build/clang-plugin/CustomMatchers.h
author Nathan Froyd <froydnj@mozilla.com>
Wed, 03 Apr 2019 00:06:04 +0000
changeset 467750 1b9e5f4b0589a636233affb84666a469a4cc4ef5
parent 465437 1133a148d29c657567b6985e08af96adab3328f7
child 476770 f99b54a6da932c5e88a6932d5d6f27629ba89a4e
permissions -rw-r--r--
Bug 1537643 - update cc crate; r=glandium This update from the official sources brings in the changes that we were using glandium's fork for, as well as changes enabling us to tweak more settings on Windows. Differential Revision: https://phabricator.services.mozilla.com/D25888

/* 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 CustomMatchers_h__
#define CustomMatchers_h__

#include "MemMoveAnnotation.h"
#include "Utils.h"

namespace clang {
namespace ast_matchers {

/// This matcher will match any function declaration that is declared as a heap
/// allocator.
AST_MATCHER(FunctionDecl, heapAllocator) {
  return hasCustomAttribute<moz_heap_allocator>(&Node);
}

/// This matcher will match any declaration that is marked as not accepting
/// arithmetic expressions in its arguments.
AST_MATCHER(Decl, noArithmeticExprInArgs) {
  return hasCustomAttribute<moz_no_arith_expr_in_arg>(&Node);
}

/// This matcher will match any C++ class that is marked as having a trivial
/// constructor and destructor.
AST_MATCHER(CXXRecordDecl, hasTrivialCtorDtor) {
  return hasCustomAttribute<moz_trivial_ctor_dtor>(&Node);
}

AST_MATCHER(CXXConstructExpr, allowsTemporary) {
  return hasCustomAttribute<moz_allow_temporary>(Node.getConstructor());
}

/// This matcher will match lvalue-ref-qualified methods.
AST_MATCHER(CXXMethodDecl, isLValueRefQualified) {
  return Node.getRefQualifier() == RQ_LValue;
}

/// This matcher will match rvalue-ref-qualified methods.
AST_MATCHER(CXXMethodDecl, isRValueRefQualified) {
  return Node.getRefQualifier() == RQ_RValue;
}

AST_POLYMORPHIC_MATCHER(isFirstParty,
                        AST_POLYMORPHIC_SUPPORTED_TYPES(Decl, Stmt)) {
  return !inThirdPartyPath(&Node, &Finder->getASTContext()) &&
         !ASTIsInSystemHeader(Finder->getASTContext(), Node);
}

/// This matcher will match temporary expressions.
/// We need this matcher for compatibility with clang 3.* (clang 4 and above
/// insert a MaterializeTemporaryExpr everywhere).
AST_MATCHER(Expr, isTemporary) {
  return Node.isRValue() || Node.isXValue() ||
         isa<MaterializeTemporaryExpr>(&Node);
}

/// This matcher will match any method declaration that is marked as returning
/// a pointer deleted by the destructor of the class.
AST_MATCHER(CXXMethodDecl, noDanglingOnTemporaries) {
  return hasCustomAttribute<moz_no_dangling_on_temporaries>(&Node);
}

/// This matcher will match any function declaration that is marked to prohibit
/// calling AddRef or Release on its return value.
AST_MATCHER(FunctionDecl, hasNoAddRefReleaseOnReturnAttr) {
  return hasCustomAttribute<moz_no_addref_release_on_return>(&Node);
}

/// This matcher will match any function declaration that is marked as being
/// allowed to run script.
AST_MATCHER(FunctionDecl, hasCanRunScriptAnnotation) {
  return hasCustomAttribute<moz_can_run_script>(&Node);
}

/// This matcher will match all arithmetic binary operators.
AST_MATCHER(BinaryOperator, binaryArithmeticOperator) {
  BinaryOperatorKind OpCode = Node.getOpcode();
  return OpCode == BO_Mul || OpCode == BO_Div || OpCode == BO_Rem ||
         OpCode == BO_Add || OpCode == BO_Sub || OpCode == BO_Shl ||
         OpCode == BO_Shr || OpCode == BO_And || OpCode == BO_Xor ||
         OpCode == BO_Or || OpCode == BO_MulAssign || OpCode == BO_DivAssign ||
         OpCode == BO_RemAssign || OpCode == BO_AddAssign ||
         OpCode == BO_SubAssign || OpCode == BO_ShlAssign ||
         OpCode == BO_ShrAssign || OpCode == BO_AndAssign ||
         OpCode == BO_XorAssign || OpCode == BO_OrAssign;
}

/// This matcher will match all arithmetic unary operators.
AST_MATCHER(UnaryOperator, unaryArithmeticOperator) {
  UnaryOperatorKind OpCode = Node.getOpcode();
  return OpCode == UO_PostInc || OpCode == UO_PostDec || OpCode == UO_PreInc ||
         OpCode == UO_PreDec || OpCode == UO_Plus || OpCode == UO_Minus ||
         OpCode == UO_Not;
}

/// This matcher will match the unary dereference operator
AST_MATCHER(UnaryOperator, unaryDereferenceOperator) {
  UnaryOperatorKind OpCode = Node.getOpcode();
  return OpCode == UO_Deref;
}

/// This matcher will match == and != binary operators.
AST_MATCHER(BinaryOperator, binaryEqualityOperator) {
  BinaryOperatorKind OpCode = Node.getOpcode();
  return OpCode == BO_EQ || OpCode == BO_NE;
}

/// This matcher will match comma operator.
AST_MATCHER(BinaryOperator, binaryCommaOperator) {
  BinaryOperatorKind OpCode = Node.getOpcode();
  return OpCode == BO_Comma;
}

/// This matcher will match floating point types.
AST_MATCHER(QualType, isFloat) { return Node->isRealFloatingType(); }

/// This matcher will match locations in system headers.  This is adopted from
/// isExpansionInSystemHeader in newer clangs, but modified in order to work
/// with old clangs that we use on infra.
AST_POLYMORPHIC_MATCHER(isInSystemHeader,                                      \
                        AST_POLYMORPHIC_SUPPORTED_TYPES(Decl, Stmt)) {
  return ASTIsInSystemHeader(Finder->getASTContext(), Node);
}

/// This matcher will match a list of files.  These files contain
/// known NaN-testing expressions which we would like to whitelist.
AST_MATCHER(BinaryOperator, isInWhitelistForNaNExpr) {
  const char *whitelist[] = {"SkScalar.h", "json_writer.cpp", "State.cpp"};

  SourceLocation Loc = Node.getOperatorLoc();
  auto &SourceManager = Finder->getASTContext().getSourceManager();
  SmallString<1024> FileName = SourceManager.getFilename(Loc);

  for (auto itr = std::begin(whitelist); itr != std::end(whitelist); itr++) {
    if (llvm::sys::path::rbegin(FileName)->equals(*itr)) {
      return true;
    }
  }

  return false;
}

/// This matcher will match all accesses to AddRef or Release methods.
AST_MATCHER(MemberExpr, isAddRefOrRelease) {
  ValueDecl *Member = Node.getMemberDecl();
  CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Member);
  if (Method) {
    const auto &Name = getNameChecked(Method);
    return Name == "AddRef" || Name == "Release";
  }
  return false;
}

/// This matcher will select classes which are refcounted AND have an mRefCnt
/// member.
AST_MATCHER(CXXRecordDecl, hasRefCntMember) {
  return isClassRefCounted(&Node) && getClassRefCntMember(&Node);
}

/// This matcher will select classes which are refcounted.
AST_MATCHER(CXXRecordDecl, isRefCounted) { return isClassRefCounted(&Node); }

AST_MATCHER(QualType, hasVTable) { return typeHasVTable(Node); }

AST_MATCHER(CXXRecordDecl, hasNeedsNoVTableTypeAttr) {
  return hasCustomAttribute<moz_needs_no_vtable_type>(&Node);
}

/// This matcher will select classes which are non-memmovable
AST_MATCHER(QualType, isNonMemMovable) {
  return NonMemMovable.hasEffectiveAnnotation(Node);
}

/// This matcher will select classes which require a memmovable template arg
AST_MATCHER(CXXRecordDecl, needsMemMovableTemplateArg) {
  return hasCustomAttribute<moz_needs_memmovable_type>(&Node);
}

/// This matcher will select classes which require all members to be memmovable
AST_MATCHER(CXXRecordDecl, needsMemMovableMembers) {
  return hasCustomAttribute<moz_needs_memmovable_members>(&Node);
}

AST_MATCHER(CXXConstructorDecl, isInterestingImplicitCtor) {
  const CXXConstructorDecl *Declaration = Node.getCanonicalDecl();
  return
      // Skip constructors in system headers
      !ASTIsInSystemHeader(Declaration->getASTContext(), *Declaration) &&
      // Skip ignored namespaces and paths
      !isInIgnoredNamespaceForImplicitCtor(Declaration) &&
      !inThirdPartyPath(Declaration) &&
      // We only want Converting constructors
      Declaration->isConvertingConstructor(false) &&
      // We don't want copy of move constructors, as those are allowed to be
      // implicit
      !Declaration->isCopyOrMoveConstructor() &&
      // We don't want deleted constructors.
      !Declaration->isDeleted();
}

AST_MATCHER_P(Expr, ignoreTrivials, internal::Matcher<Expr>, InnerMatcher) {
  return InnerMatcher.matches(*IgnoreTrivials(&Node), Finder, Builder);
}

// Takes two matchers: the first one is a condition; the second is a matcher to be
// applied once we are done unwrapping trivials.  While the condition does not match
// and we're looking at a trivial, will keep unwrapping the trivial and trying again.
// Once the condition matches, we will go ahead and unwrap all trivials and apply the
// inner matcher to the result.
//
// The expected use here is if we want to condition a match on some typecheck but
// apply the match to only non-trivials, because there are trivials (e.g. casts) that
// can change types.
AST_MATCHER_P2(Expr, ignoreTrivialsConditional,
               internal::Matcher<Expr>, Condition,
               internal::Matcher<Expr>, InnerMatcher) {
  const Expr *node = &Node;
  while (true) {
    if (Condition.matches(*node, Finder, Builder)) {
      return InnerMatcher.matches(*IgnoreTrivials(node), Finder, Builder);
    }
    const Expr *newNode = MaybeSkipOneTrivial(node);
    if (newNode == node) {
      return false;
    }
    node = newNode;
  }
}

// We can't call this "isImplicit" since it clashes with an existing matcher in
// clang.
AST_MATCHER(CXXConstructorDecl, isMarkedImplicit) {
  return hasCustomAttribute<moz_implicit>(&Node);
}

AST_MATCHER(CXXRecordDecl, isConcreteClass) { return !Node.isAbstract(); }

AST_MATCHER(QualType, autoNonAutoableType) {
  if (const AutoType *T = Node->getContainedAutoType()) {
    if (const CXXRecordDecl *Rec = T->getAsCXXRecordDecl()) {
      return hasCustomAttribute<moz_non_autoable>(Rec);
    }
  }
  return false;
}

AST_MATCHER(CXXConstructorDecl, isExplicitMoveConstructor) {
  return Node.isExplicit() && Node.isMoveConstructor();
}

AST_MATCHER(CXXConstructorDecl, isCompilerProvidedCopyConstructor) {
  return !Node.isUserProvided() && Node.isCopyConstructor();
}

AST_MATCHER(CallExpr, isAssertAssignmentTestFunc) {
  static const std::string AssertName = "MOZ_AssertAssignmentTest";
  const FunctionDecl *Method = Node.getDirectCallee();

  return Method && Method->getDeclName().isIdentifier() &&
         Method->getName() == AssertName;
}

AST_MATCHER(CallExpr, isSnprintfLikeFunc) {
  static const std::string Snprintf = "snprintf";
  static const std::string Vsnprintf = "vsnprintf";
  const FunctionDecl *Func = Node.getDirectCallee();

  if (!Func || isa<CXXMethodDecl>(Func)) {
    return false;
  }

  StringRef Name = getNameChecked(Func);
  if (Name != Snprintf && Name != Vsnprintf) {
    return false;
  }

  return !inThirdPartyPath(Node.getBeginLoc(),
                           Finder->getASTContext().getSourceManager()) &&
         !isIgnoredPathForSprintfLiteral(
             &Node, Finder->getASTContext().getSourceManager());
}

AST_MATCHER(CXXRecordDecl, isLambdaDecl) { return Node.isLambda(); }

AST_MATCHER(QualType, isRefPtr) { return typeIsRefPtr(Node); }

AST_MATCHER(QualType, isSmartPtrToRefCounted) {
  auto *D = getNonTemplateSpecializedCXXRecordDecl(Node);
  if (!D) {
    return false;
  }

  D = D->getCanonicalDecl();

  return D && hasCustomAttribute<moz_is_smartptr_to_refcounted>(D);
}

AST_MATCHER(CXXRecordDecl, hasBaseClasses) {
  const CXXRecordDecl *Decl = Node.getCanonicalDecl();

  // Must have definition and should inherit other classes
  return Decl && Decl->hasDefinition() && Decl->getNumBases();
}

AST_MATCHER(CXXMethodDecl, isRequiredBaseMethod) {
  const CXXMethodDecl *Decl = Node.getCanonicalDecl();
  return Decl && hasCustomAttribute<moz_required_base_method>(Decl);
}

AST_MATCHER(CXXMethodDecl, isNonVirtual) {
  const CXXMethodDecl *Decl = Node.getCanonicalDecl();
  return Decl && !Decl->isVirtual();
}

AST_MATCHER(FunctionDecl, isMozMustReturnFromCaller) {
  const FunctionDecl *Decl = Node.getCanonicalDecl();
  return Decl && hasCustomAttribute<moz_must_return_from_caller>(Decl);
}

/// This matcher will select default args which have nullptr as the value.
AST_MATCHER(CXXDefaultArgExpr, isNullDefaultArg) {
  const Expr *Expr = Node.getExpr();
  return Expr && Expr->isNullPointerConstant(Finder->getASTContext(),
                                             Expr::NPC_NeverValueDependent);
}

#if CLANG_VERSION_FULL < 309
/// DISCLAIMER: This is a copy/paste from the Clang source code starting from
/// Clang 3.9, so that this matcher is supported in lower versions.
///
/// \brief Matches declaration of the function the statement belongs to
///
/// Given:
/// \code
/// F& operator=(const F& o) {
///   std::copy_if(o.begin(), o.end(), begin(), [](V v) { return v > 0; });
///   return *this;
/// }
/// \endcode
/// returnStmt(forFunction(hasName("operator=")))
///   matches 'return *this'
///   but does match 'return > 0'
AST_MATCHER_P(Stmt, forFunction, internal::Matcher<FunctionDecl>,
              InnerMatcher) {
  const auto &Parents = Finder->getASTContext().getParents(Node);

  llvm::SmallVector<ast_type_traits::DynTypedNode, 8> Stack(Parents.begin(),
                                                            Parents.end());
  while (!Stack.empty()) {
    const auto &CurNode = Stack.back();
    Stack.pop_back();
    if (const auto *FuncDeclNode = CurNode.get<FunctionDecl>()) {
      if (InnerMatcher.matches(*FuncDeclNode, Finder, Builder)) {
        return true;
      }
    } else if (const auto *LambdaExprNode = CurNode.get<LambdaExpr>()) {
      if (InnerMatcher.matches(*LambdaExprNode->getCallOperator(), Finder,
                               Builder)) {
        return true;
      }
    } else {
      for (const auto &Parent : Finder->getASTContext().getParents(CurNode))
        Stack.push_back(Parent);
    }
  }
  return false;
}
#endif

} // namespace ast_matchers
} // namespace clang

#endif