ELFObjectWriter.cpp: Prune obsolete \param since r234342. [-Wdocumentation]

[oota-llvm.git] / lib / MC / MCMachOStreamer.cpp

diff --git a/lib/MC/MCMachOStreamer.cpp b/lib/MC/MCMachOStreamer.cpp
index 9e8bc942e494ea8d3b950af0d8a518f20fc9c4c4..d5c7101d0d554da05fca859546c323b67d6a3fdc 100644 (file)
--- a/lib/MC/MCMachOStreamer.cpp
+++ b/lib/MC/MCMachOStreamer.cpp
@@ -26,6 +26,7 @@
 #include "llvm/MC/MCSymbol.h"
 #include "llvm/Support/Dwarf.h"
 #include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/TargetRegistry.h"
 #include "llvm/Support/raw_ostream.h"
 
 using namespace llvm;
@@ -39,6 +40,9 @@ private:
   /// need for local relocations. False by default.
   bool LabelSections;
 
+  bool DWARFMustBeAtTheEnd;
+  bool CreatedADWARFSection;
+
   /// HasSectionLabel - map of which sections have already had a non-local
   /// label emitted to them. Used so we don't emit extraneous linker local
   /// labels in the middle of the section.
@@ -51,9 +55,15 @@ private:
 
 public:
   MCMachOStreamer(MCContext &Context, MCAsmBackend &MAB, raw_ostream &OS,
-                  MCCodeEmitter *Emitter, bool label)
-      : MCObjectStreamer(Context, MAB, OS, Emitter),
-        LabelSections(label) {}
+                  MCCodeEmitter *Emitter, bool DWARFMustBeAtTheEnd, bool label)
+      : MCObjectStreamer(Context, MAB, OS, Emitter), LabelSections(label),
+        DWARFMustBeAtTheEnd(DWARFMustBeAtTheEnd), CreatedADWARFSection(false) {}
+
+  /// state management
+  void reset() override {
+    HasSectionLabel.clear();
+    MCObjectStreamer::reset();
+  }
 
   /// @name MCStreamer Interface
   /// @{
@@ -90,8 +100,8 @@ public:
                              unsigned ByteAlignment) override;
   void EmitZerofill(const MCSection *Section, MCSymbol *Symbol = nullptr,
                     uint64_t Size = 0, unsigned ByteAlignment = 0) override;
-  virtual void EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
-                      uint64_t Size, unsigned ByteAlignment = 0) override;
+  void EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol, uint64_t Size,
+                      unsigned ByteAlignment = 0) override;
 
   void EmitFileDirective(StringRef Filename) override {
     // FIXME: Just ignore the .file; it isn't important enough to fail the
@@ -113,10 +123,43 @@ public:
 
 } // end anonymous namespace.
 
+static bool canGoAfterDWARF(const MCSectionMachO &MSec) {
+  // These sections are created by the assembler itself after the end of
+  // the .s file.
+  StringRef SegName = MSec.getSegmentName();
+  StringRef SecName = MSec.getSectionName();
+
+  if (SegName == "__LD" && SecName == "__compact_unwind")
+    return true;
+
+  if (SegName == "__IMPORT") {
+    if (SecName == "__jump_table")
+      return true;
+
+    if (SecName == "__pointers")
+      return true;
+  }
+
+  if (SegName == "__TEXT" && SecName == "__eh_frame")
+    return true;
+
+  if (SegName == "__DATA" && SecName == "__nl_symbol_ptr")
+    return true;
+
+  return false;
+}
+
 void MCMachOStreamer::ChangeSection(const MCSection *Section,
                                     const MCExpr *Subsection) {
   // Change the section normally.
-  MCObjectStreamer::ChangeSection(Section, Subsection);
+  bool Created = MCObjectStreamer::changeSectionImpl(Section, Subsection);
+  const MCSectionMachO &MSec = *cast<MCSectionMachO>(Section);
+  StringRef SegName = MSec.getSegmentName();
+  if (SegName == "__DWARF")
+    CreatedADWARFSection = true;
+  else if (Created && DWARFMustBeAtTheEnd && !canGoAfterDWARF(MSec))
+    assert(!CreatedADWARFSection && "Creating regular section after DWARF");
+
   // Output a linker-local symbol so we don't need section-relative local
   // relocations. The linker hates us when we do that.
   if (LabelSections && !HasSectionLabel[Section]) {
@@ -177,7 +220,7 @@ void MCMachOStreamer::EmitDataRegionEnd() {
   if (!getAssembler().getBackend().hasDataInCodeSupport())
     return;
   std::vector<DataRegionData> &Regions = getAssembler().getDataRegions();
-  assert(Regions.size() && "Mismatched .end_data_region!");
+  assert(!Regions.empty() && "Mismatched .end_data_region!");
   DataRegionData &Data = Regions.back();
   assert(!Data.End && "Mismatched .end_data_region!");
   // Create a temporary label to mark the end of the data region.
@@ -449,9 +492,10 @@ void MCMachOStreamer::FinishImpl() {
 
 MCStreamer *llvm::createMachOStreamer(MCContext &Context, MCAsmBackend &MAB,
                                       raw_ostream &OS, MCCodeEmitter *CE,
-                                      bool RelaxAll,
+                                      bool RelaxAll, bool DWARFMustBeAtTheEnd,
                                       bool LabelSections) {
-  MCMachOStreamer *S = new MCMachOStreamer(Context, MAB, OS, CE, LabelSections);
+  MCMachOStreamer *S = new MCMachOStreamer(Context, MAB, OS, CE,
+                                           DWARFMustBeAtTheEnd, LabelSections);
   if (RelaxAll)
     S->getAssembler().setRelaxAll(true);
   return S;