Partially revert "PECOFF: Do not add layout-after edges."

This reverts commit r230732.

sectionSize() in lib/Core/SymbolTable.cpp still depends on the layout-
after edges, so we couldn't remove them yet.

llvm-svn: 230734
This commit is contained in:
Rui Ueyama 2015-02-27 05:22:19 +00:00
parent 93c7fa209c
commit 6c39e77896
2 changed files with 12 additions and 7 deletions

View File

@ -351,16 +351,21 @@ void addLayoutEdge(T *a, U *b, uint32_t which) {
a->addReference(std::unique_ptr<COFFReference>(ref));
}
/// Connect atoms with layout-before edges. It prevents atoms from
/// being GC'ed (aka dead-stripped) if there is a reference to one of
/// the atoms in the same layout-before chain. In such case we want to
/// emit all the atoms appeared in the same chain, because the "live"
/// atom may reference other atoms in the same chain.
template <typename T, typename U> void connectWithLayoutEdge(T *a, U *b) {
addLayoutEdge(a, b, lld::Reference::kindLayoutAfter);
addLayoutEdge(b, a, lld::Reference::kindLayoutBefore);
}
/// Connect atoms with layout-before/after edges. It prevents atoms
/// from being GC'ed (aka dead-stripped) if there is a reference to
/// one of the atoms in the same layout-before chain. In such case we
/// want to emit all the atoms appeared in the same chain, because the
/// "live" atom may reference other atoms in the same chain.
template <typename T> void connectAtomsWithLayoutEdge(std::vector<T *> &atoms) {
if (atoms.size() < 2)
return;
for (auto it = atoms.begin(), e = atoms.end(); it + 1 != e; ++it)
addLayoutEdge(*(it + 1), *it, lld::Reference::kindLayoutBefore);
connectWithLayoutEdge(*it, *(it + 1));
}
} // namespace pecoff

View File

@ -756,7 +756,7 @@ std::error_code FileCOFF::AtomizeDefinedSymbols(
if (atoms.size() > 0)
atoms[0]->setAlignment(getAlignment(section));
// Connect atoms with layout-before edges.
// Connect atoms with layout-before/layout-after edges.
connectAtomsWithLayoutEdge(atoms);
for (COFFDefinedFileAtom *atom : atoms) {