Derive MachOCASWriter from MachObjectWriter

This patch rewrites MachOCASWriter to be a derived class of
MachObjectWriter which fixes a lot of the issues we see from the changes
made to MCAssembler. This also fixes the issue of the MCMachoStreamer
only having calls to the getWriter() function that returns a
MachOCASWriter.

(cherry picked from commit 895cd5a)

Author: rastogishubham

clang/test/CAS/path-independent-cas-outputs.c

@@ -44,9 +44,9 @@
 
 // Baseline to check we got expected outputs.
 // RUN: %clang -target x86_64-apple-macos11 -c %s -o %t/t.o -MMD -MT dependencies -MF %t/t.d --serialize-diagnostics %t/t.dia
-// RUN: env LLVM_CACHE_CAS_PATH=%t/a/cas CLANG_CACHE_DISABLE_MCCAS=1 %clang-cache \
+// RUN: env LLVM_CACHE_CAS_PATH=%t/a/cas %clang-cache \
 // RUN:   %clang -target x86_64-apple-macos11 -c %s -o %t/a/t1.o -MMD -MT dependencies -MF %t/a/t1.d --serialize-diagnostics %t/a/t1.dia
-// RUN: env LLVM_CACHE_CAS_PATH=%t/b/cas CLANG_CACHE_DISABLE_MCCAS=1 %clang-cache \
+// RUN: env LLVM_CACHE_CAS_PATH=%t/b/cas %clang-cache \
 // RUN:   %clang -target x86_64-apple-macos11 -c %s -o %t/b/t2.o -MMD -MT dependencies -MF %t/b/t2.d --serialize-diagnostics %t/b/t2.dia
 
 // RUN: diff %t/a/t1.o %t/b/t2.o

llvm/include/llvm/MC/MCMachOCASWriter.h

@@ -34,7 +34,7 @@ class ObjectStore;
 class CASID;
 } // namespace cas
 
-class MachOCASWriter : public MCObjectWriter {
+class MachOCASWriter : public MachObjectWriter {
 public:
   /// ObjectStore
   const Triple Target;
@@ -57,62 +57,19 @@ class MachOCASWriter : public MCObjectWriter {
 
   uint8_t getAddressSize() { return Target.isArch32Bit() ? 4 : 8; }
 
-  void recordRelocation(MCAssembler &Asm, const MCFragment *Fragment,
-                                const MCFixup &Fixup, MCValue Target,
-                                uint64_t &FixedValue) override {
-    MOW.recordRelocation(Asm, Fragment, Fixup, Target, FixedValue);
-  }
-
-  void executePostLayoutBinding(MCAssembler &Asm) override {
-    MOW.executePostLayoutBinding(Asm);
-  }
-
-  bool isSymbolRefDifferenceFullyResolvedImpl(const MCAssembler &Asm,
-                                              const MCSymbol &SymA,
-                                              const MCFragment &FB, bool InSet,
-                                              bool IsPCRel) const override {
-    return MOW.isSymbolRefDifferenceFullyResolvedImpl(Asm, SymA, FB, InSet,
-                                                      IsPCRel);
-  }
-
-  uint64_t getPaddingSize(MCAssembler &Asm, const MCSection *SD) const {
-    return MOW.getPaddingSize(Asm, SD);
-  }
-
-  void prepareObject(MCAssembler &Asm) { MOW.prepareObject(Asm); }
-
-  void writeMachOHeader(MCAssembler &Asm) { MOW.writeMachOHeader(Asm); }
-
-  void writeSectionData(MCAssembler &Asm) { MOW.writeSectionData(Asm); }
-
-  void writeRelocations(MCAssembler &Asm) { MOW.writeRelocations(Asm); }
-
-  void writeDataInCodeRegion(MCAssembler &Asm) {
-    MOW.writeDataInCodeRegion(Asm);
-  }
-
-  void writeSymbolTable(MCAssembler &Asm) { MOW.writeSymbolTable(Asm); }
-
   uint64_t writeObject(MCAssembler &Asm) override;
 
   void resetBuffer() { OSOffset = InternalOS.tell(); }
 
   StringRef getContent() const { return InternalBuffer.substr(OSOffset); }
 
-  DenseMap<const MCSection *, std::vector<MachObjectWriter::RelAndSymbol>> &
-  getRelocations() {
-    return MOW.getRelocations();
-  }
-
 private:
   raw_pwrite_stream &OS;
   raw_pwrite_stream *CasIDOS;
 
   SmallString<512> InternalBuffer;
   raw_svector_ostream InternalOS;
 
-  MachObjectWriter MOW;
-
   uint64_t OSOffset = 0;
 
   std::function<const cas::ObjectProxy(llvm::MachOCASWriter &,

llvm/lib/MC/MachOCASWriter.cpp

@@ -53,9 +53,9 @@ MachOCASWriter::MachOCASWriter(
         SerializeObjectFile,
     std::optional<MCTargetOptions::ResultCallBackTy> ResultCallBack,
     raw_pwrite_stream *CasIDOS)
-    : Target(TT), CAS(CAS), Mode(Mode), ResultCallBack(ResultCallBack), OS(OS),
+    : MachObjectWriter(std::move(MOTW), InternalOS, IsLittleEndian), Target(TT),
+      CAS(CAS), Mode(Mode), ResultCallBack(ResultCallBack), OS(OS),
       CasIDOS(CasIDOS), InternalOS(InternalBuffer),
-      MOW(std::move(MOTW), InternalOS, IsLittleEndian),
       CreateFromMcAssembler(CreateFromMcAssembler),
       SerializeObjectFile(SerializeObjectFile) {
   assert(TT.isLittleEndian() == IsLittleEndian && "Endianess should match");

llvm/test/MC/CAS/linker-options.ll

@@ -0,0 +1,37 @@
+; RUN: llc -O0 -mtriple=x86_64-apple-darwin -o - %s > %t
+; RUN: FileCheck --check-prefix=CHECK-ASM < %t %s
+
+; CHECK-ASM: .linker_option "-lz"
+; CHECK-ASM-NEXT: .linker_option "-framework", "Cocoa"
+
+; RUN: llc -O0 -mtriple=x86_64-apple-darwin -filetype=obj -o - %s | llvm-readobj --macho-linker-options - > %t
+; RUN: FileCheck --check-prefix=CHECK-OBJ < %t %s
+; RUN: mkdir -p %t.dir/cas
+; RUN: llc -O0 -mtriple=x86_64-apple-darwin -filetype=obj --cas %t.dir/cas -cas-backend -o - %s | llvm-readobj --macho-linker-options - > %t
+
+; REQUIRES: x86-registered-target
+
+; CHECK-OBJ: Linker Options {
+; CHECK-OBJ:   Size: 16
+; CHECK-OBJ:   Strings [
+; CHECK-OBJ:     Value: -lz
+; CHECK-OBJ:   ]
+; CHECK-OBJ: }
+; CHECK-OBJ: Linker Options {
+; CHECK-OBJ:   Size: 32
+; CHECK-OBJ:   Strings [
+; CHECK-OBJ:     Value: -framework
+; CHECK-OBJ:     Value: Cocoa
+; CHECK-OBJ:   ]
+; CHECK-OBJ: }
+; CHECK-OBJ: Linker Options {
+; CHECK-OBJ:   Size: 24
+; CHECK-OBJ:   Strings [
+; CHECK-OBJ:     Value: -lmath
+; CHECK-OBJ:   ]
+; CHECK-OBJ: }
+
+!0 = !{!"-lz"}
+!1 = !{!"-framework", !"Cocoa"}
+!2 = !{!"-lmath"}
+!llvm.linker.options = !{!0, !1, !2}