Fix issues reported by static analyzer tool (#1787)

Author: adurang

lib/SPIRV/SPIRVLowerBitCastToNonStandardType.cpp

@@ -203,7 +203,7 @@ SPIRVLowerBitCastToNonStandardTypePass::run(Function &F,
     // Some vector-valued instructions were replaced with undef values, so if
     // that's what we got, it's still a dead instruction.
     if (VH.pointsToAliveValue() && !isa<UndefValue>(VH)) {
-      auto *VT = dyn_cast<VectorType>(VH->getType());
+      auto *VT = cast<VectorType>(VH->getType());
       report_fatal_error(Twine("Unsupported vector type with ") +
                              Twine(VT->getElementCount().getFixedValue()) +
                              Twine(" elements"),

lib/SPIRV/SPIRVReader.cpp

@@ -1425,12 +1425,12 @@ Value *SPIRVToLLVM::transValueWithoutDecoration(SPIRVValue *BV, Function *F,
     case OpTypeVector:
       return mapValue(BV, ConstantVector::get(CV));
     case OpTypeMatrix:
-    case OpTypeArray:
-      return mapValue(
-          BV, ConstantArray::get(dyn_cast<ArrayType>(transType(BCC->getType())),
-                                 CV));
+    case OpTypeArray: {
+      auto *AT = cast<ArrayType>(transType(BCC->getType()));
+      return mapValue(BV, ConstantArray::get(AT, CV));
+    }
     case OpTypeStruct: {
-      auto BCCTy = dyn_cast<StructType>(transType(BCC->getType()));
+      auto *BCCTy = cast<StructType>(transType(BCC->getType()));
       auto Members = BCCTy->getNumElements();
       auto Constants = CV.size();
       // if we try to initialize constant TypeStruct, add bitcasts
@@ -1447,9 +1447,7 @@ Value *SPIRVToLLVM::transValueWithoutDecoration(SPIRVValue *BV, Function *F,
         }
       }
 
-      return mapValue(BV,
-                      ConstantStruct::get(
-                          dyn_cast<StructType>(transType(BCC->getType())), CV));
+      return mapValue(BV, ConstantStruct::get(BCCTy, CV));
     }
     default:
       llvm_unreachable("not implemented");

lib/SPIRV/SPIRVToOCL.cpp

@@ -73,8 +73,8 @@ void SPIRVToOCLBase::visitCallInst(CallInst &CI) {
     case OpenCLLIB::Printf: {
       // TODO: Lower the printf instruction with the non-constant address space
       // format string to suitable for OpenCL representation
-      if (dyn_cast<PointerType>(CI.getOperand(0)->getType())
-              ->getAddressSpace() == SPIR::TypeAttributeEnum::ATTR_CONST)
+      auto *PT = dyn_cast<PointerType>(CI.getOperand(0)->getType());
+      if (PT && PT->getAddressSpace() == SPIR::TypeAttributeEnum::ATTR_CONST)
         visitCallSPIRVPrintf(&CI, ExtOp);
       break;
     }

lib/SPIRV/SPIRVUtil.cpp

@@ -1381,8 +1381,10 @@ Value *getScalarOrArray(Value *V, unsigned Size, Instruction *Pos) {
   auto GEP = cast<GEPOperator>(V);
   assert(GEP->getNumOperands() == 3 && "must be a GEP from an array");
   assert(GEP->getSourceElementType()->getArrayNumElements() == Size);
-  assert(dyn_cast<ConstantInt>(GEP->getOperand(1))->getZExtValue() == 0);
-  assert(dyn_cast<ConstantInt>(GEP->getOperand(2))->getZExtValue() == 0);
+  [[maybe_unused]] auto *OP1 = cast<ConstantInt>(GEP->getOperand(1));
+  [[maybe_unused]] auto *OP2 = cast<ConstantInt>(GEP->getOperand(2));
+  assert(OP1->getZExtValue() == 0);
+  assert(OP2->getZExtValue() == 0);
   return new LoadInst(GEP->getSourceElementType(), GEP->getOperand(0), "", Pos);
 }
 

lib/SPIRV/libSPIRV/SPIRVError.h

@@ -164,6 +164,9 @@ inline bool SPIRVErrorLog::checkError(bool Cond, SPIRVErrorCode ErrCode,
     break;
   case SPIRVDbgErrorHandlingKinds::Ignore:
     // Still print info about the error into debug output stream
+    // TODO: The value Ignore is not currently used but if it would be used
+    // then places where this routine is called must be checked as just
+    // ignoring the error may lead to NULL pointer dereferences
     spvdbgs() << SS.str() << '\n';
     spvdbgs().flush();
     break;