commit 786e866fea475d0d1b5bd51c59c653685b143970
author George Rimar <grimar@accesssoftek.com> Thu Mar 17 05:57:33 2016 +0000
committer George Rimar <grimar@accesssoftek.com> Thu Mar 17 05:57:33 2016 +0000
tree 49588c36d76ebc447f7c53f286ad35ef935a9635
parent 6f66f0a343256ce8a03890d9a80447592b748137

[ELF] - -pie/--pic-executable option implemented

-pie
--pic-executable

Create a position independent executable.  This is currently only
 supported on ELF platforms.  Position independent executables are
 similar to shared libraries in that they are relocated by the
 dynamic linker to the virtual address the OS chooses for them
 (which can vary between invocations).  Like normal dynamically
 linked executables they can be executed and symbols defined in the
 executable cannot be overridden by shared libraries.

Differential revision: http://reviews.llvm.org/D18183

llvm-svn: 263693

lld/ELF/Target.cpp

diff --git a/lld/ELF/Target.cpp b/lld/ELF/Target.cpp
index dae9f51..e76e0a9 100644
--- a/lld/ELF/Target.cpp
+++ b/lld/ELF/Target.cpp
@@ -270,7 +270,7 @@
   return false;
 }
 
-uint64_t TargetInfo::getVAStart() const { return Config->Shared ? 0 : VAStart; }
+uint64_t TargetInfo::getVAStart() const { return Config->Pic ? 0 : VAStart; }
 
 bool TargetInfo::needsCopyRelImpl(uint32_t Type) const { return false; }
 
@@ -329,7 +329,7 @@
   // plt. That is identified by special relocation types (R_X86_64_JUMP_SLOT,
   // R_386_JMP_SLOT, etc).
   if (auto *SS = dyn_cast<SharedSymbol<ELFT>>(&S))
-    if (!Config->Shared && SS->Sym.getType() == STT_FUNC &&
+    if (!Config->Pic && SS->Sym.getType() == STT_FUNC &&
         !refersToGotEntry(Type))
       return Plt_Implicit;
 
@@ -439,7 +439,7 @@
 void X86TargetInfo::writePltZero(uint8_t *Buf) const {
   // Executable files and shared object files have
   // separate procedure linkage tables.
-  if (Config->Shared) {
+  if (Config->Pic) {
     const uint8_t V[] = {
         0xff, 0xb3, 0x04, 0x00, 0x00, 0x00, // pushl 4(%ebx)
         0xff, 0xa3, 0x08, 0x00, 0x00, 0x00, // jmp   *8(%ebx)
@@ -471,7 +471,7 @@
   memcpy(Buf, Inst, sizeof(Inst));
 
   // jmp *foo@GOT(%ebx) or jmp *foo_in_GOT
-  Buf[1] = Config->Shared ? 0xa3 : 0x25;
+  Buf[1] = Config->Pic ? 0xa3 : 0x25;
   uint32_t Got = UseLazyBinding ? Out<ELF32LE>::GotPlt->getVA()
                                 : Out<ELF32LE>::Got->getVA();
   write32le(Buf + 2, Config->Shared ? GotEntryAddr - Got : GotEntryAddr);