<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><br class=""><div><blockquote type="cite" class=""><div class="">On Jul 19, 2016, at 5:23 PM, Teresa Johnson <<a href="mailto:tejohnson@google.com" class="">tejohnson@google.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div dir="ltr" class=""><br class=""><div class="gmail_extra"><br class=""><div class="gmail_quote">On Tue, Jul 19, 2016 at 5:18 PM, Mehdi Amini <span dir="ltr" class=""><<a href="mailto:mehdi.amini@apple.com" target="_blank" class="">mehdi.amini@apple.com</a>></span> wrote:<br class=""><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div style="word-wrap:break-word" class=""><br class=""><div class=""><span class=""><blockquote type="cite" class=""><div class="">On Jul 19, 2016, at 6:12 AM, Teresa Johnson <<a href="mailto:tejohnson@google.com" target="_blank" class="">tejohnson@google.com</a>> wrote:</div><br class="m_-8566657295731542970Apple-interchange-newline"><div class=""><br class="m_-8566657295731542970Apple-interchange-newline"><br style="font-family:Helvetica;font-size:12px;font-style:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px" class=""><div class="gmail_quote" style="font-family:Helvetica;font-size:12px;font-style:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px">On Mon, Jul 18, 2016 at 10:40 PM, Xinliang David Li<span class="m_-8566657295731542970Apple-converted-space"> </span><span dir="ltr" class=""><<a href="mailto:davidxl@google.com" target="_blank" class="">davidxl@google.com</a>></span><span class="m_-8566657295731542970Apple-converted-space"> </span>wrote:<br class=""><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div dir="ltr" class="">Good example. I think I am convinced :)</div></blockquote><div class=""><br class=""></div><div class="">Yes, I can't think of another way to get this case to work without being far more conservative about importing, unfortunately. Ok, let me figure out what the best way is to transmit this info on to the final link through the build system. Probably through a file that can be directly used with the @ linker option in place of input files.</div></div></div></blockquote><div class=""><br class=""></div></span><div class="">Do you have an example where it matters?</div><div class="">The only case I can imagine is mixing ThinLTO files with non-ThinLTO files, and the same weak symbol defined in both.</div></div></div></blockquote><div class=""><br class=""></div><div class="">Yes, this and the follow on fix both were for cases that came from real (internal) applications. </div></div></div></div></div></blockquote><blockquote type="cite" class=""><div class=""><div dir="ltr" class=""><div class="gmail_extra"><div class="gmail_quote"><div class="">IIRC, the weak symbols came from headers included in multiple places (all ThinLTO files).</div></div></div></div></div></blockquote><div><br class=""></div><div><div>I understand the issue with back-reference because the use of —start-lib/—end-lib, but I don’t understand why you got multiple weak out of the ThinLTO backends?</div></div><div>I.e. we should turn all but one to available externally, so no duplicate should be seen during the second link.</div><div><br class=""></div><div>— </div><div>Mehdi</div><div><br class=""></div><br class=""><blockquote type="cite" class=""><div class=""><div dir="ltr" class=""><div class="gmail_extra"><div class="gmail_quote"><div class=""><br class=""></div><div class="">Working on build system changes right now, I've confirmed with a recent binutils that we have enough info that the llvm side to emit these should be trivial.</div><div class=""><br class=""></div><div class=""><br class=""></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div style="word-wrap:break-word" class=""><div class=""><div class=""><br class=""></div><div class="">— </div><span class="HOEnZb"><font color="#888888" class=""><div class="">Mehdi</div></font></span></div></div></blockquote></div><br class=""><br clear="all" class=""><div class=""><br class=""></div>-- <br class=""><div class="gmail_signature" data-smartmail="gmail_signature"><span style="font-family: Times; font-size: inherit;" class=""><table cellspacing="0" cellpadding="0" class=""><tbody class=""><tr style="color:rgb(85,85,85);font-family:sans-serif;font-size:small" class=""><td nowrap="" style="border-top-style:solid;border-top-color:rgb(213,15,37);border-top-width:2px" class="">Teresa Johnson |</td><td nowrap="" style="border-top-style:solid;border-top-color:rgb(51,105,232);border-top-width:2px" class=""> Software Engineer |</td><td nowrap="" style="border-top-style:solid;border-top-color:rgb(0,153,57);border-top-width:2px" class=""> <a href="mailto:tejohnson@google.com" target="_blank" class="">tejohnson@google.com</a> |</td><td nowrap="" style="border-top-style:solid;border-top-color:rgb(238,178,17);border-top-width:2px" class=""> 408-460-2413</td></tr></tbody></table></span></div>
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