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</o:shapelayout></xml><![endif]--></head><body lang=EN-GB link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Hi Chandler, et al.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>> </span>The vastly more common prefix for these in the rest of the world is '--'. LLVM's usage of '-' is quite strange.<o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Agreed. However, clang seems to have a lot of options that adopt the GCC-style -f<option>[=| ]<argument> format, despite not being real GCC options, and thus having no genuine compatibility concerns. <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:9.5pt;font-family:"Arial","sans-serif";color:#222222;background:white'>> I also think there is a strong technical reason to require the '=' -- it makes the relative ordering unimportant. For any tool (such as a build system) which builds up commandline flags, this is a huge advantage.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:9.5pt;font-family:"Arial","sans-serif";color:#222222;background:white'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:9.5pt;font-family:"Arial","sans-serif";color:#222222;background:white'>A fair point, but if your build system cannot handle the <option><space><argument> form, are you not going to be in trouble with all the many other clang options that do accept this style? <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:9.5pt;font-family:"Arial","sans-serif";color:#222222;background:white'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:9.5pt;font-family:"Arial","sans-serif";color:#222222;background:white'>This feels like an unnecessary line in the sand to me but you have provided decent justification for it so I guess we ought to back this change out.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:9.5pt;font-family:"Arial","sans-serif";color:#222222;background:white'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:9.5pt;font-family:"Arial","sans-serif";color:#222222;background:white'>Would you accept a patch to remove support for the legacy alias, so we genuinely do only support one version of this option?<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:9.5pt;font-family:"Arial","sans-serif";color:#222222;background:white'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:9.5pt;font-family:"Arial","sans-serif";color:#222222;background:white'>Also, could you give some guidance on what these options that must have unambiguous spellings are? AFAICT from the source, it looks like –target, –gcc-toolchain and --driver-mode? Are there others that we should know about?<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Thanks<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Rich<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><div style='border:none;border-left:solid blue 1.5pt;padding:0cm 0cm 0cm 4.0pt'><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=MsoNormal><b><span lang=EN-US style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span lang=EN-US style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> Chandler Carruth [mailto:chandlerc@google.com] <br><b>Sent:</b> 11 March 2015 21:28<br><b>To:</b> Richard Smith<br><b>Cc:</b> Richard Barton; llvm cfe<br><b>Subject:</b> Re: r231787 - Allow -target= and --target options<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><div><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal>On Wed, Mar 11, 2015 at 2:27 PM, Richard Smith <<a href="mailto:richard@metafoo.co.uk" target="_blank">richard@metafoo.co.uk</a>> wrote:<o:p></o:p></p><p class=MsoNormal>The previous state was that we allowed -target blah and --target=blah, but not -target=blah nor --target blah. This new state seems better than that in some ways, but neither is particularly satisfactory.<o:p></o:p></p></div><p class=MsoNormal><br>The support for '-target blah' was kept for compatibility with old versions of Clang where folks may have made their build systems rely on it.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>We probably should have some marking in the .td file for options that are purely for historical compatibility (as opposed to cross-tool compatibility) and sunset them after an appropriately long timeframe.<o:p></o:p></p></div></div></div></div></body></html>