1 files changed, 57 insertions, 44 deletions

diff --git a/lib/MC/WinCOFFObjectWriter.cpp b/lib/MC/WinCOFFObjectWriter.cpp
index 9ffecd99df68..b774852eabe6 100644
--- a/lib/MC/WinCOFFObjectWriter.cpp
+++ b/lib/MC/WinCOFFObjectWriter.cpp
@@ -36,6 +36,7 @@
 #include "llvm/Support/Endian.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/JamCRC.h"
+#include "llvm/Support/LEB128.h"
 #include "llvm/Support/MathExtras.h"
 #include "llvm/Support/raw_ostream.h"
 #include <algorithm>
@@ -58,8 +59,6 @@ namespace {
 using name = SmallString<COFF::NameSize>;
 
 enum AuxiliaryType {
-  ATFunctionDefinition,
-  ATbfAndefSymbol,
   ATWeakExternal,
   ATFile,
   ATSectionDefinition
@@ -147,6 +146,10 @@ public:
 
   bool UseBigObj;
 
+  bool EmitAddrsigSection = false;
+  MCSectionCOFF *AddrsigSection;
+  std::vector<const MCSymbol *> AddrsigSyms;
+
   WinCOFFObjectWriter(std::unique_ptr<MCWinCOFFObjectTargetWriter> MOTW,
                       raw_pwrite_stream &OS);
 
@@ -206,6 +209,11 @@ public:
   void assignSectionNumbers();
   void assignFileOffsets(MCAssembler &Asm, const MCAsmLayout &Layout);
 
+  void emitAddrsigSection() override { EmitAddrsigSection = true; }
+  void addAddrsigSymbol(const MCSymbol *Sym) override {
+    AddrsigSyms.push_back(Sym);
+  }
+
   uint64_t writeObject(MCAssembler &Asm, const MCAsmLayout &Layout) override;
 };
 
@@ -515,24 +523,6 @@ void WinCOFFObjectWriter::WriteAuxiliarySymbols(
     const COFFSymbol::AuxiliarySymbols &S) {
   for (const AuxSymbol &i : S) {
     switch (i.AuxType) {
-    case ATFunctionDefinition:
-      W.write<uint32_t>(i.Aux.FunctionDefinition.TagIndex);
-      W.write<uint32_t>(i.Aux.FunctionDefinition.TotalSize);
-      W.write<uint32_t>(i.Aux.FunctionDefinition.PointerToLinenumber);
-      W.write<uint32_t>(i.Aux.FunctionDefinition.PointerToNextFunction);
-      W.OS.write_zeros(sizeof(i.Aux.FunctionDefinition.unused));
-      if (UseBigObj)
-        W.OS.write_zeros(COFF::Symbol32Size - COFF::Symbol16Size);
-      break;
-    case ATbfAndefSymbol:
-      W.OS.write_zeros(sizeof(i.Aux.bfAndefSymbol.unused1));
-      W.write<uint16_t>(i.Aux.bfAndefSymbol.Linenumber);
-      W.OS.write_zeros(sizeof(i.Aux.bfAndefSymbol.unused2));
-      W.write<uint32_t>(i.Aux.bfAndefSymbol.PointerToNextFunction);
-      W.OS.write_zeros(sizeof(i.Aux.bfAndefSymbol.unused3));
-      if (UseBigObj)
-        W.OS.write_zeros(COFF::Symbol32Size - COFF::Symbol16Size);
-      break;
     case ATWeakExternal:
       W.write<uint32_t>(i.Aux.WeakExternal.TagIndex);
       W.write<uint32_t>(i.Aux.WeakExternal.Characteristics);
@@ -568,10 +558,9 @@ void WinCOFFObjectWriter::writeSectionHeaders() {
   std::vector<COFFSection *> Arr;
   for (auto &Section : Sections)
     Arr.push_back(Section.get());
-  llvm::sort(Arr.begin(), Arr.end(),
-             [](const COFFSection *A, const COFFSection *B) {
-               return A->Number < B->Number;
-             });
+  llvm::sort(Arr, [](const COFFSection *A, const COFFSection *B) {
+    return A->Number < B->Number;
+  });
 
   for (auto &Section : Arr) {
     if (Section->Number == -1)
@@ -630,14 +619,9 @@ void WinCOFFObjectWriter::writeSection(MCAssembler &Asm,
 
   // Write the section contents.
   if (Sec.Header.PointerToRawData != 0) {
-    assert(W.OS.tell() <= Sec.Header.PointerToRawData &&
+    assert(W.OS.tell() == Sec.Header.PointerToRawData &&
            "Section::PointerToRawData is insane!");
 
-    unsigned PaddingSize = Sec.Header.PointerToRawData - W.OS.tell();
-    assert(PaddingSize < 4 &&
-           "Should only need at most three bytes of padding!");
-    W.OS.write_zeros(PaddingSize);
-
     uint32_t CRC = writeSectionContents(Asm, Layout, MCSec);
 
     // Update the section definition auxiliary symbol to record the CRC.
@@ -677,6 +661,13 @@ void WinCOFFObjectWriter::writeSection(MCAssembler &Asm,
 
 void WinCOFFObjectWriter::executePostLayoutBinding(MCAssembler &Asm,
                                                    const MCAsmLayout &Layout) {
+  if (EmitAddrsigSection) {
+    AddrsigSection = Asm.getContext().getCOFFSection(
+        ".llvm_addrsig", COFF::IMAGE_SCN_LNK_REMOVE,
+        SectionKind::getMetadata());
+    Asm.registerSection(*AddrsigSection);
+  }
+
   // "Define" each section & symbol. This creates section & symbol
   // entries in the staging area.
   for (const auto &Section : Asm)
@@ -915,10 +906,7 @@ void WinCOFFObjectWriter::assignFileOffsets(MCAssembler &Asm,
     Sec->Header.SizeOfRawData = Layout.getSectionAddressSize(&Section);
 
     if (IsPhysicalSection(Sec)) {
-      // Align the section data to a four byte boundary.
-      Offset = alignTo(Offset, 4);
       Sec->Header.PointerToRawData = Offset;
-
       Offset += Sec->Header.SizeOfRawData;
     }
 
@@ -1020,22 +1008,47 @@ uint64_t WinCOFFObjectWriter::writeObject(MCAssembler &Asm,
       continue;
 
     const MCSectionCOFF &MCSec = *Section->MCSection;
+    const MCSymbol *AssocMCSym = MCSec.getCOMDATSymbol();
+    assert(AssocMCSym);
+
+    // It's an error to try to associate with an undefined symbol or a symbol
+    // without a section.
+    if (!AssocMCSym->isInSection()) {
+      Asm.getContext().reportError(
+          SMLoc(), Twine("cannot make section ") + MCSec.getSectionName() +
+                       Twine(" associative with sectionless symbol ") +
+                       AssocMCSym->getName());
+      continue;
+    }
 
-    const MCSymbol *COMDAT = MCSec.getCOMDATSymbol();
-    assert(COMDAT);
-    COFFSymbol *COMDATSymbol = GetOrCreateCOFFSymbol(COMDAT);
-    assert(COMDATSymbol);
-    COFFSection *Assoc = COMDATSymbol->Section;
-    if (!Assoc)
-      report_fatal_error(
-          Twine("Missing associated COMDAT section for section ") +
-          MCSec.getSectionName());
+    const auto *AssocMCSec = cast<MCSectionCOFF>(&AssocMCSym->getSection());
+    assert(SectionMap.count(AssocMCSec));
+    COFFSection *AssocSec = SectionMap[AssocMCSec];
 
     // Skip this section if the associated section is unused.
-    if (Assoc->Number == -1)
+    if (AssocSec->Number == -1)
       continue;
 
-    Section->Symbol->Aux[0].Aux.SectionDefinition.Number = Assoc->Number;
+    Section->Symbol->Aux[0].Aux.SectionDefinition.Number = AssocSec->Number;
+  }
+
+  // Create the contents of the .llvm_addrsig section.
+  if (EmitAddrsigSection) {
+    auto Frag = new MCDataFragment(AddrsigSection);
+    Frag->setLayoutOrder(0);
+    raw_svector_ostream OS(Frag->getContents());
+    for (const MCSymbol *S : AddrsigSyms) {
+      if (!S->isTemporary()) {
+        encodeULEB128(S->getIndex(), OS);
+        continue;
+      }
+
+      MCSection *TargetSection = &S->getSection();
+      assert(SectionMap.find(TargetSection) != SectionMap.end() &&
+             "Section must already have been defined in "
+             "executePostLayoutBinding!");
+      encodeULEB128(SectionMap[TargetSection]->Symbol->getIndex(), OS);
+    }
   }
 
   assignFileOffsets(Asm, Layout);