MC: Change MCAsmBackend::writeNopData() to take a raw_ostream instead of an MCObjectWriter. NFCI.

To make this work I needed to add an endianness field to MCAsmBackend
so that writeNopData() implementations know which endianness to use.

Part of PR37466.

Differential Revision: https://reviews.llvm.org/D47035

llvm-svn: 332857

5 files changed, 36 insertions, 38 deletions

diff --git a/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp b/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp
index 81e027e1e35..40278629a01 100644
--- a/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp
+++ b/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp
@@ -31,6 +31,7 @@
 #include "llvm/MC/MCSubtargetInfo.h"
 #include "llvm/MC/MCValue.h"
 #include "llvm/Support/Debug.h"
+#include "llvm/Support/EndianStream.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/Format.h"
 #include "llvm/Support/TargetParser.h"
@@ -155,7 +156,8 @@ const MCFixupKindInfo &ARMAsmBackend::getFixupKindInfo(MCFixupKind Kind) const {
 
   assert(unsigned(Kind - FirstTargetFixupKind) < getNumFixupKinds() &&
          "Invalid kind!");
-  return (IsLittleEndian ? InfosLE : InfosBE)[Kind - FirstTargetFixupKind];
+  return (Endian == support::little ? InfosLE
+                                    : InfosBE)[Kind - FirstTargetFixupKind];
 }
 
 void ARMAsmBackend::handleAssemblerFlag(MCAssemblerFlag Flag) {
@@ -289,7 +291,7 @@ void ARMAsmBackend::relaxInstruction(const MCInst &Inst,
   Res.setOpcode(RelaxedOp);
 }
 
-bool ARMAsmBackend::writeNopData(uint64_t Count, MCObjectWriter *OW) const {
+bool ARMAsmBackend::writeNopData(raw_ostream &OS, uint64_t Count) const {
   const uint16_t Thumb1_16bitNopEncoding = 0x46c0; // using MOV r8,r8
   const uint16_t Thumb2_16bitNopEncoding = 0xbf00; // NOP
   const uint32_t ARMv4_NopEncoding = 0xe1a00000;   // using MOV r0,r0
@@ -299,9 +301,9 @@ bool ARMAsmBackend::writeNopData(uint64_t Count, MCObjectWriter *OW) const {
         hasNOP() ? Thumb2_16bitNopEncoding : Thumb1_16bitNopEncoding;
     uint64_t NumNops = Count / 2;
     for (uint64_t i = 0; i != NumNops; ++i)
-      OW->write16(nopEncoding);
+      support::endian::write(OS, nopEncoding, Endian);
     if (Count & 1)
-      OW->write8(0);
+      OS << '\0';
     return true;
   }
   // ARM mode
@@ -309,21 +311,20 @@ bool ARMAsmBackend::writeNopData(uint64_t Count, MCObjectWriter *OW) const {
       hasNOP() ? ARMv6T2_NopEncoding : ARMv4_NopEncoding;
   uint64_t NumNops = Count / 4;
   for (uint64_t i = 0; i != NumNops; ++i)
-    OW->write32(nopEncoding);
+    support::endian::write(OS, nopEncoding, Endian);
   // FIXME: should this function return false when unable to write exactly
   // 'Count' bytes with NOP encodings?
   switch (Count % 4) {
   default:
     break; // No leftover bytes to write
   case 1:
-    OW->write8(0);
+    OS << '\0';
     break;
   case 2:
-    OW->write16(0);
+    OS.write("\0\0", 2);
     break;
   case 3:
-    OW->write16(0);
-    OW->write8(0xa0);
+    OS.write("\0\0\xa0", 3);
     break;
   }
 
@@ -413,7 +414,7 @@ unsigned ARMAsmBackend::adjustFixupValue(const MCAssembler &Asm,
     // inst{14-12} = Mid3;
     // inst{7-0} = Lo8;
     Value = (Hi4 << 16) | (i << 26) | (Mid3 << 12) | (Lo8);
-    return swapHalfWords(Value, IsLittleEndian);
+    return swapHalfWords(Value, Endian == support::little);
   }
   case ARM::fixup_arm_ldst_pcrel_12:
     // ARM PC-relative values are offset by 8.
@@ -436,7 +437,7 @@ unsigned ARMAsmBackend::adjustFixupValue(const MCAssembler &Asm,
     // Same addressing mode as fixup_arm_pcrel_10,
     // but with 16-bit halfwords swapped.
     if (Kind == ARM::fixup_t2_ldst_pcrel_12)
-      return swapHalfWords(Value, IsLittleEndian);
+      return swapHalfWords(Value, Endian == support::little);
 
     return Value;
   }
@@ -469,7 +470,7 @@ unsigned ARMAsmBackend::adjustFixupValue(const MCAssembler &Asm,
     out |= (Value & 0x700) << 4;
     out |= (Value & 0x0FF);
 
-    return swapHalfWords(out, IsLittleEndian);
+    return swapHalfWords(out, Endian == support::little);
   }
 
   case ARM::fixup_arm_condbranch:
@@ -501,7 +502,7 @@ unsigned ARMAsmBackend::adjustFixupValue(const MCAssembler &Asm,
     out |= (Value & 0x1FF800) << 5; // imm6 field
     out |= (Value & 0x0007FF);      // imm11 field
 
-    return swapHalfWords(out, IsLittleEndian);
+    return swapHalfWords(out, Endian == support::little);
   }
   case ARM::fixup_t2_condbranch: {
     Value = Value - 4;
@@ -514,7 +515,7 @@ unsigned ARMAsmBackend::adjustFixupValue(const MCAssembler &Asm,
     out |= (Value & 0x1F800) << 5; // imm6 field
     out |= (Value & 0x007FF);      // imm11 field
 
-    return swapHalfWords(out, IsLittleEndian);
+    return swapHalfWords(out, Endian == support::little);
   }
   case ARM::fixup_arm_thumb_bl: {
     // FIXME: We get both thumb1 and thumb2 in here, so we can only check for
@@ -548,7 +549,7 @@ unsigned ARMAsmBackend::adjustFixupValue(const MCAssembler &Asm,
     uint32_t FirstHalf = (((uint16_t)signBit << 10) | (uint16_t)imm10Bits);
     uint32_t SecondHalf = (((uint16_t)J1Bit << 13) | ((uint16_t)J2Bit << 11) |
                            (uint16_t)imm11Bits);
-    return joinHalfWords(FirstHalf, SecondHalf, IsLittleEndian);
+    return joinHalfWords(FirstHalf, SecondHalf, Endian == support::little);
   }
   case ARM::fixup_arm_thumb_blx: {
     // The value doesn't encode the low two bits (always zero) and is offset by
@@ -584,7 +585,7 @@ unsigned ARMAsmBackend::adjustFixupValue(const MCAssembler &Asm,
     uint32_t FirstHalf = (((uint16_t)signBit << 10) | (uint16_t)imm10HBits);
     uint32_t SecondHalf = (((uint16_t)J1Bit << 13) | ((uint16_t)J2Bit << 11) |
                            ((uint16_t)imm10LBits) << 1);
-    return joinHalfWords(FirstHalf, SecondHalf, IsLittleEndian);
+    return joinHalfWords(FirstHalf, SecondHalf, Endian == support::little);
   }
   case ARM::fixup_thumb_adr_pcrel_10:
   case ARM::fixup_arm_thumb_cp:
@@ -672,7 +673,7 @@ unsigned ARMAsmBackend::adjustFixupValue(const MCAssembler &Asm,
     // Same addressing mode as fixup_arm_pcrel_10, but with 16-bit halfwords
     // swapped.
     if (Kind == ARM::fixup_t2_pcrel_10)
-      return swapHalfWords(Value, IsLittleEndian);
+      return swapHalfWords(Value, Endian == support::little);
 
     return Value;
   }
@@ -703,7 +704,7 @@ unsigned ARMAsmBackend::adjustFixupValue(const MCAssembler &Asm,
     // Same addressing mode as fixup_arm_pcrel_9, but with 16-bit halfwords
     // swapped.
     if (Kind == ARM::fixup_t2_pcrel_9)
-      return swapHalfWords(Value, IsLittleEndian);
+      return swapHalfWords(Value, Endian == support::little);
 
     return Value;
   }
@@ -729,7 +730,7 @@ unsigned ARMAsmBackend::adjustFixupValue(const MCAssembler &Asm,
     EncValue |= (Value & 0x800) << 15;
     EncValue |= (Value & 0x700) << 4;
     EncValue |= (Value & 0xff);
-    return swapHalfWords(EncValue, IsLittleEndian);
+    return swapHalfWords(EncValue, Endian == support::little);
   }
   }
 }
@@ -893,7 +894,7 @@ void ARMAsmBackend::applyFixup(const MCAssembler &Asm, const MCFixup &Fixup,
 
   // Used to point to big endian bytes.
   unsigned FullSizeBytes;
-  if (!IsLittleEndian) {
+  if (Endian == support::big) {
     FullSizeBytes = getFixupKindContainerSizeBytes(Fixup.getKind());
     assert((Offset + FullSizeBytes) <= Data.size() && "Invalid fixup size!");
     assert(NumBytes <= FullSizeBytes && "Invalid fixup size!");
@@ -903,7 +904,7 @@ void ARMAsmBackend::applyFixup(const MCAssembler &Asm, const MCFixup &Fixup,
   // the fixup value. The Value has been "split up" into the appropriate
   // bitfields above.
   for (unsigned i = 0; i != NumBytes; ++i) {
-    unsigned Idx = IsLittleEndian ? i : (FullSizeBytes - 1 - i);
+    unsigned Idx = Endian == support::little ? i : (FullSizeBytes - 1 - i);
     Data[Offset + Idx] |= uint8_t((Value >> (i * 8)) & 0xff);
   }
 }
@@ -1155,7 +1156,7 @@ static MCAsmBackend *createARMAsmBackend(const Target &T,
                                          const MCSubtargetInfo &STI,
                                          const MCRegisterInfo &MRI,
                                          const MCTargetOptions &Options,
-                                         bool isLittle) {
+                                         support::endianness Endian) {
   const Triple &TheTriple = STI.getTargetTriple();
   switch (TheTriple.getObjectFormat()) {
   default:
@@ -1170,7 +1171,7 @@ static MCAsmBackend *createARMAsmBackend(const Target &T,
   case Triple::ELF:
     assert(TheTriple.isOSBinFormatELF() && "using ELF for non-ELF target");
     uint8_t OSABI = MCELFObjectTargetWriter::getOSABI(TheTriple.getOS());
-    return new ARMAsmBackendELF(T, STI, OSABI, isLittle);
+    return new ARMAsmBackendELF(T, STI, OSABI, Endian);
   }
 }
 
@@ -1178,12 +1179,12 @@ MCAsmBackend *llvm::createARMLEAsmBackend(const Target &T,
                                           const MCSubtargetInfo &STI,
                                           const MCRegisterInfo &MRI,
                                           const MCTargetOptions &Options) {
-  return createARMAsmBackend(T, STI, MRI, Options, true);
+  return createARMAsmBackend(T, STI, MRI, Options, support::little);
 }
 
 MCAsmBackend *llvm::createARMBEAsmBackend(const Target &T,
                                           const MCSubtargetInfo &STI,
                                           const MCRegisterInfo &MRI,
                                           const MCTargetOptions &Options) {
-  return createARMAsmBackend(T, STI, MRI, Options, false);
+  return createARMAsmBackend(T, STI, MRI, Options, support::big);
 }
diff --git a/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.h b/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.h
index 3733e443f15..b72f45d0717 100644
--- a/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.h
+++ b/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.h
@@ -21,12 +21,11 @@ namespace llvm {
 class ARMAsmBackend : public MCAsmBackend {
   const MCSubtargetInfo &STI;
   bool isThumbMode;    // Currently emitting Thumb code.
-  bool IsLittleEndian; // Big or little endian.
 public:
-  ARMAsmBackend(const Target &T, const MCSubtargetInfo &STI, bool IsLittle)
-      : MCAsmBackend(), STI(STI),
-        isThumbMode(STI.getTargetTriple().isThumb()),
-        IsLittleEndian(IsLittle) {}
+  ARMAsmBackend(const Target &T, const MCSubtargetInfo &STI,
+                support::endianness Endian)
+      : MCAsmBackend(Endian), STI(STI),
+        isThumbMode(STI.getTargetTriple().isThumb()) {}
 
   unsigned getNumFixupKinds() const override {
     return ARM::NumTargetFixupKinds;
@@ -61,14 +60,13 @@ public:
   void relaxInstruction(const MCInst &Inst, const MCSubtargetInfo &STI,
                         MCInst &Res) const override;
 
-  bool writeNopData(uint64_t Count, MCObjectWriter *OW) const override;
+  bool writeNopData(raw_ostream &OS, uint64_t Count) const override;
 
   void handleAssemblerFlag(MCAssemblerFlag Flag) override;
 
   unsigned getPointerSize() const { return 4; }
   bool isThumb() const { return isThumbMode; }
   void setIsThumb(bool it) { isThumbMode = it; }
-  bool isLittle() const { return IsLittleEndian; }
 };
 } // end namespace llvm
 
diff --git a/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackendDarwin.h b/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackendDarwin.h
index 19e3fdb7204..1055dc1aca3 100644
--- a/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackendDarwin.h
+++ b/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackendDarwin.h
@@ -21,8 +21,7 @@ public:
   const MachO::CPUSubTypeARM Subtype;
   ARMAsmBackendDarwin(const Target &T, const MCSubtargetInfo &STI,
                       const MCRegisterInfo &MRI, MachO::CPUSubTypeARM st)
-      : ARMAsmBackend(T, STI, /* IsLittleEndian */ true), MRI(MRI),
-        Subtype(st) {}
+      : ARMAsmBackend(T, STI, support::little), MRI(MRI), Subtype(st) {}
 
   std::unique_ptr<MCObjectWriter>
   createObjectWriter(raw_pwrite_stream &OS) const override {
diff --git a/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackendELF.h b/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackendELF.h
index 361ea304084..d497e295e55 100644
--- a/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackendELF.h
+++ b/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackendELF.h
@@ -21,12 +21,12 @@ class ARMAsmBackendELF : public ARMAsmBackend {
 public:
   uint8_t OSABI;
   ARMAsmBackendELF(const Target &T, const MCSubtargetInfo &STI, uint8_t OSABI,
-                   bool IsLittle)
-      : ARMAsmBackend(T, STI, IsLittle), OSABI(OSABI) {}
+                   support::endianness Endian)
+      : ARMAsmBackend(T, STI, Endian), OSABI(OSABI) {}
 
   std::unique_ptr<MCObjectWriter>
   createObjectWriter(raw_pwrite_stream &OS) const override {
-    return createARMELFObjectWriter(OS, OSABI, isLittle());
+    return createARMELFObjectWriter(OS, OSABI, Endian);
   }
 };
 }
diff --git a/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackendWinCOFF.h b/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackendWinCOFF.h
index 0ac6d4270aa..d02e4d126e4 100644
--- a/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackendWinCOFF.h
+++ b/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackendWinCOFF.h
@@ -18,7 +18,7 @@ namespace {
 class ARMAsmBackendWinCOFF : public ARMAsmBackend {
 public:
   ARMAsmBackendWinCOFF(const Target &T, const MCSubtargetInfo &STI)
-      : ARMAsmBackend(T, STI, true) {}
+      : ARMAsmBackend(T, STI, support::little) {}
   std::unique_ptr<MCObjectWriter>
   createObjectWriter(raw_pwrite_stream &OS) const override {
     return createARMWinCOFFObjectWriter(OS, /*Is64Bit=*/false);