From 0913dcd7471bc98672139df38d436a64d10ecfeb Mon Sep 17 00:00:00 2001
From: Paul Semel <semelpaul@gmail.com>
Date: Wed, 25 Jul 2018 11:09:20 +0000
Subject: [llvm-objdump] Add dynamic section printing to private-headers option

Differential Revision: https://reviews.llvm.org/D49016

llvm-svn: 337902
---
 llvm/lib/Object/ELF.cpp | 138 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 138 insertions(+)

(limited to 'llvm/lib/Object/ELF.cpp')

diff --git a/llvm/lib/Object/ELF.cpp b/llvm/lib/Object/ELF.cpp
index 3e2161a9396..2eefb7ef13a 100644
--- a/llvm/lib/Object/ELF.cpp
+++ b/llvm/lib/Object/ELF.cpp
@@ -420,6 +420,144 @@ ELFFile<ELFT>::android_relas(const Elf_Shdr *Sec) const {
   return Relocs;
 }
 
+template <class ELFT>
+const char *ELFFile<ELFT>::getDynamicTagAsString(unsigned Arch,
+                                                 uint64_t Type) const {
+#define DYNAMIC_STRINGIFY_ENUM(tag, value)                                     \
+  case value:                                                                  \
+    return #tag;
+
+#define DYNAMIC_TAG(n, v)
+  switch (Arch) {
+  case ELF::EM_HEXAGON:
+    switch (Type) {
+#define HEXAGON_DYNAMIC_TAG(name, value) DYNAMIC_STRINGIFY_ENUM(name, value)
+#include "llvm/BinaryFormat/DynamicTags.def"
+#undef HEXAGON_DYNAMIC_TAG
+    }
+
+  case ELF::EM_MIPS:
+    switch (Type) {
+#define MIPS_DYNAMIC_TAG(name, value) DYNAMIC_STRINGIFY_ENUM(name, value)
+#include "llvm/BinaryFormat/DynamicTags.def"
+#undef MIPS_DYNAMIC_TAG
+    }
+
+  case ELF::EM_PPC64:
+    switch (Type) {
+#define PPC64_DYNAMIC_TAG(name, value) DYNAMIC_STRINGIFY_ENUM(name, value)
+#include "llvm/BinaryFormat/DynamicTags.def"
+#undef PPC64_DYNAMIC_TAG
+    }
+  }
+#undef DYNAMIC_TAG
+  switch (Type) {
+// Now handle all dynamic tags except the architecture specific ones
+#define MIPS_DYNAMIC_TAG(name, value)
+#define HEXAGON_DYNAMIC_TAG(name, value)
+#define PPC64_DYNAMIC_TAG(name, value)
+// Also ignore marker tags such as DT_HIOS (maps to DT_VERNEEDNUM), etc.
+#define DYNAMIC_TAG_MARKER(name, value)
+#define DYNAMIC_TAG(name, value) DYNAMIC_STRINGIFY_ENUM(name, value)
+#include "llvm/BinaryFormat/DynamicTags.def"
+#undef DYNAMIC_TAG
+#undef MIPS_DYNAMIC_TAG
+#undef HEXAGON_DYNAMIC_TAG
+#undef PPC64_DYNAMIC_TAG
+#undef DYNAMIC_TAG_MARKER
+#undef DYNAMIC_STRINGIFY_ENUM
+  default:
+    return "unknown";
+  }
+}
+
+template <class ELFT>
+const char *ELFFile<ELFT>::getDynamicTagAsString(uint64_t Type) const {
+  return getDynamicTagAsString(getHeader()->e_machine, Type);
+}
+
+template <class ELFT>
+Expected<typename ELFT::DynRange> ELFFile<ELFT>::dynamicEntries() const {
+  ArrayRef<Elf_Dyn> Dyn;
+  size_t DynSecSize = 0;
+
+  auto ProgramHeadersOrError = program_headers();
+  if (!ProgramHeadersOrError)
+    return ProgramHeadersOrError.takeError();
+
+  for (const Elf_Phdr &Phdr : *ProgramHeadersOrError) {
+    if (Phdr.p_type == ELF::PT_DYNAMIC) {
+      Dyn = makeArrayRef(
+          reinterpret_cast<const Elf_Dyn *>(base() + Phdr.p_offset),
+          Phdr.p_filesz / sizeof(Elf_Dyn));
+      DynSecSize = Phdr.p_filesz;
+      break;
+    }
+  }
+
+  // If we can't find the dynamic section in the program headers, we just fall
+  // back on the sections.
+  if (Dyn.empty()) {
+    auto SectionsOrError = sections();
+    if (!SectionsOrError)
+      return SectionsOrError.takeError();
+
+    for (const Elf_Shdr &Sec : *SectionsOrError) {
+      if (Sec.sh_type == ELF::SHT_DYNAMIC) {
+        Expected<ArrayRef<Elf_Dyn>> DynOrError =
+            getSectionContentsAsArray<Elf_Dyn>(&Sec);
+        if (!DynOrError)
+          return DynOrError.takeError();
+        Dyn = *DynOrError;
+        DynSecSize = Sec.sh_size;
+        break;
+      }
+    }
+
+    if (!Dyn.data())
+      return ArrayRef<Elf_Dyn>();
+  }
+
+  if (Dyn.empty())
+    return createError("invalid empty dynamic section");
+
+  if (DynSecSize % sizeof(Elf_Dyn) != 0)
+    return createError("malformed dynamic section");
+
+  if (Dyn.back().d_tag != ELF::DT_NULL)
+    return createError("dynamic sections must be DT_NULL terminated");
+
+  return Dyn;
+}
+
+template <class ELFT>
+Expected<const uint8_t *> ELFFile<ELFT>::toMappedAddr(uint64_t VAddr) const {
+  auto ProgramHeadersOrError = program_headers();
+  if (!ProgramHeadersOrError)
+    return ProgramHeadersOrError.takeError();
+
+  llvm::SmallVector<Elf_Phdr *, 4> LoadSegments;
+
+  for (const Elf_Phdr &Phdr : *ProgramHeadersOrError)
+    if (Phdr.p_type == ELF::PT_LOAD)
+      LoadSegments.push_back(const_cast<Elf_Phdr *>(&Phdr));
+
+  const Elf_Phdr *const *I =
+      std::upper_bound(LoadSegments.begin(), LoadSegments.end(), VAddr,
+                       [](uint64_t VAddr, const Elf_Phdr_Impl<ELFT> *Phdr) {
+                         return VAddr < Phdr->p_vaddr;
+                       });
+
+  if (I == LoadSegments.begin())
+    return createError("Virtual address is not in any segment");
+  --I;
+  const Elf_Phdr &Phdr = **I;
+  uint64_t Delta = VAddr - Phdr.p_vaddr;
+  if (Delta >= Phdr.p_filesz)
+    return createError("Virtual address is not in any segment");
+  return base() + Phdr.p_offset + Delta;
+}
+
 template class llvm::object::ELFFile<ELF32LE>;
 template class llvm::object::ELFFile<ELF32BE>;
 template class llvm::object::ELFFile<ELF64LE>;
-- 
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