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</o:shapelayout></xml><![endif]--></head><body lang=EN-GB link=blue vlink=purple><div class=WordSection1><p class=MsoNormal>When the BasicBlock containing the return instrution has a PHI with 2<o:p></o:p></p><p class=MsoNormal>incoming values, FoldReturnIntoUncondBranch will remove the no longer<o:p></o:p></p><p class=MsoNormal>used incoming value and remove the no longer needed phi as well. This<o:p></o:p></p><p class=MsoNormal>leaves us with a BB that no longer has a PHI, but the subsequent call<o:p></o:p></p><p class=MsoNormal>to FoldReturnIntoUncondBranch from FoldReturnAndProcessPred will not<o:p></o:p></p><p class=MsoNormal>remove the return instruction (which still uses the result of the call<o:p></o:p></p><p class=MsoNormal>instruction). This prevents EliminateRecursiveTailCall to remove<o:p></o:p></p><p class=MsoNormal>the value, as it is still being used in a basicblock which has no<o:p></o:p></p><p class=MsoNormal>predecessors.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>The basicblock can not be erased on the spot, because its iterator is<o:p></o:p></p><p class=MsoNormal>still being used in runTRE.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>This issue was exposed when removing the threshold on size for lifetime<o:p></o:p></p><p class=MsoNormal>marker insertion for named temporaries in clang. The testcase is a much<o:p></o:p></p><p class=MsoNormal>reduced version of peelOffOuterExpr(const Expr*, const ExplodedNode *)<o:p></o:p></p><p class=MsoNormal>from clang/lib/StaticAnalyzer/Core/BugReporterVisitors.cpp.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Cheers,<o:p></o:p></p><p class=MsoNormal><span style='mso-fareast-language:EN-GB'>--<o:p></o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-GB'>Arnaud A. de Grandmaison<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p></div></body></html>