101 строка
3.8 KiB
C++
101 строка
3.8 KiB
C++
//===--- DeclRefExprUtils.cpp - clang-tidy---------------------------------===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "DeclRefExprUtils.h"
|
|
#include "clang/AST/ASTContext.h"
|
|
#include "clang/AST/DeclCXX.h"
|
|
#include "clang/ASTMatchers/ASTMatchFinder.h"
|
|
#include "llvm/ADT/SmallPtrSet.h"
|
|
|
|
namespace clang {
|
|
namespace tidy {
|
|
namespace utils {
|
|
namespace decl_ref_expr {
|
|
|
|
using namespace ::clang::ast_matchers;
|
|
using llvm::SmallPtrSet;
|
|
|
|
namespace {
|
|
|
|
template <typename S> bool isSetDifferenceEmpty(const S &S1, const S &S2) {
|
|
for (const auto &E : S1)
|
|
if (S2.count(E) == 0)
|
|
return false;
|
|
return true;
|
|
}
|
|
|
|
// Extracts all Nodes keyed by ID from Matches and inserts them into Nodes.
|
|
template <typename Node>
|
|
void extractNodesByIdTo(ArrayRef<BoundNodes> Matches, StringRef ID,
|
|
SmallPtrSet<const Node *, 16> &Nodes) {
|
|
for (const auto &Match : Matches)
|
|
Nodes.insert(Match.getNodeAs<Node>(ID));
|
|
}
|
|
|
|
// Finds all DeclRefExprs to VarDecl in Stmt.
|
|
SmallPtrSet<const DeclRefExpr *, 16>
|
|
declRefExprs(const VarDecl &VarDecl, const Stmt &Stmt, ASTContext &Context) {
|
|
auto Matches = match(
|
|
findAll(declRefExpr(to(varDecl(equalsNode(&VarDecl)))).bind("declRef")),
|
|
Stmt, Context);
|
|
SmallPtrSet<const DeclRefExpr *, 16> DeclRefs;
|
|
extractNodesByIdTo(Matches, "declRef", DeclRefs);
|
|
return DeclRefs;
|
|
}
|
|
|
|
// Finds all DeclRefExprs where a const method is called on VarDecl or VarDecl
|
|
// is the a const reference or value argument to a CallExpr or CXXConstructExpr.
|
|
SmallPtrSet<const DeclRefExpr *, 16>
|
|
constReferenceDeclRefExprs(const VarDecl &VarDecl, const Stmt &Stmt,
|
|
ASTContext &Context) {
|
|
auto DeclRefToVar =
|
|
declRefExpr(to(varDecl(equalsNode(&VarDecl)))).bind("declRef");
|
|
auto ConstMethodCallee = callee(cxxMethodDecl(isConst()));
|
|
// Match method call expressions where the variable is referenced as the this
|
|
// implicit object argument and opertor call expression for member operators
|
|
// where the variable is the 0-th argument.
|
|
auto Matches = match(
|
|
findAll(expr(anyOf(cxxMemberCallExpr(ConstMethodCallee, on(DeclRefToVar)),
|
|
cxxOperatorCallExpr(ConstMethodCallee,
|
|
hasArgument(0, DeclRefToVar))))),
|
|
Stmt, Context);
|
|
SmallPtrSet<const DeclRefExpr *, 16> DeclRefs;
|
|
extractNodesByIdTo(Matches, "declRef", DeclRefs);
|
|
auto ConstReferenceOrValue =
|
|
qualType(anyOf(referenceType(pointee(qualType(isConstQualified()))),
|
|
unless(anyOf(referenceType(), pointerType()))));
|
|
auto UsedAsConstRefOrValueArg = forEachArgumentWithParam(
|
|
DeclRefToVar, parmVarDecl(hasType(ConstReferenceOrValue)));
|
|
Matches = match(findAll(callExpr(UsedAsConstRefOrValueArg)), Stmt, Context);
|
|
extractNodesByIdTo(Matches, "declRef", DeclRefs);
|
|
Matches =
|
|
match(findAll(cxxConstructExpr(UsedAsConstRefOrValueArg)), Stmt, Context);
|
|
extractNodesByIdTo(Matches, "declRef", DeclRefs);
|
|
return DeclRefs;
|
|
}
|
|
|
|
} // namespace
|
|
|
|
bool isOnlyUsedAsConst(const VarDecl &Var, const Stmt &Stmt,
|
|
ASTContext &Context) {
|
|
// Collect all DeclRefExprs to the loop variable and all CallExprs and
|
|
// CXXConstructExprs where the loop variable is used as argument to a const
|
|
// reference parameter.
|
|
// If the difference is empty it is safe for the loop variable to be a const
|
|
// reference.
|
|
auto AllDeclRefs = declRefExprs(Var, Stmt, Context);
|
|
auto ConstReferenceDeclRefs = constReferenceDeclRefExprs(Var, Stmt, Context);
|
|
return isSetDifferenceEmpty(AllDeclRefs, ConstReferenceDeclRefs);
|
|
}
|
|
|
|
} // namespace decl_ref_expr
|
|
} // namespace utils
|
|
} // namespace tidy
|
|
} // namespace clang
|