llvm-readobj: Add support for reading relocations in the Android packed format.

This is in preparation for testing lld's upcoming relocation packing
feature (D39152). I have verified that this implementation correctly
unpacks the relocations from a Chromium DSO built with gold and the
Android relocation packer for ARM32 and ARM64.

Differential Revision: https://reviews.llvm.org/D39272

llvm-svn: 316543

1 files changed, 24 insertions, 5 deletions

diff --git a/llvm/tools/llvm-readobj/ELFDumper.cpp b/llvm/tools/llvm-readobj/ELFDumper.cpp
index be976ca8826..27fa99cb9b8 100644
--- a/llvm/tools/llvm-readobj/ELFDumper.cpp
+++ b/llvm/tools/llvm-readobj/ELFDumper.cpp
@@ -2591,7 +2591,9 @@ static inline void printRelocHeader(raw_ostream &OS, bool Is64, bool IsRela) {
 template <class ELFT> void GNUStyle<ELFT>::printRelocations(const ELFO *Obj) {
   bool HasRelocSections = false;
   for (const Elf_Shdr &Sec : unwrapOrError(Obj->sections())) {
-    if (Sec.sh_type != ELF::SHT_REL && Sec.sh_type != ELF::SHT_RELA)
+    if (Sec.sh_type != ELF::SHT_REL && Sec.sh_type != ELF::SHT_RELA &&
+        Sec.sh_type != ELF::SHT_ANDROID_REL &&
+        Sec.sh_type != ELF::SHT_ANDROID_RELA)
       continue;
     HasRelocSections = true;
     StringRef Name = unwrapOrError(Obj->getSectionName(&Sec));
@@ -2600,9 +2602,12 @@ template <class ELFT> void GNUStyle<ELFT>::printRelocations(const ELFO *Obj) {
     OS << "\nRelocation section '" << Name << "' at offset 0x"
        << to_hexString(Offset, false) << " contains " << Entries
        << " entries:\n";
-    printRelocHeader(OS,  ELFT::Is64Bits, (Sec.sh_type == ELF::SHT_RELA));
+    printRelocHeader(OS, ELFT::Is64Bits,
+                     Sec.sh_type == ELF::SHT_RELA ||
+                         Sec.sh_type == ELF::SHT_ANDROID_RELA);
     const Elf_Shdr *SymTab = unwrapOrError(Obj->getSection(Sec.sh_link));
-    if (Sec.sh_type == ELF::SHT_REL) {
+    switch (Sec.sh_type) {
+    case ELF::SHT_REL:
       for (const auto &R : unwrapOrError(Obj->rels(&Sec))) {
         Elf_Rela Rela;
         Rela.r_offset = R.r_offset;
@@ -2610,9 +2615,16 @@ template <class ELFT> void GNUStyle<ELFT>::printRelocations(const ELFO *Obj) {
         Rela.r_addend = 0;
         printRelocation(Obj, SymTab, Rela, false);
       }
-    } else {
+      break;
+    case ELF::SHT_RELA:
       for (const auto &R : unwrapOrError(Obj->relas(&Sec)))
         printRelocation(Obj, SymTab, R, true);
+      break;
+    case ELF::SHT_ANDROID_REL:
+    case ELF::SHT_ANDROID_RELA:
+      for (const auto &R : unwrapOrError(Obj->android_relas(&Sec)))
+        printRelocation(Obj, SymTab, R, Sec.sh_type == ELF::SHT_ANDROID_RELA);
+      break;
     }
   }
   if (!HasRelocSections)
@@ -3650,7 +3662,9 @@ template <class ELFT> void LLVMStyle<ELFT>::printRelocations(const ELFO *Obj) {
   for (const Elf_Shdr &Sec : unwrapOrError(Obj->sections())) {
     ++SectionNumber;
 
-    if (Sec.sh_type != ELF::SHT_REL && Sec.sh_type != ELF::SHT_RELA)
+    if (Sec.sh_type != ELF::SHT_REL && Sec.sh_type != ELF::SHT_RELA &&
+        Sec.sh_type != ELF::SHT_ANDROID_REL &&
+        Sec.sh_type != ELF::SHT_ANDROID_RELA)
       continue;
 
     StringRef Name = unwrapOrError(Obj->getSectionName(&Sec));
@@ -3683,6 +3697,11 @@ void LLVMStyle<ELFT>::printRelocations(const Elf_Shdr *Sec, const ELFO *Obj) {
     for (const Elf_Rela &R : unwrapOrError(Obj->relas(Sec)))
       printRelocation(Obj, R, SymTab);
     break;
+  case ELF::SHT_ANDROID_REL:
+  case ELF::SHT_ANDROID_RELA:
+    for (const Elf_Rela &R : unwrapOrError(Obj->android_relas(Sec)))
+      printRelocation(Obj, R, SymTab);
+    break;
   }
 }