diff options
Diffstat (limited to 'components/script_plugins/trace_in_no_trace.rs')
| -rw-r--r-- | components/script_plugins/trace_in_no_trace.rs | 202 |
1 files changed, 0 insertions, 202 deletions
diff --git a/components/script_plugins/trace_in_no_trace.rs b/components/script_plugins/trace_in_no_trace.rs deleted file mode 100644 index 102f1ae68de..00000000000 --- a/components/script_plugins/trace_in_no_trace.rs +++ /dev/null @@ -1,202 +0,0 @@ -/* This Source Code Form is subject to the terms of the Mozilla Public - * License, v. 2.0. If a copy of the MPL was not distributed with this - * file, You can obtain one at https://mozilla.org/MPL/2.0/. */ - -use rustc_ast::ast::{AttrKind, Attribute}; -use rustc_ast::token::TokenKind; -use rustc_ast::tokenstream::TokenTree; -use rustc_ast::AttrArgs; -use rustc_driver::plugin::Registry; -use rustc_error_messages::MultiSpan; -use rustc_hir::{self as hir}; -use rustc_lint::{LateContext, LateLintPass, LintContext, LintPass}; -use rustc_middle::ty; -use rustc_session::declare_lint; -use rustc_span::symbol::Symbol; - -use crate::{get_trait_def_id, implements_trait, symbols}; - -declare_lint!( - TRACE_IN_NO_TRACE, - Deny, - "Warn and report incorrect usage of Traceable (jsmanaged) objects in must_not_have_traceable marked wrappers" -); - -declare_lint!( - EMPTY_TRACE_IN_NO_TRACE, - Warn, - "Warn about usage of empty Traceable objects in must_not_have_traceable marked wrappers" -); -const EMPTY_TRACE_IN_NO_TRACE_MSG: &str = - "must_not_have_traceable marked wrapper is not needed for types that implements \ -empty Traceable (like primitive types). Consider removing the wrapper."; - -pub fn register(reg: &mut Registry) { - let symbols = Symbols::new(); - reg.lint_store - .register_lints(&[&TRACE_IN_NO_TRACE, &EMPTY_TRACE_IN_NO_TRACE]); - reg.lint_store - .register_late_pass(move |_| Box::new(NotracePass::new(symbols.clone()))); -} - -/// Lint for ensuring safe usage of NoTrace wrappers -/// -/// This lint (disable with `-A trace-in-no-trace`/`#[allow(trace_in_no_trace)]`) ensures that -/// wrappers marked with must_not_have_traceable(i: usize) only stores -/// non-jsmanaged (DOES NOT implement JSTraceble) type in i-th generic -/// -/// For example usage look at the tests -pub(crate) struct NotracePass { - symbols: Symbols, -} - -impl NotracePass { - pub(crate) fn new(symbols: Symbols) -> Self { - Self { symbols } - } -} - -impl LintPass for NotracePass { - fn name(&self) -> &'static str { - "ServoNotracePass" - } -} - -fn get_must_not_have_traceable(sym: &Symbols, attrs: &[Attribute]) -> Option<usize> { - attrs - .iter() - .find(|attr| { - matches!( - &attr.kind, - AttrKind::Normal(normal) - if normal.item.path.segments.len() == 2 && - normal.item.path.segments[0].ident.name == sym.trace_in_no_trace_lint && - normal.item.path.segments[1].ident.name == sym.must_not_have_traceable - ) - }) - .map(|x| match &x.get_normal_item().args { - AttrArgs::Empty => 0, - AttrArgs::Delimited(a) => match a - .tokens - .trees() - .next() - .expect("Arguments not found for must_not_have_traceable") - { - TokenTree::Token(tok, _) => match tok.kind { - TokenKind::Literal(lit) => lit.symbol.as_str().parse().unwrap(), - _ => panic!("must_not_have_traceable expected integer literal here"), - }, - TokenTree::Delimited(_, _, _) => { - todo!("must_not_have_traceable does not support multiple notraceable positions") - }, - }, - _ => { - panic!("must_not_have_traceable does not support key-value arguments") - }, - }) -} - -fn is_jstraceable<'tcx>(cx: &LateContext<'tcx>, ty: ty::Ty<'tcx>) -> bool { - // TODO(sagudev): get_trait_def_id is expensive, use lazy and cache it for whole pass - if let Some(trait_id) = get_trait_def_id(cx, &["mozjs", "gc", "Traceable"]) { - return implements_trait(cx, ty, trait_id, &[]); - } - // when running tests - if let Some(trait_id) = get_trait_def_id( - cx, - &[ - "script_plugins_tests", - "trace_in_no_trace_lint", - "JSTraceable", - ], - ) { - return implements_trait(cx, ty, trait_id, &[]); - } - panic!("JSTraceable not found"); -} - -/// Gives warrning or errors for incorect usage of NoTrace like `NoTrace<impl Traceable>`. -fn incorrect_no_trace<'tcx, I: Into<MultiSpan> + Copy>( - sym: &'_ Symbols, - cx: &LateContext<'tcx>, - ty: ty::Ty<'tcx>, - span: I, -) { - let mut walker = ty.walk(); - while let Some(generic_arg) = walker.next() { - let t = match generic_arg.unpack() { - rustc_middle::ty::subst::GenericArgKind::Type(t) => t, - _ => { - walker.skip_current_subtree(); - continue; - }, - }; - let recur_into_subtree = match t.kind() { - ty::Adt(did, substs) => { - if let Some(pos) = - get_must_not_have_traceable(sym, &cx.tcx.get_attrs_unchecked(did.did())) - { - let inner = substs.type_at(pos); - if inner.is_primitive_ty() { - cx.lint( - EMPTY_TRACE_IN_NO_TRACE, - EMPTY_TRACE_IN_NO_TRACE_MSG, - |lint| lint.set_span(span), - ) - } else if is_jstraceable(cx, inner) { - cx.lint( - TRACE_IN_NO_TRACE, - format!( - "must_not_have_traceable marked wrapper must not have \ -jsmanaged inside on {pos}-th position. Consider removing the wrapper." - ), - |lint| lint.set_span(span), - ) - } - false - } else { - true - } - }, - _ => !t.is_primitive_ty(), - }; - if !recur_into_subtree { - walker.skip_current_subtree(); - } - } -} - -// NoTrace correct usage of NoTrace must only be checked on Struct (item) and Enums (variants) -// as these are the only ones that are actually traced -impl<'tcx> LateLintPass<'tcx> for NotracePass { - fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::Item) { - // TODO: better performance if we limit with lint attr??? - /*let attrs = cx.tcx.hir().attrs(item.hir_id()); - if has_lint_attr(&self.symbols, &attrs, self.symbols.must_root) { - return; - }*/ - if let hir::ItemKind::Struct(def, ..) = &item.kind { - for ref field in def.fields() { - let field_type = cx.tcx.type_of(field.def_id); - incorrect_no_trace(&self.symbols, cx, field_type.0, field.span); - } - } - } - - fn check_variant(&mut self, cx: &LateContext, var: &hir::Variant) { - match var.data { - hir::VariantData::Tuple(fields, ..) => { - for field in fields { - let field_type = cx.tcx.type_of(field.def_id); - incorrect_no_trace(&self.symbols, cx, field_type.0, field.ty.span); - } - }, - _ => (), // Struct variants already caught by check_struct_def - } - } -} - -symbols! { - trace_in_no_trace_lint - must_not_have_traceable -} |