Revert "[llvm-objcopy] Add support for .dynamic, .dynsym, and .dynstr"

This reverts commit r313663. Broken because overlapping-sections was
reverted.

llvm-svn: 313665

7 files changed, 31 insertions, 237 deletions

diff --git a/llvm/test/tools/llvm-objcopy/Inputs/dynamic.so b/llvm/test/tools/llvm-objcopy/Inputs/dynamic.so
deleted file mode 100755
index cf5757d5931..00000000000
--- a/llvm/test/tools/llvm-objcopy/Inputs/dynamic.so
+++ /dev/null
diff --git a/llvm/test/tools/llvm-objcopy/Inputs/dynsym.so b/llvm/test/tools/llvm-objcopy/Inputs/dynsym.so
deleted file mode 100755
index 2f62627543a..00000000000
--- a/llvm/test/tools/llvm-objcopy/Inputs/dynsym.so
+++ /dev/null
diff --git a/llvm/test/tools/llvm-objcopy/dynamic.test b/llvm/test/tools/llvm-objcopy/dynamic.test
deleted file mode 100644
index 3e9ea2069f9..00000000000
--- a/llvm/test/tools/llvm-objcopy/dynamic.test
+++ /dev/null
@@ -1,27 +0,0 @@
-# RUN: llvm-objcopy %p/Inputs/dynamic.so %t
-# RUN: llvm-readobj -dynamic-table %t | FileCheck %s
-# RUN: llvm-readobj -sections %t | FileCheck -check-prefix=LINK %s
-
-#CHECK: DynamicSection [
-#CHECK-NEXT:  Tag                Type                 Name/Value
-#CHECK-NEXT:  0x0000000000000006 SYMTAB               0x1C8
-#CHECK-NEXT:  0x000000000000000B SYMENT               24
-#CHECK-NEXT:  0x0000000000000005 STRTAB               0x210
-#CHECK-NEXT:  0x000000000000000A STRSZ                5
-#CHECK-NEXT:  0x0000000000000004 HASH                 0x1F8
-#CHECK-NEXT:  0x0000000000000000 NULL                 0x0
-#CHECK-NEXT:]
-
-#LINK:         Index: 3
-#LINK-NEXT:    Name: .dynstr
-
-#LINK:         Name: .dynamic
-#LINK-NEXT:    Type: SHT_DYNAMIC
-#LINK-NEXT:    Flags [
-#LINK-NEXT:      SHF_ALLOC
-#LINK-NEXT:      SHF_WRITE
-#LINK-NEXT:    ]
-#LINK-NEXT:    Address:
-#LINK-NEXT:    Offset:
-#LINK-NEXT:    Size:
-#LINK-NEXT:    Link: 3
diff --git a/llvm/test/tools/llvm-objcopy/dynstr.test b/llvm/test/tools/llvm-objcopy/dynstr.test
deleted file mode 100644
index 6e193065a77..00000000000
--- a/llvm/test/tools/llvm-objcopy/dynstr.test
+++ /dev/null
@@ -1,32 +0,0 @@
-# RUN: yaml2obj %s > %t
-# RUN: llvm-objcopy %t %t2
-# RUN: llvm-readobj -sections -section-data %t2 | FileCheck %s
-
-!ELF
-FileHeader:
-  Class:           ELFCLASS64
-  Data:            ELFDATA2LSB
-  Type:            ET_EXEC
-  Machine:         EM_X86_64
-Sections:
-  - Name:            .dynstr
-    Type:            SHT_STRTAB
-    Flags:           [ SHF_ALLOC ]
-    Address:         0x1000
-    Content:         "002EDEADBEEF002EBAADF00D00"
-
-#CHECK:         Name: .dynstr
-#CHECK-NEXT:    Type: SHT_STRTAB
-#CHECK-NEXT:    Flags [
-#CHECK-NEXT:      SHF_ALLOC
-#CHECK-NEXT:    ]
-#CHECK-NEXT:    Address: 0x1000
-#CHECK-NEXT:    Offset:
-#CHECK-NEXT:    Size: 13
-#CHECK-NEXT:    Link:
-#CHECK-NEXT:    Info:
-#CHECK-NEXT:    AddressAlignment:
-#CHECK-NEXT:    EntrySize:
-#CHECK-NEXT:    SectionData (
-#CHECK-NEXT:      0000: 002EDEAD BEEF002E BAADF00D 00
-#CHECK-NEXT:    )
diff --git a/llvm/test/tools/llvm-objcopy/dynsym.test b/llvm/test/tools/llvm-objcopy/dynsym.test
deleted file mode 100644
index b7d09536f69..00000000000
--- a/llvm/test/tools/llvm-objcopy/dynsym.test
+++ /dev/null
@@ -1,64 +0,0 @@
-# RUN: llvm-objcopy %p/Inputs/dynsym.so %t
-# RUN: llvm-readobj -dyn-symbols %t | FileCheck %s
-# RUN: llvm-readobj -sections %t | FileCheck -check-prefix=LINK %s
-
-#LINK:         Name: .dynsym
-#LINK-NEXT:    Type: SHT_DYNSYM
-#LINK-NEXT:    Flags [
-#LINK-NEXT:      SHF_ALLOC
-#LINK-NEXT:    ]
-#LINK-NEXT:    Address:
-#LINK-NEXT:    Offset:
-#LINK-NEXT:    Size:
-#LINK-NEXT:    Link: 3
-
-#LINK:         Index: 3
-#LINK-NEXT:    Name: .dynstr
-
-#CHECK: DynamicSymbols [
-#CHECK-NEXT:  Symbol {
-#CHECK-NEXT:    Name: @ (0)
-#CHECK-NEXT:    Value: 0x0
-#CHECK-NEXT:    Size: 0
-#CHECK-NEXT:    Binding: Local
-#CHECK-NEXT:    Type: None (0x0)
-#CHECK-NEXT:    Other: 0
-#CHECK-NEXT:    Section: Undefined (0x0)
-#CHECK-NEXT:  }
-#CHECK-NEXT:  Symbol {
-#CHECK-NEXT:    Name: bang@ (1)
-#CHECK-NEXT:    Value: 0x4000
-#CHECK-NEXT:    Size: 8
-#CHECK-NEXT:    Binding: Global (0x1)
-#CHECK-NEXT:    Type: Object (0x1)
-#CHECK-NEXT:    Other: 0
-#CHECK-NEXT:    Section: .bss (0x7)
-#CHECK-NEXT:  }
-#CHECK-NEXT:  Symbol {
-#CHECK-NEXT:    Name: bar@ (6)
-#CHECK-NEXT:    Value: 0x1001
-#CHECK-NEXT:    Size: 0
-#CHECK-NEXT:    Binding: Global (0x1)
-#CHECK-NEXT:    Type: Function (0x2)
-#CHECK-NEXT:    Other: 0
-#CHECK-NEXT:    Section: .text (0x4)
-#CHECK-NEXT:  }
-#CHECK-NEXT:  Symbol {
-#CHECK-NEXT:    Name: baz@ (10)
-#CHECK-NEXT:    Value: 0x2000
-#CHECK-NEXT:    Size: 0
-#CHECK-NEXT:    Binding: Global (0x1)
-#CHECK-NEXT:    Type: Object (0x1)
-#CHECK-NEXT:    Other: 0
-#CHECK-NEXT:    Section: .data (0x5)
-#CHECK-NEXT:  }
-#CHECK-NEXT:  Symbol {
-#CHECK-NEXT:    Name: foo@ (14)
-#CHECK-NEXT:    Value: 0x1000
-#CHECK-NEXT:    Size: 0
-#CHECK-NEXT:    Binding: Global (0x1)
-#CHECK-NEXT:    Type: Function (0x2)
-#CHECK-NEXT:    Other: 0
-#CHECK-NEXT:    Section: .text (0x4)
-#CHECK-NEXT:  }
-#CHECK-NEXT:]
diff --git a/llvm/tools/llvm-objcopy/Object.cpp b/llvm/tools/llvm-objcopy/Object.cpp
index 0d16e69923d..fd3add98418 100644
--- a/llvm/tools/llvm-objcopy/Object.cpp
+++ b/llvm/tools/llvm-objcopy/Object.cpp
@@ -228,12 +228,6 @@ void RelocationSection<ELFT>::writeSection(llvm::FileOutputBuffer &Out) const {
     writeRel(reinterpret_cast<Elf_Rela *>(Buf));
 }
 
-bool SectionWithStrTab::classof(const SectionBase *S) {
-  return isa<DynamicSymbolTableSection>(S) || isa<DynamicSection>(S);
-}
-
-void SectionWithStrTab::finalize() { this->Link = StrTab->Index; }
-
 // Returns true IFF a section is wholly inside the range of a segment
 static bool sectionWithinSegment(const SectionBase &Section,
                                  const Segment &Segment) {
@@ -281,12 +275,16 @@ void Object<ELFT>::initSymbolTable(const llvm::object::ELFFile<ELFT> &ElfFile,
                                    SymbolTableSection *SymTab) {
 
   SymTab->Size = 0;
-  SymTab->setStrTab(getSectionOfType<StringTableSection>(
-      SymbolTable->Link,
-      "Symbol table has link index of " + Twine(SymTab->Link) +
-          " which is not a valid index",
-      "Symbol table has link index of " + Twine(SymTab->Link) +
-          " which is not a string table"));
+  if (SymbolTable->Link - 1 >= Sections.size())
+    error("Symbol table has link index of " + Twine(SymbolTable->Link) +
+          " which is not a valid index");
+
+  if (auto StrTab =
+          dyn_cast<StringTableSection>(Sections[SymbolTable->Link - 1].get()))
+    SymTab->setStrTab(StrTab);
+  else
+    error("Symbol table has link index of " + Twine(SymbolTable->Link) +
+          "which is not a string table");
 
   const Elf_Shdr &Shdr = *unwrapOrError(ElfFile.getSection(SymTab->Index));
   StringRef StrTabData = unwrapOrError(ElfFile.getStringTableForSymtab(Shdr));
@@ -294,7 +292,6 @@ void Object<ELFT>::initSymbolTable(const llvm::object::ELFFile<ELFT> &ElfFile,
   for (const auto &Sym : unwrapOrError(ElfFile.symbols(&Shdr))) {
     SectionBase *DefSection = nullptr;
     StringRef Name = unwrapOrError(Sym.getName(StrTabData));
-
     if (Sym.st_shndx >= SHN_LORESERVE) {
       if (!isValidReservedSectionIndex(Sym.st_shndx, Machine)) {
         error(
@@ -303,12 +300,12 @@ void Object<ELFT>::initSymbolTable(const llvm::object::ELFFile<ELFT> &ElfFile,
             Twine(Sym.st_shndx));
       }
     } else if (Sym.st_shndx != SHN_UNDEF) {
-      DefSection = getSection(
-          Sym.st_shndx,
-          "Symbol '" + Name + "' is defined in invalid section with index " +
+      if (Sym.st_shndx >= Sections.size())
+        error("Symbol '" + Name +
+              "' is defined in invalid section with index " +
               Twine(Sym.st_shndx));
+      DefSection = Sections[Sym.st_shndx - 1].get();
     }
-
     SymTab->addSymbol(Name, Sym.getBinding(), Sym.getType(), DefSection,
                       Sym.getValue(), Sym.st_shndx, Sym.st_size);
   }
@@ -336,22 +333,6 @@ void initRelocations(RelocationSection<ELFT> *Relocs,
 }
 
 template <class ELFT>
-SectionBase *Object<ELFT>::getSection(uint16_t Index, Twine ErrMsg) {
-  if (Index == SHN_UNDEF || Index > Sections.size())
-    error(ErrMsg);
-  return Sections[Index - 1].get();
-}
-
-template <class ELFT>
-template <class T>
-T *Object<ELFT>::getSectionOfType(uint16_t Index, Twine IndexErrMsg,
-                                  Twine TypeErrMsg) {
-  if (T *TSec = llvm::dyn_cast<T>(getSection(Index, IndexErrMsg)))
-    return TSec;
-  error(TypeErrMsg);
-}
-
-template <class ELFT>
 std::unique_ptr<SectionBase>
 Object<ELFT>::makeSection(const llvm::object::ELFFile<ELFT> &ElfFile,
                           const Elf_Shdr &Shdr) {
@@ -361,26 +342,7 @@ Object<ELFT>::makeSection(const llvm::object::ELFFile<ELFT> &ElfFile,
   case SHT_RELA:
     return llvm::make_unique<RelocationSection<ELFT>>();
   case SHT_STRTAB:
-    // If a string table is allocated we don't want to mess with it. That would
-    // mean altering the memory image. There are no special link types or
-    // anything so we can just use a Section.
-    if (Shdr.sh_flags & SHF_ALLOC) {
-      Data = unwrapOrError(ElfFile.getSectionContents(&Shdr));
-      return llvm::make_unique<Section>(Data);
-    }
     return llvm::make_unique<StringTableSection>();
-  case SHT_HASH:
-  case SHT_GNU_HASH:
-    // Hash tables should refer to SHT_DYNSYM which we're not going to change.
-    // Because of this we don't need to mess with the hash tables either.
-    Data = unwrapOrError(ElfFile.getSectionContents(&Shdr));
-    return llvm::make_unique<Section>(Data);
-  case SHT_DYNSYM:
-    Data = unwrapOrError(ElfFile.getSectionContents(&Shdr));
-    return llvm::make_unique<DynamicSymbolTableSection>(Data);
-  case SHT_DYNAMIC:
-    Data = unwrapOrError(ElfFile.getSectionContents(&Shdr));
-    return llvm::make_unique<DynamicSection>(Data);
   case SHT_SYMTAB: {
     auto SymTab = llvm::make_unique<SymbolTableSectionImpl<ELFT>>();
     SymbolTable = SymTab.get();
@@ -428,35 +390,28 @@ void Object<ELFT>::readSectionHeaders(const ELFFile<ELFT> &ElfFile) {
   // relocation sections.
   for (auto &Section : Sections) {
     if (auto RelSec = dyn_cast<RelocationSection<ELFT>>(Section.get())) {
-
-      auto SymTab = getSectionOfType<SymbolTableSection>(
-          RelSec->Link,
-          "Link field value " + Twine(RelSec->Link) + " in section " +
-              RelSec->Name + " is invalid",
-          "Link field value " + Twine(RelSec->Link) + " in section " +
-              RelSec->Name + " is not a symbol table");
+      if (RelSec->Link - 1 >= Sections.size() || RelSec->Link == 0) {
+        error("Link field value " + Twine(RelSec->Link) + " in section " +
+              RelSec->Name + " is invalid");
+      }
+      if (RelSec->Info - 1 >= Sections.size() || RelSec->Info == 0) {
+        error("Info field value " + Twine(RelSec->Link) + " in section " +
+              RelSec->Name + " is invalid");
+      }
+      auto SymTab =
+          dyn_cast<SymbolTableSection>(Sections[RelSec->Link - 1].get());
+      if (SymTab == nullptr) {
+        error("Link field of relocation section " + RelSec->Name +
+              " is not a symbol table");
+      }
       RelSec->setSymTab(SymTab);
-
-      RelSec->setSection(getSection(RelSec->Info,
-                                    "Info field value " + Twine(RelSec->Link) +
-                                        " in section " + RelSec->Name +
-                                        " is invalid"));
-
+      RelSec->setSection(Sections[RelSec->Info - 1].get());
       auto Shdr = unwrapOrError(ElfFile.sections()).begin() + RelSec->Index;
       if (RelSec->Type == SHT_REL)
         initRelocations(RelSec, SymTab, unwrapOrError(ElfFile.rels(Shdr)));
       else
         initRelocations(RelSec, SymTab, unwrapOrError(ElfFile.relas(Shdr)));
     }
-
-    if (auto Sec = dyn_cast<SectionWithStrTab>(Section.get())) {
-      Sec->setStrTab(getSectionOfType<StringTableSection>(
-          Sec->Link,
-          "Link field value " + Twine(Sec->Link) + " in section " + Sec->Name +
-              " is invalid",
-          "Link field value " + Twine(Sec->Link) + " in section " + Sec->Name +
-              " is not a string table"));
-    }
   }
 }
 
@@ -474,12 +429,8 @@ template <class ELFT> Object<ELFT>::Object(const ELFObjectFile<ELFT> &Obj) {
   readSectionHeaders(ElfFile);
   readProgramHeaders(ElfFile);
 
-  SectionNames = getSectionOfType<StringTableSection>(
-      Ehdr.e_shstrndx,
-      "e_shstrndx field value " + Twine(Ehdr.e_shstrndx) + " in elf header " +
-          " is invalid",
-      "e_shstrndx field value " + Twine(Ehdr.e_shstrndx) + " in elf header " +
-          " is not a string table");
+  SectionNames =
+      dyn_cast<StringTableSection>(Sections[Ehdr.e_shstrndx - 1].get());
 }
 
 template <class ELFT>
diff --git a/llvm/tools/llvm-objcopy/Object.h b/llvm/tools/llvm-objcopy/Object.h
index 9b144a81a8c..dff3fc40893 100644
--- a/llvm/tools/llvm-objcopy/Object.h
+++ b/llvm/tools/llvm-objcopy/Object.h
@@ -193,34 +193,6 @@ public:
   }
 };
 
-class SectionWithStrTab : public Section {
-private:
-  StringTableSection *StrTab;
-
-public:
-  SectionWithStrTab(llvm::ArrayRef<uint8_t> Data) : Section(Data) {}
-  void setStrTab(StringTableSection *StringTable) { StrTab = StringTable; }
-  void finalize() override;
-  static bool classof(const SectionBase *S);
-};
-
-class DynamicSymbolTableSection : public SectionWithStrTab {
-public:
-  DynamicSymbolTableSection(llvm::ArrayRef<uint8_t> Data)
-      : SectionWithStrTab(Data) {}
-  static bool classof(const SectionBase *S) {
-    return S->Type == llvm::ELF::SHT_DYNSYM;
-  }
-};
-
-class DynamicSection : public SectionWithStrTab {
-public:
-  DynamicSection(llvm::ArrayRef<uint8_t> Data) : SectionWithStrTab(Data) {}
-  static bool classof(const SectionBase *S) {
-    return S->Type == llvm::ELF::SHT_DYNAMIC;
-  }
-};
-
 template <class ELFT> class Object {
 private:
   typedef std::unique_ptr<SectionBase> SecPtr;
@@ -237,12 +209,6 @@ private:
   void readProgramHeaders(const llvm::object::ELFFile<ELFT> &ElfFile);
   void readSectionHeaders(const llvm::object::ELFFile<ELFT> &ElfFile);
 
-  SectionBase *getSection(uint16_t Index, llvm::Twine ErrMsg);
-
-  template <class T>
-  T *getSectionOfType(uint16_t Index, llvm::Twine IndexErrMsg,
-                      llvm::Twine TypeErrMsg);
-
 protected:
   StringTableSection *SectionNames;
   SymbolTableSection *SymbolTable;