From ee982d4355a10790993ab65f80730ba75395e140 Mon Sep 17 00:00:00 2001 From: Ariel Ben-Yehuda Date: Tue, 23 May 2017 23:47:15 +0300 Subject: [PATCH] fix translation of MSVC funclets that loop to their own start --- src/librustc_data_structures/indexed_vec.rs | 7 ++ src/librustc_trans/common.rs | 9 -- src/librustc_trans/mir/analyze.rs | 10 +++ src/librustc_trans/mir/block.rs | 97 ++++++++++----------- src/librustc_trans/mir/mod.rs | 50 +++++++---- 5 files changed, 93 insertions(+), 80 deletions(-) diff --git a/src/librustc_data_structures/indexed_vec.rs b/src/librustc_data_structures/indexed_vec.rs index 0642ddc71622b..29ac650aa7053 100644 --- a/src/librustc_data_structures/indexed_vec.rs +++ b/src/librustc_data_structures/indexed_vec.rs @@ -212,6 +212,13 @@ impl IndexMut for IndexVec { } } +impl Default for IndexVec { + #[inline] + fn default() -> Self { + Self::new() + } +} + impl Extend for IndexVec { #[inline] fn extend>(&mut self, iter: J) { diff --git a/src/librustc_trans/common.rs b/src/librustc_trans/common.rs index efd4f13678502..903c74edd1c5e 100644 --- a/src/librustc_trans/common.rs +++ b/src/librustc_trans/common.rs @@ -191,15 +191,6 @@ impl Funclet { } } -impl Clone for Funclet { - fn clone(&self) -> Funclet { - Funclet { - cleanuppad: self.cleanuppad, - operand: OperandBundleDef::new("funclet", &[self.cleanuppad]), - } - } -} - pub fn val_ty(v: ValueRef) -> Type { unsafe { Type::from_ref(llvm::LLVMTypeOf(v)) diff --git a/src/librustc_trans/mir/analyze.rs b/src/librustc_trans/mir/analyze.rs index 0f95668302c88..45afcf51b5203 100644 --- a/src/librustc_trans/mir/analyze.rs +++ b/src/librustc_trans/mir/analyze.rs @@ -197,6 +197,16 @@ pub enum CleanupKind { Internal { funclet: mir::BasicBlock } } +impl CleanupKind { + pub fn funclet_bb(self, for_bb: mir::BasicBlock) -> Option { + match self { + CleanupKind::NotCleanup => None, + CleanupKind::Funclet => Some(for_bb), + CleanupKind::Internal { funclet } => Some(funclet), + } + } +} + pub fn cleanup_kinds<'a, 'tcx>(mir: &mir::Mir<'tcx>) -> IndexVec { fn discover_masters<'tcx>(result: &mut IndexVec, mir: &mir::Mir<'tcx>) { diff --git a/src/librustc_trans/mir/block.rs b/src/librustc_trans/mir/block.rs index f6c8ee0c82564..4926485a12125 100644 --- a/src/librustc_trans/mir/block.rs +++ b/src/librustc_trans/mir/block.rs @@ -19,8 +19,7 @@ use adt; use base::{self, Lifetime}; use callee; use builder::Builder; -use common::{self, Funclet}; -use common::{C_bool, C_str_slice, C_struct, C_u32, C_undef}; +use common::{self, C_bool, C_str_slice, C_struct, C_u32, C_undef}; use consts; use machine::llalign_of_min; use meth; @@ -28,95 +27,88 @@ use monomorphize; use type_of; use type_::Type; -use rustc_data_structures::indexed_vec::IndexVec; use syntax::symbol::Symbol; use std::cmp; use super::{MirContext, LocalRef}; -use super::analyze::CleanupKind; use super::constant::Const; use super::lvalue::{Alignment, LvalueRef}; use super::operand::OperandRef; use super::operand::OperandValue::{Pair, Ref, Immediate}; impl<'a, 'tcx> MirContext<'a, 'tcx> { - pub fn trans_block(&mut self, bb: mir::BasicBlock, - funclets: &IndexVec>) { + pub fn trans_block(&mut self, bb: mir::BasicBlock) { let mut bcx = self.get_builder(bb); let data = &self.mir[bb]; debug!("trans_block({:?}={:?})", bb, data); - let funclet = match self.cleanup_kinds[bb] { - CleanupKind::Internal { funclet } => funclets[funclet].as_ref(), - _ => funclets[bb].as_ref(), - }; - for statement in &data.statements { bcx = self.trans_statement(bcx, statement); } - self.trans_terminator(bcx, bb, data.terminator(), funclet); + self.trans_terminator(bcx, bb, data.terminator()); } fn trans_terminator(&mut self, mut bcx: Builder<'a, 'tcx>, bb: mir::BasicBlock, - terminator: &mir::Terminator<'tcx>, - funclet: Option<&Funclet>) + terminator: &mir::Terminator<'tcx>) { debug!("trans_terminator: {:?}", terminator); // Create the cleanup bundle, if needed. let tcx = bcx.tcx(); + let span = terminator.source_info.span; + let funclet_bb = self.cleanup_kinds[bb].funclet_bb(bb); + let funclet = funclet_bb.and_then(|funclet_bb| self.funclets[funclet_bb].as_ref()); + let cleanup_pad = funclet.map(|lp| lp.cleanuppad()); let cleanup_bundle = funclet.map(|l| l.bundle()); - let funclet_br = |this: &Self, bcx: Builder, bb: mir::BasicBlock| { - let lltarget = this.blocks[bb]; - if let Some(cp) = cleanup_pad { - match this.cleanup_kinds[bb] { - CleanupKind::Funclet => { - // micro-optimization: generate a `ret` rather than a jump - // to a return block - bcx.cleanup_ret(cp, Some(lltarget)); - } - CleanupKind::Internal { .. } => bcx.br(lltarget), - CleanupKind::NotCleanup => bug!("jump from cleanup bb to bb {:?}", bb) + let lltarget = |this: &mut Self, target: mir::BasicBlock| { + let lltarget = this.blocks[target]; + let target_funclet = this.cleanup_kinds[target].funclet_bb(target); + match (funclet_bb, target_funclet) { + (None, None) => (lltarget, false), + (Some(f), Some(t_f)) + if f == t_f || !base::wants_msvc_seh(tcx.sess) + => (lltarget, false), + (None, Some(_)) => { + // jump *into* cleanup - need a landing pad if GNU + (this.landing_pad_to(target), false) + } + (Some(_), None) => span_bug!(span, "{:?} - jump out of cleanup?", terminator), + (Some(_), Some(_)) => { + (this.landing_pad_to(target), true) } - } else { - bcx.br(lltarget); } }; let llblock = |this: &mut Self, target: mir::BasicBlock| { - let lltarget = this.blocks[target]; - - if let Some(cp) = cleanup_pad { - match this.cleanup_kinds[target] { - CleanupKind::Funclet => { - // MSVC cross-funclet jump - need a trampoline + let (lltarget, is_cleanupret) = lltarget(this, target); + if is_cleanupret { + // MSVC cross-funclet jump - need a trampoline + + debug!("llblock: creating cleanup trampoline for {:?}", target); + let name = &format!("{:?}_cleanup_trampoline_{:?}", bb, target); + let trampoline = this.new_block(name); + trampoline.cleanup_ret(cleanup_pad.unwrap(), Some(lltarget)); + trampoline.llbb() + } else { + lltarget + } + }; - debug!("llblock: creating cleanup trampoline for {:?}", target); - let name = &format!("{:?}_cleanup_trampoline_{:?}", bb, target); - let trampoline = this.new_block(name); - trampoline.cleanup_ret(cp, Some(lltarget)); - trampoline.llbb() - } - CleanupKind::Internal { .. } => lltarget, - CleanupKind::NotCleanup => - bug!("jump from cleanup bb {:?} to bb {:?}", bb, target) - } + let funclet_br = |this: &mut Self, bcx: Builder, target: mir::BasicBlock| { + let (lltarget, is_cleanupret) = lltarget(this, target); + if is_cleanupret { + // micro-optimization: generate a `ret` rather than a jump + // to a trampoline. + bcx.cleanup_ret(cleanup_pad.unwrap(), Some(lltarget)); } else { - if let (CleanupKind::NotCleanup, CleanupKind::Funclet) = - (this.cleanup_kinds[bb], this.cleanup_kinds[target]) - { - // jump *into* cleanup - need a landing pad if GNU - this.landing_pad_to(target) - } else { - lltarget - } + bcx.br(lltarget); } }; @@ -168,7 +160,6 @@ impl<'a, 'tcx> MirContext<'a, 'tcx> { } }; - let span = terminator.source_info.span; self.set_debug_loc(&bcx, terminator.source_info); match terminator.kind { mir::TerminatorKind::Resume => { @@ -752,7 +743,7 @@ impl<'a, 'tcx> MirContext<'a, 'tcx> { fn landing_pad_uncached(&mut self, target_bb: BasicBlockRef) -> BasicBlockRef { if base::wants_msvc_seh(self.ccx.sess()) { - return target_bb; + span_bug!(self.mir.span, "landing pad was not inserted?") } let bcx = self.new_block("cleanup"); diff --git a/src/librustc_trans/mir/mod.rs b/src/librustc_trans/mir/mod.rs index 19a556bf3f0f9..c54dfb375c0b6 100644 --- a/src/librustc_trans/mir/mod.rs +++ b/src/librustc_trans/mir/mod.rs @@ -69,6 +69,10 @@ pub struct MirContext<'a, 'tcx:'a> { /// The funclet status of each basic block cleanup_kinds: IndexVec, + /// When targeting MSVC, this stores the cleanup info for each funclet + /// BB. This is initialized as we compute the funclets' head block in RPO. + funclets: &'a IndexVec>, + /// This stores the landing-pad block for a given BB, computed lazily on GNU /// and eagerly on MSVC. landing_pads: IndexVec>, @@ -202,8 +206,11 @@ pub fn trans_mir<'a, 'tcx: 'a>( debuginfo::create_function_debug_context(ccx, instance, sig, llfn, mir); let bcx = Builder::new_block(ccx, llfn, "start"); - let cleanup_kinds = analyze::cleanup_kinds(&mir); + if mir.basic_blocks().iter().any(|bb| bb.is_cleanup) { + bcx.set_personality_fn(ccx.eh_personality()); + } + let cleanup_kinds = analyze::cleanup_kinds(&mir); // Allocate a `Block` for every basic block, except // the start block, if nothing loops back to it. let reentrant_start_block = !mir.predecessors_for(mir::START_BLOCK).is_empty(); @@ -218,6 +225,7 @@ pub fn trans_mir<'a, 'tcx: 'a>( // Compute debuginfo scopes from MIR scopes. let scopes = debuginfo::create_mir_scopes(ccx, mir, &debug_context); + let (landing_pads, funclets) = create_funclets(&bcx, &cleanup_kinds, &block_bcxs); let mut mircx = MirContext { mir: mir, @@ -228,7 +236,8 @@ pub fn trans_mir<'a, 'tcx: 'a>( blocks: block_bcxs, unreachable_block: None, cleanup_kinds: cleanup_kinds, - landing_pads: IndexVec::from_elem(None, mir.basic_blocks()), + landing_pads: landing_pads, + funclets: &funclets, scopes: scopes, locals: IndexVec::new(), debug_context: debug_context, @@ -306,28 +315,13 @@ pub fn trans_mir<'a, 'tcx: 'a>( // emitting should be enabled. debuginfo::start_emitting_source_locations(&mircx.debug_context); - let funclets: IndexVec> = - mircx.cleanup_kinds.iter_enumerated().map(|(bb, cleanup_kind)| { - if let CleanupKind::Funclet = *cleanup_kind { - let bcx = mircx.get_builder(bb); - unsafe { - llvm::LLVMSetPersonalityFn(mircx.llfn, mircx.ccx.eh_personality()); - } - if base::wants_msvc_seh(ccx.sess()) { - return Some(Funclet::new(bcx.cleanup_pad(None, &[]))); - } - } - - None - }).collect(); - let rpo = traversal::reverse_postorder(&mir); let mut visited = BitVector::new(mir.basic_blocks().len()); // Translate the body of each block using reverse postorder for (bb, _) in rpo { visited.insert(bb.index()); - mircx.trans_block(bb, &funclets); + mircx.trans_block(bb); } // Remove blocks that haven't been visited, or have no @@ -343,6 +337,26 @@ pub fn trans_mir<'a, 'tcx: 'a>( } } +fn create_funclets<'a, 'tcx>( + bcx: &Builder<'a, 'tcx>, + cleanup_kinds: &IndexVec, + block_bcxs: &IndexVec) + -> (IndexVec>, + IndexVec>) +{ + block_bcxs.iter_enumerated().zip(cleanup_kinds).map(|((bb, &llbb), cleanup_kind)| { + match *cleanup_kind { + CleanupKind::Funclet if base::wants_msvc_seh(bcx.sess()) => { + let cleanup_bcx = bcx.build_sibling_block(&format!("funclet_{:?}", bb)); + let cleanup = cleanup_bcx.cleanup_pad(None, &[]); + cleanup_bcx.br(llbb); + (Some(cleanup_bcx.llbb()), Some(Funclet::new(cleanup))) + } + _ => (None, None) + } + }).unzip() +} + /// Produce, for each argument, a `ValueRef` pointing at the /// argument's value. As arguments are lvalues, these are always /// indirect.