1 files changed, 128 insertions, 0 deletions
diff --git a/contrib/llvm-project/clang/lib/StaticAnalyzer/Checkers/WebKit/ASTUtils.cpp b/contrib/llvm-project/clang/lib/StaticAnalyzer/Checkers/WebKit/ASTUtils.cpp
new file mode 100644
index 000000000000..be07cf51eefb
--- /dev/null
+++ b/contrib/llvm-project/clang/lib/StaticAnalyzer/Checkers/WebKit/ASTUtils.cpp
@@ -0,0 +1,128 @@
+//=======- ASTUtils.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 "ASTUtils.h"
+#include "PtrTypesSemantics.h"
+#include "clang/AST/CXXInheritance.h"
+#include "clang/AST/Decl.h"
+#include "clang/AST/DeclCXX.h"
+#include "clang/AST/ExprCXX.h"
+#include <optional>
+
+namespace clang {
+
+bool tryToFindPtrOrigin(
+    const Expr *E, bool StopAtFirstRefCountedObj,
+    std::function<bool(const clang::Expr *, bool)> callback) {
+  while (E) {
+    if (auto *tempExpr = dyn_cast<MaterializeTemporaryExpr>(E)) {
+      E = tempExpr->getSubExpr();
+      continue;
+    }
+    if (auto *tempExpr = dyn_cast<CXXBindTemporaryExpr>(E)) {
+      E = tempExpr->getSubExpr();
+      continue;
+    }
+    if (auto *tempExpr = dyn_cast<CXXTemporaryObjectExpr>(E)) {
+      if (auto *C = tempExpr->getConstructor()) {
+        if (auto *Class = C->getParent(); Class && isRefCounted(Class))
+          return callback(E, true);
+        break;
+      }
+    }
+    if (auto *tempExpr = dyn_cast<ParenExpr>(E)) {
+      E = tempExpr->getSubExpr();
+      continue;
+    }
+    if (auto *Expr = dyn_cast<ConditionalOperator>(E)) {
+      return tryToFindPtrOrigin(Expr->getTrueExpr(), StopAtFirstRefCountedObj,
+                                callback) &&
+             tryToFindPtrOrigin(Expr->getFalseExpr(), StopAtFirstRefCountedObj,
+                                callback);
+    }
+    if (auto *cast = dyn_cast<CastExpr>(E)) {
+      if (StopAtFirstRefCountedObj) {
+        if (auto *ConversionFunc =
+                dyn_cast_or_null<FunctionDecl>(cast->getConversionFunction())) {
+          if (isCtorOfRefCounted(ConversionFunc))
+            return callback(E, true);
+        }
+      }
+      // FIXME: This can give false "origin" that would lead to false negatives
+      // in checkers. See https://reviews.llvm.org/D37023 for reference.
+      E = cast->getSubExpr();
+      continue;
+    }
+    if (auto *call = dyn_cast<CallExpr>(E)) {
+      if (auto *memberCall = dyn_cast<CXXMemberCallExpr>(call)) {
+        if (auto *decl = memberCall->getMethodDecl()) {
+          std::optional<bool> IsGetterOfRefCt = isGetterOfRefCounted(decl);
+          if (IsGetterOfRefCt && *IsGetterOfRefCt) {
+            E = memberCall->getImplicitObjectArgument();
+            if (StopAtFirstRefCountedObj) {
+              return callback(E, true);
+            }
+            continue;
+          }
+        }
+      }
+
+      if (auto *operatorCall = dyn_cast<CXXOperatorCallExpr>(E)) {
+        if (operatorCall->getNumArgs() == 1) {
+          E = operatorCall->getArg(0);
+          continue;
+        }
+      }
+
+      if (auto *callee = call->getDirectCallee()) {
+        if (isCtorOfRefCounted(callee)) {
+          if (StopAtFirstRefCountedObj)
+            return callback(E, true);
+
+          E = call->getArg(0);
+          continue;
+        }
+
+        if (isReturnValueRefCounted(callee))
+          return callback(E, true);
+
+        if (isSingleton(callee))
+          return callback(E, true);
+
+        if (isPtrConversion(callee)) {
+          E = call->getArg(0);
+          continue;
+        }
+      }
+    }
+    if (auto *unaryOp = dyn_cast<UnaryOperator>(E)) {
+      // FIXME: Currently accepts ANY unary operator. Is it OK?
+      E = unaryOp->getSubExpr();
+      continue;
+    }
+
+    break;
+  }
+  // Some other expression.
+  return callback(E, false);
+}
+
+bool isASafeCallArg(const Expr *E) {
+  assert(E);
+  if (auto *Ref = dyn_cast<DeclRefExpr>(E)) {
+    if (auto *D = dyn_cast_or_null<VarDecl>(Ref->getFoundDecl())) {
+      if (isa<ParmVarDecl>(D) || D->isLocalVarDecl())
+        return true;
+    }
+  }
+
+  // TODO: checker for method calls on non-refcounted objects
+  return isa<CXXThisExpr>(E);
+}
+
+} // namespace clang