From 464daadc3de8be1801e3aace6366c7255f08e531 Mon Sep 17 00:00:00 2001
From: Rui Ueyama <ruiu@google.com>
Date: Mon, 22 Aug 2016 04:55:20 +0000
Subject: [PATCH] Do not add .interp, .dynamic nor .eh_frame_hdr to segments
 just by type.

Summary:
We previously added these output sections to segments just by type.
Therefore, if there's a PHDRS command like this

  PHDRS {
    headers PT_PHDR PHDRS;
    interp PT_INTERP;
  }

  SECTIONS {
    . = SIZEOF_HEADERS;
    .interp : { *(.interp) } :text
  }

then .interp was added to "interp" segment even though the linker
is not instructed to do so by SECTIONS command. This patch removes
the default behavior to simplify.

Differential Revision: https://reviews.llvm.org/D23702

llvm-svn: 279414
---
 lld/ELF/LinkerScript.cpp | 26 +++++---------------------
 1 file changed, 5 insertions(+), 21 deletions(-)

diff --git a/lld/ELF/LinkerScript.cpp b/lld/ELF/LinkerScript.cpp
index 9cfbb48..ed6b39e 100644
--- a/lld/ELF/LinkerScript.cpp
+++ b/lld/ELF/LinkerScript.cpp
@@ -430,11 +430,13 @@ template <class ELFT> void LinkerScript<ELFT>::assignAddresses() {
   Out<ELFT>::ProgramHeaders->setVA(Out<ELFT>::ElfHeader->getSize() + MinVA);
 }
 
+// Creates program headers as instructed by PHDRS linker script command.
 template <class ELFT>
 std::vector<PhdrEntry<ELFT>> LinkerScript<ELFT>::createPhdrs() {
-  ArrayRef<OutputSectionBase<ELFT> *> Sections = *OutputSections;
   std::vector<PhdrEntry<ELFT>> Ret;
 
+  // Process PHDRS and FILEHDR keywords because they are not
+  // real output sections and cannot be added in the following loop.
   for (const PhdrsCommand &Cmd : Opt.PhdrsCommands) {
     Ret.emplace_back(Cmd.Type, Cmd.Flags == UINT_MAX ? PF_R : Cmd.Flags);
     PhdrEntry<ELFT> &Phdr = Ret.back();
@@ -443,30 +445,12 @@ std::vector<PhdrEntry<ELFT>> LinkerScript<ELFT>::createPhdrs() {
       Phdr.add(Out<ELFT>::ElfHeader);
     if (Cmd.HasPhdrs)
       Phdr.add(Out<ELFT>::ProgramHeaders);
-
-    switch (Cmd.Type) {
-    case PT_INTERP:
-      if (Out<ELFT>::Interp)
-        Phdr.add(Out<ELFT>::Interp);
-      break;
-    case PT_DYNAMIC:
-      if (Out<ELFT>::DynSymTab) {
-        Phdr.H.p_flags = Out<ELFT>::Dynamic->getPhdrFlags();
-        Phdr.add(Out<ELFT>::Dynamic);
-      }
-      break;
-    case PT_GNU_EH_FRAME:
-      if (!Out<ELFT>::EhFrame->empty() && Out<ELFT>::EhFrameHdr) {
-        Phdr.H.p_flags = Out<ELFT>::EhFrameHdr->getPhdrFlags();
-        Phdr.add(Out<ELFT>::EhFrameHdr);
-      }
-      break;
-    }
   }
 
+  // Add output sections to program headers.
   PhdrEntry<ELFT> *Load = nullptr;
   uintX_t Flags = PF_R;
-  for (OutputSectionBase<ELFT> *Sec : Sections) {
+  for (OutputSectionBase<ELFT> *Sec : *OutputSections) {
     if (!(Sec->getFlags() & SHF_ALLOC))
       break;
 
-- 
2.7.4