1 files changed, 499 insertions, 0 deletions
diff --git a/build/clang-plugin/Utils.h b/build/clang-plugin/Utils.h
new file mode 100644
index 0000000000..c25caf43ee
--- /dev/null
+++ b/build/clang-plugin/Utils.h
@@ -0,0 +1,499 @@
+/* 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 Utils_h__
+#define Utils_h__
+
+#include "CustomAttributes.h"
+#include "ThirdPartyPaths.h"
+#include "ThreadAllows.h"
+#include "plugin.h"
+
+#if CLANG_VERSION_FULL >= 1300
+// Starting with clang-13 some functions from StringRef have been renamed
+#define compare_lower compare_insensitive
+#endif
+
+inline StringRef getFilename(const SourceManager &SM, SourceLocation Loc) {
+  // We use the presumed location to handle #line directives and such, so the
+  // plugin is friendly to icecc / sccache users.
+  auto PL = SM.getPresumedLoc(Loc);
+  if (PL.isValid()) {
+    return StringRef(PL.getFilename());
+  }
+  return SM.getFilename(Loc);
+}
+
+// Check if the given expression contains an assignment expression.
+// This can either take the form of a Binary Operator or a
+// Overloaded Operator Call.
+inline bool hasSideEffectAssignment(const Expr *Expression) {
+  if (auto OpCallExpr = dyn_cast_or_null<CXXOperatorCallExpr>(Expression)) {
+    auto BinOp = OpCallExpr->getOperator();
+    if (BinOp == OO_Equal || (BinOp >= OO_PlusEqual && BinOp <= OO_PipeEqual)) {
+      return true;
+    }
+  } else if (auto BinOpExpr = dyn_cast_or_null<BinaryOperator>(Expression)) {
+    if (BinOpExpr->isAssignmentOp()) {
+      return true;
+    }
+  }
+
+  // Recurse to children.
+  for (const Stmt *SubStmt : Expression->children()) {
+    auto ChildExpr = dyn_cast_or_null<Expr>(SubStmt);
+    if (ChildExpr && hasSideEffectAssignment(ChildExpr)) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
+template <class T>
+inline bool ASTIsInSystemHeader(const ASTContext &AC, const T &D) {
+  auto &SourceManager = AC.getSourceManager();
+  auto ExpansionLoc = SourceManager.getExpansionLoc(D.getBeginLoc());
+  if (ExpansionLoc.isInvalid()) {
+    return false;
+  }
+  return SourceManager.isInSystemHeader(ExpansionLoc);
+}
+
+template <typename T> inline StringRef getNameChecked(const T &D) {
+  return D->getIdentifier() ? D->getName() : "";
+}
+
+/// A cached data of whether classes are refcounted or not.
+typedef DenseMap<const CXXRecordDecl *, std::pair<const Decl *, bool>>
+    RefCountedMap;
+extern RefCountedMap RefCountedClasses;
+
+inline bool classHasAddRefRelease(const CXXRecordDecl *D) {
+  const RefCountedMap::iterator &It = RefCountedClasses.find(D);
+  if (It != RefCountedClasses.end()) {
+    return It->second.second;
+  }
+
+  bool SeenAddRef = false;
+  bool SeenRelease = false;
+  for (CXXRecordDecl::method_iterator Method = D->method_begin();
+       Method != D->method_end(); ++Method) {
+    const auto &Name = getNameChecked(Method);
+    if (Name == "AddRef") {
+      SeenAddRef = true;
+    } else if (Name == "Release") {
+      SeenRelease = true;
+    }
+  }
+  RefCountedClasses[D] = std::make_pair(D, SeenAddRef && SeenRelease);
+  return SeenAddRef && SeenRelease;
+}
+
+inline bool isClassRefCounted(QualType T);
+
+inline bool isClassRefCounted(const CXXRecordDecl *D) {
+  // Normalize so that D points to the definition if it exists.
+  if (!D->hasDefinition())
+    return false;
+  D = D->getDefinition();
+  // Base class: anyone with AddRef/Release is obviously a refcounted class.
+  if (classHasAddRefRelease(D))
+    return true;
+
+  // Look through all base cases to figure out if the parent is a refcounted
+  // class.
+  for (CXXRecordDecl::base_class_const_iterator Base = D->bases_begin();
+       Base != D->bases_end(); ++Base) {
+    bool Super = isClassRefCounted(Base->getType());
+    if (Super) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
+inline bool isClassRefCounted(QualType T) {
+  while (const clang::ArrayType *ArrTy = T->getAsArrayTypeUnsafe())
+    T = ArrTy->getElementType();
+  CXXRecordDecl *Clazz = T->getAsCXXRecordDecl();
+  return Clazz ? isClassRefCounted(Clazz) : false;
+}
+
+inline const FieldDecl *getClassRefCntMember(const CXXRecordDecl *D) {
+  for (RecordDecl::field_iterator Field = D->field_begin(), E = D->field_end();
+       Field != E; ++Field) {
+    if (getNameChecked(Field) == "mRefCnt") {
+      return *Field;
+    }
+  }
+  return 0;
+}
+
+inline bool typeHasVTable(QualType T) {
+  while (const clang::ArrayType *ArrTy = T->getAsArrayTypeUnsafe())
+    T = ArrTy->getElementType();
+  CXXRecordDecl *Offender = T->getAsCXXRecordDecl();
+  return Offender && Offender->hasDefinition() && Offender->isDynamicClass();
+}
+
+inline StringRef getDeclarationNamespace(const Decl *Declaration) {
+  const DeclContext *DC =
+      Declaration->getDeclContext()->getEnclosingNamespaceContext();
+  const NamespaceDecl *ND = dyn_cast<NamespaceDecl>(DC);
+  if (!ND) {
+    return "";
+  }
+
+  while (const DeclContext *ParentDC = ND->getParent()) {
+    if (!isa<NamespaceDecl>(ParentDC)) {
+      break;
+    }
+    ND = cast<NamespaceDecl>(ParentDC);
+  }
+
+  const auto &Name = ND->getName();
+  return Name;
+}
+
+inline bool isInIgnoredNamespaceForImplicitCtor(const Decl *Declaration) {
+  StringRef Name = getDeclarationNamespace(Declaration);
+  if (Name == "") {
+    return false;
+  }
+
+  return Name == "std" ||               // standard C++ lib
+         Name == "__gnu_cxx" ||         // gnu C++ lib
+         Name == "boost" ||             // boost
+         Name == "webrtc" ||            // upstream webrtc
+         Name == "rtc" ||               // upstream webrtc 'base' package
+         Name.startswith("icu_") ||     // icu
+         Name == "google" ||            // protobuf
+         Name == "google_breakpad" ||   // breakpad
+         Name == "soundtouch" ||        // libsoundtouch
+         Name == "stagefright" ||       // libstagefright
+         Name == "MacFileUtilities" ||  // MacFileUtilities
+         Name == "dwarf2reader" ||      // dwarf2reader
+         Name == "arm_ex_to_module" ||  // arm_ex_to_module
+         Name == "testing" ||           // gtest
+         Name == "Json" ||              // jsoncpp
+         Name == "rlbox" ||             // rlbox
+         Name == "v8";                  // irregexp
+}
+
+inline bool isInIgnoredNamespaceForImplicitConversion(const Decl *Declaration) {
+  StringRef Name = getDeclarationNamespace(Declaration);
+  if (Name == "") {
+    return false;
+  }
+
+  return Name == "std" ||             // standard C++ lib
+         Name == "__gnu_cxx" ||       // gnu C++ lib
+         Name == "google_breakpad" || // breakpad
+         Name == "webrtc" ||          // libwebrtc
+         Name == "testing" ||         // gtest
+         Name == "rlbox";             // rlbox
+}
+
+inline bool isIgnoredPathForImplicitConversion(const Decl *Declaration) {
+  Declaration = Declaration->getCanonicalDecl();
+  SourceLocation Loc = Declaration->getLocation();
+  const SourceManager &SM = Declaration->getASTContext().getSourceManager();
+  SmallString<1024> FileName = getFilename(SM, Loc);
+  llvm::sys::fs::make_absolute(FileName);
+  llvm::sys::path::reverse_iterator Begin = llvm::sys::path::rbegin(FileName),
+                                    End = llvm::sys::path::rend(FileName);
+  for (; Begin != End; ++Begin) {
+    if (Begin->compare_lower(StringRef("graphite2")) == 0) {
+      return true;
+    }
+    if (Begin->compare_lower(StringRef("chromium")) == 0) {
+      // Ignore security/sandbox/chromium but not ipc/chromium.
+      ++Begin;
+      return Begin != End && Begin->compare_lower(StringRef("sandbox")) == 0;
+    }
+  }
+  return false;
+}
+
+inline bool isIgnoredPathForSprintfLiteral(const CallExpr *Call,
+                                           const SourceManager &SM) {
+  SourceLocation Loc = Call->getBeginLoc();
+  SmallString<1024> FileName = getFilename(SM, Loc);
+  llvm::sys::fs::make_absolute(FileName);
+  llvm::sys::path::reverse_iterator Begin = llvm::sys::path::rbegin(FileName),
+                                    End = llvm::sys::path::rend(FileName);
+  for (; Begin != End; ++Begin) {
+    if (Begin->compare_lower(StringRef("angle")) == 0 ||
+        Begin->compare_lower(StringRef("chromium")) == 0 ||
+        Begin->compare_lower(StringRef("crashreporter")) == 0 ||
+        Begin->compare_lower(StringRef("google-breakpad")) == 0 ||
+        Begin->compare_lower(StringRef("gflags")) == 0 ||
+        Begin->compare_lower(StringRef("harfbuzz")) == 0 ||
+        Begin->compare_lower(StringRef("icu")) == 0 ||
+        Begin->compare_lower(StringRef("jsoncpp")) == 0 ||
+        Begin->compare_lower(StringRef("libstagefright")) == 0 ||
+        Begin->compare_lower(StringRef("transport")) == 0 ||
+        Begin->compare_lower(StringRef("protobuf")) == 0 ||
+        Begin->compare_lower(StringRef("skia")) == 0 ||
+        Begin->compare_lower(StringRef("sfntly")) == 0 ||
+        // Gtest uses snprintf as GTEST_SNPRINTF_ with sizeof
+        Begin->compare_lower(StringRef("testing")) == 0) {
+      return true;
+    }
+    if (Begin->compare_lower(StringRef("webrtc")) == 0) {
+      // Ignore trunk/webrtc, but not media/webrtc
+      ++Begin;
+      return Begin != End && Begin->compare_lower(StringRef("trunk")) == 0;
+    }
+  }
+  return false;
+}
+
+inline bool isInterestingDeclForImplicitConversion(const Decl *Declaration) {
+  return !isInIgnoredNamespaceForImplicitConversion(Declaration) &&
+         !isIgnoredPathForImplicitConversion(Declaration);
+}
+
+inline bool isIgnoredExprForMustUse(const Expr *E) {
+  if (const CXXOperatorCallExpr *OpCall = dyn_cast<CXXOperatorCallExpr>(E)) {
+    switch (OpCall->getOperator()) {
+    case OO_Equal:
+    case OO_PlusEqual:
+    case OO_MinusEqual:
+    case OO_StarEqual:
+    case OO_SlashEqual:
+    case OO_PercentEqual:
+    case OO_CaretEqual:
+    case OO_AmpEqual:
+    case OO_PipeEqual:
+    case OO_LessLessEqual:
+    case OO_GreaterGreaterEqual:
+      return true;
+    default:
+      return false;
+    }
+  }
+
+  if (const BinaryOperator *Op = dyn_cast<BinaryOperator>(E)) {
+    return Op->isAssignmentOp();
+  }
+
+  return false;
+}
+
+inline bool typeIsRefPtr(QualType Q) {
+  CXXRecordDecl *D = Q->getAsCXXRecordDecl();
+  if (!D || !D->getIdentifier()) {
+    return false;
+  }
+
+  StringRef name = D->getName();
+  if (name == "RefPtr" || name == "nsCOMPtr") {
+    return true;
+  }
+  return false;
+}
+
+// The method defined in clang for ignoring implicit nodes doesn't work with
+// some AST trees. To get around this, we define our own implementation of
+// IgnoreTrivials.
+inline const Stmt *MaybeSkipOneTrivial(const Stmt *s) {
+  if (!s) {
+    return nullptr;
+  }
+  if (auto *ewc = dyn_cast<ExprWithCleanups>(s)) {
+    return ewc->getSubExpr();
+  }
+  if (auto *mte = dyn_cast<MaterializeTemporaryExpr>(s)) {
+    // With clang 10 and up `getTemporary` has been replaced with the more
+    // versatile `getSubExpr`.
+#if CLANG_VERSION_FULL >= 1000
+    return mte->getSubExpr();
+#else
+    return mte->GetTemporaryExpr();
+#endif
+  }
+  if (auto *bte = dyn_cast<CXXBindTemporaryExpr>(s)) {
+    return bte->getSubExpr();
+  }
+  if (auto *ce = dyn_cast<CastExpr>(s)) {
+    s = ce->getSubExpr();
+  }
+  if (auto *pe = dyn_cast<ParenExpr>(s)) {
+    s = pe->getSubExpr();
+  }
+  // Not a trivial.
+  return s;
+}
+
+inline const Stmt *IgnoreTrivials(const Stmt *s) {
+  while (true) {
+    const Stmt *newS = MaybeSkipOneTrivial(s);
+    if (newS == s) {
+      return newS;
+    }
+    s = newS;
+  }
+
+  // Unreachable
+  return nullptr;
+}
+
+inline const Expr *IgnoreTrivials(const Expr *e) {
+  return cast_or_null<Expr>(IgnoreTrivials(static_cast<const Stmt *>(e)));
+}
+
+// Returns the input if the input is not a trivial.
+inline const Expr *MaybeSkipOneTrivial(const Expr *e) {
+  return cast_or_null<Expr>(MaybeSkipOneTrivial(static_cast<const Stmt *>(e)));
+}
+
+const FieldDecl *getBaseRefCntMember(QualType T);
+
+inline const FieldDecl *getBaseRefCntMember(const CXXRecordDecl *D) {
+  const FieldDecl *RefCntMember = getClassRefCntMember(D);
+  if (RefCntMember && isClassRefCounted(D)) {
+    return RefCntMember;
+  }
+
+  for (CXXRecordDecl::base_class_const_iterator Base = D->bases_begin(),
+                                                E = D->bases_end();
+       Base != E; ++Base) {
+    RefCntMember = getBaseRefCntMember(Base->getType());
+    if (RefCntMember) {
+      return RefCntMember;
+    }
+  }
+  return 0;
+}
+
+inline const FieldDecl *getBaseRefCntMember(QualType T) {
+  while (const clang::ArrayType *ArrTy = T->getAsArrayTypeUnsafe())
+    T = ArrTy->getElementType();
+  CXXRecordDecl *Clazz = T->getAsCXXRecordDecl();
+  return Clazz ? getBaseRefCntMember(Clazz) : 0;
+}
+
+inline bool isPlacementNew(const CXXNewExpr *Expression) {
+  // Regular new expressions aren't placement new
+  if (Expression->getNumPlacementArgs() == 0)
+    return false;
+  const FunctionDecl *Declaration = Expression->getOperatorNew();
+  if (Declaration && hasCustomAttribute<moz_heap_allocator>(Declaration)) {
+    return false;
+  }
+  return true;
+}
+
+extern DenseMap<StringRef, bool> InThirdPartyPathCache;
+
+inline bool inThirdPartyPath(SourceLocation Loc, const SourceManager &SM) {
+  StringRef OriginalFileName = getFilename(SM, Loc);
+  auto pair = InThirdPartyPathCache.find(OriginalFileName);
+  if (pair != InThirdPartyPathCache.end()) {
+    return pair->second;
+  }
+
+  SmallString<1024> FileName = OriginalFileName;
+  llvm::sys::fs::make_absolute(FileName);
+
+  for (uint32_t i = 0; i < MOZ_THIRD_PARTY_PATHS_COUNT; ++i) {
+    auto PathB = sys::path::begin(FileName);
+    auto PathE = sys::path::end(FileName);
+
+    auto ThirdPartyB = sys::path::begin(MOZ_THIRD_PARTY_PATHS[i]);
+    auto ThirdPartyE = sys::path::end(MOZ_THIRD_PARTY_PATHS[i]);
+
+    for (; PathB != PathE; ++PathB) {
+      // Perform an inner loop to compare path segments, checking if the current
+      // segment is the start of the current third party path.
+      auto IPathB = PathB;
+      auto IThirdPartyB = ThirdPartyB;
+      for (; IPathB != PathE && IThirdPartyB != ThirdPartyE;
+           ++IPathB, ++IThirdPartyB) {
+        if (IPathB->compare_lower(*IThirdPartyB) != 0) {
+          break;
+        }
+      }
+
+      // We found a match!
+      if (IThirdPartyB == ThirdPartyE) {
+        InThirdPartyPathCache.insert(std::make_pair(OriginalFileName, true));
+        return true;
+      }
+    }
+  }
+
+  InThirdPartyPathCache.insert(std::make_pair(OriginalFileName, false));
+  return false;
+}
+
+inline bool inThirdPartyPath(const Decl *D, ASTContext *context) {
+  D = D->getCanonicalDecl();
+  SourceLocation Loc = D->getLocation();
+  const SourceManager &SM = context->getSourceManager();
+
+  return inThirdPartyPath(Loc, SM);
+}
+
+inline CXXRecordDecl *getNonTemplateSpecializedCXXRecordDecl(QualType Q) {
+  auto *D = Q->getAsCXXRecordDecl();
+
+  if (!D) {
+    auto TemplateQ = Q->getAs<TemplateSpecializationType>();
+    if (!TemplateQ) {
+      return nullptr;
+    }
+
+    auto TemplateDecl = TemplateQ->getTemplateName().getAsTemplateDecl();
+    if (!TemplateDecl) {
+      return nullptr;
+    }
+
+    D = dyn_cast_or_null<CXXRecordDecl>(TemplateDecl->getTemplatedDecl());
+    if (!D) {
+      return nullptr;
+    }
+  }
+
+  return D;
+}
+
+inline bool inThirdPartyPath(const Decl *D) {
+  return inThirdPartyPath(D, &D->getASTContext());
+}
+
+inline bool inThirdPartyPath(const Stmt *S, ASTContext *context) {
+  SourceLocation Loc = S->getBeginLoc();
+  const SourceManager &SM = context->getSourceManager();
+  auto ExpansionLoc = SM.getExpansionLoc(Loc);
+  if (ExpansionLoc.isInvalid()) {
+    return inThirdPartyPath(Loc, SM);
+  }
+  return inThirdPartyPath(ExpansionLoc, SM);
+}
+
+/// Polyfill for CXXOperatorCallExpr::isInfixBinaryOp()
+inline bool isInfixBinaryOp(const CXXOperatorCallExpr *OpCall) {
+#if CLANG_VERSION_FULL >= 400
+  return OpCall->isInfixBinaryOp();
+#else
+  // Taken from clang source.
+  if (OpCall->getNumArgs() != 2)
+    return false;
+
+  switch (OpCall->getOperator()) {
+  case OO_Call:
+  case OO_Subscript:
+    return false;
+  default:
+    return true;
+  }
+#endif
+}
+
+#undef compare_lower
+#endif