[clang-tidy] Check for dynamically initialized statics in headers.

Finds instances where variables with static storage are initialized dynamically in header files.

Reviewed By: aaron.ballman, alexfh

Patch by Charles Zhang!

Differential Revision: https://reviews.llvm.org/D62829

llvm-svn: 369568

1 files changed, 68 insertions, 0 deletions

diff --git a/clang-tools-extra/clang-tidy/bugprone/DynamicStaticInitializersCheck.cpp b/clang-tools-extra/clang-tidy/bugprone/DynamicStaticInitializersCheck.cpp
new file mode 100644
index 00000000000..2c6f3b13fa7
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/bugprone/DynamicStaticInitializersCheck.cpp
@@ -0,0 +1,68 @@
+//===--- DynamicStaticInitializersCheck.cpp - clang-tidy ------------------===//
+//
+// 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 "DynamicStaticInitializersCheck.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang {
+namespace tidy {
+namespace bugprone {
+
+AST_MATCHER(clang::VarDecl, hasConstantDeclaration) {
+  const Expr *Init = Node.getInit();
+  if (Init && !Init->isValueDependent()) {
+    if (Node.isConstexpr())
+      return true;
+    return Node.checkInitIsICE();
+  }
+  return false;
+}
+
+DynamicStaticInitializersCheck::DynamicStaticInitializersCheck(StringRef Name,
+                                                               ClangTidyContext *Context)
+    : ClangTidyCheck(Name, Context),
+      RawStringHeaderFileExtensions(Options.getLocalOrGlobal(
+        "HeaderFileExtensions", utils::defaultHeaderFileExtensions())) {
+  if (!utils::parseHeaderFileExtensions(RawStringHeaderFileExtensions,
+                                        HeaderFileExtensions, ',')) {
+    llvm::errs() << "Invalid header file extension: "
+                 << RawStringHeaderFileExtensions << "\n";
+  }
+}
+
+void DynamicStaticInitializersCheck::storeOptions(
+    ClangTidyOptions::OptionMap &Opts) {
+  Options.store(Opts, "HeaderFileExtensions", RawStringHeaderFileExtensions);
+}
+
+void DynamicStaticInitializersCheck::registerMatchers(MatchFinder *Finder) {
+  if (!getLangOpts().CPlusPlus || getLangOpts().ThreadsafeStatics)
+    return;
+  Finder->addMatcher(
+      varDecl(hasGlobalStorage(), unless(hasConstantDeclaration())).bind("var"),
+      this);
+}
+
+void DynamicStaticInitializersCheck::check(const MatchFinder::MatchResult &Result) {
+  const auto *Var = Result.Nodes.getNodeAs<VarDecl>("var");
+  SourceLocation Loc = Var->getLocation();
+  if (!Loc.isValid() || !utils::isPresumedLocInHeaderFile(Loc, *Result.SourceManager,
+                                                          HeaderFileExtensions))
+    return;
+  // If the initializer is a constant expression, then the compiler
+  // doesn't have to dynamically initialize it.
+  diag(Loc, "static variable %0 may be dynamically initialized in this header file")
+    << Var;
+}
+
+} // namespace bugprone
+} // namespace tidy
+} // namespace clang