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--></style></head><body lang=DE link=blue vlink="#954F72"><div class=WordSection1><p class=MsoNormal><span lang=EN-GB>Hi,<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-GB><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-GB>thanks, that’s interesting, but I’m not sure how this relates to trailing comments + semicolon?<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-GB>Why does it matter whether Expr is wrapped or not? It can contain comments in general. But doesn’t contain those at the end.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-GB>At least for such examples I find it strange: <a href="http://ce.steveire.com/z/KdXBDg">http://ce.steveire.com/z/KdXBDg</a><o:p></o:p></span></p><p class=MsoNormal><span lang=EN-GB><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-GB><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-GB>Is Expr the only Stmt that doesn’t include „it’s end“?<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-GB>Would it make sense to have some unifyStmtRange() in SourceCode.h with special handling for Expr which would extend it with (n x comment) + (optional comma or semi) [+ all the special cases I’m not thinking about right now]?<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-GB><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-GB>Currently the check mentioned below always subtracts one char and then checks whether it’s a semicolon. Might be nicer to distinguish by isa<Expr>?<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-GB><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-GB>Regards,<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-GB>Alex<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-GB><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-GB><o:p> </o:p></span></p><p class=MsoNormal><o:p> </o:p></p><div style='mso-element:para-border-div;border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=MsoNormal style='border:none;padding:0cm'><b>Von: </b><a href="mailto:yitzhakm@google.com">Yitzhak Mandelbaum</a><br><b>Gesendet: </b>Mittwoch, 26. Februar 2020 16:40<br><b>An: </b><a href="mailto:alex@lanin.de">Alexander Lanin</a><br><b>Cc: </b><a href="mailto:cfe-dev@lists.llvm.org">cfe-dev@lists.llvm.org</a><br><b>Betreff: </b>Re: [cfe-dev] Stmt.getEndLoc() vs semicolon</p></div><p class=MsoNormal><o:p> </o:p></p><div><div><p class=MsoNormal><span style='font-family:"Arial",sans-serif'>Alexander,<o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-family:"Arial",sans-serif'><o:p> </o:p></span></p></div><div><p class=MsoNormal><span style='font-family:"Arial",sans-serif'>I agree that this behavior is rather confusing, especially to first-time users. The cause of the issue is that Expr derives from Stmt so that Exprs can appear directly in, for example, compound statements, rather than being wrapped in an explicit node to represent statements that consist only of an expression. As far as I understand, this choice to avoid an explicit node had some (positive) performance implications for the AST when it was originally designed. While I'd love to see this choice revisited, I think it would be a significant effort and don't expect it to happen.<o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-family:"Arial",sans-serif'><o:p> </o:p></span></p></div><div><p class=MsoNormal><span style='font-family:"Arial",sans-serif'>Instead, we tend to work around the issue. For getting proper ranges of statements, you might find clang::tooling::getExtendedText/getExtendedRange meet your needs:<o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-family:"Arial",sans-serif'><a href="https://github.com/llvm/llvm-project/blob/master/clang/include/clang/Tooling/Transformer/SourceCode.h#L56">https://github.com/llvm/llvm-project/blob/master/clang/include/clang/Tooling/Transformer/SourceCode.h#L56</a><o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-family:"Arial",sans-serif'><o:p> </o:p></span></p></div><div><p class=MsoNormal><span style='font-family:"Arial",sans-serif'>For declarations, the (just added!) getAssociatedRange might be even better: <a href="https://github.com/llvm/llvm-project/blob/master/clang/include/clang/Tooling/Transformer/SourceCode.h#L39">https://github.com/llvm/llvm-project/blob/master/clang/include/clang/Tooling/Transformer/SourceCode.h#L39</a><o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-family:"Arial",sans-serif'><o:p> </o:p></span></p></div><div><p class=MsoNormal><span style='font-family:"Arial",sans-serif'>Cheers,<o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-family:"Arial",sans-serif'>Yitzhak<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><div><p class=MsoNormal>On Tue, Feb 25, 2020 at 5:15 PM Alexander Lanin via cfe-dev <<a href="mailto:cfe-dev@lists.llvm.org" target="_blank">cfe-dev@lists.llvm.org</a>> wrote:</p></div><blockquote style='border:none;border-left:solid #CCCCCC 1.0pt;padding:0cm 0cm 0cm 6.0pt;margin-left:4.8pt;margin-right:0cm'><div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=EN-GB>Hello,</span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=EN-GB> </span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=EN-GB>I’m having trouble with the locations returned by Stmt getEndLoc()/getSourceRange() and am wondering whether this is a bug/flaw:</span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=EN-GB>the returned location sometimes includes and sometimes excludes the semicolon in the end.</span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=EN-GB>This gets even more interesting when there are (multiple) comments before the semicolon, simply because the difference between the returned values gets even bigger.</span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=EN-GB>Here is an example showing how DeclStmt includes the semicolon, while CallExpr and BinaryOperator exclude the semicolon <a href="http://ce.steveire.com/z/TW3IAG" target="_blank">http://ce.steveire.com/z/TW3IAG</a>.</span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=EN-GB> </span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=EN-GB>So Stmt behaves “completely differently” depending on it’s type, which is no way suggested by it’s interface.</span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=EN-GB>Wouldn’t it be better for Stmt-Users if it would always be the same?</span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=EN-GB>(Not sure whether it should always be included or excluded. It’s not even always a semicolon as in that 3rd foo() in the example)</span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=EN-GB><a href="https://en.wikipedia.org/wiki/Liskov_substitution_principle" target="_blank">https://en.wikipedia.org/wiki/Liskov_substitution_principle</a></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=EN-GB> </span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=EN-GB>Here is one of the effects of this complexity for users of Stmt as they struggle to find that semicolon:</span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=EN-GB><a href="https://bugs.llvm.org/show_bug.cgi?id=25970" target="_blank">https://bugs.llvm.org/show_bug.cgi?id=25970</a> / <a href="https://reviews.llvm.org/D16267" target="_blank">https://reviews.llvm.org/D16267</a></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=EN-GB>Of course it’s fixable there, but that would imply working around the issue in multiple places.</span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=EN-GB> </span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=EN-GB>Regards,</span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=EN-GB>Alexander Lanin</span></p></div></div></blockquote></div><p class=MsoNormal style='margin-left:4.8pt'>_______________________________________________<br>cfe-dev mailing list<br><a href="mailto:cfe-dev@lists.llvm.org" target="_blank">cfe-dev@lists.llvm.org</a><br><a href="https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-dev" target="_blank">https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-dev</a></p><p class=MsoNormal><o:p> </o:p></p></div></body></html>