From 0a57f6551467db634bf8efa6585981a4a6dfd3c2 Mon Sep 17 00:00:00 2001 From: Reid Kleckner Date: Wed, 14 Jan 2015 01:05:27 +0000 Subject: CodeGen support for x86_64 SEH catch handlers in LLVM This adds handling for ExceptionHandling::MSVC, used by the x86_64-pc-windows-msvc triple. It assumes that filter functions have already been outlined in either the frontend or the backend. Filter functions are used in place of the landingpad catch clause type info operands. In catch clause order, the first filter to return true will catch the exception. The C specific handler table expects the landing pad to be split into one block per handler, but LLVM IR uses a single landing pad for all possible unwind actions. This patch papers over the mismatch by synthesizing single instruction BBs for every catch clause to fill in the EH selector that the landing pad block expects. Missing functionality: - Accessing data in the parent frame from outlined filters - Cleanups (from __finally) are unsupported, as they will require outlining and parent frame access - Filter clauses are unsupported, as there's no clear analogue in SEH In other words, this is the minimal set of changes needed to write IR to catch arbitrary exceptions and resume normal execution. Reviewers: majnemer Differential Revision: http://reviews.llvm.org/D6300 llvm-svn: 225904 --- llvm/lib/CodeGen/MachineModuleInfo.cpp | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'llvm/lib/CodeGen/MachineModuleInfo.cpp') diff --git a/llvm/lib/CodeGen/MachineModuleInfo.cpp b/llvm/lib/CodeGen/MachineModuleInfo.cpp index baad411e2c5..32d511285eb 100644 --- a/llvm/lib/CodeGen/MachineModuleInfo.cpp +++ b/llvm/lib/CodeGen/MachineModuleInfo.cpp @@ -452,6 +452,14 @@ void MachineModuleInfo::addCleanup(MachineBasicBlock *LandingPad) { LP.TypeIds.push_back(0); } +MCSymbol * +MachineModuleInfo::addClauseForLandingPad(MachineBasicBlock *LandingPad) { + MCSymbol *ClauseLabel = Context.CreateTempSymbol(); + LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad); + LP.ClauseLabels.push_back(ClauseLabel); + return ClauseLabel; +} + /// TidyLandingPads - Remap landing pad labels and remove any deleted landing /// pads. void MachineModuleInfo::TidyLandingPads(DenseMap *LPMap) { -- cgit v1.2.3