[lld] r247056 - Start creating the .dynamic section.

[Rafael Espindola via llvm-commits]

Author: rafael
Date: Tue Sep  8 14:43:27 2015
New Revision: 247056

URL: http://llvm.org/viewvc/llvm-project?rev=247056&view=rev
Log:
Start creating the .dynamic section.

For now it is always empty.

Modified:
    lld/trunk/ELF/SymbolTable.h
    lld/trunk/ELF/Writer.cpp
    lld/trunk/test/elf2/shared.s

Modified: lld/trunk/ELF/SymbolTable.h
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/SymbolTable.h?rev=247056&r1=247055&r2=247056&view=diff
==============================================================================
--- lld/trunk/ELF/SymbolTable.h (original)
+++ lld/trunk/ELF/SymbolTable.h Tue Sep  8 14:43:27 2015
@@ -50,6 +50,10 @@ public:
     return ObjectFiles;
   }
 
+  const std::vector<std::unique_ptr<SharedFileBase>> &getSharedFiles() const {
+    return SharedFiles;
+  }
+
 private:
   Symbol *insert(SymbolBody *New);
   template <class ELFT> void addELFFile(ELFFileBase *File);

Modified: lld/trunk/ELF/Writer.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Writer.cpp?rev=247056&r1=247055&r2=247056&view=diff
==============================================================================
--- lld/trunk/ELF/Writer.cpp (original)
+++ lld/trunk/ELF/Writer.cpp Tue Sep  8 14:43:27 2015
@@ -156,13 +156,36 @@ private:
   const StringTableSection<ELFT::Is64Bits> &StrTabSec;
 };
 
+template <bool Is64Bits>
+class DynamicSection final : public OutputSectionBase<Is64Bits> {
+public:
+  DynamicSection(const StringTableSection<Is64Bits> &StrTabSec)
+      : OutputSectionBase<Is64Bits>(".dynamic", SHT_DYNAMIC,
+                                    SHF_ALLOC | SHF_WRITE),
+        StrTabSec(StrTabSec) {
+    typedef OutputSectionBase<Is64Bits> Base;
+    typename Base::HeaderT &Header = this->Header;
+    Header.sh_addralign = Is64Bits ? 8 : 4;
+    Header.sh_entsize = Is64Bits ? 16 : 8;
+  }
+
+  void finalize() override {
+    this->Header.sh_link = StrTabSec.getSectionIndex();
+  }
+
+  void writeTo(uint8_t *Buf) override {}
+
+private:
+  const StringTableSection<Is64Bits> &StrTabSec;
+};
+
 // The writer writes a SymbolTable result to a file.
 template <class ELFT> class Writer {
 public:
   typedef typename llvm::object::ELFFile<ELFT>::uintX_t uintX_t;
   typedef typename llvm::object::ELFFile<ELFT>::Elf_Shdr Elf_Shdr;
   typedef typename llvm::object::ELFFile<ELFT>::Elf_Sym Elf_Sym;
-  Writer(SymbolTable *T) : SymTable(*T, StringTable) {}
+  Writer(SymbolTable *T) : SymTable(*T, StringTable), DynamicSec(StringTable) {}
   void run();
 
 private:
@@ -184,6 +207,8 @@ private:
   StringTableSection<ELFT::Is64Bits> StringTable;
 
   SymbolTableSection<ELFT> SymTable;
+
+  DynamicSection<ELFT::Is64Bits> DynamicSec;
 };
 } // anonymous namespace
 
@@ -491,6 +516,11 @@ template <class ELFT> void Writer<ELFT>:
   OutputSections.push_back(&SymTable);
   OutputSections.push_back(&StringTable);
 
+  const std::vector<std::unique_ptr<SharedFileBase>> &SharedFiles =
+      Symtab.getSharedFiles();
+  if (!SharedFiles.empty())
+    OutputSections.push_back(&DynamicSec);
+
   std::stable_sort(OutputSections.begin(), OutputSections.end(),
                    compSec<ELFT::Is64Bits>);
   for (unsigned I = 0, N = OutputSections.size(); I < N; ++I)

Modified: lld/trunk/test/elf2/shared.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/elf2/shared.s?rev=247056&r1=247055&r2=247056&view=diff
==============================================================================
--- lld/trunk/test/elf2/shared.s (original)
+++ lld/trunk/test/elf2/shared.s Tue Sep  8 14:43:27 2015
@@ -1,8 +1,38 @@
 // RUN: llvm-mc -filetype=obj -triple=i686-unknown-linux %s -o %t.o
 // RUN: lld -flavor gnu2 %t.o %p/Inputs/i686-simple-library.so -o %t
-// RUN: llvm-readobj -t %t | FileCheck %s
+// RUN: llvm-readobj -t -s %t | FileCheck %s
 // REQUIRES: x86
 
+// CHECK:        Name: .dynamic
+// CHECK-NEXT:   Type: SHT_DYNAMIC
+// CHECK-NEXT:   Flags [
+// CHECK-NEXT:     SHF_ALLOC
+// CHECK-NEXT:     SHF_WRITE
+// CHECK-NEXT:   ]
+// CHECK-NEXT:   Address:
+// CHECK-NEXT:   Offset:
+// CHECK-NEXT:   Size:
+// CHECK-NEXT:   Link: 6
+// CHECK-NEXT:   Info: 0
+// CHECK-NEXT:   AddressAlignment: 4
+// CHECK-NEXT:   EntrySize: 8
+// CHECK-NEXT: }
+
+// CHECK:        Index: 6
+// CHECK-NEXT:   Name: .strtab
+// CHECK-NEXT:   Type: SHT_STRTAB
+// CHECK-NEXT:   Flags [
+// CHECK-NEXT:   ]
+// CHECK-NEXT:   Address:
+// CHECK-NEXT:   Offset:
+// CHECK-NEXT:   Size:
+// CHECK-NEXT:   Link: 0
+// CHECK-NEXT:   Info: 0
+// CHECK-NEXT:   AddressAlignment: 1
+// CHECK-NEXT:   EntrySize: 0
+// CHECK-NEXT: }
+
+
 // CHECK:      Symbols [
 // CHECK-NEXT:   Symbol {
 // CHECK-NEXT:     Name: