[ClangTidy] Add UsingInserter and NamespaceAliaser

Summary: This adds helper classes to add using declaractions and namespace aliases to function bodies. These help making function calls to deeply nested functions concise (e.g. when calling helpers in a refactoring)

Patch by Julian Bangert!

Reviewers: alexfh, hokein

Subscribers: cfe-commits

Tags: #clang-tools-extra

Differential Revision: https://reviews.llvm.org/D24997

llvm-svn: 283981

1 files changed, 115 insertions, 0 deletions

diff --git a/clang-tools-extra/unittests/clang-tidy/UsingInserterTest.cpp b/clang-tools-extra/unittests/clang-tidy/UsingInserterTest.cpp
new file mode 100644
index 00000000000..5932bd3a0d2
--- /dev/null
+++ b/clang-tools-extra/unittests/clang-tidy/UsingInserterTest.cpp
@@ -0,0 +1,115 @@
+//===---- UsingInserterTest.cpp - clang-tidy ----------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "../clang-tidy/utils/UsingInserter.h"
+
+#include "ClangTidyTest.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/ASTMatchers/ASTMatchers.h"
+#include "gtest/gtest.h"
+
+namespace clang {
+namespace tidy {
+namespace utils {
+
+// Replace all function calls with calls to foo::func. Inserts using
+// declarations as necessary. This checker is for testing only. It
+// can only run on one test case (e.g. wih one SourceManager).
+class InsertUsingCheck : public clang::tidy::ClangTidyCheck {
+public:
+  using clang::tidy::ClangTidyCheck::ClangTidyCheck;
+  void registerMatchers(clang::ast_matchers::MatchFinder *Finder) override {
+    Finder->addMatcher(clang::ast_matchers::callExpr().bind("foo"), this);
+  }
+  void
+  check(const clang::ast_matchers::MatchFinder::MatchResult &Result) override {
+    if (!Inserter)
+      Inserter.reset(new UsingInserter(*Result.SourceManager,
+                                       Result.Context->getLangOpts()));
+
+    const clang::CallExpr *Call =
+        Result.Nodes.getNodeAs<clang::CallExpr>("foo");
+    assert(Call != nullptr && "Did not find node \"foo\"");
+    auto Hint =
+        Inserter->createUsingDeclaration(*Result.Context, *Call, "::foo::func");
+
+    if (Hint.hasValue())
+      diag(Call->getLocStart(), "Fix for testing") << Hint.getValue();
+
+    diag(Call->getLocStart(), "insert call")
+        << clang::FixItHint::CreateReplacement(
+               Call->getCallee()->getSourceRange(),
+               Inserter->getShortName(*Result.Context, *Call, "::foo::func"));
+  }
+
+private:
+  std::unique_ptr<UsingInserter> Inserter;
+};
+
+template <typename Check>
+std::string runChecker(StringRef Code, int ExpectedWarningCount) {
+  std::map<StringRef, StringRef> AdditionalFileContents = {{"foo.h",
+                                                            "namespace foo {\n"
+                                                            "namespace bar {\n"
+                                                            "}\n"
+                                                            "void func() { }\n"
+                                                            "}"}};
+  std::vector<ClangTidyError> errors;
+
+  std::string result =
+      test::runCheckOnCode<Check>(Code, &errors, "foo.cc", None,
+                                  ClangTidyOptions(), AdditionalFileContents);
+
+  EXPECT_EQ(ExpectedWarningCount, errors.size());
+  return result;
+}
+
+TEST(UsingInserterTest, ReusesExisting) {
+  EXPECT_EQ("#include \"foo.h\"\n"
+            "namespace {"
+            "using ::foo::func;\n"
+            "void f() { func(); }"
+            "}",
+            runChecker<InsertUsingCheck>("#include \"foo.h\"\n"
+                                         "namespace {"
+                                         "using ::foo::func;\n"
+                                         "void f() { f(); }"
+                                         "}",
+                                         1));
+}
+
+TEST(UsingInserterTest, ReusesExistingGlobal) {
+  EXPECT_EQ("#include \"foo.h\"\n"
+            "using ::foo::func;\n"
+            "namespace {"
+            "void f() { func(); }"
+            "}",
+            runChecker<InsertUsingCheck>("#include \"foo.h\"\n"
+                                         "using ::foo::func;\n"
+                                         "namespace {"
+                                         "void f() { f(); }"
+                                         "}",
+                                         1));
+}
+
+TEST(UsingInserterTest, AvoidsConflict) {
+  EXPECT_EQ("#include \"foo.h\"\n"
+            "namespace {"
+            "void f() { int func; ::foo::func(); }"
+            "}",
+            runChecker<InsertUsingCheck>("#include \"foo.h\"\n"
+                                         "namespace {"
+                                         "void f() { int func; f(); }"
+                                         "}",
+                                         1));
+}
+
+} // namespace utils
+} // namespace tidy
+} // namespace clang