diff options
Diffstat (limited to 'lld/ELF/MarkLive.cpp')
| -rw-r--r-- | lld/ELF/MarkLive.cpp | 25 |
1 files changed, 18 insertions, 7 deletions
diff --git a/lld/ELF/MarkLive.cpp b/lld/ELF/MarkLive.cpp index 02ab6d18e537..bb0105c28928 100644 --- a/lld/ELF/MarkLive.cpp +++ b/lld/ELF/MarkLive.cpp @@ -165,9 +165,11 @@ static bool isReserved(InputSectionBase *sec) { switch (sec->type) { case SHT_FINI_ARRAY: case SHT_INIT_ARRAY: - case SHT_NOTE: case SHT_PREINIT_ARRAY: return true; + case SHT_NOTE: + // SHT_NOTE sections in a group are subject to garbage collection. + return !sec->nextInSectionGroup; default: StringRef s = sec->name; return s.startswith(".ctors") || s.startswith(".dtors") || @@ -217,10 +219,9 @@ template <class ELFT> void MarkLive<ELFT>::run() { // Preserve externally-visible symbols if the symbols defined by this // file can interrupt other ELF file's symbols at runtime. - symtab->forEachSymbol([&](Symbol *sym) { + for (Symbol *sym : symtab->symbols()) if (sym->includeInDynsym() && sym->partition == partition) markSymbol(sym); - }); // If this isn't the main partition, that's all that we need to preserve. if (partition != 1) { @@ -283,6 +284,10 @@ template <class ELFT> void MarkLive<ELFT>::mark() { for (InputSectionBase *isec : sec.dependentSections) enqueue(isec, 0); + + // Mark the next group member. + if (sec.nextInSectionGroup) + enqueue(sec.nextInSectionGroup, 0); } } @@ -324,15 +329,14 @@ template <class ELFT> void markLive() { sec->markLive(); // If a DSO defines a symbol referenced in a regular object, it is needed. - symtab->forEachSymbol([](Symbol *sym) { + for (Symbol *sym : symtab->symbols()) if (auto *s = dyn_cast<SharedSymbol>(sym)) if (s->isUsedInRegularObj && !s->isWeak()) s->getFile().isNeeded = true; - }); return; } - // Otheriwse, do mark-sweep GC. + // Otherwise, do mark-sweep GC. // // The -gc-sections option works only for SHF_ALLOC sections // (sections that are memory-mapped at runtime). So we can @@ -353,12 +357,19 @@ template <class ELFT> void markLive() { // or -emit-reloc were given. And they are subject of garbage // collection because, if we remove a text section, we also // remove its relocation section. + // + // Note on nextInSectionGroup: The ELF spec says that group sections are + // included or omitted as a unit. We take the interpretation that: + // + // - Group members (nextInSectionGroup != nullptr) are subject to garbage + // collection. + // - Groups members are retained or discarded as a unit. for (InputSectionBase *sec : inputSections) { bool isAlloc = (sec->flags & SHF_ALLOC); bool isLinkOrder = (sec->flags & SHF_LINK_ORDER); bool isRel = (sec->type == SHT_REL || sec->type == SHT_RELA); - if (!isAlloc && !isLinkOrder && !isRel) + if (!isAlloc && !isLinkOrder && !isRel && !sec->nextInSectionGroup) sec->markLive(); } |
