1 files changed, 45 insertions, 18 deletions

diff --git a/lib/AsmParser/LLParser.cpp b/lib/AsmParser/LLParser.cpp
index e5813f0d21..b457672d77 100644
--- a/lib/AsmParser/LLParser.cpp
+++ b/lib/AsmParser/LLParser.cpp
@@ -630,10 +630,11 @@ static bool isValidVisibilityForLinkage(unsigned V, unsigned L) {
 /// ParseAlias:
 ///   ::= GlobalVar '=' OptionalVisibility OptionalDLLStorageClass 'alias'
 ///                     OptionalLinkage Aliasee
+///   ::= GlobalVar '=' OptionalVisibility OptionalDLLStorageClass 'alias'
+///                     OptionalLinkage OptionalAddrSpace Type, Aliasee
+///
 /// Aliasee
 ///   ::= TypeAndValue
-///   ::= 'bitcast' '(' TypeAndValue 'to' Type ')'
-///   ::= 'getelementptr' 'inbounds'? '(' ... ')'
 ///
 /// Everything through DLL storage class has already been parsed.
 ///
@@ -655,28 +656,49 @@ bool LLParser::ParseAlias(const std::string &Name, LocTy NameLoc,
     return Error(LinkageLoc,
                  "symbol with local linkage must have default visibility");
 
-  Constant *Aliasee;
-  LocTy AliaseeLoc = Lex.getLoc();
-  if (Lex.getKind() != lltok::kw_bitcast &&
-      Lex.getKind() != lltok::kw_getelementptr) {
-    if (ParseGlobalTypeAndValue(Aliasee)) return true;
+  bool HasAddrSpace = Lex.getKind() == lltok::kw_addrspace;
+  unsigned AddrSpace;
+  LocTy AddrSpaceLoc = Lex.getLoc();
+  if (ParseOptionalAddrSpace(AddrSpace))
+    return true;
+
+  LocTy TyLoc = Lex.getLoc();
+  Type *Ty = nullptr;
+  if (ParseType(Ty))
+    return true;
+
+  bool DifferentType = EatIfPresent(lltok::comma);
+  if (HasAddrSpace && !DifferentType)
+    return Error(AddrSpaceLoc, "A type is required if addrspace is given");
+
+  Type *AliaseeType = nullptr;
+  if (DifferentType) {
+    if (ParseType(AliaseeType))
+      return true;
   } else {
-    // The bitcast dest type is not present, it is implied by the dest type.
-    ValID ID;
-    if (ParseValID(ID)) return true;
-    if (ID.Kind != ValID::t_Constant)
-      return Error(AliaseeLoc, "invalid aliasee");
-    Aliasee = ID.ConstantVal;
+    AliaseeType = Ty;
+    auto *PTy = dyn_cast<PointerType>(Ty);
+    if (!PTy)
+      return Error(TyLoc, "An alias must have pointer type");
+    Ty = PTy->getElementType();
+    AddrSpace = PTy->getAddressSpace();
   }
 
-  if (!Aliasee->getType()->isPointerTy())
-    return Error(AliaseeLoc, "alias must have pointer type");
+  LocTy AliaseeLoc = Lex.getLoc();
+  Constant *C;
+  if (ParseGlobalValue(AliaseeType, C))
+    return true;
+
+  auto *Aliasee = dyn_cast<GlobalObject>(C);
+  if (!Aliasee)
+    return Error(AliaseeLoc, "Alias must point to function or variable");
+
+  assert(Aliasee->getType()->isPointerTy());
 
   // Okay, create the alias but do not insert it into the module yet.
-  PointerType *PTy = cast<PointerType>(Aliasee->getType());
   std::unique_ptr<GlobalAlias> GA(
-      new GlobalAlias(PTy->getElementType(), (GlobalValue::LinkageTypes)Linkage,
-                      Name, Aliasee, nullptr, PTy->getAddressSpace()));
+      new GlobalAlias(Ty, (GlobalValue::LinkageTypes)Linkage, Name, Aliasee,
+                      /*Parent*/ nullptr, AddrSpace));
   GA->setVisibility((GlobalValue::VisibilityTypes)Visibility);
   GA->setDLLStorageClass((GlobalValue::DLLStorageClassTypes)DLLStorageClass);
 
@@ -698,6 +720,11 @@ bool LLParser::ParseAlias(const std::string &Name, LocTy NameLoc,
 
     // If they agree, just RAUW the old value with the alias and remove the
     // forward ref info.
+    for (auto *User : Val->users()) {
+      if (auto *GA = dyn_cast<GlobalAlias>(User))
+        return Error(NameLoc, "Alias is pointed by alias " + GA->getName());
+    }
+
     Val->replaceAllUsesWith(GA.get());
     Val->eraseFromParent();
     ForwardRefVals.erase(I);