[MC] Export llvm::WinCOFFObjectWriter and access it from MCWinCOFFStreamer

MaskRay · MaskRay · commit 9539a7796094 · 2024-07-21T12:04:47.000-07:00
Similar to commit 28fcafb (2011) for MachObjectWriter. MCWinCOFFStreamer can now access WinCOFFObjectWriter directly without holding object file format specific inforamtion in MCAssembler (e.g. IncrementalLinkerCompatible).
diff --git a/llvm/include/llvm/MC/MCAssembler.h b/llvm/include/llvm/MC/MCAssembler.h
@@ -84,7 +84,6 @@ class MCAssembler {
   bool HasLayout = false;
   bool RelaxAll = false;
   bool SubsectionsViaSymbols = false;
-  bool IncrementalLinkerCompatible = false;
 
   SectionListType Sections;
 
@@ -298,13 +297,6 @@ class MCAssembler {
   bool getSubsectionsViaSymbols() const { return SubsectionsViaSymbols; }
   void setSubsectionsViaSymbols(bool Value) { SubsectionsViaSymbols = Value; }
 
-  bool isIncrementalLinkerCompatible() const {
-    return IncrementalLinkerCompatible;
-  }
-  void setIncrementalLinkerCompatible(bool Value) {
-    IncrementalLinkerCompatible = Value;
-  }
-
   bool hasLayout() const { return HasLayout; }
   bool getRelaxAll() const { return RelaxAll; }
   void setRelaxAll(bool Value) { RelaxAll = Value; }
diff --git a/llvm/include/llvm/MC/MCWinCOFFObjectWriter.h b/llvm/include/llvm/MC/MCWinCOFFObjectWriter.h
@@ -43,6 +43,37 @@ class MCWinCOFFObjectTargetWriter : public MCObjectTargetWriter {
   virtual bool recordRelocation(const MCFixup &) const { return true; }
 };
 
+class WinCOFFWriter;
+
+class WinCOFFObjectWriter : public MCObjectWriter {
+  friend class WinCOFFWriter;
+
+  std::unique_ptr<MCWinCOFFObjectTargetWriter> TargetObjectWriter;
+  std::unique_ptr<WinCOFFWriter> ObjWriter, DwoWriter;
+  bool IncrementalLinkerCompatible = false;
+
+public:
+  WinCOFFObjectWriter(std::unique_ptr<MCWinCOFFObjectTargetWriter> MOTW,
+                      raw_pwrite_stream &OS);
+  WinCOFFObjectWriter(std::unique_ptr<MCWinCOFFObjectTargetWriter> MOTW,
+                      raw_pwrite_stream &OS, raw_pwrite_stream &DwoOS);
+
+  // MCObjectWriter interface implementation.
+  void reset() override;
+  void setIncrementalLinkerCompatible(bool Value) {
+    IncrementalLinkerCompatible = Value;
+  }
+  void executePostLayoutBinding(MCAssembler &Asm) override;
+  bool isSymbolRefDifferenceFullyResolvedImpl(const MCAssembler &Asm,
+                                              const MCSymbol &SymA,
+                                              const MCFragment &FB, bool InSet,
+                                              bool IsPCRel) const override;
+  void recordRelocation(MCAssembler &Asm, const MCFragment *Fragment,
+                        const MCFixup &Fixup, MCValue Target,
+                        uint64_t &FixedValue) override;
+  uint64_t writeObject(MCAssembler &Asm) override;
+};
+
 /// Construct a new Win COFF writer instance.
 ///
 /// \param MOTW - The target specific WinCOFF writer subclass.
diff --git a/llvm/include/llvm/MC/MCWinCOFFStreamer.h b/llvm/include/llvm/MC/MCWinCOFFStreamer.h
@@ -22,6 +22,7 @@ class MCSection;
 class MCSubtargetInfo;
 class MCSymbol;
 class StringRef;
+class WinCOFFObjectWriter;
 class raw_pwrite_stream;
 
 class MCWinCOFFStreamer : public MCObjectStreamer {
@@ -36,6 +37,8 @@ class MCWinCOFFStreamer : public MCObjectStreamer {
     MCObjectStreamer::reset();
   }
 
+  WinCOFFObjectWriter &getWriter();
+
   /// \name MCStreamer interface
   /// \{
 
diff --git a/llvm/lib/MC/MCAssembler.cpp b/llvm/lib/MC/MCAssembler.cpp
@@ -94,7 +94,6 @@ MCAssembler::~MCAssembler() = default;
 void MCAssembler::reset() {
   RelaxAll = false;
   SubsectionsViaSymbols = false;
-  IncrementalLinkerCompatible = false;
   Sections.clear();
   Symbols.clear();
   LinkerOptions.clear();
diff --git a/llvm/lib/MC/MCWinCOFFStreamer.cpp b/llvm/lib/MC/MCWinCOFFStreamer.cpp
@@ -28,6 +28,7 @@
 #include "llvm/MC/MCSectionCOFF.h"
 #include "llvm/MC/MCSymbolCOFF.h"
 #include "llvm/MC/MCTargetOptions.h"
+#include "llvm/MC/MCWinCOFFObjectWriter.h"
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/MathExtras.h"
@@ -49,7 +50,11 @@ MCWinCOFFStreamer::MCWinCOFFStreamer(MCContext &Context,
       CurSymbol(nullptr) {
   auto *TO = Context.getTargetOptions();
   if (TO && TO->MCIncrementalLinkerCompatible)
-    getAssembler().setIncrementalLinkerCompatible(true);
+    getWriter().setIncrementalLinkerCompatible(true);
+}
+
+WinCOFFObjectWriter &MCWinCOFFStreamer::getWriter() {
+  return static_cast<WinCOFFObjectWriter &>(getAssembler().getWriter());
 }
 
 void MCWinCOFFStreamer::emitInstToData(const MCInst &Inst,
diff --git a/llvm/lib/MC/WinCOFFObjectWriter.cpp b/llvm/lib/MC/WinCOFFObjectWriter.cpp
@@ -119,10 +119,9 @@ class COFFSection {
 
   SmallVector<COFFSymbol *, 1> OffsetSymbols;
 };
+} // namespace
 
-class WinCOFFObjectWriter;
-
-class WinCOFFWriter {
+class llvm::WinCOFFWriter {
   WinCOFFObjectWriter &OWriter;
   support::endian::Writer W;
 
@@ -196,41 +195,19 @@ class WinCOFFWriter {
   void assignFileOffsets(MCAssembler &Asm);
 };
 
-class WinCOFFObjectWriter : public MCObjectWriter {
-  friend class WinCOFFWriter;
-
-  std::unique_ptr<MCWinCOFFObjectTargetWriter> TargetObjectWriter;
-  std::unique_ptr<WinCOFFWriter> ObjWriter, DwoWriter;
-
-public:
-  WinCOFFObjectWriter(std::unique_ptr<MCWinCOFFObjectTargetWriter> MOTW,
-                      raw_pwrite_stream &OS)
-      : TargetObjectWriter(std::move(MOTW)),
-        ObjWriter(std::make_unique<WinCOFFWriter>(*this, OS,
-                                                  WinCOFFWriter::AllSections)) {
-  }
-  WinCOFFObjectWriter(std::unique_ptr<MCWinCOFFObjectTargetWriter> MOTW,
-                      raw_pwrite_stream &OS, raw_pwrite_stream &DwoOS)
-      : TargetObjectWriter(std::move(MOTW)),
-        ObjWriter(std::make_unique<WinCOFFWriter>(*this, OS,
-                                                  WinCOFFWriter::NonDwoOnly)),
-        DwoWriter(std::make_unique<WinCOFFWriter>(*this, DwoOS,
-                                                  WinCOFFWriter::DwoOnly)) {}
-
-  // MCObjectWriter interface implementation.
-  void reset() override;
-  void executePostLayoutBinding(MCAssembler &Asm) override;
-  bool isSymbolRefDifferenceFullyResolvedImpl(const MCAssembler &Asm,
-                                              const MCSymbol &SymA,
-                                              const MCFragment &FB, bool InSet,
-                                              bool IsPCRel) const override;
-  void recordRelocation(MCAssembler &Asm, const MCFragment *Fragment,
-                        const MCFixup &Fixup, MCValue Target,
-                        uint64_t &FixedValue) override;
-  uint64_t writeObject(MCAssembler &Asm) override;
-};
-
-} // end anonymous namespace
+WinCOFFObjectWriter::WinCOFFObjectWriter(
+    std::unique_ptr<MCWinCOFFObjectTargetWriter> MOTW, raw_pwrite_stream &OS)
+    : TargetObjectWriter(std::move(MOTW)),
+      ObjWriter(std::make_unique<WinCOFFWriter>(*this, OS,
+                                                WinCOFFWriter::AllSections)) {}
+WinCOFFObjectWriter::WinCOFFObjectWriter(
+    std::unique_ptr<MCWinCOFFObjectTargetWriter> MOTW, raw_pwrite_stream &OS,
+    raw_pwrite_stream &DwoOS)
+    : TargetObjectWriter(std::move(MOTW)),
+      ObjWriter(std::make_unique<WinCOFFWriter>(*this, OS,
+                                                WinCOFFWriter::NonDwoOnly)),
+      DwoWriter(std::make_unique<WinCOFFWriter>(*this, DwoOS,
+                                                WinCOFFWriter::DwoOnly)) {}
 
 static bool isDwoSection(const MCSection &Sec) {
   return Sec.getName().ends_with(".dwo");
@@ -1125,7 +1102,7 @@ uint64_t WinCOFFWriter::writeObject(MCAssembler &Asm) {
 
   // MS LINK expects to be able to use this timestamp to implement their
   // /INCREMENTAL feature.
-  if (Asm.isIncrementalLinkerCompatible()) {
+  if (OWriter.IncrementalLinkerCompatible) {
     Header.TimeDateStamp = getTime();
   } else {
     // Have deterministic output if /INCREMENTAL isn't needed. Also matches GNU.
@@ -1174,6 +1151,7 @@ uint64_t WinCOFFWriter::writeObject(MCAssembler &Asm) {
 // MCObjectWriter interface implementations
 
 void WinCOFFObjectWriter::reset() {
+  IncrementalLinkerCompatible = false;
   ObjWriter->reset();
   if (DwoWriter)
     DwoWriter->reset();
diff --git a/llvm/lib/MC/XCOFFObjectWriter.cpp b/llvm/lib/MC/XCOFFObjectWriter.cpp
@@ -825,8 +825,6 @@ uint64_t XCOFFObjectWriter::writeObject(MCAssembler &Asm) {
   // We always emit a timestamp of 0 for reproducibility, so ensure incremental
   // linking is not enabled, in case, like with Windows COFF, such a timestamp
   // is incompatible with incremental linking of XCOFF.
-  if (Asm.isIncrementalLinkerCompatible())
-    report_fatal_error("Incremental linking not supported for XCOFF.");
 
   finalizeSectionInfo();
   uint64_t StartOffset = W.OS.tell();
