1 files changed, 75 insertions, 0 deletions
diff --git a/clang/lib/Analysis/LifetimeAnnotations.cpp b/clang/lib/Analysis/LifetimeAnnotations.cpp
new file mode 100644
index 0000000..e791224
--- /dev/null
+++ b/clang/lib/Analysis/LifetimeAnnotations.cpp
@@ -0,0 +1,75 @@
+//===- LifetimeAnnotations.cpp -  -*--------------- 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 "clang/Analysis/Analyses/LifetimeAnnotations.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/Attr.h"
+#include "clang/AST/Decl.h"
+#include "clang/AST/DeclCXX.h"
+#include "clang/AST/Type.h"
+#include "clang/AST/TypeLoc.h"
+
+namespace clang {
+namespace lifetimes {
+
+const FunctionDecl *
+getDeclWithMergedLifetimeBoundAttrs(const FunctionDecl *FD) {
+  return FD != nullptr ? FD->getMostRecentDecl() : nullptr;
+}
+
+const CXXMethodDecl *
+getDeclWithMergedLifetimeBoundAttrs(const CXXMethodDecl *CMD) {
+  const FunctionDecl *FD = CMD;
+  return cast_if_present<CXXMethodDecl>(
+      getDeclWithMergedLifetimeBoundAttrs(FD));
+}
+
+bool isNormalAssignmentOperator(const FunctionDecl *FD) {
+  OverloadedOperatorKind OO = FD->getDeclName().getCXXOverloadedOperator();
+  bool IsAssignment = OO == OO_Equal || isCompoundAssignmentOperator(OO);
+  if (!IsAssignment)
+    return false;
+  QualType RetT = FD->getReturnType();
+  if (!RetT->isLValueReferenceType())
+    return false;
+  ASTContext &Ctx = FD->getASTContext();
+  QualType LHST;
+  auto *MD = dyn_cast<CXXMethodDecl>(FD);
+  if (MD && MD->isCXXInstanceMember())
+    LHST = Ctx.getLValueReferenceType(MD->getFunctionObjectParameterType());
+  else
+    LHST = FD->getParamDecl(0)->getType();
+  return Ctx.hasSameType(RetT, LHST);
+}
+
+bool isAssignmentOperatorLifetimeBound(const CXXMethodDecl *CMD) {
+  CMD = getDeclWithMergedLifetimeBoundAttrs(CMD);
+  return CMD && isNormalAssignmentOperator(CMD) && CMD->param_size() == 1 &&
+         CMD->getParamDecl(0)->hasAttr<clang::LifetimeBoundAttr>();
+}
+
+bool implicitObjectParamIsLifetimeBound(const FunctionDecl *FD) {
+  FD = getDeclWithMergedLifetimeBoundAttrs(FD);
+  const TypeSourceInfo *TSI = FD->getTypeSourceInfo();
+  if (!TSI)
+    return false;
+  // Don't declare this variable in the second operand of the for-statement;
+  // GCC miscompiles that by ending its lifetime before evaluating the
+  // third operand. See gcc.gnu.org/PR86769.
+  AttributedTypeLoc ATL;
+  for (TypeLoc TL = TSI->getTypeLoc();
+       (ATL = TL.getAsAdjusted<AttributedTypeLoc>());
+       TL = ATL.getModifiedLoc()) {
+    if (ATL.getAttrAs<clang::LifetimeBoundAttr>())
+      return true;
+  }
+
+  return isNormalAssignmentOperator(FD);
+}
+
+} // namespace lifetimes
+} // namespace clang