Refactor check for dllimport in the Verifier

[• espindola]

Summary

This avoids duplicated code and now also rejects dllimport aliases.

[rnk]

lgtm

[• espindola]

r326814

lib/IR/Verifier.cpp

if (GV.hasAppendingLinkage()) {
     const GlobalVariable *GVar = dyn_cast<GlobalVariable>(&GV);
     Assert(GVar && GVar->getValueType()->isArrayTy(),
            "Only global arrays can have appending linkage!", GVar);
   }
 
   if (GV.isDeclarationForLinker())
     Assert(!GV.hasComdat(), "Declaration may not be in a Comdat!", &GV);
 
-  if (GV.hasDLLImportStorageClass())
+  if (GV.hasDLLImportStorageClass()) {
     Assert(!GV.isDSOLocal(),
            "GlobalValue with DLLImport Storage is dso_local!", &GV);
 
+    Assert((GV.isDeclaration() && GV.hasExternalLinkage()) ||
+               GV.hasAvailableExternallyLinkage(),
+           "Global is marked as dllimport, but not external", &GV);
+  }
+
   if (GV.hasLocalLinkage())
     Assert(GV.isDSOLocal(),
            "GlobalValue with private or internal linkage must be dso_local!",
            &GV);
 
   if (!GV.hasDefaultVisibility() && !GV.hasExternalWeakLinkage())
     Assert(GV.isDSOLocal(),
            "GlobalValue with non default visibility must be dso_local!", &GV);
if (ArrayType *ATy = dyn_cast<ArrayType>(GVType)) {
                      isa<GlobalAlias>(V),
                  "invalid llvm.used member", V);
           Assert(V->hasName(), "members of llvm.used must be named", V);
         }
       }
     }
   }
 
-  Assert(!GV.hasDLLImportStorageClass() ||
-             (GV.isDeclaration() && GV.hasExternalLinkage()) ||
-             GV.hasAvailableExternallyLinkage(),
-         "Global is marked as dllimport, but not external", &GV);
-
   // Visit any debug info attachments.
   SmallVector<MDNode *, 1> MDs;
   GV.getMetadata(LLVMContext::MD_dbg, MDs);
   for (auto *MD : MDs) {
     if (auto *GVE = dyn_cast<DIGlobalVariableExpression>(MD))
       visitDIGlobalVariableExpression(*GVE);
     else
       AssertDI(false, "!dbg attachment of global variable must be a "
void Verifier::visitFunction(const Function &F) {
   // Only do this if the module is materialized, otherwise we don't have all the
   // uses.
   if (F.getIntrinsicID() && F.getParent()->isMaterialized()) {
     const User *U;
     if (F.hasAddressTaken(&U))
       Assert(false, "Invalid user of intrinsic instruction!", U);
   }
 
-  Assert(!F.hasDLLImportStorageClass() ||
-             (F.isDeclaration() && F.hasExternalLinkage()) ||
-             F.hasAvailableExternallyLinkage(),
-         "Function is marked as dllimport, but not external.", &F);
-
   auto *N = F.getSubprogram();
   HasDebugInfo = (N != nullptr);
   if (!HasDebugInfo)
     return;
 
   // Check that all !dbg attachments lead to back to N (or, at least, another
   // subprogram that describes the same function).
   //

test/Bitcode/compatibility.ll

 @a.hidden = hidden alias i32, i32* @g.hidden
 ; CHECK: @a.hidden = hidden alias i32, i32* @g.hidden
 @a.protected = protected alias i32, i32* @g.protected
 ; CHECK: @a.protected = protected alias i32, i32* @g.protected
 
 ; Aliases -- DLLStorageClass
 @a.dlldefault = default alias i32, i32* @g.dlldefault
 ; CHECK: @a.dlldefault = alias i32, i32* @g.dlldefault
[e-mail] = dllimport alias i32, i32* @g1
-; CHECK: @a.dllimport = dllimport alias i32, i32* @g1
 @a.dllexport = dllexport alias i32, i32* @g.dllexport
 ; CHECK: @a.dllexport = dllexport alias i32, i32* @g.dllexport
 
 ; Aliases -- ThreadLocal
 @a.notthreadlocal = alias i32, i32* @g.notthreadlocal
 ; CHECK: @a.notthreadlocal = alias i32, i32* @g.notthreadlocal
 @a.generaldynamic = thread_local alias i32, i32* @g.generaldynamic
 ; CHECK: @a.generaldynamic = thread_local alias i32, i32* @g.generaldynamic