1 files changed, 62 insertions, 0 deletions
diff --git a/build/clang-plugin/MemMoveAnnotation.h b/build/clang-plugin/MemMoveAnnotation.h
new file mode 100644
index 0000000000..0a1a96e8ff
--- /dev/null
+++ b/build/clang-plugin/MemMoveAnnotation.h
@@ -0,0 +1,62 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef MemMoveAnnotation_h__
+#define MemMoveAnnotation_h__
+
+#include "CustomMatchers.h"
+#include "CustomTypeAnnotation.h"
+#include "Utils.h"
+
+#include <unordered_set>
+
+class MemMoveAnnotation final : public CustomTypeAnnotation {
+public:
+  MemMoveAnnotation()
+      : CustomTypeAnnotation(moz_non_memmovable, "non-memmove()able") {}
+
+  virtual ~MemMoveAnnotation() {}
+
+protected:
+  std::string getImplicitReason(const TagDecl *D,
+                                VisitFlags &ToVisit) const override {
+    // Annotate everything in ::std, with a few exceptions; see bug
+    // 1201314 for discussion.
+    if (getDeclarationNamespace(D) != "std") {
+      return "";
+    }
+
+    StringRef Name = getNameChecked(D);
+
+    // If the type has a trivial move constructor and destructor, it is safe to
+    // memmove, and we don't need to visit any fields.
+    auto RD = dyn_cast<CXXRecordDecl>(D);
+    if (RD && RD->isCompleteDefinition() &&
+        (RD->hasTrivialMoveConstructor() ||
+         (!RD->hasMoveConstructor() && RD->hasTrivialCopyConstructor())) &&
+        RD->hasTrivialDestructor()) {
+      ToVisit = VISIT_NONE;
+      return "";
+    }
+
+    // This doesn't check that it's really ::std::pair and not
+    // ::std::something_else::pair, but should be good enough.
+    if (isNameExcepted(Name.data())) {
+      // If we're an excepted name, stop traversing within the type further,
+      // and only check template arguments for foreign types.
+      ToVisit = VISIT_TMPL_ARGS;
+      return "";
+    }
+    return "it is an stl-provided type not guaranteed to be memmove-able";
+  }
+
+private:
+  bool isNameExcepted(StringRef Name) const {
+    return Name == "pair" || Name == "atomic" || Name == "tuple";
+  }
+};
+
+extern MemMoveAnnotation NonMemMovable;
+
+#endif