forked from rust-lang/rust
-
-
Notifications
You must be signed in to change notification settings - Fork 0
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
Rollup merge of rust-lang#109949 - notriddle:notriddle/type-layout, r…
…=jsha rustdoc: migrate `document_type_layout` to askama
- Loading branch information
Showing
5 changed files
with
154 additions
and
116 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,86 @@ | ||
| 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") | ||
| }; | ||
| 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() | ||
| } 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()) | ||
| }) | ||
| } |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,53 @@ | ||
| <h2 id="layout" class="small-section-header"> {# #} | ||
| Layout<a href="#layout" class="anchor">§</a> {# #} | ||
| </h2> {# #} | ||
| <div class="docblock"> {# #} | ||
| {% match type_layout_size %} | ||
| {% when Ok(type_layout_size) %} | ||
| <div class="warning"> {# #} | ||
| <p> {# #} | ||
| <strong>Note:</strong> Most layout information is <strong>completely {#+ #} | ||
| unstable</strong> and may even differ between compilations. {#+ #} | ||
| The only exception is types with certain <code>repr(...)</code> {#+ #} | ||
| attributes. Please see the Rust Reference’s {#+ #} | ||
| <a href="https://doc.rust-lang.org/reference/type-layout.html">“Type Layout”</a> {#+ #} | ||
| chapter for details on type layout guarantees. {# #} | ||
| </p> {# #} | ||
| </div> {# #} | ||
| <p><strong>Size:</strong> {{ type_layout_size|safe }}</p> {# #} | ||
| {% if !variants.is_empty() %} | ||
| <p> {# #} | ||
| <strong>Size for each variant:</strong> {# #} | ||
| </p> {# #} | ||
| <ul> {# #} | ||
| {% for (name, layout_size) in variants %} | ||
| <li> {# #} | ||
| <code>{{ name }}</code>: {#+ #} | ||
| {{ layout_size|safe }} | ||
| </li> {# #} | ||
| {% endfor %} | ||
| </ul> {# #} | ||
| {% endif %} | ||
| {# This kind of layout error can occur with valid code, e.g. if you try to | ||
| get the layout of a generic type such as `Vec<T>`. #} | ||
| {% when Err(LayoutError::Unknown(_)) %} | ||
| <p> {# #} | ||
| <strong>Note:</strong> Unable to compute type layout, {#+ #} | ||
| possibly due to this type having generic parameters. {#+ #} | ||
| Layout can only be computed for concrete, fully-instantiated types. {# #} | ||
| </p> {# #} | ||
| {# This kind of error probably can't happen with valid code, but we don't | ||
| want to panic and prevent the docs from building, so we just let the | ||
| user know that we couldn't compute the layout. #} | ||
| {% when Err(LayoutError::SizeOverflow(_)) %} | ||
| <p> {# #} | ||
| <strong>Note:</strong> Encountered an error during type layout; {#+ #} | ||
| the type was too big. {# #} | ||
| </p> {# #} | ||
| {% when Err(LayoutError::NormalizationFailure(_, _)) %} | ||
| <p> {# #} | ||
| <strong>Note:</strong> Encountered an error during type layout; {#+ #} | ||
| the type failed to be normalized. {# #} | ||
| </p> {# #} | ||
| {% endmatch %} | ||
| </div> {# #} |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,12 @@ | ||
| {% if is_unsized %} | ||
| (unsized) | ||
| {% else %} | ||
| {% if size == 1 %} | ||
| 1 byte | ||
| {% else %} | ||
| {{ size +}} bytes | ||
| {% endif %} | ||
| {% if is_uninhabited %} | ||
| {# +#} (<a href="https://doc.rust-lang.org/stable/reference/glossary.html#uninhabited">uninhabited</a>) | ||
| {% endif %} | ||
| {% endif %} |