<div dir="ltr">I'm trying to learn about LTO. I have a static variable that I try to give a non-compile-time-constant value to. With LTO turned off, the sprintf happens i.e. a breakpoint set on that line does get triggered. With LTO turned on (either Monolithic or Incremental), the code appears to be removed/elided/deleted/forgotten/dropped/lost/ignored and the breakpoint is never tripped. <br><br>What can I do to make my code survive through LTO? The variable makes it through but the sprinf() line doesn't. Can I somehow tell LTO to not apply to this function or line of code or file of code? (In reality this is something I am trying to do via Xcode for iOS targets.)<div><br></div><div>thank you.<br><div><br></div><div><ol start="1" class="gmail-dp-j" style="box-sizing:border-box;padding:0px;border:none;font-size:12px;font-family:consolas,"courier new",courier,mono,serif;vertical-align:baseline;list-style-position:initial;color:rgb(92,92,92);margin:0px 0px 1px 45px"><li class="gmail-alt" style="box-sizing:border-box;border-top:none;border-right:none;border-bottom:none;border-left:3px solid rgb(255,255,255);font-style:inherit;font-size:1em;font-family:inherit;vertical-align:baseline;line-height:12pt;list-style:decimal-leading-zero outside;color:inherit;height:12pt;white-space:nowrap;margin:0px;padding:0px 3px 0px 10px"><span style="box-sizing:border-box;margin:0px;padding:0px;border:0px;font-weight:inherit;font-style:inherit;vertical-align:baseline;color:black;background-color:inherit;font-size:9pt"><span class="gmail-keyword" style="box-sizing:border-box;margin:0px;padding:0px;border:0px;vertical-align:baseline;color:rgb(0,102,153);font-stretch:normal;line-height:normal;background-color:inherit;font-size:9pt">static</span><span style="box-sizing:border-box;margin:0px;padding:0px;border:0px;font-weight:inherit;font-style:inherit;vertical-align:baseline;background-color:inherit;font-size:9pt"> </span><span class="gmail-keyword" style="box-sizing:border-box;margin:0px;padding:0px;border:0px;vertical-align:baseline;color:rgb(0,102,153);font-stretch:normal;line-height:normal;background-color:inherit;font-size:9pt">void</span><span style="box-sizing:border-box;margin:0px;padding:0px;border:0px;font-weight:inherit;font-style:inherit;vertical-align:baseline;background-color:inherit;font-size:9pt"> __attribute__((constructor))_initv1 () {  </span></span></li><li class="gmail-" style="box-sizing:border-box;border-top:none;border-right:none;border-bottom:none;border-left:3px solid rgb(255,255,255);font-style:inherit;font-size:1em;font-family:inherit;vertical-align:baseline;line-height:12pt;list-style:decimal-leading-zero outside;background-color:rgb(248,248,248);height:12pt;white-space:nowrap;margin:0px;padding:0px 3px 0px 10px"><span style="box-sizing:border-box;margin:0px;padding:0px;border:0px;font-weight:inherit;font-style:inherit;vertical-align:baseline;color:black;background-color:inherit;font-size:9pt">    <span class="gmail-keyword" style="box-sizing:border-box;margin:0px;padding:0px;border:0px;vertical-align:baseline;color:rgb(0,102,153);font-stretch:normal;line-height:normal;background-color:inherit;font-size:9pt">static</span><span style="box-sizing:border-box;margin:0px;padding:0px;border:0px;font-weight:inherit;font-style:inherit;vertical-align:baseline;background-color:inherit;font-size:9pt"> </span><span class="gmail-keyword" style="box-sizing:border-box;margin:0px;padding:0px;border:0px;vertical-align:baseline;color:rgb(0,102,153);font-stretch:normal;line-height:normal;background-color:inherit;font-size:9pt">char</span><span style="box-sizing:border-box;margin:0px;padding:0px;border:0px;font-weight:inherit;font-style:inherit;vertical-align:baseline;background-color:inherit;font-size:9pt"> default_[] = </span><span class="gmail-string" style="box-sizing:border-box;margin:0px;padding:0px;border:0px;font-weight:inherit;font-style:inherit;vertical-align:baseline;color:blue;background-color:inherit;font-size:9pt">"0000000000000000000000000000000000000000000000000000000000000000"</span><span style="box-sizing:border-box;margin:0px;padding:0px;border:0px;font-weight:inherit;font-style:inherit;vertical-align:baseline;background-color:inherit;font-size:9pt">;  </span></span></li><li class="gmail-alt" style="box-sizing:border-box;border-top:none;border-right:none;border-bottom:none;border-left:3px solid rgb(255,255,255);font-style:inherit;font-size:1em;font-family:inherit;vertical-align:baseline;line-height:12pt;list-style:decimal-leading-zero outside;color:inherit;height:12pt;white-space:nowrap;margin:0px;padding:0px 3px 0px 10px"><span style="box-sizing:border-box;margin:0px;padding:0px;border:0px;font-weight:inherit;font-style:inherit;vertical-align:baseline;color:black;background-color:inherit;font-size:9pt">    sprintf( default_, <span class="gmail-string" style="box-sizing:border-box;margin:0px;padding:0px;border:0px;font-weight:inherit;font-style:inherit;vertical-align:baseline;color:blue;background-color:inherit;font-size:9pt">"%lu"</span><span style="box-sizing:border-box;margin:0px;padding:0px;border:0px;font-weight:inherit;font-style:inherit;vertical-align:baseline;background-color:inherit;font-size:9pt">, (unsigned </span><span class="gmail-keyword" style="box-sizing:border-box;margin:0px;padding:0px;border:0px;vertical-align:baseline;color:rgb(0,102,153);font-stretch:normal;line-height:normal;background-color:inherit;font-size:9pt">long</span><span style="box-sizing:border-box;margin:0px;padding:0px;border:0px;font-weight:inherit;font-style:inherit;vertical-align:baseline;background-color:inherit;font-size:9pt">)</span><span class="gmail-number" style="box-sizing:border-box;margin:0px;padding:0px;border:0px;font-weight:inherit;font-style:inherit;vertical-align:baseline;color:rgb(192,0,0);background-color:inherit;font-size:9pt">5</span><span style="box-sizing:border-box;margin:0px;padding:0px;border:0px;font-weight:inherit;font-style:inherit;vertical-align:baseline;background-color:inherit;font-size:9pt"> );  </span></span></li><li class="gmail-" style="box-sizing:border-box;border-top:none;border-right:none;border-bottom:none;border-left:3px solid rgb(255,255,255);font-style:inherit;font-size:1em;font-family:inherit;vertical-align:baseline;line-height:12pt;list-style:decimal-leading-zero outside;background-color:rgb(248,248,248);height:12pt;white-space:nowrap;margin:0px;padding:0px 3px 0px 10px"><span style="box-sizing:border-box;margin:0px;padding:0px;border:0px;font-weight:inherit;font-style:inherit;vertical-align:baseline;color:black;background-color:inherit;font-size:9pt">}</span></li></ol></div></div></div>