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//===--- SemaFixItUtils.cpp - Sema FixIts ---------------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// This file defines helper classes for generation of Sema FixItHints.
//
//===----------------------------------------------------------------------===//
#include "clang/AST/ASTContext.h"
#include "clang/AST/ExprCXX.h"
#include "clang/AST/ExprObjC.h"
#include "clang/Lex/Preprocessor.h"
#include "clang/Sema/Sema.h"
#include "clang/Sema/SemaFixItUtils.h"
using namespace clang;
bool ConversionFixItGenerator::compareTypesSimple(CanQualType From,
CanQualType To,
Sema &S,
SourceLocation Loc,
ExprValueKind FromVK) {
if (!To.isAtLeastAsQualifiedAs(From))
return false;
From = From.getNonReferenceType();
To = To.getNonReferenceType();
// If both are pointer types, work with the pointee types.
if (isa<PointerType>(From) && isa<PointerType>(To)) {
From = S.Context.getCanonicalType(
(cast<PointerType>(From))->getPointeeType());
To = S.Context.getCanonicalType(
(cast<PointerType>(To))->getPointeeType());
}
const CanQualType FromUnq = From.getUnqualifiedType();
const CanQualType ToUnq = To.getUnqualifiedType();
if ((FromUnq == ToUnq || (S.IsDerivedFrom(Loc, FromUnq, ToUnq)) ) &&
To.isAtLeastAsQualifiedAs(From))
return true;
return false;
}
bool ConversionFixItGenerator::tryToFixConversion(const Expr *FullExpr,
const QualType FromTy,
const QualType ToTy,
Sema &S) {
if (!FullExpr)
return false;
const CanQualType FromQTy = S.Context.getCanonicalType(FromTy);
const CanQualType ToQTy = S.Context.getCanonicalType(ToTy);
const SourceLocation Begin = FullExpr->getSourceRange().getBegin();
const SourceLocation End = S.getLocForEndOfToken(FullExpr->getSourceRange()
.getEnd());
// Strip the implicit casts - those are implied by the compiler, not the
// original source code.
const Expr* Expr = FullExpr->IgnoreImpCasts();
bool NeedParen = true;
if (isa<ArraySubscriptExpr>(Expr) ||
isa<CallExpr>(Expr) ||
isa<DeclRefExpr>(Expr) ||
isa<CastExpr>(Expr) ||
isa<CXXNewExpr>(Expr) ||
isa<CXXConstructExpr>(Expr) ||
isa<CXXDeleteExpr>(Expr) ||
isa<CXXNoexceptExpr>(Expr) ||
isa<CXXPseudoDestructorExpr>(Expr) ||
isa<CXXScalarValueInitExpr>(Expr) ||
isa<CXXThisExpr>(Expr) ||
isa<CXXTypeidExpr>(Expr) ||
isa<CXXUnresolvedConstructExpr>(Expr) ||
isa<ObjCMessageExpr>(Expr) ||
isa<ObjCPropertyRefExpr>(Expr) ||
isa<ObjCProtocolExpr>(Expr) ||
isa<MemberExpr>(Expr) ||
isa<ParenExpr>(FullExpr) ||
isa<ParenListExpr>(Expr) ||
isa<SizeOfPackExpr>(Expr) ||
isa<UnaryOperator>(Expr))
NeedParen = false;
// Check if the argument needs to be dereferenced:
// (type * -> type) or (type * -> type &).
if (const PointerType *FromPtrTy = dyn_cast<PointerType>(FromQTy)) {
OverloadFixItKind FixKind = OFIK_Dereference;
bool CanConvert = CompareTypes(
S.Context.getCanonicalType(FromPtrTy->getPointeeType()), ToQTy,
S, Begin, VK_LValue);
if (CanConvert) {
// Do not suggest dereferencing a Null pointer.
if (Expr->IgnoreParenCasts()->
isNullPointerConstant(S.Context, Expr::NPC_ValueDependentIsNotNull))
return false;
if (const UnaryOperator *UO = dyn_cast<UnaryOperator>(Expr)) {
if (UO->getOpcode() == UO_AddrOf) {
FixKind = OFIK_RemoveTakeAddress;
Hints.push_back(FixItHint::CreateRemoval(
CharSourceRange::getTokenRange(Begin, Begin)));
}
} else if (NeedParen) {
Hints.push_back(FixItHint::CreateInsertion(Begin, "*("));
Hints.push_back(FixItHint::CreateInsertion(End, ")"));
} else {
Hints.push_back(FixItHint::CreateInsertion(Begin, "*"));
}
NumConversionsFixed++;
if (NumConversionsFixed == 1)
Kind = FixKind;
return true;
}
}
// Check if the pointer to the argument needs to be passed:
// (type -> type *) or (type & -> type *).
if (isa<PointerType>(ToQTy)) {
bool CanConvert = false;
OverloadFixItKind FixKind = OFIK_TakeAddress;
// Only suggest taking address of L-values.
if (!Expr->isLValue() || Expr->getObjectKind() != OK_Ordinary)
return false;
CanConvert = CompareTypes(S.Context.getPointerType(FromQTy), ToQTy, S,
Begin, VK_PRValue);
if (CanConvert) {
if (const UnaryOperator *UO = dyn_cast<UnaryOperator>(Expr)) {
if (UO->getOpcode() == UO_Deref) {
FixKind = OFIK_RemoveDereference;
Hints.push_back(FixItHint::CreateRemoval(
CharSourceRange::getTokenRange(Begin, Begin)));
}
} else if (NeedParen) {
Hints.push_back(FixItHint::CreateInsertion(Begin, "&("));
Hints.push_back(FixItHint::CreateInsertion(End, ")"));
} else {
Hints.push_back(FixItHint::CreateInsertion(Begin, "&"));
}
NumConversionsFixed++;
if (NumConversionsFixed == 1)
Kind = FixKind;
return true;
}
}
return false;
}
static bool isMacroDefined(const Sema &S, SourceLocation Loc, StringRef Name) {
return (bool)S.PP.getMacroDefinitionAtLoc(&S.getASTContext().Idents.get(Name),
Loc);
}
static std::string getScalarZeroExpressionForType(
const Type &T, SourceLocation Loc, const Sema &S) {
assert(T.isScalarType() && "use scalar types only");
// Suggest "0" for non-enumeration scalar types, unless we can find a
// better initializer.
if (T.isEnumeralType())
return std::string();
if ((T.isObjCObjectPointerType() || T.isBlockPointerType()) &&
isMacroDefined(S, Loc, "nil"))
return "nil";
if (T.isRealFloatingType())
return "0.0";
if (T.isBooleanType() &&
(S.LangOpts.CPlusPlus || isMacroDefined(S, Loc, "false")))
return "false";
if (T.isPointerType() || T.isMemberPointerType()) {
if (S.LangOpts.CPlusPlus11)
return "nullptr";
if (isMacroDefined(S, Loc, "NULL"))
return "NULL";
}
if (T.isCharType())
return "'\\0'";
if (T.isWideCharType())
return "L'\\0'";
if (T.isChar16Type())
return "u'\\0'";
if (T.isChar32Type())
return "U'\\0'";
return "0";
}
std::string
Sema::getFixItZeroInitializerForType(QualType T, SourceLocation Loc) const {
if (T->isScalarType()) {
std::string s = getScalarZeroExpressionForType(*T, Loc, *this);
if (!s.empty())
s = " = " + s;
return s;
}
const CXXRecordDecl *RD = T->getAsCXXRecordDecl();
if (!RD || !RD->hasDefinition())
return std::string();
if (LangOpts.CPlusPlus11 && !RD->hasUserProvidedDefaultConstructor())
return "{}";
if (RD->isAggregate())
return " = {}";
return std::string();
}
std::string
Sema::getFixItZeroLiteralForType(QualType T, SourceLocation Loc) const {
return getScalarZeroExpressionForType(*T, Loc, *this);
}