diff options
| -rw-r--r-- | compiler/rustc_metadata/src/lib.rs | 2 | ||||
| -rw-r--r-- | compiler/rustc_metadata/src/rmeta/encoder.rs | 106 | ||||
| -rw-r--r-- | compiler/rustc_metadata/src/rmeta/mod.rs | 2 | ||||
| -rw-r--r-- | src/librustdoc/clean/types.rs | 7 | ||||
| -rw-r--r-- | src/librustdoc/clean/utils.rs | 97 | ||||
| -rw-r--r-- | src/librustdoc/json/conversions.rs | 4 | ||||
| -rw-r--r-- | tests/rustdoc/show-const-contents.rs | 2 |
7 files changed, 107 insertions, 113 deletions
diff --git a/compiler/rustc_metadata/src/lib.rs b/compiler/rustc_metadata/src/lib.rs index 87373d99743..99fef84931e 100644 --- a/compiler/rustc_metadata/src/lib.rs +++ b/compiler/rustc_metadata/src/lib.rs @@ -42,6 +42,6 @@ pub mod locator; pub use fs::{emit_wrapper_file, METADATA_FILENAME}; pub use native_libs::find_native_static_library; -pub use rmeta::{encode_metadata, EncodedMetadata, METADATA_HEADER}; +pub use rmeta::{encode_metadata, rendered_const, EncodedMetadata, METADATA_HEADER}; fluent_messages! { "../messages.ftl" } diff --git a/compiler/rustc_metadata/src/rmeta/encoder.rs b/compiler/rustc_metadata/src/rmeta/encoder.rs index ecb15c41eef..4f4351633a2 100644 --- a/compiler/rustc_metadata/src/rmeta/encoder.rs +++ b/compiler/rustc_metadata/src/rmeta/encoder.rs @@ -17,8 +17,8 @@ use rustc_hir::def_id::{ CrateNum, DefId, DefIndex, LocalDefId, CRATE_DEF_ID, CRATE_DEF_INDEX, LOCAL_CRATE, }; use rustc_hir::definitions::DefPathData; -use rustc_hir::intravisit; use rustc_hir::lang_items::LangItem; +use rustc_hir_pretty::id_to_string; use rustc_middle::middle::debugger_visualizer::DebuggerVisualizerFile; use rustc_middle::middle::dependency_format::Linkage; use rustc_middle::middle::exported_symbols::{ @@ -1615,7 +1615,7 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> { record!(self.tables.mir_const_qualif[def_id.to_def_id()] <- qualifs); let body_id = tcx.hir().maybe_body_owned_by(def_id); if let Some(body_id) = body_id { - let const_data = self.encode_rendered_const_for_body(body_id); + let const_data = rendered_const(self.tcx, body_id); record!(self.tables.rendered_const[def_id.to_def_id()] <- const_data); } } @@ -1683,14 +1683,6 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> { } } - fn encode_rendered_const_for_body(&mut self, body_id: hir::BodyId) -> String { - let hir = self.tcx.hir(); - let body = hir.body(body_id); - rustc_hir_pretty::to_string(&(&hir as &dyn intravisit::Map<'_>), |s| { - s.print_expr(&body.value) - }) - } - #[instrument(level = "debug", skip(self))] fn encode_info_for_macro(&mut self, def_id: LocalDefId) { let tcx = self.tcx; @@ -2292,3 +2284,97 @@ pub fn provide(providers: &mut Providers) { ..*providers } } + +/// Build a textual representation of an unevaluated constant expression. +/// +/// If the const expression is too complex, an underscore `_` is returned. +/// For const arguments, it's `{ _ }` to be precise. +/// This means that the output is not necessarily valid Rust code. +/// +/// Currently, only +/// +/// * literals (optionally with a leading `-`) +/// * unit `()` +/// * blocks (`{ … }`) around simple expressions and +/// * paths without arguments +/// +/// are considered simple enough. Simple blocks are included since they are +/// necessary to disambiguate unit from the unit type. +/// This list might get extended in the future. +/// +/// Without this censoring, in a lot of cases the output would get too large +/// and verbose. Consider `match` expressions, blocks and deeply nested ADTs. +/// Further, private and `doc(hidden)` fields of structs would get leaked +/// since HIR datatypes like the `body` parameter do not contain enough +/// semantic information for this function to be able to hide them – +/// at least not without significant performance overhead. +/// +/// Whenever possible, prefer to evaluate the constant first and try to +/// use a different method for pretty-printing. Ideally this function +/// should only ever be used as a fallback. +pub fn rendered_const<'tcx>(tcx: TyCtxt<'tcx>, body: hir::BodyId) -> String { + let hir = tcx.hir(); + let value = &hir.body(body).value; + + #[derive(PartialEq, Eq)] + enum Classification { + Literal, + Simple, + Complex, + } + + use Classification::*; + + fn classify(expr: &hir::Expr<'_>) -> Classification { + match &expr.kind { + hir::ExprKind::Unary(hir::UnOp::Neg, expr) => { + if matches!(expr.kind, hir::ExprKind::Lit(_)) { Literal } else { Complex } + } + hir::ExprKind::Lit(_) => Literal, + hir::ExprKind::Tup([]) => Simple, + hir::ExprKind::Block(hir::Block { stmts: [], expr: Some(expr), .. }, _) => { + if classify(expr) == Complex { Complex } else { Simple } + } + // Paths with a self-type or arguments are too “complex” following our measure since + // they may leak private fields of structs (with feature `adt_const_params`). + // Consider: `<Self as Trait<{ Struct { private: () } }>>::CONSTANT`. + // Paths without arguments are definitely harmless though. + hir::ExprKind::Path(hir::QPath::Resolved(_, hir::Path { segments, .. })) => { + if segments.iter().all(|segment| segment.args.is_none()) { Simple } else { Complex } + } + // FIXME: Claiming that those kinds of QPaths are simple is probably not true if the Ty + // contains const arguments. Is there a *concise* way to check for this? + hir::ExprKind::Path(hir::QPath::TypeRelative(..)) => Simple, + // FIXME: Can they contain const arguments and thus leak private struct fields? + hir::ExprKind::Path(hir::QPath::LangItem(..)) => Simple, + _ => Complex, + } + } + + let classification = classify(value); + + if classification == Literal + && !value.span.from_expansion() + && let Ok(snippet) = tcx.sess.source_map().span_to_snippet(value.span) { + // For literals, we avoid invoking the pretty-printer and use the source snippet instead to + // preserve certain stylistic choices the user likely made for the sake legibility like + // + // * hexadecimal notation + // * underscores + // * character escapes + // + // FIXME: This passes through `-/*spacer*/0` verbatim. + snippet + } else if classification == Simple { + // Otherwise we prefer pretty-printing to get rid of extraneous whitespace, comments and + // other formatting artifacts. + id_to_string(&hir, body.hir_id) + } else if tcx.def_kind(hir.body_owner_def_id(body).to_def_id()) == DefKind::AnonConst { + // FIXME: Omit the curly braces if the enclosing expression is an array literal + // with a repeated element (an `ExprKind::Repeat`) as in such case it + // would not actually need any disambiguation. + "{ _ }".to_owned() + } else { + "_".to_owned() + } +} diff --git a/compiler/rustc_metadata/src/rmeta/mod.rs b/compiler/rustc_metadata/src/rmeta/mod.rs index 1f68e83e0ab..71269779d42 100644 --- a/compiler/rustc_metadata/src/rmeta/mod.rs +++ b/compiler/rustc_metadata/src/rmeta/mod.rs @@ -42,7 +42,7 @@ pub use decoder::provide_extern; use decoder::DecodeContext; pub(crate) use decoder::{CrateMetadata, CrateNumMap, MetadataBlob}; use encoder::EncodeContext; -pub use encoder::{encode_metadata, EncodedMetadata}; +pub use encoder::{encode_metadata, rendered_const, EncodedMetadata}; use rustc_span::hygiene::SyntaxContextData; mod decoder; diff --git a/src/librustdoc/clean/types.rs b/src/librustdoc/clean/types.rs index 9cf3c068b60..9134d5268da 100644 --- a/src/librustdoc/clean/types.rs +++ b/src/librustdoc/clean/types.rs @@ -22,6 +22,7 @@ use rustc_hir::lang_items::LangItem; use rustc_hir::{BodyId, Mutability}; use rustc_hir_analysis::check::intrinsic::intrinsic_operation_unsafety; use rustc_index::IndexVec; +use rustc_metadata::rendered_const; use rustc_middle::ty::fast_reject::SimplifiedType; use rustc_middle::ty::{self, TyCtxt, Visibility}; use rustc_resolve::rustdoc::{add_doc_fragment, attrs_to_doc_fragments, inner_docs, DocFragment}; @@ -35,7 +36,7 @@ use rustc_target::spec::abi::Abi; use crate::clean::cfg::Cfg; use crate::clean::external_path; use crate::clean::inline::{self, print_inlined_const}; -use crate::clean::utils::{is_literal_expr, print_const_expr, print_evaluated_const}; +use crate::clean::utils::{is_literal_expr, print_evaluated_const}; use crate::core::DocContext; use crate::formats::cache::Cache; use crate::formats::item_type::ItemType; @@ -2086,7 +2087,7 @@ impl Discriminant { /// Will be `None` in the case of cross-crate reexports, and may be /// simplified pub(crate) fn expr(&self, tcx: TyCtxt<'_>) -> Option<String> { - self.expr.map(|body| print_const_expr(tcx, body)) + self.expr.map(|body| rendered_const(tcx, body)) } /// Will always be a machine readable number, without underscores or suffixes. pub(crate) fn value(&self, tcx: TyCtxt<'_>) -> String { @@ -2326,7 +2327,7 @@ impl ConstantKind { ConstantKind::TyConst { ref expr } => expr.to_string(), ConstantKind::Extern { def_id } => print_inlined_const(tcx, def_id), ConstantKind::Local { body, .. } | ConstantKind::Anonymous { body } => { - print_const_expr(tcx, body) + rendered_const(tcx, body) } } } diff --git a/src/librustdoc/clean/utils.rs b/src/librustdoc/clean/utils.rs index a86bbcc7679..7696ea0f449 100644 --- a/src/librustdoc/clean/utils.rs +++ b/src/librustdoc/clean/utils.rs @@ -14,6 +14,7 @@ use rustc_ast::tokenstream::TokenTree; use rustc_hir as hir; use rustc_hir::def::{DefKind, Res}; use rustc_hir::def_id::{DefId, LocalDefId, LOCAL_CRATE}; +use rustc_metadata::rendered_const; use rustc_middle::mir; use rustc_middle::mir::interpret::ConstValue; use rustc_middle::ty::{self, GenericArgKind, GenericArgsRef, TyCtxt}; @@ -255,7 +256,7 @@ pub(crate) fn print_const(cx: &DocContext<'_>, n: ty::Const<'_>) -> String { match n.kind() { ty::ConstKind::Unevaluated(ty::UnevaluatedConst { def, args: _ }) => { let s = if let Some(def) = def.as_local() { - print_const_expr(cx.tcx, cx.tcx.hir().body_owned_by(def)) + rendered_const(cx.tcx, cx.tcx.hir().body_owned_by(def)) } else { inline::print_inlined_const(cx.tcx, def) }; @@ -367,100 +368,6 @@ pub(crate) fn is_literal_expr(tcx: TyCtxt<'_>, hir_id: hir::HirId) -> bool { false } -/// Build a textual representation of an unevaluated constant expression. -/// -/// If the const expression is too complex, an underscore `_` is returned. -/// For const arguments, it's `{ _ }` to be precise. -/// This means that the output is not necessarily valid Rust code. -/// -/// Currently, only -/// -/// * literals (optionally with a leading `-`) -/// * unit `()` -/// * blocks (`{ … }`) around simple expressions and -/// * paths without arguments -/// -/// are considered simple enough. Simple blocks are included since they are -/// necessary to disambiguate unit from the unit type. -/// This list might get extended in the future. -/// -/// Without this censoring, in a lot of cases the output would get too large -/// and verbose. Consider `match` expressions, blocks and deeply nested ADTs. -/// Further, private and `doc(hidden)` fields of structs would get leaked -/// since HIR datatypes like the `body` parameter do not contain enough -/// semantic information for this function to be able to hide them – -/// at least not without significant performance overhead. -/// -/// Whenever possible, prefer to evaluate the constant first and try to -/// use a different method for pretty-printing. Ideally this function -/// should only ever be used as a fallback. -pub(crate) fn print_const_expr(tcx: TyCtxt<'_>, body: hir::BodyId) -> String { - let hir = tcx.hir(); - let value = &hir.body(body).value; - - #[derive(PartialEq, Eq)] - enum Classification { - Literal, - Simple, - Complex, - } - - use Classification::*; - - fn classify(expr: &hir::Expr<'_>) -> Classification { - match &expr.kind { - hir::ExprKind::Unary(hir::UnOp::Neg, expr) => { - if matches!(expr.kind, hir::ExprKind::Lit(_)) { Literal } else { Complex } - } - hir::ExprKind::Lit(_) => Literal, - hir::ExprKind::Tup([]) => Simple, - hir::ExprKind::Block(hir::Block { stmts: [], expr: Some(expr), .. }, _) => { - if classify(expr) == Complex { Complex } else { Simple } - } - // Paths with a self-type or arguments are too “complex” following our measure since - // they may leak private fields of structs (with feature `adt_const_params`). - // Consider: `<Self as Trait<{ Struct { private: () } }>>::CONSTANT`. - // Paths without arguments are definitely harmless though. - hir::ExprKind::Path(hir::QPath::Resolved(_, hir::Path { segments, .. })) => { - if segments.iter().all(|segment| segment.args.is_none()) { Simple } else { Complex } - } - // FIXME: Claiming that those kinds of QPaths are simple is probably not true if the Ty - // contains const arguments. Is there a *concise* way to check for this? - hir::ExprKind::Path(hir::QPath::TypeRelative(..)) => Simple, - // FIXME: Can they contain const arguments and thus leak private struct fields? - hir::ExprKind::Path(hir::QPath::LangItem(..)) => Simple, - _ => Complex, - } - } - - let classification = classify(value); - - if classification == Literal - && !value.span.from_expansion() - && let Ok(snippet) = tcx.sess.source_map().span_to_snippet(value.span) { - // For literals, we avoid invoking the pretty-printer and use the source snippet instead to - // preserve certain stylistic choices the user likely made for the sake legibility like - // - // * hexadecimal notation - // * underscores - // * character escapes - // - // FIXME: This passes through `-/*spacer*/0` verbatim. - snippet - } else if classification == Simple { - // Otherwise we prefer pretty-printing to get rid of extraneous whitespace, comments and - // other formatting artifacts. - rustc_hir_pretty::id_to_string(&hir, body.hir_id) - } else if tcx.def_kind(hir.body_owner_def_id(body).to_def_id()) == DefKind::AnonConst { - // FIXME: Omit the curly braces if the enclosing expression is an array literal - // with a repeated element (an `ExprKind::Repeat`) as in such case it - // would not actually need any disambiguation. - "{ _ }".to_owned() - } else { - "_".to_owned() - } -} - /// Given a type Path, resolve it to a Type using the TyCtxt pub(crate) fn resolve_type(cx: &mut DocContext<'_>, path: Path) -> Type { debug!("resolve_type({path:?})"); diff --git a/src/librustdoc/json/conversions.rs b/src/librustdoc/json/conversions.rs index 66b5798797f..0c18f5687f5 100644 --- a/src/librustdoc/json/conversions.rs +++ b/src/librustdoc/json/conversions.rs @@ -8,6 +8,7 @@ use std::fmt; use rustc_ast::ast; use rustc_hir::{def::CtorKind, def::DefKind, def_id::DefId}; +use rustc_metadata::rendered_const; use rustc_middle::ty::{self, TyCtxt}; use rustc_span::symbol::sym; use rustc_span::{Pos, Symbol}; @@ -15,7 +16,6 @@ use rustc_target::spec::abi::Abi as RustcAbi; use rustdoc_json_types::*; -use crate::clean::utils::print_const_expr; use crate::clean::{self, ItemId}; use crate::formats::item_type::ItemType; use crate::json::JsonRenderer; @@ -805,7 +805,7 @@ impl FromWithTcx<clean::Static> for Static { Static { type_: stat.type_.into_tcx(tcx), mutable: stat.mutability == ast::Mutability::Mut, - expr: stat.expr.map(|e| print_const_expr(tcx, e)).unwrap_or_default(), + expr: stat.expr.map(|e| rendered_const(tcx, e)).unwrap_or_default(), } } } diff --git a/tests/rustdoc/show-const-contents.rs b/tests/rustdoc/show-const-contents.rs index 69e742ee747..91df03adbbc 100644 --- a/tests/rustdoc/show-const-contents.rs +++ b/tests/rustdoc/show-const-contents.rs @@ -47,7 +47,7 @@ pub struct MyTypeWithStr(&'static str); // @!hasraw show_const_contents/constant.MY_TYPE_WITH_STR.html '; //' pub const MY_TYPE_WITH_STR: MyTypeWithStr = MyTypeWithStr("show this"); -// @hasraw show_const_contents/constant.PI.html '= 3.14159265358979323846264338327950288f32;' +// @hasraw show_const_contents/constant.PI.html '= 3.14159265358979323846264338327950288_f32;' // @hasraw show_const_contents/constant.PI.html '; // 3.14159274f32' pub use std::f32::consts::PI; |