[Flang][Unit Test] Move the declaration of kindMap to the class

[kiranchandramohan]

Summary

kindMap variable is declared in the Setup function but passed as
a reference to the firBuilder class. The firBuilder is declared in
the class and hence its lifetime exceeds that of kindMap. This can
lead to undefined behaviour. Move the kindMap variable into the class
to avoid this.

This is part of the upstreaming effort from the fir-dev branch in [1].
[1] https://github.com/flang-compiler/f18-llvm-project

[awarzynski]

LGTM, thanks!

flang/unittests/Optimizer/Builder/CharacterTest.cpp

 #include "flang/Optimizer/Builder/BoxValue.h"
 #include "flang/Optimizer/Builder/FIRBuilder.h"
 #include "flang/Optimizer/Support/InitFIR.h"
 #include "flang/Optimizer/Support/KindMapping.h"
 
 struct CharacterTest : public testing::Test {
 public:
   void SetUp() override {
-    fir::KindMapping kindMap(&context,
+    kindMap = std::make_unique<fir::KindMapping>(&context,
         "i10:80,l3:24,a1:8,r54:Double,c20:X86_FP80,r11:PPC_FP128,"
         "r12:FP128,r13:X86_FP80,r14:Double,r15:Float,r16:Half,r23:BFloat");
     mlir::OpBuilder builder(&context);
     auto loc = builder.getUnknownLoc();
 
     // Set up a Module with a dummy function operation inside.
     // Set the insertion point in the function entry block.
     mlir::ModuleOp mod = builder.create<mlir::ModuleOp>(loc);
     mlir::FuncOp func = mlir::FuncOp::create(
         loc, "func1", builder.getFunctionType(llvm::None, llvm::None));
     auto *entryBlock = func.addEntryBlock();
     mod.push_back(mod);
     builder.setInsertionPointToStart(entryBlock);
 
     fir::support::loadDialects(context);
-    firBuilder = std::make_unique<fir::FirOpBuilder>(mod, kindMap);
+    firBuilder = std::make_unique<fir::FirOpBuilder>(mod, *kindMap);
   }
 
   fir::FirOpBuilder &getBuilder() { return *firBuilder; }
 
   mlir::MLIRContext context;
+  std::unique_ptr<fir::KindMapping> kindMap;
   std::unique_ptr<fir::FirOpBuilder> firBuilder;
 };
 
 TEST_F(CharacterTest, smallUtilityFunctions) {
   auto builder = getBuilder();
   auto loc = builder.getUnknownLoc();
   llvm::StringRef strValue("onestringliteral");
   auto strLit = fir::factory::createStringLiteral(builder, loc, strValue);

flang/unittests/Optimizer/Builder/DoLoopHelperTest.cpp

 #include "gtest/gtest.h"
 #include "flang/Optimizer/Support/InitFIR.h"
 #include "flang/Optimizer/Support/KindMapping.h"
 #include <string>
 
 struct DoLoopHelperTest : public testing::Test {
 public:
   void SetUp() {
-    fir::KindMapping kindMap(&context);
+    kindMap = std::make_unique<fir::KindMapping>(&context);
     mlir::OpBuilder builder(&context);
-    firBuilder = new fir::FirOpBuilder(builder, kindMap);
+    firBuilder = new fir::FirOpBuilder(builder, *kindMap);
     fir::support::loadDialects(context);
   }
   void TearDown() { delete firBuilder; }
 
   fir::FirOpBuilder &getBuilder() { return *firBuilder; }
 
   mlir::MLIRContext context;
+  std::unique_ptr<fir::KindMapping> kindMap;
   fir::FirOpBuilder *firBuilder;
 };
 
 void checkConstantValue(const mlir::Value &value, int64_t v) {
   EXPECT_TRUE(mlir::isa<ConstantOp>(value.getDefiningOp()));
   auto cstOp = dyn_cast<ConstantOp>(value.getDefiningOp());
   auto valueAttr = cstOp.getValue().dyn_cast_or_null<IntegerAttr>();
   EXPECT_EQ(v, valueAttr.getInt());