[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, 124 insertions, 0 deletions

diff --git a/clang-tools-extra/unittests/clang-tidy/NamespaceAliaserTest.cpp b/clang-tools-extra/unittests/clang-tidy/NamespaceAliaserTest.cpp
new file mode 100644
index 00000000000..9102298a9b3
--- /dev/null
+++ b/clang-tools-extra/unittests/clang-tidy/NamespaceAliaserTest.cpp
@@ -0,0 +1,124 @@
+//===---- NamespaceAliaserTest.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/NamespaceAliaser.h"
+
+#include "ClangTidyTest.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/ASTMatchers/ASTMatchers.h"
+#include "gtest/gtest.h"
+
+namespace clang {
+namespace tidy {
+namespace utils {
+// This checker is for testing only. It can only run on one test case
+// (e.g. with one SourceManager).
+class InsertAliasCheck : public ClangTidyCheck {
+public:
+  using ClangTidyCheck::ClangTidyCheck;
+  void registerMatchers(ast_matchers::MatchFinder *Finder) override {
+    Finder->addMatcher(ast_matchers::callExpr().bind("foo"), this);
+  }
+  void
+  check(const ast_matchers::MatchFinder::MatchResult &Result) override {
+    if (!Aliaser)
+      Aliaser.reset(new NamespaceAliaser(*Result.SourceManager));
+
+    const CallExpr *Call =
+        Result.Nodes.getNodeAs<CallExpr>("foo");
+    assert(Call != nullptr && "Did not find node \"foo\"");
+    auto Hint = Aliaser->createAlias(*Result.Context, *Call, "::foo::bar",
+                                     {"b", "some_alias"});
+    if (Hint.hasValue())
+      diag(Call->getLocStart(), "Fix for testing") << Hint.getValue();
+
+    diag(Call->getLocStart(), "insert call")
+        << FixItHint::CreateInsertion(
+               Call->getLocStart(),
+               Aliaser->getNamespaceName(*Result.Context, *Call, "::foo::bar") +
+                   "::");
+  }
+
+private:
+  std::unique_ptr<NamespaceAliaser> Aliaser;
+};
+
+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(NamespaceAliaserTest, AddNewAlias) {
+  EXPECT_EQ("#include \"foo.h\"\n"
+            "void f() {\n"
+            "namespace b = ::foo::bar;"
+            " b::f(); }",
+            runChecker<InsertAliasCheck>("#include \"foo.h\"\n"
+                                         "void f() { f(); }",
+                                         2));
+}
+
+TEST(NamespaceAliaserTest, ReuseAlias) {
+  EXPECT_EQ(
+      "#include \"foo.h\"\n"
+      "void f() { namespace x = foo::bar; x::f(); }",
+      runChecker<InsertAliasCheck>("#include \"foo.h\"\n"
+                                   "void f() { namespace x = foo::bar; f(); }",
+                                   1));
+}
+
+TEST(NamespaceAliaserTest, AddsOnlyOneAlias) {
+  EXPECT_EQ("#include \"foo.h\"\n"
+            "void f() {\n"
+            "namespace b = ::foo::bar;"
+            " b::f(); b::f(); }",
+            runChecker<InsertAliasCheck>("#include \"foo.h\"\n"
+                                         "void f() { f(); f(); }",
+                                         3));
+}
+
+TEST(NamespaceAliaserTest, LocalConflict) {
+  EXPECT_EQ("#include \"foo.h\"\n"
+            "void f() {\n"
+            "namespace some_alias = ::foo::bar;"
+            " namespace b = foo; some_alias::f(); }",
+            runChecker<InsertAliasCheck>("#include \"foo.h\"\n"
+                                         "void f() { namespace b = foo; f(); }",
+                                         2));
+}
+
+TEST(NamespaceAliaserTest, GlobalConflict) {
+  EXPECT_EQ("#include \"foo.h\"\n"
+            "namespace b = foo;\n"
+            "void f() {\n"
+            "namespace some_alias = ::foo::bar;"
+            " some_alias::f(); }",
+            runChecker<InsertAliasCheck>("#include \"foo.h\"\n"
+                                         "namespace b = foo;\n"
+                                         "void f() { f(); }",
+                                         2));
+}
+
+} // namespace utils
+} // namespace tidy
+} // namespace clang