Enable merging of SHF_MERGE sections with linker scripts.

This also fixes the related problem of non SHF_MERGE sections with
different flags not being merged.

Fixes pr30355.

llvm-svn: 281338

1 files changed, 20 insertions, 5 deletions

diff --git a/lld/ELF/OutputSections.cpp b/lld/ELF/OutputSections.cpp
index ce5bac9deb1..c984cb11cde 100644
--- a/lld/ELF/OutputSections.cpp
+++ b/lld/ELF/OutputSections.cpp
@@ -1831,11 +1831,16 @@ void MipsAbiFlagsOutputSection<ELFT>::addSection(InputSectionBase<ELFT> *C) {
 }
 
 template <class ELFT>
+static typename ELFT::uint getOutFlags(InputSectionBase<ELFT> *S) {
+  return S->getSectionHdr()->sh_flags & ~SHF_GROUP & ~SHF_COMPRESSED;
+}
+
+template <class ELFT>
 static SectionKey<ELFT::Is64Bits> createKey(InputSectionBase<ELFT> *C,
                                             StringRef OutsecName) {
   const typename ELFT::Shdr *H = C->getSectionHdr();
   typedef typename ELFT::uint uintX_t;
-  uintX_t Flags = H->sh_flags & ~SHF_GROUP & ~SHF_COMPRESSED;
+  uintX_t Flags = getOutFlags(C);
 
   // For SHF_MERGE we create different output sections for each alignment.
   // This makes each output section simple and keeps a single level mapping from
@@ -1853,19 +1858,29 @@ std::pair<OutputSectionBase<ELFT> *, bool>
 OutputSectionFactory<ELFT>::create(InputSectionBase<ELFT> *C,
                                    StringRef OutsecName) {
   SectionKey<ELFT::Is64Bits> Key = createKey(C, OutsecName);
+  return create(Key, C);
+}
+
+template <class ELFT>
+std::pair<OutputSectionBase<ELFT> *, bool>
+OutputSectionFactory<ELFT>::create(const SectionKey<ELFT::Is64Bits> &Key,
+                                   InputSectionBase<ELFT> *C) {
+  uintX_t Flags = getOutFlags(C);
   OutputSectionBase<ELFT> *&Sec = Map[Key];
-  if (Sec)
+  if (Sec) {
+    Sec->updateFlags(Flags);
     return {Sec, false};
+  }
 
+  uint32_t Type = C->getSectionHdr()->sh_type;
   switch (C->kind()) {
   case InputSectionBase<ELFT>::Regular:
-    Sec = new OutputSection<ELFT>(Key.Name, Key.Type, Key.Flags);
+    Sec = new OutputSection<ELFT>(Key.Name, Type, Flags);
     break;
   case InputSectionBase<ELFT>::EHFrame:
     return {Out<ELFT>::EhFrame, false};
   case InputSectionBase<ELFT>::Merge:
-    Sec = new MergeOutputSection<ELFT>(Key.Name, Key.Type, Key.Flags,
-                                       Key.Alignment);
+    Sec = new MergeOutputSection<ELFT>(Key.Name, Type, Flags, Key.Alignment);
     break;
   case InputSectionBase<ELFT>::MipsReginfo:
     Sec = new MipsReginfoOutputSection<ELFT>();