[SPV->LLVM] Fix global c/dtors type if SPV is from opaque type LLVM

lib/SPIRV/SPIRVReader.cpp

@@ -3286,10 +3286,11 @@ bool SPIRVToLLVM::translate() {
 
   for (unsigned I = 0, E = BM->getNumVariables(); I != E; ++I) {
     auto *BV = BM->getVariable(I);
-    if (BV->getStorageClass() != StorageClassFunction)
-      transValue(BV, nullptr, nullptr);
-    else
+    if (BV->getName() == "llvm.global_ctors" ||
+        BV->getName() == "llvm.global_dtors")
       transGlobalCtorDtors(BV);
+    else if (BV->getStorageClass() != StorageClassFunction)
+      transValue(BV, nullptr, nullptr);
   }
 
   // Then translate all debug instructions.
@@ -3768,13 +3769,56 @@ bool SPIRVToLLVM::transDecoration(SPIRVValue *BV, Value *V) {
   return true;
 }
 
-void SPIRVToLLVM::transGlobalCtorDtors(SPIRVVariable *BV) {
-  if (BV->getName() != "llvm.global_ctors" &&
-      BV->getName() != "llvm.global_dtors")
-    return;
+/// When spirv is generated from LLVM IR with opaque pointer enabled and then
+/// the spirv is translated to LLVM IR with typed pointer, function pointer is
+/// casted to i8* type in GlobalVariable \p GV, which causes error in LLVM IR
+/// verifier. E.g.
+///   [1 x %0][%0 { i32 1, i8* bitcast (void ()* @ctor to i8*), i8* null }]
+/// This function removes the cast so that LLVM IR is valid.
+static GlobalVariable *mutateGlobalCtorDtors(GlobalVariable *GV) {
+  if (!GV->hasInitializer())
+    return GV;
+  auto *InitArr = cast<ConstantArray>(GV->getInitializer());
+  unsigned NumEltsInArr = InitArr->getType()->getNumElements();
+  if (NumEltsInArr == 0)
+    return GV;
+  auto *CS = cast<ConstantStruct>(InitArr->getAggregateElement(0u));
+  auto *Elt1 = CS->getAggregateElement(1);
+  if (!isa<ConstantExpr>(Elt1))
+    return GV;
+
+  auto *STy = CS->getType();
+  assert(STy->getNumElements() == 3 &&
+         "expect 3 fields in global variable element struct type");
+  auto *NewSTy = StructType::create(GV->getContext(),
+                                    {STy->getElementType(0),
+                                     Elt1->stripPointerCasts()->getType(),
+                                     STy->getElementType(2)},
+                                    STy->getName(), STy->isPacked());
+  auto *NewTy = ArrayType::get(NewSTy, NumEltsInArr);
+  SmallVector<Constant *, 4> ArrElts;
+  for (unsigned I = 0; I < NumEltsInArr; ++I) {
+    auto *CS = cast<ConstantStruct>(InitArr->getAggregateElement(I));
+    ArrElts.push_back(ConstantStruct::get(
+        NewSTy, {CS->getAggregateElement(0u),
+                 CS->getAggregateElement(1)->stripPointerCasts(),
+                 CS->getAggregateElement(2)}));
+  }
+  auto *NewInitializer = ConstantArray::get(NewTy, ArrElts);
+  auto *NewGV = new GlobalVariable(
+      *GV->getParent(), NewTy, GV->isConstant(), GV->getLinkage(),
+      NewInitializer, "", 0, GV->getThreadLocalMode(), GV->getAddressSpace(),
+      GV->isExternallyInitialized());
+  NewGV->copyAttributesFrom(GV);
+  NewGV->takeName(GV);
+  GV->eraseFromParent();
+  return NewGV;
+}
 
-  Value *V = transValue(BV, nullptr, nullptr);
-  cast<GlobalValue>(V)->setLinkage(GlobalValue::AppendingLinkage);
+void SPIRVToLLVM::transGlobalCtorDtors(SPIRVVariable *BV) {
+  GlobalVariable *V = cast<GlobalVariable>(transValue(BV, nullptr, nullptr));
+  V = mutateGlobalCtorDtors(V);
+  V->setLinkage(GlobalVariable::AppendingLinkage);
 }
 
 void SPIRVToLLVM::createCXXStructor(const char *ListName,

test/transcoding/SPV_INTEL_function_pointers/global_ctor_dtor_opaque.spt

@@ -0,0 +1,54 @@
+119734787 65792 393230 22 0
+2 Capability Addresses
+2 Capability Linkage
+2 Capability Kernel
+2 Capability Int64
+2 Capability Int8
+2 Capability FunctionPointersINTEL
+8 Extension "SPV_INTEL_function_pointers"
+5 ExtInstImport 1 "OpenCL.std"
+3 MemoryModel 2 2
+3 Source 0 0
+7 Name 14 "asan.module_ctor"
+7 Name 15 "asan.module_ctor"
+7 Name 20 "llvm.global_ctors"
+
+9 Decorate 20 LinkageAttributes "llvm.global_ctors" Export
+4 TypeInt 3 32 0
+4 TypeInt 4 8 0
+4 TypeInt 6 64 0
+5 Constant 6 7 1 0
+4 Constant 3 10 1
+4 TypePointer 5 7 4
+5 TypeStruct 2 3 5 5
+
+4 TypeArray 8 2 7
+4 TypePointer 9 7 8
+2 TypeVoid 11
+3 TypeFunction 12 11
+4 TypePointer 13 7 12
+4 ConstantFunctionPointerINTEL 13 15 14
+5 SpecConstantOp 5 16 124 15
+3 ConstantNull 5 17
+6 ConstantComposite 2 18 10 16 17
+
+4 ConstantComposite 8 19 18
+
+5 Variable 9 20 7 19
+
+
+
+5 Function 11 14 0 12
+
+2 Label 21
+1 Return
+
+1 FunctionEnd
+
+; RUN: llvm-spirv %s --to-binary -o %t.spv
+; RUN: llvm-spirv -r %t.spv -o %t.bc
+; RUN: llvm-dis %t.bc -o %t.ll
+; RUN: FileCheck --input-file=%t.ll %s --check-prefix=CHECK-LLVM
+
+; CHECK-LLVM: [[TY:%.*]] = type { i32, void ()*, i8* }
+; CHECK-LLVM: @llvm.global_ctors = appending global [1 x [[TY]]] [[[TY]] { i32 1, void ()* @asan.module_ctor, i8* null }]