[PATCH] D27131: [ELF] - Add support of proccessing of the rest allocatable synthetic sections from linkerscript.

[Rui Ueyama via Phabricator via llvm-commits]

ruiu added inline comments.


================
Comment at: ELF/LinkerScript.cpp:484-485
     auto *IB = static_cast<InputSectionBase<ELFT> *>(ID);
+    // OutSec can be null when synthetic section listed under
+    // output section command was removed because was not needed.
+    if (!IB->OutSec)
----------------
More explicit code would be easier to understand.

  // We tentatively added all synthetic sections at the beginning and removed
  // empty ones afterwards (because there is no way to know whether they were
  // going be empty or not other than actually running linker scripts.)
  // We need to ignore remains of empty sections.
  if (auto *Sec = SyntheticSection<ELFT>(ID))
    if (Sec->empty())
      continue;


================
Comment at: ELF/Writer.cpp:256
 
-  if (Config->EhFrameHdr)
-    In<ELFT>::EhFrameHdr = make<EhFrameHeader<ELFT>>();
-
-  if (Config->GdbIndex)
-    In<ELFT>::GdbIndex = make<GdbIndexSection<ELFT>>();
+  // Initialize linker generated sections
+  if (!Config->Relocatable)
----------------
Remove this comment because throughout this function we initialize linker generated sections.


================
Comment at: ELF/Writer.cpp:340
+  // We always need to add rel[a].plt to output if it has entries.
+  // Even during static linking it can contain R_[*]_IRELATIVE relocations.
+  In<ELFT>::RelaPlt = make<RelocationSection<ELFT>>(
----------------
Even for ...


================
Comment at: ELF/Writer.cpp:922-923
         std::find(OutSec->Sections.begin(), OutSec->Sections.end(), SS));
+    // Mark section as unused to stop finalizing it and proccessing from script.
+    SS->OutSec = nullptr;
     // If there is no other sections in output section, remove it from output.
----------------
I don't think using this as a marker is a good idea. Please read the above comment.


================
Comment at: ELF/Writer.cpp:1025-1027
+  addInputSec(In<ELFT>::SymTab);
+  addInputSec(In<ELFT>::ShStrTab);
+  addInputSec(In<ELFT>::StrTab);
----------------
I do not understand why only these sections are handled in this function. Is there any reason you can't add them in createSyntheticSections?


https://reviews.llvm.org/D27131