diff options
Diffstat (limited to 'compiler/rustc_codegen_ssa/src')
| -rw-r--r-- | compiler/rustc_codegen_ssa/src/mir/analyze.rs | 2 | ||||
| -rw-r--r-- | compiler/rustc_codegen_ssa/src/mir/block.rs | 149 | ||||
| -rw-r--r-- | compiler/rustc_codegen_ssa/src/mir/mod.rs | 7 |
3 files changed, 81 insertions, 77 deletions
diff --git a/compiler/rustc_codegen_ssa/src/mir/analyze.rs b/compiler/rustc_codegen_ssa/src/mir/analyze.rs index 3f5b46333d9..7fda2d5fadf 100644 --- a/compiler/rustc_codegen_ssa/src/mir/analyze.rs +++ b/compiler/rustc_codegen_ssa/src/mir/analyze.rs @@ -285,7 +285,7 @@ pub fn cleanup_kinds(mir: &mir::Body<'_>) -> IndexVec<mir::BasicBlock, CleanupKi match data.terminator().kind { TerminatorKind::Goto { .. } | TerminatorKind::UnwindResume - | TerminatorKind::UnwindTerminate + | TerminatorKind::UnwindTerminate(_) | TerminatorKind::Return | TerminatorKind::GeneratorDrop | TerminatorKind::Unreachable diff --git a/compiler/rustc_codegen_ssa/src/mir/block.rs b/compiler/rustc_codegen_ssa/src/mir/block.rs index 19228183462..6aef1664394 100644 --- a/compiler/rustc_codegen_ssa/src/mir/block.rs +++ b/compiler/rustc_codegen_ssa/src/mir/block.rs @@ -12,7 +12,7 @@ use crate::MemFlags; use rustc_ast as ast; use rustc_ast::{InlineAsmOptions, InlineAsmTemplatePiece}; use rustc_hir::lang_items::LangItem; -use rustc_middle::mir::{self, AssertKind, SwitchTargets}; +use rustc_middle::mir::{self, AssertKind, SwitchTargets, UnwindTerminateReason}; use rustc_middle::ty::layout::{HasTyCtxt, LayoutOf, ValidityRequirement}; use rustc_middle::ty::print::{with_no_trimmed_paths, with_no_visible_paths}; use rustc_middle::ty::{self, Instance, Ty}; @@ -178,7 +178,7 @@ impl<'a, 'tcx> TerminatorCodegenHelper<'tcx> { mir::UnwindAction::Cleanup(cleanup) => Some(self.llbb_with_cleanup(fx, cleanup)), mir::UnwindAction::Continue => None, mir::UnwindAction::Unreachable => None, - mir::UnwindAction::Terminate => { + mir::UnwindAction::Terminate(reason) => { if fx.mir[self.bb].is_cleanup && base::wants_new_eh_instructions(fx.cx.tcx().sess) { // MSVC SEH will abort automatically if an exception tries to // propagate out from cleanup. @@ -191,7 +191,7 @@ impl<'a, 'tcx> TerminatorCodegenHelper<'tcx> { None } else { - Some(fx.terminate_block()) + Some(fx.terminate_block(reason)) } } }; @@ -264,7 +264,7 @@ impl<'a, 'tcx> TerminatorCodegenHelper<'tcx> { ) -> MergingSucc { let unwind_target = match unwind { mir::UnwindAction::Cleanup(cleanup) => Some(self.llbb_with_cleanup(fx, cleanup)), - mir::UnwindAction::Terminate => Some(fx.terminate_block()), + mir::UnwindAction::Terminate(reason) => Some(fx.terminate_block(reason)), mir::UnwindAction::Continue => None, mir::UnwindAction::Unreachable => None, }; @@ -649,12 +649,13 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { helper: TerminatorCodegenHelper<'tcx>, bx: &mut Bx, terminator: &mir::Terminator<'tcx>, + reason: UnwindTerminateReason, ) { let span = terminator.source_info.span; self.set_debug_loc(bx, terminator.source_info); // Obtain the panic entry point. - let (fn_abi, llfn) = common::build_langcall(bx, Some(span), LangItem::PanicCannotUnwind); + let (fn_abi, llfn) = common::build_langcall(bx, Some(span), reason.lang_item()); // Codegen the actual panic invoke/call. let merging_succ = helper.do_call( @@ -1229,8 +1230,8 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { MergingSucc::False } - mir::TerminatorKind::UnwindTerminate => { - self.codegen_terminate_terminator(helper, bx, terminator); + mir::TerminatorKind::UnwindTerminate(reason) => { + self.codegen_terminate_terminator(helper, bx, terminator, reason); MergingSucc::False } @@ -1579,79 +1580,81 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { }) } - fn terminate_block(&mut self) -> Bx::BasicBlock { - self.terminate_block.unwrap_or_else(|| { - let funclet; - let llbb; - let mut bx; - if base::wants_msvc_seh(self.cx.sess()) { - // This is a basic block that we're aborting the program for, - // notably in an `extern` function. These basic blocks are inserted - // so that we assert that `extern` functions do indeed not panic, - // and if they do we abort the process. - // - // On MSVC these are tricky though (where we're doing funclets). If - // we were to do a cleanuppad (like below) the normal functions like - // `longjmp` would trigger the abort logic, terminating the - // program. Instead we insert the equivalent of `catch(...)` for C++ - // which magically doesn't trigger when `longjmp` files over this - // frame. - // - // Lots more discussion can be found on #48251 but this codegen is - // modeled after clang's for: - // - // try { - // foo(); - // } catch (...) { - // bar(); - // } - // - // which creates an IR snippet like - // - // cs_terminate: - // %cs = catchswitch within none [%cp_terminate] unwind to caller - // cp_terminate: - // %cp = catchpad within %cs [null, i32 64, null] - // ... - - llbb = Bx::append_block(self.cx, self.llfn, "cs_terminate"); - let cp_llbb = Bx::append_block(self.cx, self.llfn, "cp_terminate"); - - let mut cs_bx = Bx::build(self.cx, llbb); - let cs = cs_bx.catch_switch(None, None, &[cp_llbb]); - - // The "null" here is actually a RTTI type descriptor for the - // C++ personality function, but `catch (...)` has no type so - // it's null. The 64 here is actually a bitfield which - // represents that this is a catch-all block. - bx = Bx::build(self.cx, cp_llbb); - let null = - bx.const_null(bx.type_ptr_ext(bx.cx().data_layout().instruction_address_space)); - let sixty_four = bx.const_i32(64); - funclet = Some(bx.catch_pad(cs, &[null, sixty_four, null])); - } else { - llbb = Bx::append_block(self.cx, self.llfn, "terminate"); - bx = Bx::build(self.cx, llbb); + fn terminate_block(&mut self, reason: UnwindTerminateReason) -> Bx::BasicBlock { + if let Some((cached_bb, cached_reason)) = self.terminate_block && reason == cached_reason { + return cached_bb; + } - let llpersonality = self.cx.eh_personality(); - bx.filter_landing_pad(llpersonality); + let funclet; + let llbb; + let mut bx; + if base::wants_msvc_seh(self.cx.sess()) { + // This is a basic block that we're aborting the program for, + // notably in an `extern` function. These basic blocks are inserted + // so that we assert that `extern` functions do indeed not panic, + // and if they do we abort the process. + // + // On MSVC these are tricky though (where we're doing funclets). If + // we were to do a cleanuppad (like below) the normal functions like + // `longjmp` would trigger the abort logic, terminating the + // program. Instead we insert the equivalent of `catch(...)` for C++ + // which magically doesn't trigger when `longjmp` files over this + // frame. + // + // Lots more discussion can be found on #48251 but this codegen is + // modeled after clang's for: + // + // try { + // foo(); + // } catch (...) { + // bar(); + // } + // + // which creates an IR snippet like + // + // cs_terminate: + // %cs = catchswitch within none [%cp_terminate] unwind to caller + // cp_terminate: + // %cp = catchpad within %cs [null, i32 64, null] + // ... + + llbb = Bx::append_block(self.cx, self.llfn, "cs_terminate"); + let cp_llbb = Bx::append_block(self.cx, self.llfn, "cp_terminate"); + + let mut cs_bx = Bx::build(self.cx, llbb); + let cs = cs_bx.catch_switch(None, None, &[cp_llbb]); + + // The "null" here is actually a RTTI type descriptor for the + // C++ personality function, but `catch (...)` has no type so + // it's null. The 64 here is actually a bitfield which + // represents that this is a catch-all block. + bx = Bx::build(self.cx, cp_llbb); + let null = + bx.const_null(bx.type_ptr_ext(bx.cx().data_layout().instruction_address_space)); + let sixty_four = bx.const_i32(64); + funclet = Some(bx.catch_pad(cs, &[null, sixty_four, null])); + } else { + llbb = Bx::append_block(self.cx, self.llfn, "terminate"); + bx = Bx::build(self.cx, llbb); - funclet = None; - } + let llpersonality = self.cx.eh_personality(); + bx.filter_landing_pad(llpersonality); + + funclet = None; + } - self.set_debug_loc(&mut bx, mir::SourceInfo::outermost(self.mir.span)); + self.set_debug_loc(&mut bx, mir::SourceInfo::outermost(self.mir.span)); - let (fn_abi, fn_ptr) = common::build_langcall(&bx, None, LangItem::PanicCannotUnwind); - let fn_ty = bx.fn_decl_backend_type(&fn_abi); + let (fn_abi, fn_ptr) = common::build_langcall(&bx, None, reason.lang_item()); + let fn_ty = bx.fn_decl_backend_type(&fn_abi); - let llret = bx.call(fn_ty, None, Some(&fn_abi), fn_ptr, &[], funclet.as_ref()); - bx.do_not_inline(llret); + let llret = bx.call(fn_ty, None, Some(&fn_abi), fn_ptr, &[], funclet.as_ref()); + bx.do_not_inline(llret); - bx.unreachable(); + bx.unreachable(); - self.terminate_block = Some(llbb); - llbb - }) + self.terminate_block = Some((llbb, reason)); + llbb } /// Get the backend `BasicBlock` for a MIR `BasicBlock`, either already diff --git a/compiler/rustc_codegen_ssa/src/mir/mod.rs b/compiler/rustc_codegen_ssa/src/mir/mod.rs index ccf93f208d5..37a209cec5e 100644 --- a/compiler/rustc_codegen_ssa/src/mir/mod.rs +++ b/compiler/rustc_codegen_ssa/src/mir/mod.rs @@ -5,6 +5,7 @@ use rustc_index::IndexVec; use rustc_middle::mir; use rustc_middle::mir::interpret::ErrorHandled; use rustc_middle::mir::traversal; +use rustc_middle::mir::UnwindTerminateReason; use rustc_middle::ty::layout::{FnAbiOf, HasTyCtxt, TyAndLayout}; use rustc_middle::ty::{self, Instance, Ty, TyCtxt, TypeFoldable, TypeVisitableExt}; use rustc_target::abi::call::{FnAbi, PassMode}; @@ -83,8 +84,8 @@ pub struct FunctionCx<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> { /// Cached unreachable block unreachable_block: Option<Bx::BasicBlock>, - /// Cached terminate upon unwinding block - terminate_block: Option<Bx::BasicBlock>, + /// Cached terminate upon unwinding block and its reason + terminate_block: Option<(Bx::BasicBlock, UnwindTerminateReason)>, /// The location where each MIR arg/var/tmp/ret is stored. This is /// usually an `PlaceRef` representing an alloca, but not always: @@ -174,7 +175,7 @@ pub fn codegen_mir<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>( let mut start_bx = Bx::build(cx, start_llbb); if mir.basic_blocks.iter().any(|bb| { - bb.is_cleanup || matches!(bb.terminator().unwind(), Some(mir::UnwindAction::Terminate)) + bb.is_cleanup || matches!(bb.terminator().unwind(), Some(mir::UnwindAction::Terminate(_))) }) { start_bx.set_personality_fn(cx.eh_personality()); } |