[unittests] Add a fixture for Sema unit tests

include/swift/Sema/ConstraintSystem.h

@@ -4942,6 +4942,7 @@ class ConstraintSystem {
   Optional<Type> checkTypeOfBinding(TypeVariableType *typeVar, Type type) const;
   Optional<PotentialBindings> determineBestBindings();
 
+public:
   /// Infer bindings for the given type variable based on current
   /// state of the constraint system.
   PotentialBindings inferBindingsFor(TypeVariableType *typeVar,

unittests/CMakeLists.txt

@@ -12,6 +12,7 @@ if(SWIFT_INCLUDE_TOOLS)
   add_subdirectory(Localization)
   add_subdirectory(IDE)
   add_subdirectory(Parse)
+  add_subdirectory(Sema)
   add_subdirectory(SwiftDemangle)
   add_subdirectory(Syntax)
   if(SWIFT_BUILD_SYNTAXPARSERLIB)

unittests/Sema/BindingInferenceTests.cpp

@@ -0,0 +1,46 @@
+//===--- BindingInferenceTests.cpp ----------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2020 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+#include "SemaFixture.h"
+#include "swift/AST/Expr.h"
+#include "swift/Sema/ConstraintSystem.h"
+
+using namespace swift;
+using namespace swift::unittest;
+using namespace swift::constraints;
+
+TEST_F(SemaTest, TestIntLiteralBindingInference) {
+  ConstraintSystemOptions options;
+  options |= ConstraintSystemFlags::AllowUnresolvedTypeVariables;
+
+  ConstraintSystem cs(DC, options);
+
+  auto *intLiteral = IntegerLiteralExpr::createFromUnsigned(Context, 42);
+
+  auto *literalTy = cs.createTypeVariable(cs.getConstraintLocator(intLiteral),
+                                          /*options=*/0);
+
+  cs.addConstraint(
+      ConstraintKind::LiteralConformsTo, literalTy,
+      Context.getProtocol(KnownProtocolKind::ExpressibleByIntegerLiteral)
+          ->getDeclaredInterfaceType(),
+      cs.getConstraintLocator(intLiteral));
+
+  auto bindings = cs.inferBindingsFor(literalTy);
+
+  ASSERT_EQ(bindings.Bindings.size(), (unsigned)1);
+
+  const auto &binding = bindings.Bindings.front();
+
+  ASSERT_TRUE(binding.BindingType->isEqual(getStdlibType("Int")));
+  ASSERT_TRUE(binding.hasDefaultedLiteralProtocol());
+}

unittests/Sema/CMakeLists.txt

@@ -0,0 +1,13 @@
+
+add_swift_unittest(swiftSemaTests
+  SemaFixture.cpp
+  BindingInferenceTests.cpp)
+
+target_link_libraries(swiftSemaTests
+  PRIVATE
+    swiftAST
+    swiftSema
+    swiftSerialization)
+
+target_compile_definitions(swiftSemaTests PRIVATE
+  SWIFTLIB_DIR=\"${SWIFTLIB_DIR}\")

unittests/Sema/SemaFixture.cpp

@@ -0,0 +1,76 @@
+//===--- SemaFixture.cpp - Helper for setting up Sema context --------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2020 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+#include "SemaFixture.h"
+#include "swift/AST/Decl.h"
+#include "swift/AST/Import.h"
+#include "swift/AST/Module.h"
+#include "swift/AST/ParseRequests.h"
+#include "swift/AST/SourceFile.h"
+#include "swift/AST/Type.h"
+#include "swift/AST/Types.h"
+#include "swift/Basic/LLVMInitialize.h"
+#include "swift/ClangImporter/ClangImporter.h"
+#include "swift/Serialization/SerializedModuleLoader.h"
+#include "swift/Subsystems.h"
+
+using namespace swift;
+using namespace swift::unittest;
+
+SemaTest::SemaTest()
+    : Context(*ASTContext::get(LangOpts, TypeCheckerOpts, SearchPathOpts,
+                               ClangImporterOpts, SourceMgr, Diags)) {
+  INITIALIZE_LLVM();
+
+  registerParseRequestFunctions(Context.evaluator);
+  registerTypeCheckerRequestFunctions(Context.evaluator);
+
+  Context.addModuleLoader(ImplicitSerializedModuleLoader::create(Context));
+  Context.addModuleLoader(ClangImporter::create(Context), /*isClang=*/true);
+
+  auto *stdlib = Context.getStdlibModule(/*loadIfAbsent=*/true);
+  assert(stdlib && "Failed to load standard library");
+
+  auto *module =
+      ModuleDecl::create(Context.getIdentifier("SemaTests"), Context);
+
+  MainFile = new (Context) SourceFile(*module, SourceFileKind::Main,
+                                      /*buffer=*/None);
+
+  AttributedImport<ImportedModule> stdlibImport{{ImportPath::Access(), stdlib},
+                                                /*options=*/{}};
+
+  MainFile->setImports(stdlibImport);
+  module->addFile(*MainFile);
+
+  DC = module;
+}
+
+Type SemaTest::getStdlibType(StringRef name) const {
+  auto typeName = Context.getIdentifier(name);
+
+  auto *stdlib = Context.getStdlibModule();
+
+  llvm::SmallVector<ValueDecl *, 4> results;
+  stdlib->lookupValue(typeName, NLKind::UnqualifiedLookup, results);
+
+  if (results.size() != 1)
+    return Type();
+
+  if (auto *decl = dyn_cast<TypeDecl>(results.front())) {
+    if (auto *NTD = dyn_cast<NominalTypeDecl>(decl))
+      return NTD->getDeclaredType();
+    return decl->getDeclaredInterfaceType();
+  }
+
+  return Type();
+}

unittests/Sema/SemaFixture.h

@@ -0,0 +1,68 @@
+//===--- SemaFixture.h - Helper for setting up Sema context -----*- C++ -*-===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2020 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+#include "swift/AST/ASTContext.h"
+#include "swift/AST/DiagnosticEngine.h"
+#include "swift/AST/Module.h"
+#include "swift/AST/SourceFile.h"
+#include "swift/AST/Type.h"
+#include "swift/Basic/LangOptions.h"
+#include "swift/Basic/Platform.h"
+#include "swift/Basic/SourceManager.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/Support/Host.h"
+#include "llvm/Support/Path.h"
+#include "gtest/gtest.h"
+#include <string>
+
+namespace swift {
+namespace unittest {
+
+class SemaTestBase : public ::testing::Test {
+public:
+  LangOptions LangOpts;
+  TypeCheckerOptions TypeCheckerOpts;
+  SearchPathOptions SearchPathOpts;
+  ClangImporterOptions ClangImporterOpts;
+  SourceManager SourceMgr;
+  DiagnosticEngine Diags;
+
+  SemaTestBase() : Diags(SourceMgr) {
+    LangOpts.Target = llvm::Triple(llvm::sys::getDefaultTargetTriple());
+
+    llvm::SmallString<128> libDir(SWIFTLIB_DIR);
+    llvm::sys::path::append(libDir, getPlatformNameForTriple(LangOpts.Target));
+
+    SearchPathOpts.RuntimeResourcePath = SWIFTLIB_DIR;
+    SearchPathOpts.RuntimeLibraryPaths.push_back(std::string(libDir.str()));
+    SearchPathOpts.RuntimeLibraryImportPaths.push_back(
+        std::string(libDir.str()));
+  }
+};
+
+/// Owns an ASTContext and the associated types.
+class SemaTest : public SemaTestBase {
+  SourceFile *MainFile;
+
+public:
+  ASTContext &Context;
+  DeclContext *DC;
+
+  SemaTest();
+
+protected:
+  Type getStdlibType(StringRef name) const;
+};
+
+} // end namespace unittest
+} // end namespace swift