From 24a669d225f9cacf1cd3846e333f9690a06d1e1c Mon Sep 17 00:00:00 2001 From: Rafael Espindola Date: Thu, 27 Mar 2014 15:26:56 +0000 Subject: Prevent alias from pointing to weak aliases. This adds back r204781. Original message: Aliases are just another name for a position in a file. As such, the regular symbol resolutions are not applied. For example, given define void @my_func() { ret void } @my_alias = alias weak void ()* @my_func @my_alias2 = alias void ()* @my_alias We produce without this patch: .weak my_alias my_alias = my_func .globl my_alias2 my_alias2 = my_alias That is, in the resulting ELF file my_alias, my_func and my_alias are just 3 names pointing to offset 0 of .text. That is *not* the semantics of IR linking. For example, linking in a @my_alias = alias void ()* @other_func would require the strong my_alias to override the weak one and my_alias2 would end up pointing to other_func. There is no way to represent that with aliases being just another name, so the best solution seems to be to just disallow it, converting a miscompile into an error. llvm-svn: 204934 --- llvm/lib/Target/PowerPC/PPCFastISel.cpp | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'llvm/lib/Target/PowerPC/PPCFastISel.cpp') diff --git a/llvm/lib/Target/PowerPC/PPCFastISel.cpp b/llvm/lib/Target/PowerPC/PPCFastISel.cpp index 4753160e091..dd45683032a 100644 --- a/llvm/lib/Target/PowerPC/PPCFastISel.cpp +++ b/llvm/lib/Target/PowerPC/PPCFastISel.cpp @@ -1863,7 +1863,7 @@ unsigned PPCFastISel::PPCMaterializeGV(const GlobalValue *GV, MVT VT) { if (!GVar) { // If GV is an alias, use the aliasee for determining thread-locality. if (const GlobalAlias *GA = dyn_cast(GV)) - GVar = dyn_cast_or_null(GA->resolveAliasedGlobal(false)); + GVar = dyn_cast_or_null(GA->getAliasedGlobal()); } // FIXME: We don't yet handle the complexity of TLS. -- cgit v1.2.3