Override weak stuff during linking of aliases. This fixes PR2463.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53156 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Linker/LinkModules.cpp b/lib/Linker/LinkModules.cpp
index a915a8b..1722ca5 100644
--- a/lib/Linker/LinkModules.cpp
+++ b/lib/Linker/LinkModules.cpp
@@ -760,8 +760,12 @@
return Error(Err, "Alias Collision on '" + SGA->getName()+
"': aliases have different aliasees");
} else if (GlobalVariable *DGVar = dyn_cast_or_null<GlobalVariable>(DGV)) {
- // The only allowed way is to link alias with external declaration.
- if (DGVar->isDeclaration()) {
+ // The only allowed way is to link alias with external declaration or weak
+ // symbol..
+ if (DGVar->isDeclaration() ||
+ DGVar->hasWeakLinkage() ||
+ DGVar->hasLinkOnceLinkage() ||
+ DGVar->hasCommonLinkage()) {
// But only if aliasee is global too...
if (!isa<GlobalVariable>(DAliasee))
return Error(Err, "Global-Alias Collision on '" + SGA->getName() +
@@ -788,8 +792,12 @@
return Error(Err, "Global-Alias Collision on '" + SGA->getName() +
"': symbol multiple defined");
} else if (Function *DF = dyn_cast_or_null<Function>(DGV)) {
- // The only allowed way is to link alias with external declaration.
- if (DF->isDeclaration()) {
+ // The only allowed way is to link alias with external declaration or weak
+ // symbol...
+ if (DF->isDeclaration() ||
+ DF->hasWeakLinkage() ||
+ DF->hasLinkOnceLinkage() ||
+ DF->hasCommonLinkage()) {
// But only if aliasee is function too...
if (!isa<Function>(DAliasee))
return Error(Err, "Function-Alias Collision on '" + SGA->getName() +
@@ -940,14 +948,19 @@
ValueMap[SF] = NewDF;
continue;
} else if (GlobalAlias *DGA = dyn_cast<GlobalAlias>(DGV)) {
- // SF is global, but DF is alias. The only valid mapping is when SF is
- // external declaration, which is effectively a no-op.
- if (!SF->isDeclaration())
+ // SF is function, but DF is alias.
+ // The only valid mappings are:
+ // - SF is external declaration, which is effectively a no-op.
+ // - SF is weak, when we just need to throw SF out.
+ if (!SF->isDeclaration() &&
+ !SF->hasWeakLinkage() &&
+ !SF->hasLinkOnceLinkage() &&
+ !SF->hasCommonLinkage())
return Error(Err, "Function-Alias Collision on '" + SF->getName() +
"': symbol multiple defined");
// Make sure to remember this mapping...
- ValueMap[SF] = DGA;
+ ValueMap[SF] = ConstantExpr::getBitCast(DGA, SF->getType());
continue;
}