Handle ffunction-sections w/ filetype=obj.

src/IceELFObjectWriter.cpp

 //===- subzero/src/IceELFObjectWriter.cpp - ELF object file writer --------===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file defines the writer for ELF relocatable object files.
@@ skipping 200 matching lines @@
   Str.writeZeroPadding(AlignDiff);
   OffsetInFile += AlignDiff;
   return OffsetInFile;
 }
 
 void ELFObjectWriter::writeFunctionCode(const IceString &FuncName,
                                         bool IsInternal, const Assembler *Asm) {
   assert(!SectionNumbersAssigned);
   ELFTextSection *Section = nullptr;
   ELFRelocationSection *RelSection = nullptr;
-  if (TextSections.empty()) {
-    // TODO(jvoung): handle ffunction-sections.
+  const bool FunctionSections = Ctx.getFlags().getFunctionSections();
+  if (TextSections.empty() || FunctionSections) {
     IceString SectionName = ".text";
+    if (FunctionSections)
+      SectionName += "." + FuncName;
     bool IsELF64 = isELF64(Ctx.getTargetArch());
     const Elf64_Xword ShFlags = SHF_ALLOC | SHF_EXECINSTR;
     // TODO(jvoung): Should be bundle size. Grab it from that target?
     const Elf64_Xword ShAlign = 32;
     Section = createSection<ELFTextSection>(SectionName, SHT_PROGBITS, ShFlags,
                                             ShAlign, 0);
     Elf64_Off OffsetInFile = alignFileOffset(Section->getSectionAlign());
     Section->setFileOffset(OffsetInFile);
     TextSections.push_back(Section);
     RelSection = createRelocationSection(IsELF64, Section);
@@ skipping 13 matching lines @@
     SymbolType = STT_NOTYPE;
     SymbolBinding = STB_LOCAL;
   } else {
     SymbolType = STT_FUNC;
     SymbolBinding = STB_GLOBAL;
   }
   SymTab->createDefinedSym(FuncName, SymbolType, SymbolBinding, Section,
                            OffsetInSection, SymbolSize);
   StrTab->add(FuncName);
 
-  // Create a relocation section for the text section if needed, and copy the
-  // fixup information from per-function Assembler memory to the object
-  // writer's memory, for writing later.
+  // Copy the fixup information from per-function Assembler memory to the
+  // object writer's memory, for writing later.
   if (!Asm->fixups().empty()) {
     RelSection->addRelocations(OffsetInSection, Asm->fixups());
   }
 }
 
 namespace {
 
 ELFObjectWriter::SectionType
 classifyGlobalSection(const VariableDeclaration *Var) {
   if (Var->getIsConstant())
@@ skipping 339 matching lines @@
   if (IsELF64) {
     writeELFHeaderInternal<true>(ShOffset, ShStrTab->getNumber(),
                                  AllSections.size());
   } else {
     writeELFHeaderInternal<false>(ShOffset, ShStrTab->getNumber(),
                                   AllSections.size());
   }
 }
 
 } // end of namespace Ice