diff options
Diffstat (limited to 'lib/Transforms/IPO/DeadArgumentElimination.cpp')
-rw-r--r-- | lib/Transforms/IPO/DeadArgumentElimination.cpp | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/lib/Transforms/IPO/DeadArgumentElimination.cpp b/lib/Transforms/IPO/DeadArgumentElimination.cpp index 6ee6162ac3..8621f1a78d 100644 --- a/lib/Transforms/IPO/DeadArgumentElimination.cpp +++ b/lib/Transforms/IPO/DeadArgumentElimination.cpp @@ -357,6 +357,19 @@ bool DAE::RemoveDeadArgumentsFromCallers(Function &Fn) if (Fn.hasLocalLinkage() && !Fn.getFunctionType()->isVarArg()) return false; + // If a function seen at compile time is not necessarily the one linked to + // the binary being built, it is illegal to change the actual arguments + // passing to it. These functions can be captured by isWeakForLinker(). + // *NOTE* that mayBeOverridden() is insufficient for this purpose as it + // dosen't include linkage types like AvailableExternallyLinkage and + // LinkOnceODRLinkage. Take link_odr* as an example, it indicates a set of + // *EQUIVALENT* globals that can be merged at link-time. However, the + // semantic of *EQUIVALENT*-functions includes parameters. Changing + // parameters breaks the assumption. + // + if (Fn.isWeakForLinker()) + return false; + if (Fn.use_empty()) return false; |