Teresa Johnson d203f88115 [LTO] Fix a crash caused by accessing an empty ValueInfo ... ModuleSummaryIndex::exportToDot crashes when linking the Linux kernel under ThinLTO using LLVMgold.so. This is due to the exportToDot function trying to get the GUID of an empty ValueInfo. The root cause related to the fact that we attempt to get the GUID of an aliasee via its OriginalGUID recorded in the aliasee summary, and that is not always possible. Specifically, we cannot do this mapping when the value is internal linkage and there were other internal linkage symbols with the same name. There are 2 fixes for the problem included here. 1) In all cases where we can currently print the dot file from the command line (which is only via save-temps), we have a valid AliaseeGUID in the AliasSummary. Use that when it is available, so that we can get the correct aliasee GUID whenever possible. 2) However, if we were to invoke exportToDot from the debugger right after it is built during the initial analysis step (i.e. the per-module summary), we won't have the AliaseeGUID field populated. In that case, we have a fallback fix that will simply print "@"+GUID when we aren't able to get the GUID from the OriginalGUID. It simply checks if the VI is valid or not before attempting to get the name. Additionally, since getAliaseeGUID will assert that the AliaseeGUID is non-zero, guard the earlier fix #1 by a new function hasAliaseeGUID(). Reviewers: pcc, tmroeder Subscribers: evgeny777, mehdi_amini, inglorion, dexonsmith, arphaman, llvm-commits Differential Revision: https://reviews.llvm.org/D53986 llvm-svn: 346055		2018-11-02 23:49:21 +00:00
..
llvm	[LTO] Fix a crash caused by accessing an empty ValueInfo	2018-11-02 23:49:21 +00:00
llvm-c	Fix a typo in a function name	2018-11-02 09:57:24 +00:00