[clang-tidy] Add check for underscores in googletest names.

Summary: Adds a clang-tidy warning for underscores in googletest names.

Patch by Kar Epker!

Reviewers: hokein, alexfh, aaron.ballman

Reviewed By: hokein

Subscribers: Eugene.Zelenko, JonasToth, MyDeveloperDay, lebedev.ri, xazax.hun, mgorny, cfe-commits

Tags: #clang-tools-extra

Differential Revision: https://reviews.llvm.org/D56424

llvm-svn: 352183

1 files changed, 89 insertions, 0 deletions

diff --git a/clang-tools-extra/clang-tidy/google/AvoidUnderscoreInGoogletestNameCheck.cpp b/clang-tools-extra/clang-tidy/google/AvoidUnderscoreInGoogletestNameCheck.cpp
new file mode 100644
index 00000000000..fbc47b77e15
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/google/AvoidUnderscoreInGoogletestNameCheck.cpp
@@ -0,0 +1,89 @@
+//===--- AvoidUnderscoreInGoogletestNameCheck.cpp - clang-tidy --*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include <string>
+
+#include "AvoidUnderscoreInGoogletestNameCheck.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/ASTMatchers/ASTMatchers.h"
+#include "clang/Frontend/CompilerInstance.h"
+#include "clang/Lex/MacroArgs.h"
+
+namespace clang {
+namespace tidy {
+namespace google {
+namespace readability {
+
+constexpr llvm::StringLiteral kDisabledTestPrefix = "DISABLED_";
+
+// Determines whether the macro is a Googletest test macro.
+static bool isGoogletestTestMacro(StringRef MacroName) {
+  static const llvm::StringSet<> MacroNames = {"TEST", "TEST_F", "TEST_P",
+                                               "TYPED_TEST", "TYPED_TEST_P"};
+  return MacroNames.find(MacroName) != MacroNames.end();
+}
+
+namespace {
+
+class AvoidUnderscoreInGoogletestNameCallback : public PPCallbacks {
+public:
+  AvoidUnderscoreInGoogletestNameCallback(
+      Preprocessor *PP, AvoidUnderscoreInGoogletestNameCheck *Check)
+      : PP(PP), Check(Check) {}
+
+  // Detects expansions of the TEST, TEST_F, TEST_P, TYPED_TEST, TYPED_TEST_P
+  // macros and checks that their arguments do not have any underscores.
+  void MacroExpands(const Token &MacroNameToken,
+                    const MacroDefinition &MacroDefinition, SourceRange Range,
+                    const MacroArgs *Args) override {
+    IdentifierInfo *NameIdentifierInfo = MacroNameToken.getIdentifierInfo();
+    if (!NameIdentifierInfo)
+      return;
+    StringRef MacroName = NameIdentifierInfo->getName();
+    if (!isGoogletestTestMacro(MacroName) || !Args ||
+        Args->getNumMacroArguments() < 2)
+      return;
+    const Token *TestCaseNameToken = Args->getUnexpArgument(0);
+    const Token *TestNameToken = Args->getUnexpArgument(1);
+    if (!TestCaseNameToken || !TestNameToken)
+      return;
+    std::string TestCaseName = PP->getSpelling(*TestCaseNameToken);
+    if (TestCaseName.find('_') != std::string::npos)
+      Check->diag(TestCaseNameToken->getLocation(),
+                  "avoid using \"_\" in test case name \"%0\" according to "
+                  "Googletest FAQ")
+          << TestCaseName;
+
+    std::string TestNameMaybeDisabled = PP->getSpelling(*TestNameToken);
+    StringRef TestName = TestNameMaybeDisabled;
+    TestName.consume_front(kDisabledTestPrefix);
+    if (TestName.contains('_'))
+      Check->diag(TestNameToken->getLocation(),
+                  "avoid using \"_\" in test name \"%0\" according to "
+                  "Googletest FAQ")
+          << TestName;
+  }
+
+private:
+  Preprocessor *PP;
+  AvoidUnderscoreInGoogletestNameCheck *Check;
+};
+
+} // namespace
+
+void AvoidUnderscoreInGoogletestNameCheck::registerPPCallbacks(
+    CompilerInstance &Compiler) {
+  Compiler.getPreprocessor().addPPCallbacks(
+      llvm::make_unique<AvoidUnderscoreInGoogletestNameCallback>(
+          &Compiler.getPreprocessor(), this));
+}
+
+} // namespace readability
+} // namespace google
+} // namespace tidy
+} // namespace clang