Вагина В.Д. 381806-1 #53
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| auto ReplaceRange = CharSourceRange::getCharRange( | ||
| CastExpr->getLParenLoc(), CastExpr->getSubExprAsWritten()->getBeginLoc()); | ||
| auto castIgnore = CastExpr->getSubExprAsWritten()->IgnoreImpCasts(); | ||
| if (!isa<ParenExpr>(castIgnore)) { |
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What does this check mean? Please describe examples of when this check returns true and when this check returns false.
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Данная проверка нужна в тех случаях, когда переменная после static_cast стоит не в скобках.
Если убрать проверку получается: int i = static_castf
А нужно: int i = static_cast(f)
Если проверка возвращает истину int i = (int)f, то добавляется открывающаяся и закрывающаяся скобки до и после переменной.
Если проверка возвращает ложь int i = (int)(f), в этом случае уже есть скобки и ничего добавлять не надо.
| std::string replaceText = ("static_cast<" + DestTypeString + ">").str(); | ||
| auto ReplaceRange = CharSourceRange::getCharRange( | ||
| CastExpr->getLParenLoc(), CastExpr->getSubExprAsWritten()->getBeginLoc()); | ||
| auto castIgnore = CastExpr->getSubExprAsWritten()->IgnoreImpCasts(); |
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Please describe why you are using IgnoreImpCasts() here.
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IgnoreImpCasts() пропускает неявные приведения типов. В этом примере можно не использовать.
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If you try to print the AST of the test.cpp example, you will see that you have several ImplicitCastExpr nodes:
Depending on which approaches you use to get the subexpression node, you will get different result nodes for the test.cpp example:
Code:
// getSubExpr() retrieves the first cast subexpression
llvm::outs() << "getSubExpr(): " << castNode->getSubExpr()->getStmtClassName();
// getSubExprAsWritten() retrieves the cast subexpression as it was written in the source
// code, looking through any implicit casts or other intermediate nodes
// introduced by semantic analysis.
llvm::outs() << "getSubExprAsWritten(): " << castNode->getSubExprAsWritten()->getStmtClassName();
// getSubExpr() retrieves the first cast subexpression.
// ignoreImpCasts() skips past any implicit casts which might surround this expression until
// reaching a fixed point. It skips the following AST nodes: ImplicitCastExpr, FullExpr.
llvm::outs() << "getSubExpr()->ignoreImpCasts(): " << castNode->getSubExpr()->IgnoreImpCasts()->getStmtClassName();Output:
getSubExpr(): ImplicitCastExpr
getSubExprAsWritten(): DeclRefExpr
getSubExpr()->ignoreImpCasts(): DeclRefExpr| auto castIgnore = CastExpr->getSubExprAsWritten()->IgnoreImpCasts(); | ||
| if (!isa<ParenExpr>(castIgnore)) { | ||
| replaceText.push_back('('); | ||
| _rewriter.InsertText(Lexer::getLocForEndOfToken(castIgnore->getEndLoc(), |
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Please describe the reason of using the Lexer::getLocForEndOfToken() function here.
What would be the difference if SubExpr->getEndLoc().getLocOffset(1) was used here?
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С помощью Lexer::getLocForEndOfToken мы можем произвести захват всего токена,
а subExpr->getEndLoc().getLocWithOffset(1) позволяет захватить переменные состоящие из 1 символа.
| SourceManager &SM = *Result.SourceManager; | ||
| if (CastExpr->getExprLoc().isMacroID()) | ||
| return; | ||
| if (CastExpr->getCastKind() == CK_ToVoid) |
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Please describe what this check does and why it is there.
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Здесь используется isMacroID(), то есть проверка приведение в макросе, если проверка сработает, то дальнейшие действия выполняться не будут.
CK_ToVoid - если проверка выполнится, то приведение к войду будет проигнорировано
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Describing the reason for having these checks here would be a plus.
No description provided.