();
TypeLayoutSize { is_unsized, is_uninhabited, size }
});
Ok(TypeLayout { variants, type_layout_size }.render_into(f).unwrap())
})
}