[clang-tidy] Add a check to detect static definitions in anonymous namespace.

Summary: Fixes PR26595

Reviewers: alexfh

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D18180

llvm-svn: 265384

1 files changed, 72 insertions, 0 deletions

diff --git a/clang-tools-extra/clang-tidy/readability/StaticDefinitionInAnonymousNamespaceCheck.cpp b/clang-tools-extra/clang-tidy/readability/StaticDefinitionInAnonymousNamespaceCheck.cpp
new file mode 100644
index 0000000..9de2d40
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/readability/StaticDefinitionInAnonymousNamespaceCheck.cpp
@@ -0,0 +1,72 @@
+//===--- StaticDefinitionInAnonymousNamespaceCheck.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 "StaticDefinitionInAnonymousNamespaceCheck.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/Lex/Lexer.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang {
+namespace tidy {
+namespace readability {
+
+namespace {
+AST_POLYMORPHIC_MATCHER(isStatic, AST_POLYMORPHIC_SUPPORTED_TYPES(FunctionDecl,
+                                                                  VarDecl)) {
+  return Node.getStorageClass() == SC_Static;
+}
+} // namespace
+
+void StaticDefinitionInAnonymousNamespaceCheck::registerMatchers(
+    MatchFinder *Finder) {
+  Finder->addMatcher(namedDecl(anyOf(functionDecl(isDefinition(), isStatic()),
+                                     varDecl(isDefinition(), isStatic())),
+                               hasParent(namespaceDecl(isAnonymous())))
+                         .bind("static-def"),
+                     this);
+}
+
+void StaticDefinitionInAnonymousNamespaceCheck::check(
+    const MatchFinder::MatchResult &Result) {
+  const auto *Def = Result.Nodes.getNodeAs<NamedDecl>("static-def");
+  // Skips all static definitions defined in Macro.
+  if (Def->getLocation().isMacroID())
+    return;
+
+  // Skips all static definitions in function scope.
+  const DeclContext *DC = Def->getDeclContext();
+  if (DC->getDeclKind() != Decl::Namespace)
+    return;
+
+  auto Diag =
+      diag(Def->getLocation(), "%0 is a static definition in "
+                               "anonymous namespace; static is redundant here")
+      << Def;
+  Token Tok;
+  SourceLocation Loc = Def->getSourceRange().getBegin();
+  while (Loc < Def->getSourceRange().getEnd() &&
+         !Lexer::getRawToken(Loc, Tok, *Result.SourceManager,
+                             Result.Context->getLangOpts(), true)) {
+    SourceRange TokenRange(Tok.getLocation(), Tok.getEndLoc());
+    StringRef SourceText = Lexer::getSourceText(
+        CharSourceRange::getTokenRange(TokenRange),
+        *Result.SourceManager, Result.Context->getLangOpts());
+    if (SourceText == "static") {
+      Diag << FixItHint::CreateRemoval(TokenRange);
+      break;
+    }
+    Loc = Tok.getEndLoc();
+  }
+}
+
+} // namespace readability
+} // namespace tidy
+} // namespace clang