diff options
Diffstat (limited to 'compiler/rustc_mir/src')
| -rw-r--r-- | compiler/rustc_mir/src/transform/function_references.rs | 204 | ||||
| -rw-r--r-- | compiler/rustc_mir/src/transform/mod.rs | 2 |
2 files changed, 113 insertions, 93 deletions
diff --git a/compiler/rustc_mir/src/transform/function_references.rs b/compiler/rustc_mir/src/transform/function_references.rs index 2daa468136f..8adeac7623b 100644 --- a/compiler/rustc_mir/src/transform/function_references.rs +++ b/compiler/rustc_mir/src/transform/function_references.rs @@ -1,134 +1,154 @@ use rustc_hir::def_id::DefId; use rustc_middle::mir::visit::Visitor; use rustc_middle::mir::*; -use rustc_middle::ty::{self, Ty, TyCtxt}; -use rustc_session::lint::builtin::FUNCTION_REFERENCES; -use rustc_span::Span; +use rustc_middle::ty::{self, subst::GenericArgKind, PredicateAtom, Ty, TyCtxt, TyS}; +use rustc_session::lint::builtin::FUNCTION_ITEM_REFERENCES; +use rustc_span::{symbol::sym, Span}; use rustc_target::spec::abi::Abi; -use crate::transform::{MirPass, MirSource}; +use crate::transform::MirPass; -pub struct FunctionReferences; +pub struct FunctionItemReferences; -impl<'tcx> MirPass<'tcx> for FunctionReferences { - fn run_pass(&self, tcx: TyCtxt<'tcx>, _src: MirSource<'tcx>, body: &mut Body<'tcx>) { - let source_info = SourceInfo::outermost(body.span); - let mut checker = FunctionRefChecker { - tcx, - body, - potential_lints: Vec::new(), - casts: Vec::new(), - calls: Vec::new(), - source_info, - }; +impl<'tcx> MirPass<'tcx> for FunctionItemReferences { + fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { + let mut checker = FunctionItemRefChecker { tcx, body }; checker.visit_body(&body); } } -struct FunctionRefChecker<'a, 'tcx> { +struct FunctionItemRefChecker<'a, 'tcx> { tcx: TyCtxt<'tcx>, body: &'a Body<'tcx>, - potential_lints: Vec<FunctionRefLint>, - casts: Vec<Span>, - calls: Vec<Span>, - source_info: SourceInfo, } -impl<'a, 'tcx> Visitor<'tcx> for FunctionRefChecker<'a, 'tcx> { - fn visit_basic_block_data(&mut self, block: BasicBlock, data: &BasicBlockData<'tcx>) { - self.super_basic_block_data(block, data); - for cast_span in self.casts.drain(..) { - self.potential_lints.retain(|lint| lint.source_info.span != cast_span); - } - for call_span in self.calls.drain(..) { - self.potential_lints.retain(|lint| lint.source_info.span != call_span); - } - for lint in self.potential_lints.drain(..) { - lint.emit(self.tcx, self.body); - } - } - fn visit_statement(&mut self, statement: &Statement<'tcx>, location: Location) { - self.source_info = statement.source_info; - self.super_statement(statement, location); - } +impl<'a, 'tcx> Visitor<'tcx> for FunctionItemRefChecker<'a, 'tcx> { fn visit_terminator(&mut self, terminator: &Terminator<'tcx>, location: Location) { - self.source_info = terminator.source_info; if let TerminatorKind::Call { func, - args: _, + args, destination: _, cleanup: _, from_hir_call: _, fn_span: _, } = &terminator.kind { - let span = match func { - Operand::Copy(place) | Operand::Move(place) => { - self.body.local_decls[place.local].source_info.span + let func_ty = func.ty(self.body, self.tcx); + if let ty::FnDef(def_id, substs_ref) = *func_ty.kind() { + //check arguments for `std::mem::transmute` + if self.tcx.is_diagnostic_item(sym::transmute, def_id) { + let arg_ty = args[0].ty(self.body, self.tcx); + for generic_inner_ty in arg_ty.walk() { + if let GenericArgKind::Type(inner_ty) = generic_inner_ty.unpack() { + if let Some(fn_id) = FunctionItemRefChecker::is_fn_ref(inner_ty) { + let ident = self.tcx.item_name(fn_id).to_ident_string(); + let source_info = *self.body.source_info(location); + let span = self.nth_arg_span(&args, 0); + self.emit_lint(ident, fn_id, source_info, span); + } + } + } + } else { + //check arguments for any function with `std::fmt::Pointer` as a bound trait + let param_env = self.tcx.param_env(def_id); + let bounds = param_env.caller_bounds(); + for bound in bounds { + if let Some(bound_ty) = self.is_pointer_trait(&bound.skip_binders()) { + let arg_defs = self.tcx.fn_sig(def_id).skip_binder().inputs(); + for (arg_num, arg_def) in arg_defs.iter().enumerate() { + for generic_inner_ty in arg_def.walk() { + if let GenericArgKind::Type(inner_ty) = + generic_inner_ty.unpack() + { + //if any type reachable from the argument types in the fn sig matches the type bound by `Pointer` + if TyS::same_type(inner_ty, bound_ty) { + //check if this type is a function reference in the function call + let norm_ty = + self.tcx.subst_and_normalize_erasing_regions( + substs_ref, param_env, &inner_ty, + ); + if let Some(fn_id) = + FunctionItemRefChecker::is_fn_ref(norm_ty) + { + let ident = + self.tcx.item_name(fn_id).to_ident_string(); + let source_info = *self.body.source_info(location); + let span = self.nth_arg_span(&args, arg_num); + self.emit_lint(ident, fn_id, source_info, span); + } + } + } + } + } + } + } } - Operand::Constant(constant) => constant.span, - }; - self.calls.push(span); - }; + } + } self.super_terminator(terminator, location); } - fn visit_rvalue(&mut self, rvalue: &Rvalue<'tcx>, location: Location) { - match rvalue { - Rvalue::Ref(_, _, place) | Rvalue::AddressOf(_, place) => { - let decl = &self.body.local_decls[place.local]; - if let ty::FnDef(def_id, _) = decl.ty.kind { - let ident = self - .body - .var_debug_info - .iter() - .find(|info| info.source_info.span == decl.source_info.span) - .map(|info| info.name.to_ident_string()) - .unwrap_or(self.tcx.def_path_str(def_id)); - let lint = FunctionRefLint { ident, def_id, source_info: self.source_info }; - self.potential_lints.push(lint); - } - } - Rvalue::Cast(_, op, _) => { - let op_ty = op.ty(self.body, self.tcx); - if self.is_fn_ref(op_ty) { - self.casts.push(self.source_info.span); + //check for `std::fmt::Pointer::<T>::fmt` where T is a function reference + //this is used in formatting macros, but doesn't rely on the specific expansion + fn visit_operand(&mut self, operand: &Operand<'tcx>, location: Location) { + let op_ty = operand.ty(self.body, self.tcx); + if let ty::FnDef(def_id, substs_ref) = *op_ty.kind() { + if self.tcx.is_diagnostic_item(sym::pointer_trait_fmt, def_id) { + let param_ty = substs_ref.type_at(0); + if let Some(fn_id) = FunctionItemRefChecker::is_fn_ref(param_ty) { + let source_info = *self.body.source_info(location); + let callsite_ctxt = source_info.span.source_callsite().ctxt(); + let span = source_info.span.with_ctxt(callsite_ctxt); + let ident = self.tcx.item_name(fn_id).to_ident_string(); + self.emit_lint(ident, fn_id, source_info, span); } } - _ => {} } - self.super_rvalue(rvalue, location); + self.super_operand(operand, location); } } -impl<'a, 'tcx> FunctionRefChecker<'a, 'tcx> { - fn is_fn_ref(&self, ty: Ty<'tcx>) -> bool { - let referent_ty = match ty.kind { +impl<'a, 'tcx> FunctionItemRefChecker<'a, 'tcx> { + //return the bound parameter type if the trait is `std::fmt::Pointer` + fn is_pointer_trait(&self, bound: &PredicateAtom<'tcx>) -> Option<Ty<'tcx>> { + if let ty::PredicateAtom::Trait(predicate, _) = bound { + if self.tcx.is_diagnostic_item(sym::pointer_trait, predicate.def_id()) { + Some(predicate.trait_ref.self_ty()) + } else { + None + } + } else { + None + } + } + fn is_fn_ref(ty: Ty<'tcx>) -> Option<DefId> { + let referent_ty = match ty.kind() { ty::Ref(_, referent_ty, _) => Some(referent_ty), - ty::RawPtr(ty_and_mut) => Some(ty_and_mut.ty), + ty::RawPtr(ty_and_mut) => Some(&ty_and_mut.ty), _ => None, }; referent_ty - .map(|ref_ty| if let ty::FnDef(..) = ref_ty.kind { true } else { false }) - .unwrap_or(false) + .map( + |ref_ty| { + if let ty::FnDef(def_id, _) = *ref_ty.kind() { Some(def_id) } else { None } + }, + ) + .unwrap_or(None) } -} - -struct FunctionRefLint { - ident: String, - def_id: DefId, - source_info: SourceInfo, -} - -impl<'tcx> FunctionRefLint { - fn emit(&self, tcx: TyCtxt<'tcx>, body: &Body<'tcx>) { - let def_id = self.def_id; - let source_info = self.source_info; - let lint_root = body.source_scopes[source_info.scope] + fn nth_arg_span(&self, args: &Vec<Operand<'tcx>>, n: usize) -> Span { + match &args[n] { + Operand::Copy(place) | Operand::Move(place) => { + self.body.local_decls[place.local].source_info.span + } + Operand::Constant(constant) => constant.span, + } + } + fn emit_lint(&self, ident: String, fn_id: DefId, source_info: SourceInfo, span: Span) { + let lint_root = self.body.source_scopes[source_info.scope] .local_data .as_ref() .assert_crate_local() .lint_root; - let fn_sig = tcx.fn_sig(def_id); + let fn_sig = self.tcx.fn_sig(fn_id); let unsafety = fn_sig.unsafety().prefix_str(); let abi = match fn_sig.abi() { Abi::Rust => String::from(""), @@ -142,17 +162,17 @@ impl<'tcx> FunctionRefLint { let num_args = fn_sig.inputs().map_bound(|inputs| inputs.len()).skip_binder(); let variadic = if fn_sig.c_variadic() { ", ..." } else { "" }; let ret = if fn_sig.output().skip_binder().is_unit() { "" } else { " -> _" }; - tcx.struct_span_lint_hir(FUNCTION_REFERENCES, lint_root, source_info.span, |lint| { + self.tcx.struct_span_lint_hir(FUNCTION_ITEM_REFERENCES, lint_root, span, |lint| { lint.build(&format!( "cast `{}` with `as {}{}fn({}{}){}` to use it as a pointer", - self.ident, + ident, unsafety, abi, vec!["_"; num_args].join(", "), variadic, ret, )) - .emit() + .emit(); }); } } diff --git a/compiler/rustc_mir/src/transform/mod.rs b/compiler/rustc_mir/src/transform/mod.rs index 3f50420b86b..e43a238c1ba 100644 --- a/compiler/rustc_mir/src/transform/mod.rs +++ b/compiler/rustc_mir/src/transform/mod.rs @@ -267,7 +267,7 @@ fn mir_const<'tcx>( // MIR-level lints. &check_packed_ref::CheckPackedRef, &check_const_item_mutation::CheckConstItemMutation, - &function_references::FunctionReferences, + &function_references::FunctionItemReferences, // What we need to do constant evaluation. &simplify::SimplifyCfg::new("initial"), &rustc_peek::SanityCheck, |