1 files changed, 144 insertions, 2 deletions

diff --git a/lib/CodeGen/AsmPrinter/Win64Exception.cpp b/lib/CodeGen/AsmPrinter/Win64Exception.cpp
index 0f0ad75..2b03877 100644
--- a/lib/CodeGen/AsmPrinter/Win64Exception.cpp
+++ b/lib/CodeGen/AsmPrinter/Win64Exception.cpp
@@ -60,7 +60,7 @@ void Win64Exception::beginFunction(const MachineFunction *MF) {
 
   const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
   unsigned PerEncoding = TLOF.getPersonalityEncoding();
-  const Function *Per = MMI->getPersonalities()[MMI->getPersonalityIndex()];
+  const Function *Per = MF->getMMI().getPersonality();
 
   shouldEmitPersonality = hasLandingPads &&
     PerEncoding != dwarf::DW_EH_PE_omit && Per;
@@ -99,9 +99,151 @@ void Win64Exception::endFunction(const MachineFunction *) {
 
   if (shouldEmitPersonality) {
     Asm->OutStreamer.PushSection();
+
+    // Emit an UNWIND_INFO struct describing the prologue.
     Asm->OutStreamer.EmitWinEHHandlerData();
-    emitExceptionTable();
+
+    // Emit the tables appropriate to the personality function in use. If we
+    // don't recognize the personality, assume it uses an Itanium-style LSDA.
+    EHPersonality Per = MMI->getPersonalityType();
+    if (Per == EHPersonality::MSVC_Win64SEH)
+      emitCSpecificHandlerTable();
+    else
+      emitExceptionTable();
+
     Asm->OutStreamer.PopSection();
   }
   Asm->OutStreamer.EmitWinCFIEndProc();
 }
+
+const MCSymbolRefExpr *Win64Exception::createImageRel32(const MCSymbol *Value) {
+  return MCSymbolRefExpr::Create(Value, MCSymbolRefExpr::VK_COFF_IMGREL32,
+                                 Asm->OutContext);
+}
+
+/// Emit the language-specific data that __C_specific_handler expects.  This
+/// handler lives in the x64 Microsoft C runtime and allows catching or cleaning
+/// up after faults with __try, __except, and __finally.  The typeinfo values
+/// are not really RTTI data, but pointers to filter functions that return an
+/// integer (1, 0, or -1) indicating how to handle the exception. For __finally
+/// blocks and other cleanups, the landing pad label is zero, and the filter
+/// function is actually a cleanup handler with the same prototype.  A catch-all
+/// entry is modeled with a null filter function field and a non-zero landing
+/// pad label.
+///
+/// Possible filter function return values:
+///   EXCEPTION_EXECUTE_HANDLER (1):
+///     Jump to the landing pad label after cleanups.
+///   EXCEPTION_CONTINUE_SEARCH (0):
+///     Continue searching this table or continue unwinding.
+///   EXCEPTION_CONTINUE_EXECUTION (-1):
+///     Resume execution at the trapping PC.
+///
+/// Inferred table structure:
+///   struct Table {
+///     int NumEntries;
+///     struct Entry {
+///       imagerel32 LabelStart;
+///       imagerel32 LabelEnd;
+///       imagerel32 FilterOrFinally;  // One means catch-all.
+///       imagerel32 LabelLPad;        // Zero means __finally.
+///     } Entries[NumEntries];
+///   };
+void Win64Exception::emitCSpecificHandlerTable() {
+  const std::vector<LandingPadInfo> &PadInfos = MMI->getLandingPads();
+
+  // Simplifying assumptions for first implementation:
+  // - Cleanups are not implemented.
+  // - Filters are not implemented.
+
+  // The Itanium LSDA table sorts similar landing pads together to simplify the
+  // actions table, but we don't need that.
+  SmallVector<const LandingPadInfo *, 64> LandingPads;
+  LandingPads.reserve(PadInfos.size());
+  for (const auto &LP : PadInfos)
+    LandingPads.push_back(&LP);
+
+  // Compute label ranges for call sites as we would for the Itanium LSDA, but
+  // use an all zero action table because we aren't using these actions.
+  SmallVector<unsigned, 64> FirstActions;
+  FirstActions.resize(LandingPads.size());
+  SmallVector<CallSiteEntry, 64> CallSites;
+  computeCallSiteTable(CallSites, LandingPads, FirstActions);
+
+  MCSymbol *EHFuncBeginSym =
+      Asm->GetTempSymbol("eh_func_begin", Asm->getFunctionNumber());
+  MCSymbol *EHFuncEndSym =
+      Asm->GetTempSymbol("eh_func_end", Asm->getFunctionNumber());
+
+  // Emit the number of table entries.
+  unsigned NumEntries = 0;
+  for (const CallSiteEntry &CSE : CallSites) {
+    if (!CSE.LPad)
+      continue; // Ignore gaps.
+    for (int Selector : CSE.LPad->TypeIds) {
+      // Ignore C++ filter clauses in SEH.
+      // FIXME: Implement cleanup clauses.
+      if (isCatchEHSelector(Selector))
+        ++NumEntries;
+    }
+  }
+  Asm->OutStreamer.EmitIntValue(NumEntries, 4);
+
+  // Emit the four-label records for each call site entry. The table has to be
+  // sorted in layout order, and the call sites should already be sorted.
+  for (const CallSiteEntry &CSE : CallSites) {
+    // Ignore gaps. Unlike the Itanium model, unwinding through a frame without
+    // an EH table entry will propagate the exception rather than terminating
+    // the program.
+    if (!CSE.LPad)
+      continue;
+    const LandingPadInfo *LPad = CSE.LPad;
+
+    // Compute the label range. We may reuse the function begin and end labels
+    // rather than forming new ones.
+    const MCExpr *Begin =
+        createImageRel32(CSE.BeginLabel ? CSE.BeginLabel : EHFuncBeginSym);
+    const MCExpr *End;
+    if (CSE.EndLabel) {
+      // The interval is half-open, so we have to add one to include the return
+      // address of the last invoke in the range.
+      End = MCBinaryExpr::CreateAdd(createImageRel32(CSE.EndLabel),
+                                    MCConstantExpr::Create(1, Asm->OutContext),
+                                    Asm->OutContext);
+    } else {
+      End = createImageRel32(EHFuncEndSym);
+    }
+
+    // These aren't really type info globals, they are actually pointers to
+    // filter functions ordered by selector. The zero selector is used for
+    // cleanups, so slot zero corresponds to selector 1.
+    const std::vector<const GlobalValue *> &SelectorToFilter = MMI->getTypeInfos();
+
+    // Do a parallel iteration across typeids and clause labels, skipping filter
+    // clauses.
+    size_t NextClauseLabel = 0;
+    for (size_t I = 0, E = LPad->TypeIds.size(); I < E; ++I) {
+      // AddLandingPadInfo stores the clauses in reverse, but there is a FIXME
+      // to change that.
+      int Selector = LPad->TypeIds[E - I - 1];
+
+      // Ignore C++ filter clauses in SEH.
+      // FIXME: Implement cleanup clauses.
+      if (!isCatchEHSelector(Selector))
+        continue;
+
+      Asm->OutStreamer.EmitValue(Begin, 4);
+      Asm->OutStreamer.EmitValue(End, 4);
+      if (isCatchEHSelector(Selector)) {
+        assert(unsigned(Selector - 1) < SelectorToFilter.size());
+        const GlobalValue *TI = SelectorToFilter[Selector - 1];
+        if (TI) // Emit the filter function pointer.
+          Asm->OutStreamer.EmitValue(createImageRel32(Asm->getSymbol(TI)), 4);
+        else  // Otherwise, this is a "catch i8* null", or catch all.
+          Asm->OutStreamer.EmitIntValue(1, 4);
+      }
+      MCSymbol *ClauseLabel = LPad->ClauseLabels[NextClauseLabel++];
+      Asm->OutStreamer.EmitValue(createImageRel32(ClauseLabel), 4);
+    }
+  }
+}