diff options
Diffstat (limited to 'compiler')
| -rw-r--r-- | compiler/rustc_codegen_ssa/Cargo.toml | 1 | ||||
| -rw-r--r-- | compiler/rustc_codegen_ssa/src/mir/block.rs | 32 | ||||
| -rw-r--r-- | compiler/rustc_lint_defs/src/builtin.rs | 33 | ||||
| -rw-r--r-- | compiler/rustc_monomorphize/src/collector.rs | 30 |
4 files changed, 90 insertions, 6 deletions
diff --git a/compiler/rustc_codegen_ssa/Cargo.toml b/compiler/rustc_codegen_ssa/Cargo.toml index 30956fd1855..6a8971de746 100644 --- a/compiler/rustc_codegen_ssa/Cargo.toml +++ b/compiler/rustc_codegen_ssa/Cargo.toml @@ -26,6 +26,7 @@ rustc_hashes = { path = "../rustc_hashes" } rustc_hir = { path = "../rustc_hir" } rustc_incremental = { path = "../rustc_incremental" } rustc_index = { path = "../rustc_index" } +rustc_lint_defs = { path = "../rustc_lint_defs" } rustc_macros = { path = "../rustc_macros" } rustc_metadata = { path = "../rustc_metadata" } rustc_middle = { path = "../rustc_middle" } diff --git a/compiler/rustc_codegen_ssa/src/mir/block.rs b/compiler/rustc_codegen_ssa/src/mir/block.rs index e96590441fa..f151e24947e 100644 --- a/compiler/rustc_codegen_ssa/src/mir/block.rs +++ b/compiler/rustc_codegen_ssa/src/mir/block.rs @@ -5,6 +5,7 @@ use rustc_ast as ast; use rustc_ast::{InlineAsmOptions, InlineAsmTemplatePiece}; use rustc_data_structures::packed::Pu128; use rustc_hir::lang_items::LangItem; +use rustc_lint_defs::builtin::TAIL_CALL_TRACK_CALLER; use rustc_middle::mir::{self, AssertKind, InlineAsmMacro, SwitchTargets, UnwindTerminateReason}; use rustc_middle::ty::layout::{HasTyCtxt, LayoutOf, ValidityRequirement}; use rustc_middle::ty::print::{with_no_trimmed_paths, with_no_visible_paths}; @@ -906,7 +907,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { fn_span, ); - let instance = match instance.def { + match instance.def { // We don't need AsyncDropGlueCtorShim here because it is not `noop func`, // it is `func returning noop future` ty::InstanceKind::DropGlue(_, None) => { @@ -995,14 +996,35 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { intrinsic.name, ); } - instance + (Some(instance), None) } } } - _ => instance, - }; - (Some(instance), None) + _ if kind == CallKind::Tail + && instance.def.requires_caller_location(bx.tcx()) => + { + if let Some(hir_id) = + terminator.source_info.scope.lint_root(&self.mir.source_scopes) + { + let msg = "tail calling a function marked with `#[track_caller]` has no special effect"; + bx.tcx().node_lint(TAIL_CALL_TRACK_CALLER, hir_id, |d| { + _ = d.primary_message(msg).span(fn_span) + }); + } + + let instance = ty::Instance::resolve_for_fn_ptr( + bx.tcx(), + bx.typing_env(), + def_id, + generic_args, + ) + .unwrap(); + + (None, Some(bx.get_fn_addr(instance))) + } + _ => (Some(instance), None), + } } ty::FnPtr(..) => (None, Some(callee.immediate())), _ => bug!("{} is not callable", callee.layout.ty), diff --git a/compiler/rustc_lint_defs/src/builtin.rs b/compiler/rustc_lint_defs/src/builtin.rs index 3b84c6b6110..a258d26c817 100644 --- a/compiler/rustc_lint_defs/src/builtin.rs +++ b/compiler/rustc_lint_defs/src/builtin.rs @@ -5100,3 +5100,36 @@ declare_lint! { report_in_deps: true, }; } + +declare_lint! { + /// The `tail_call_track_caller` lint detects usage of `become` attempting to tail call + /// a function marked with `#[track_caller]`. + /// + /// ### Example + /// + /// ```rust + /// #![feature(explicit_tail_calls)] + /// #![expect(incomplete_features)] + /// + /// #[track_caller] + /// fn f() {} + /// + /// fn g() { + /// become f(); + /// } + /// + /// g(); + /// ``` + /// + /// {{produces}} + /// + /// ### Explanation + /// + /// Due to implementation details of tail calls and `#[track_caller]` attribute, calls to + /// functions marked with `#[track_caller]` cannot become tail calls. As such using `become` + /// is no different than a normal call (except for changes in drop order). + pub TAIL_CALL_TRACK_CALLER, + Warn, + "detects tail calls of functions marked with `#[track_caller]`", + @feature_gate = explicit_tail_calls; +} diff --git a/compiler/rustc_monomorphize/src/collector.rs b/compiler/rustc_monomorphize/src/collector.rs index 35b80a9b96f..5c94242b450 100644 --- a/compiler/rustc_monomorphize/src/collector.rs +++ b/compiler/rustc_monomorphize/src/collector.rs @@ -788,7 +788,35 @@ impl<'a, 'tcx> MirVisitor<'tcx> for MirUsedCollector<'a, 'tcx> { // *Before* monomorphizing, record that we already handled this mention. self.used_mentioned_items.insert(MentionedItem::Fn(callee_ty)); let callee_ty = self.monomorphize(callee_ty); - visit_fn_use(self.tcx, callee_ty, true, source, &mut self.used_items) + + // HACK(explicit_tail_calls): collect tail calls to `#[track_caller]` functions as indirect, + // because we later call them as such, to prevent issues with ABI incompatibility. + // Ideally we'd replace such tail calls with normal call + return, but this requires + // post-mono MIR optimizations, which we don't yet have. + let force_indirect_call = + if matches!(terminator.kind, mir::TerminatorKind::TailCall { .. }) + && let &ty::FnDef(def_id, args) = callee_ty.kind() + && let instance = ty::Instance::expect_resolve( + self.tcx, + ty::TypingEnv::fully_monomorphized(), + def_id, + args, + source, + ) + && instance.def.requires_caller_location(self.tcx) + { + true + } else { + false + }; + + visit_fn_use( + self.tcx, + callee_ty, + !force_indirect_call, + source, + &mut self.used_items, + ) } mir::TerminatorKind::Drop { ref place, .. } => { let ty = place.ty(self.body, self.tcx).ty; |