SourceCodeBuilders.cpp
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//===--- SourceCodeBuilder.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 "clang/Tooling/Transformer/SourceCodeBuilders.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/Expr.h"
#include "clang/AST/ExprCXX.h"
#include "clang/Tooling/Transformer/SourceCode.h"
#include "llvm/ADT/Twine.h"
#include <string>
using namespace clang;
using namespace tooling;
const Expr *tooling::reallyIgnoreImplicit(const Expr &E) {
const Expr *Expr = E.IgnoreImplicit();
if (const auto *CE = dyn_cast<CXXConstructExpr>(Expr)) {
if (CE->getNumArgs() > 0 &&
CE->getArg(0)->getSourceRange() == Expr->getSourceRange())
return CE->getArg(0)->IgnoreImplicit();
}
return Expr;
}
bool tooling::mayEverNeedParens(const Expr &E) {
const Expr *Expr = reallyIgnoreImplicit(E);
// We always want parens around unary, binary, and ternary operators, because
// they are lower precedence.
if (isa<UnaryOperator>(Expr) || isa<BinaryOperator>(Expr) ||
isa<AbstractConditionalOperator>(Expr))
return true;
// We need parens around calls to all overloaded operators except: function
// calls, subscripts, and expressions that are already part of an (implicit)
// call to operator->. These latter are all in the same precedence level as
// dot/arrow and that level is left associative, so they don't need parens
// when appearing on the left.
if (const auto *Op = dyn_cast<CXXOperatorCallExpr>(Expr))
return Op->getOperator() != OO_Call && Op->getOperator() != OO_Subscript &&
Op->getOperator() != OO_Arrow;
return false;
}
bool tooling::needParensAfterUnaryOperator(const Expr &E) {
const Expr *Expr = reallyIgnoreImplicit(E);
if (isa<BinaryOperator>(Expr) || isa<AbstractConditionalOperator>(Expr))
return true;
if (const auto *Op = dyn_cast<CXXOperatorCallExpr>(Expr))
return Op->getNumArgs() == 2 && Op->getOperator() != OO_PlusPlus &&
Op->getOperator() != OO_MinusMinus && Op->getOperator() != OO_Call &&
Op->getOperator() != OO_Subscript;
return false;
}
llvm::Optional<std::string> tooling::buildParens(const Expr &E,
const ASTContext &Context) {
StringRef Text = getText(E, Context);
if (Text.empty())
return llvm::None;
if (mayEverNeedParens(E))
return ("(" + Text + ")").str();
return Text.str();
}
llvm::Optional<std::string>
tooling::buildDereference(const Expr &E, const ASTContext &Context) {
if (const auto *Op = dyn_cast<UnaryOperator>(&E))
if (Op->getOpcode() == UO_AddrOf) {
// Strip leading '&'.
StringRef Text =
getText(*Op->getSubExpr()->IgnoreParenImpCasts(), Context);
if (Text.empty())
return llvm::None;
return Text.str();
}
StringRef Text = getText(E, Context);
if (Text.empty())
return llvm::None;
// Add leading '*'.
if (needParensAfterUnaryOperator(E))
return ("*(" + Text + ")").str();
return ("*" + Text).str();
}
llvm::Optional<std::string> tooling::buildAddressOf(const Expr &E,
const ASTContext &Context) {
if (const auto *Op = dyn_cast<UnaryOperator>(&E))
if (Op->getOpcode() == UO_Deref) {
// Strip leading '*'.
StringRef Text =
getText(*Op->getSubExpr()->IgnoreParenImpCasts(), Context);
if (Text.empty())
return llvm::None;
return Text.str();
}
// Add leading '&'.
StringRef Text = getText(E, Context);
if (Text.empty())
return llvm::None;
if (needParensAfterUnaryOperator(E)) {
return ("&(" + Text + ")").str();
}
return ("&" + Text).str();
}
llvm::Optional<std::string> tooling::buildDot(const Expr &E,
const ASTContext &Context) {
if (const auto *Op = llvm::dyn_cast<UnaryOperator>(&E))
if (Op->getOpcode() == UO_Deref) {
// Strip leading '*', add following '->'.
const Expr *SubExpr = Op->getSubExpr()->IgnoreParenImpCasts();
StringRef DerefText = getText(*SubExpr, Context);
if (DerefText.empty())
return llvm::None;
if (needParensBeforeDotOrArrow(*SubExpr))
return ("(" + DerefText + ")->").str();
return (DerefText + "->").str();
}
// Add following '.'.
StringRef Text = getText(E, Context);
if (Text.empty())
return llvm::None;
if (needParensBeforeDotOrArrow(E)) {
return ("(" + Text + ").").str();
}
return (Text + ".").str();
}
llvm::Optional<std::string> tooling::buildArrow(const Expr &E,
const ASTContext &Context) {
if (const auto *Op = llvm::dyn_cast<UnaryOperator>(&E))
if (Op->getOpcode() == UO_AddrOf) {
// Strip leading '&', add following '.'.
const Expr *SubExpr = Op->getSubExpr()->IgnoreParenImpCasts();
StringRef DerefText = getText(*SubExpr, Context);
if (DerefText.empty())
return llvm::None;
if (needParensBeforeDotOrArrow(*SubExpr))
return ("(" + DerefText + ").").str();
return (DerefText + ".").str();
}
// Add following '->'.
StringRef Text = getText(E, Context);
if (Text.empty())
return llvm::None;
if (needParensBeforeDotOrArrow(E))
return ("(" + Text + ")->").str();
return (Text + "->").str();
}