llvm · Jul 31, 2015
diff --git a/‎clang/include/clang/Driver/CC1Options.td
+2 b/‎clang/include/clang/Driver/CC1Options.td
+2
diff --git a/‎clang/include/clang/Frontend/CodeGenOptions.def
+1 b/‎clang/include/clang/Frontend/CodeGenOptions.def
+1
diff --git a/‎clang/lib/CodeGen/CGCleanup.cpp
+19-1 b/‎clang/lib/CodeGen/CGCleanup.cpp
+19-1
diff --git a/‎clang/lib/CodeGen/CGCleanup.h
+34-4 b/‎clang/lib/CodeGen/CGCleanup.h
+34-4
@@ -486,6 +486,8 @@ def fblocks_runtime_optional : Flag<["-"], "fblocks-runtime-optional">,
   HelpText<"Weakly link in the blocks runtime">;
 def fsjlj_exceptions : Flag<["-"], "fsjlj-exceptions">,
   HelpText<"Use SjLj style exceptions">;
+def fnew_ms_eh: Flag<["-"], "fnew-ms-eh">,
+  HelpText<"Use the new IR representation for MS exceptions">;
 def split_dwarf_file : Separate<["-"], "split-dwarf-file">,
   HelpText<"File name to use for split dwarf debug info output">;
 def fno_wchar : Flag<["-"], "fno-wchar">,
 
@@ -33,6 +33,7 @@ CODEGENOPT(CompressDebugSections, 1, 0) ///< -Wa,-compress-debug-sections
 CODEGENOPT(Autolink          , 1, 1) ///< -fno-autolink
 CODEGENOPT(AsmVerbose        , 1, 0) ///< -dA, -fverbose-asm.
 CODEGENOPT(ObjCAutoRefCountExceptions , 1, 0) ///< Whether ARC should be EH-safe.
+CODEGENOPT(NewMSEH           , 1, 0) ///< Whether we should use the new IR representation for MS exceptions
 CODEGENOPT(CoverageExtraChecksum, 1, 0) ///< Whether we need a second checksum for functions in GCNO files.
 CODEGENOPT(CoverageNoFunctionNamesInData, 1, 0) ///< Do not include function names in GCDA files.
 CODEGENOPT(CoverageExitBlockBeforeBody, 1, 0) ///< Whether to emit the exit block before the body blocks in GCNO files.
 
@@ -247,6 +247,13 @@ void EHScopeStack::pushTerminate() {
   InnermostEHScope = stable_begin();
 }
 
+void EHScopeStack::pushCatchEnd(llvm::BasicBlock *CatchEndBlockBB) {
+  char *Buffer = allocate(EHCatchEndScope::getSize());
+  auto *CES = new (Buffer) EHCatchEndScope(InnermostEHScope);
+  CES->setCachedEHDispatchBlock(CatchEndBlockBB);
+  InnermostEHScope = stable_begin();
+}
+
 /// Remove any 'null' fixups on the stack.  However, we can't pop more
 /// fixups than the fixup depth on the innermost normal cleanup, or
 /// else fixups that we try to add to that cleanup will end up in the
@@ -896,6 +903,14 @@ void CodeGenFunction::PopCleanupBlock(bool FallthroughIsBranchThrough) {
     CGBuilderTy::InsertPoint SavedIP = Builder.saveAndClearIP();
 
     EmitBlock(EHEntry);
+    llvm::BasicBlock *NextAction = getEHDispatchBlock(EHParent);
+    if (CGM.getCodeGenOpts().NewMSEH &&
+        EHPersonality::get(*this).isMSVCPersonality()) {
+      if (NextAction)
+        Builder.CreateCleanupPad(VoidTy, NextAction);
+      else
+        Builder.CreateCleanupPad(VoidTy, {});
+    }
 
     // We only actually emit the cleanup code if the cleanup is either
     // active or was used before it was deactivated.
@@ -905,7 +920,10 @@ void CodeGenFunction::PopCleanupBlock(bool FallthroughIsBranchThrough) {
       EmitCleanup(*this, Fn, cleanupFlags, EHActiveFlag);
     }
 
-    Builder.CreateBr(getEHDispatchBlock(EHParent));
+    if (CGM.getCodeGenOpts().NewMSEH && EHPersonality::get(*this).isMSVCPersonality())
+      Builder.CreateCleanupRet(NextAction);
+    else
+      Builder.CreateBr(NextAction);
 
     Builder.restoreIP(SavedIP);
 
 
@@ -40,9 +40,9 @@ class EHScope {
 
   class CommonBitFields {
     friend class EHScope;
-    unsigned Kind : 2;
+    unsigned Kind : 3;
   };
-  enum { NumCommonBits = 2 };
+  enum { NumCommonBits = 3 };
 
 protected:
   class CatchBitFields {
@@ -81,7 +81,7 @@ class EHScope {
     /// The number of fixups required by enclosing scopes (not including
     /// this one).  If this is the top cleanup scope, all the fixups
     /// from this index onwards belong to this scope.
-    unsigned FixupDepth : 32 - 18 - NumCommonBits; // currently 13
+    unsigned FixupDepth : 32 - 18 - NumCommonBits; // currently 12
   };
 
   class FilterBitFields {
@@ -99,7 +99,7 @@ class EHScope {
   };
 
 public:
-  enum Kind { Cleanup, Catch, Terminate, Filter };
+  enum Kind { Cleanup, Catch, Terminate, Filter, CatchEnd };
 
   EHScope(Kind kind, EHScopeStack::stable_iterator enclosingEHScope)
     : CachedLandingPad(nullptr), CachedEHDispatchBlock(nullptr),
@@ -466,6 +466,17 @@ class EHTerminateScope : public EHScope {
   }
 };
 
+class EHCatchEndScope : public EHScope {
+public:
+  EHCatchEndScope(EHScopeStack::stable_iterator enclosingEHScope)
+      : EHScope(CatchEnd, enclosingEHScope) {}
+  static size_t getSize() { return sizeof(EHCatchEndScope); }
+
+  static bool classof(const EHScope *scope) {
+    return scope->getKind() == CatchEnd;
+  }
+};
+
 /// A non-stable pointer into the scope stack.
 class EHScopeStack::iterator {
   char *Ptr;
@@ -503,6 +514,10 @@ class EHScopeStack::iterator {
     case EHScope::Terminate:
       Size = EHTerminateScope::getSize();
       break;
+
+    case EHScope::CatchEnd:
+      Size = EHCatchEndScope::getSize();
+      break;
     }
     Ptr += llvm::RoundUpToAlignment(Size, ScopeStackAlignment);
     return *this;
@@ -551,6 +566,14 @@ inline void EHScopeStack::popTerminate() {
   deallocate(EHTerminateScope::getSize());
 }
 
+inline void EHScopeStack::popCatchEnd() {
+  assert(!empty() && "popping exception stack when not empty");
+
+  EHCatchEndScope &scope = cast<EHCatchEndScope>(*begin());
+  InnermostEHScope = scope.getEnclosingEHScope();
+  deallocate(EHCatchEndScope::getSize());
+}
+
 inline EHScopeStack::iterator EHScopeStack::find(stable_iterator sp) const {
   assert(sp.isValid() && "finding invalid savepoint");
   assert(sp.Size <= stable_begin().Size && "finding savepoint after pop");
@@ -588,6 +611,13 @@ struct EHPersonality {
   static const EHPersonality MSVC_except_handler;
   static const EHPersonality MSVC_C_specific_handler;
   static const EHPersonality MSVC_CxxFrameHandler3;
+
+  bool isMSVCPersonality() const {
+    return this == &MSVC_except_handler || this == &MSVC_C_specific_handler ||
+           this == &MSVC_CxxFrameHandler3;
+  }
+
+  bool isMSVCXXPersonality() const { return this == &MSVC_CxxFrameHandler3; }
 };
 }
 }