Move ELFCodeEmiter stuff to new files

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72785 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 94 insertions, 0 deletions

diff --git a/lib/CodeGen/ELFCodeEmitter.cpp b/lib/CodeGen/ELFCodeEmitter.cpp
new file mode 100644
index 0000000000..0a0245f3dd
--- /dev/null
+++ b/lib/CodeGen/ELFCodeEmitter.cpp
@@ -0,0 +1,94 @@
+//===-- lib/CodeGen/ELFCodeEmitter.cpp ------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "ELFCodeEmitter.h"
+#include "llvm/Constants.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/Function.h"
+#include "llvm/CodeGen/MachineConstantPool.h"
+#include "llvm/CodeGen/MachineJumpTableInfo.h"
+#include "llvm/Target/TargetAsmInfo.h"
+#include "llvm/Target/TargetData.h"
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/Support/Mangler.h"
+#include "llvm/Support/OutputBuffer.h"
+
+//===----------------------------------------------------------------------===//
+//                       ELFCodeEmitter Implementation
+//===----------------------------------------------------------------------===//
+
+namespace llvm {
+
+/// startFunction - This callback is invoked when a new machine function is
+/// about to be emitted.
+void ELFCodeEmitter::startFunction(MachineFunction &F) {
+  // Align the output buffer to the appropriate alignment.
+  unsigned Align = 16;   // FIXME: GENERICIZE!!
+  // Get the ELF Section that this function belongs in.
+  ES = &EW.getSection(".text", ELFWriter::ELFSection::SHT_PROGBITS,
+                      ELFWriter::ELFSection::SHF_EXECINSTR |
+                      ELFWriter::ELFSection::SHF_ALLOC);
+  OutBuffer = &ES->SectionData;
+  cerr << "FIXME: This code needs to be updated for changes in the "
+       << "CodeEmitter interfaces.  In particular, this should set "
+       << "BufferBegin/BufferEnd/CurBufferPtr, not deal with OutBuffer!";
+  abort();
+
+  // Upgrade the section alignment if required.
+  if (ES->Align < Align) ES->Align = Align;
+
+  // Add padding zeros to the end of the buffer to make sure that the
+  // function will start on the correct byte alignment within the section.
+  OutputBuffer OB(*OutBuffer,
+                  TM.getTargetData()->getPointerSizeInBits() == 64,
+                  TM.getTargetData()->isLittleEndian());
+  OB.align(Align);
+  FnStart = OutBuffer->size();
+}
+
+/// finishFunction - This callback is invoked after the function is completely
+/// finished.
+bool ELFCodeEmitter::finishFunction(MachineFunction &F) {
+  // We now know the size of the function, add a symbol to represent it.
+  ELFWriter::ELFSym FnSym(F.getFunction());
+
+  // Figure out the binding (linkage) of the symbol.
+  switch (F.getFunction()->getLinkage()) {
+  default:
+    // appending linkage is illegal for functions.
+    assert(0 && "Unknown linkage type!");
+  case GlobalValue::ExternalLinkage:
+    FnSym.SetBind(ELFWriter::ELFSym::STB_GLOBAL);
+    break;
+  case GlobalValue::LinkOnceAnyLinkage:
+  case GlobalValue::LinkOnceODRLinkage:
+  case GlobalValue::WeakAnyLinkage:
+  case GlobalValue::WeakODRLinkage:
+    FnSym.SetBind(ELFWriter::ELFSym::STB_WEAK);
+    break;
+  case GlobalValue::PrivateLinkage:
+    assert (0 && "PrivateLinkage should not be in the symbol table.");
+  case GlobalValue::InternalLinkage:
+    FnSym.SetBind(ELFWriter::ELFSym::STB_LOCAL);
+    break;
+  }
+
+  ES->Size = OutBuffer->size();
+
+  FnSym.SetType(ELFWriter::ELFSym::STT_FUNC);
+  FnSym.SectionIdx = ES->SectionIdx;
+  FnSym.Value = FnStart;   // Value = Offset from start of Section.
+  FnSym.Size = OutBuffer->size()-FnStart;
+
+  // Finally, add it to the symtab.
+  EW.SymbolTable.push_back(FnSym);
+  return false;
+}
+
+} // end namespace llvm