MC: Clean up method names in MCContext.
[oota-llvm.git] / lib / Target / ARM / MCTargetDesc / ARMMachObjectWriter.cpp
index a51e0fa3fbc53cca7eea301f74a95e8e969aec20..5b85a2a41fa804e5e186040fc4364334d7afa015 100644 (file)
@@ -7,22 +7,22 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "MCTargetDesc/ARMMCTargetDesc.h"
 #include "MCTargetDesc/ARMBaseInfo.h"
 #include "MCTargetDesc/ARMFixupKinds.h"
 #include "llvm/ADT/Twine.h"
-#include "llvm/MC/MCAssembler.h"
 #include "llvm/MC/MCAsmLayout.h"
-#include "llvm/MC/MCMachObjectWriter.h"
+#include "llvm/MC/MCAssembler.h"
 #include "llvm/MC/MCContext.h"
 #include "llvm/MC/MCExpr.h"
 #include "llvm/MC/MCFixup.h"
 #include "llvm/MC/MCFixupKindInfo.h"
 #include "llvm/MC/MCMachOSymbolFlags.h"
+#include "llvm/MC/MCMachObjectWriter.h"
 #include "llvm/MC/MCValue.h"
-#include "llvm/Object/MachOFormat.h"
 #include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/MachO.h"
 using namespace llvm;
-using namespace llvm::object;
 
 namespace {
 class ARMMachObjectWriter : public MCMachObjectTargetWriter {
@@ -32,6 +32,7 @@ class ARMMachObjectWriter : public MCMachObjectTargetWriter {
                                     const MCFragment *Fragment,
                                     const MCFixup &Fixup,
                                     MCValue Target,
+                                    unsigned Type,
                                     unsigned Log2Size,
                                     uint64_t &FixedValue);
   void RecordARMScatteredHalfRelocation(MachObjectWriter *Writer,
@@ -41,22 +42,28 @@ class ARMMachObjectWriter : public MCMachObjectTargetWriter {
                                         const MCFixup &Fixup, MCValue Target,
                                         uint64_t &FixedValue);
 
+  bool requiresExternRelocation(MachObjectWriter *Writer,
+                                const MCAssembler &Asm,
+                                const MCFragment &Fragment,
+                                unsigned RelocType, const MCSymbolData *SD,
+                                uint64_t FixedValue);
+
 public:
   ARMMachObjectWriter(bool Is64Bit, uint32_t CPUType,
                       uint32_t CPUSubtype)
     : MCMachObjectTargetWriter(Is64Bit, CPUType, CPUSubtype,
                                /*UseAggressiveSymbolFolding=*/true) {}
 
-  void RecordRelocation(MachObjectWriter *Writer,
-                        const MCAssembler &Asm, const MCAsmLayout &Layout,
-                        const MCFragment *Fragment, const MCFixup &Fixup,
-                        MCValue Target, uint64_t &FixedValue);
+  void RecordRelocation(MachObjectWriter *Writer, MCAssembler &Asm,
+                        const MCAsmLayout &Layout, const MCFragment *Fragment,
+                        const MCFixup &Fixup, MCValue Target,
+                        uint64_t &FixedValue) override;
 };
 }
 
 static bool getARMFixupKindMachOInfo(unsigned Kind, unsigned &RelocType,
                               unsigned &Log2Size) {
-  RelocType = unsigned(macho::RIT_Vanilla);
+  RelocType = unsigned(MachO::ARM_RELOC_VANILLA);
   Log2Size = ~0U;
 
   switch (Kind) {
@@ -76,30 +83,29 @@ static bool getARMFixupKindMachOInfo(unsigned Kind, unsigned &RelocType,
     Log2Size = llvm::Log2_32(8);
     return true;
 
-    // Handle 24-bit branch kinds.
+    // These fixups are expected to always be resolvable at assembly time and
+    // have no relocations supported.
   case ARM::fixup_arm_ldst_pcrel_12:
   case ARM::fixup_arm_pcrel_10:
   case ARM::fixup_arm_adr_pcrel_12:
+  case ARM::fixup_arm_thumb_br:
+    return false;
+
+    // Handle 24-bit branch kinds.
   case ARM::fixup_arm_condbranch:
   case ARM::fixup_arm_uncondbranch:
   case ARM::fixup_arm_uncondbl:
   case ARM::fixup_arm_condbl:
   case ARM::fixup_arm_blx:
-    RelocType = unsigned(macho::RIT_ARM_Branch24Bit);
+    RelocType = unsigned(MachO::ARM_RELOC_BR24);
     // Report as 'long', even though that is not quite accurate.
     Log2Size = llvm::Log2_32(4);
     return true;
 
-    // Handle Thumb branches.
-  case ARM::fixup_arm_thumb_br:
-    RelocType = unsigned(macho::RIT_ARM_ThumbBranch22Bit);
-    Log2Size = llvm::Log2_32(2);
-    return true;
-
   case ARM::fixup_t2_uncondbranch:
   case ARM::fixup_arm_thumb_bl:
   case ARM::fixup_arm_thumb_blx:
-    RelocType = unsigned(macho::RIT_ARM_ThumbBranch22Bit);
+    RelocType = unsigned(MachO::ARM_THUMB_RELOC_BR22);
     Log2Size = llvm::Log2_32(4);
     return true;
 
@@ -113,24 +119,20 @@ static bool getARMFixupKindMachOInfo(unsigned Kind, unsigned &RelocType,
   //      0 - arm instructions
   //      1 - thumb instructions
   case ARM::fixup_arm_movt_hi16:
-  case ARM::fixup_arm_movt_hi16_pcrel:
-    RelocType = unsigned(macho::RIT_ARM_Half);
+    RelocType = unsigned(MachO::ARM_RELOC_HALF);
     Log2Size = 1;
     return true;
   case ARM::fixup_t2_movt_hi16:
-  case ARM::fixup_t2_movt_hi16_pcrel:
-    RelocType = unsigned(macho::RIT_ARM_Half);
+    RelocType = unsigned(MachO::ARM_RELOC_HALF);
     Log2Size = 3;
     return true;
 
   case ARM::fixup_arm_movw_lo16:
-  case ARM::fixup_arm_movw_lo16_pcrel:
-    RelocType = unsigned(macho::RIT_ARM_Half);
+    RelocType = unsigned(MachO::ARM_RELOC_HALF);
     Log2Size = 0;
     return true;
   case ARM::fixup_t2_movw_lo16:
-  case ARM::fixup_t2_movw_lo16_pcrel:
-    RelocType = unsigned(macho::RIT_ARM_Half);
+    RelocType = unsigned(MachO::ARM_RELOC_HALF);
     Log2Size = 2;
     return true;
   }
@@ -146,14 +148,14 @@ RecordARMScatteredHalfRelocation(MachObjectWriter *Writer,
                                  uint64_t &FixedValue) {
   uint32_t FixupOffset = Layout.getFragmentOffset(Fragment)+Fixup.getOffset();
   unsigned IsPCRel = Writer->isFixupKindPCRel(Asm, Fixup.getKind());
-  unsigned Type = macho::RIT_ARM_Half;
+  unsigned Type = MachO::ARM_RELOC_HALF;
 
   // See <reloc.h>.
   const MCSymbol *A = &Target.getSymA()->getSymbol();
-  MCSymbolData *A_SD = &Asm.getSymbolData(*A);
+  const MCSymbolData *A_SD = &Asm.getSymbolData(*A);
 
   if (!A_SD->getFragment())
-    Asm.getContext().FatalError(Fixup.getLoc(),
+    Asm.getContext().reportFatalError(Fixup.getLoc(),
                        "symbol '" + A->getName() +
                        "' can not be undefined in a subtraction expression");
 
@@ -164,15 +166,15 @@ RecordARMScatteredHalfRelocation(MachObjectWriter *Writer,
   FixedValue += SecAddr;
 
   if (const MCSymbolRefExpr *B = Target.getSymB()) {
-    MCSymbolData *B_SD = &Asm.getSymbolData(B->getSymbol());
+    const MCSymbolData *B_SD = &Asm.getSymbolData(B->getSymbol());
 
     if (!B_SD->getFragment())
-      Asm.getContext().FatalError(Fixup.getLoc(),
+      Asm.getContext().reportFatalError(Fixup.getLoc(),
                          "symbol '" + B->getSymbol().getName() +
                          "' can not be undefined in a subtraction expression");
 
     // Select the appropriate difference relocation type.
-    Type = macho::RIT_ARM_HalfDifference;
+    Type = MachO::ARM_RELOC_HALF_SECTDIFF;
     Value2 = Writer->getSymbolAddress(B_SD, Layout);
     FixedValue -= Writer->getSectionAddress(B_SD->getFragment()->getParent());
   }
@@ -196,50 +198,47 @@ RecordARMScatteredHalfRelocation(MachObjectWriter *Writer,
   switch ((unsigned)Fixup.getKind()) {
   default: break;
   case ARM::fixup_arm_movt_hi16:
-  case ARM::fixup_arm_movt_hi16_pcrel:
     MovtBit = 1;
     // The thumb bit shouldn't be set in the 'other-half' bit of the
     // relocation, but it will be set in FixedValue if the base symbol
     // is a thumb function. Clear it out here.
-    if (A_SD->getFlags() & SF_ThumbFunc)
+    if (Asm.isThumbFunc(A))
       FixedValue &= 0xfffffffe;
     break;
   case ARM::fixup_t2_movt_hi16:
-  case ARM::fixup_t2_movt_hi16_pcrel:
-    if (A_SD->getFlags() & SF_ThumbFunc)
+    if (Asm.isThumbFunc(A))
       FixedValue &= 0xfffffffe;
     MovtBit = 1;
     // Fallthrough
   case ARM::fixup_t2_movw_lo16:
-  case ARM::fixup_t2_movw_lo16_pcrel:
     ThumbBit = 1;
     break;
   }
 
-  if (Type == macho::RIT_ARM_HalfDifference) {
+  if (Type == MachO::ARM_RELOC_HALF_SECTDIFF) {
     uint32_t OtherHalf = MovtBit
       ? (FixedValue & 0xffff) : ((FixedValue & 0xffff0000) >> 16);
 
-    macho::RelocationEntry MRE;
-    MRE.Word0 = ((OtherHalf       <<  0) |
-                 (macho::RIT_Pair << 24) |
-                 (MovtBit         << 28) |
-                 (ThumbBit        << 29) |
-                 (IsPCRel         << 30) |
-                 macho::RF_Scattered);
-    MRE.Word1 = Value2;
-    Writer->addRelocation(Fragment->getParent(), MRE);
+    MachO::any_relocation_info MRE;
+    MRE.r_word0 = ((OtherHalf             <<  0) |
+                   (MachO::ARM_RELOC_PAIR << 24) |
+                   (MovtBit               << 28) |
+                   (ThumbBit              << 29) |
+                   (IsPCRel               << 30) |
+                   MachO::R_SCATTERED);
+    MRE.r_word1 = Value2;
+    Writer->addRelocation(nullptr, Fragment->getParent(), MRE);
   }
 
-  macho::RelocationEntry MRE;
-  MRE.Word0 = ((FixupOffset <<  0) |
-               (Type        << 24) |
-               (MovtBit     << 28) |
-               (ThumbBit    << 29) |
-               (IsPCRel     << 30) |
-               macho::RF_Scattered);
-  MRE.Word1 = Value;
-  Writer->addRelocation(Fragment->getParent(), MRE);
+  MachO::any_relocation_info MRE;
+  MRE.r_word0 = ((FixupOffset <<  0) |
+                 (Type        << 24) |
+                 (MovtBit     << 28) |
+                 (ThumbBit    << 29) |
+                 (IsPCRel     << 30) |
+                 MachO::R_SCATTERED);
+  MRE.r_word1 = Value;
+  Writer->addRelocation(nullptr, Fragment->getParent(), MRE);
 }
 
 void ARMMachObjectWriter::RecordARMScatteredRelocation(MachObjectWriter *Writer,
@@ -248,18 +247,18 @@ void ARMMachObjectWriter::RecordARMScatteredRelocation(MachObjectWriter *Writer,
                                                     const MCFragment *Fragment,
                                                     const MCFixup &Fixup,
                                                     MCValue Target,
+                                                    unsigned Type,
                                                     unsigned Log2Size,
                                                     uint64_t &FixedValue) {
   uint32_t FixupOffset = Layout.getFragmentOffset(Fragment)+Fixup.getOffset();
   unsigned IsPCRel = Writer->isFixupKindPCRel(Asm, Fixup.getKind());
-  unsigned Type = macho::RIT_Vanilla;
 
   // See <reloc.h>.
   const MCSymbol *A = &Target.getSymA()->getSymbol();
-  MCSymbolData *A_SD = &Asm.getSymbolData(*A);
+  const MCSymbolData *A_SD = &Asm.getSymbolData(*A);
 
   if (!A_SD->getFragment())
-    Asm.getContext().FatalError(Fixup.getLoc(),
+    Asm.getContext().reportFatalError(Fixup.getLoc(),
                        "symbol '" + A->getName() +
                        "' can not be undefined in a subtraction expression");
 
@@ -269,73 +268,114 @@ void ARMMachObjectWriter::RecordARMScatteredRelocation(MachObjectWriter *Writer,
   uint32_t Value2 = 0;
 
   if (const MCSymbolRefExpr *B = Target.getSymB()) {
-    MCSymbolData *B_SD = &Asm.getSymbolData(B->getSymbol());
+    assert(Type == MachO::ARM_RELOC_VANILLA && "invalid reloc for 2 symbols");
+    const MCSymbolData *B_SD = &Asm.getSymbolData(B->getSymbol());
 
     if (!B_SD->getFragment())
-      Asm.getContext().FatalError(Fixup.getLoc(),
+      Asm.getContext().reportFatalError(Fixup.getLoc(),
                          "symbol '" + B->getSymbol().getName() +
                          "' can not be undefined in a subtraction expression");
 
     // Select the appropriate difference relocation type.
-    Type = macho::RIT_Difference;
+    Type = MachO::ARM_RELOC_SECTDIFF;
     Value2 = Writer->getSymbolAddress(B_SD, Layout);
     FixedValue -= Writer->getSectionAddress(B_SD->getFragment()->getParent());
   }
 
   // Relocations are written out in reverse order, so the PAIR comes first.
-  if (Type == macho::RIT_Difference ||
-      Type == macho::RIT_Generic_LocalDifference) {
-    macho::RelocationEntry MRE;
-    MRE.Word0 = ((0         <<  0) |
-                 (macho::RIT_Pair  << 24) |
-                 (Log2Size  << 28) |
-                 (IsPCRel   << 30) |
-                 macho::RF_Scattered);
-    MRE.Word1 = Value2;
-    Writer->addRelocation(Fragment->getParent(), MRE);
+  if (Type == MachO::ARM_RELOC_SECTDIFF ||
+      Type == MachO::ARM_RELOC_LOCAL_SECTDIFF) {
+    MachO::any_relocation_info MRE;
+    MRE.r_word0 = ((0                     <<  0) |
+                   (MachO::ARM_RELOC_PAIR << 24) |
+                   (Log2Size              << 28) |
+                   (IsPCRel               << 30) |
+                   MachO::R_SCATTERED);
+    MRE.r_word1 = Value2;
+    Writer->addRelocation(nullptr, Fragment->getParent(), MRE);
   }
 
-  macho::RelocationEntry MRE;
-  MRE.Word0 = ((FixupOffset <<  0) |
-               (Type        << 24) |
-               (Log2Size    << 28) |
-               (IsPCRel     << 30) |
-               macho::RF_Scattered);
-  MRE.Word1 = Value;
-  Writer->addRelocation(Fragment->getParent(), MRE);
+  MachO::any_relocation_info MRE;
+  MRE.r_word0 = ((FixupOffset <<  0) |
+                 (Type        << 24) |
+                 (Log2Size    << 28) |
+                 (IsPCRel     << 30) |
+                 MachO::R_SCATTERED);
+  MRE.r_word1 = Value;
+  Writer->addRelocation(nullptr, Fragment->getParent(), MRE);
+}
+
+bool ARMMachObjectWriter::requiresExternRelocation(MachObjectWriter *Writer,
+                                                   const MCAssembler &Asm,
+                                                   const MCFragment &Fragment,
+                                                   unsigned RelocType,
+                                                   const MCSymbolData *SD,
+                                                   uint64_t FixedValue) {
+  // Most cases can be identified purely from the symbol.
+  if (Writer->doesSymbolRequireExternRelocation(SD))
+    return true;
+  int64_t Value = (int64_t)FixedValue;  // The displacement is signed.
+  int64_t Range;
+  switch (RelocType) {
+  default:
+    return false;
+  case MachO::ARM_RELOC_BR24:
+    // PC pre-adjustment of 8 for these instructions.
+    Value -= 8;
+    // ARM BL/BLX has a 25-bit offset.
+    Range = 0x1ffffff;
+    break;
+  case MachO::ARM_THUMB_RELOC_BR22:
+    // PC pre-adjustment of 4 for these instructions.
+    Value -= 4;
+    // Thumb BL/BLX has a 24-bit offset.
+    Range = 0xffffff;
+  }
+  // BL/BLX also use external relocations when an internal relocation
+  // would result in the target being out of range. This gives the linker
+  // enough information to generate a branch island.
+  const MCSectionData &SymSD = Asm.getSectionData(
+    SD->getSymbol().getSection());
+  Value += Writer->getSectionAddress(&SymSD);
+  Value -= Writer->getSectionAddress(Fragment.getParent());
+  // If the resultant value would be out of range for an internal relocation,
+  // use an external instead.
+  if (Value > Range || Value < -(Range + 1))
+    return true;
+  return false;
 }
 
 void ARMMachObjectWriter::RecordRelocation(MachObjectWriter *Writer,
-                                           const MCAssembler &Asm,
+                                           MCAssembler &Asm,
                                            const MCAsmLayout &Layout,
                                            const MCFragment *Fragment,
-                                           const MCFixup &Fixup,
-                                           MCValue Target,
+                                           const MCFixup &Fixup, MCValue Target,
                                            uint64_t &FixedValue) {
   unsigned IsPCRel = Writer->isFixupKindPCRel(Asm, Fixup.getKind());
   unsigned Log2Size;
-  unsigned RelocType = macho::RIT_Vanilla;
+  unsigned RelocType = MachO::ARM_RELOC_VANILLA;
   if (!getARMFixupKindMachOInfo(Fixup.getKind(), RelocType, Log2Size))
     // If we failed to get fixup kind info, it's because there's no legal
     // relocation type for the fixup kind. This happens when it's a fixup that's
     // expected to always be resolvable at assembly time and not have any
     // relocations needed.
-    Asm.getContext().FatalError(Fixup.getLoc(),
+    Asm.getContext().reportFatalError(Fixup.getLoc(),
                                 "unsupported relocation on symbol");
 
   // If this is a difference or a defined symbol plus an offset, then we need a
   // scattered relocation entry.  Differences always require scattered
   // relocations.
   if (Target.getSymB()) {
-    if (RelocType == macho::RIT_ARM_Half)
+    if (RelocType == MachO::ARM_RELOC_HALF)
       return RecordARMScatteredHalfRelocation(Writer, Asm, Layout, Fragment,
                                               Fixup, Target, FixedValue);
     return RecordARMScatteredRelocation(Writer, Asm, Layout, Fragment, Fixup,
-                                        Target, Log2Size, FixedValue);
+                                        Target, RelocType, Log2Size,
+                                        FixedValue);
   }
 
   // Get the symbol data, if any.
-  MCSymbolData *SD = 0;
+  const MCSymbolData *SD = nullptr;
   if (Target.getSymA())
     SD = &Asm.getSymbolData(Target.getSymA()->getSymbol());
 
@@ -345,17 +385,18 @@ void ARMMachObjectWriter::RecordRelocation(MachObjectWriter *Writer,
   //
   // Is this right for ARM?
   uint32_t Offset = Target.getConstant();
-  if (IsPCRel && RelocType == macho::RIT_Vanilla)
+  if (IsPCRel && RelocType == MachO::ARM_RELOC_VANILLA)
     Offset += 1 << Log2Size;
   if (Offset && SD && !Writer->doesSymbolRequireExternRelocation(SD))
     return RecordARMScatteredRelocation(Writer, Asm, Layout, Fragment, Fixup,
-                                        Target, Log2Size, FixedValue);
+                                        Target, RelocType, Log2Size,
+                                        FixedValue);
 
   // See <reloc.h>.
   uint32_t FixupOffset = Layout.getFragmentOffset(Fragment)+Fixup.getOffset();
   unsigned Index = 0;
-  unsigned IsExtern = 0;
   unsigned Type = 0;
+  const MCSymbol *RelSymbol = nullptr;
 
   if (Target.isAbsolute()) { // constant
     // FIXME!
@@ -373,14 +414,14 @@ void ARMMachObjectWriter::RecordRelocation(MachObjectWriter *Writer,
     }
 
     // Check whether we need an external or internal relocation.
-    if (Writer->doesSymbolRequireExternRelocation(SD)) {
-      IsExtern = 1;
-      Index = SD->getIndex();
+    if (requiresExternRelocation(Writer, Asm, *Fragment, RelocType, SD,
+                                 FixedValue)) {
+      RelSymbol = &SD->getSymbol();
 
       // For external relocations, make sure to offset the fixup value to
       // compensate for the addend of the symbol address, if it was
       // undefined. This occurs with weak definitions, for example.
-      if (!SD->Symbol->isUndefined())
+      if (!SD->getSymbol().isUndefined())
         FixedValue -= Layout.getSymbolOffset(SD);
     } else {
       // The index is the section ordinal (1-based).
@@ -397,50 +438,42 @@ void ARMMachObjectWriter::RecordRelocation(MachObjectWriter *Writer,
   }
 
   // struct relocation_info (8 bytes)
-  macho::RelocationEntry MRE;
-  MRE.Word0 = FixupOffset;
-  MRE.Word1 = ((Index     <<  0) |
-               (IsPCRel   << 24) |
-               (Log2Size  << 25) |
-               (IsExtern  << 27) |
-               (Type      << 28));
+  MachO::any_relocation_info MRE;
+  MRE.r_word0 = FixupOffset;
+  MRE.r_word1 =
+      (Index << 0) | (IsPCRel << 24) | (Log2Size << 25) | (Type << 28);
 
   // Even when it's not a scattered relocation, movw/movt always uses
   // a PAIR relocation.
-  if (Type == macho::RIT_ARM_Half) {
+  if (Type == MachO::ARM_RELOC_HALF) {
     // The other-half value only gets populated for the movt and movw
     // relocation entries.
-    uint32_t Value = 0;;
+    uint32_t Value = 0;
     switch ((unsigned)Fixup.getKind()) {
     default: break;
     case ARM::fixup_arm_movw_lo16:
-    case ARM::fixup_arm_movw_lo16_pcrel:
     case ARM::fixup_t2_movw_lo16:
-    case ARM::fixup_t2_movw_lo16_pcrel:
       Value = (FixedValue >> 16) & 0xffff;
       break;
     case ARM::fixup_arm_movt_hi16:
-    case ARM::fixup_arm_movt_hi16_pcrel:
     case ARM::fixup_t2_movt_hi16:
-    case ARM::fixup_t2_movt_hi16_pcrel:
       Value = FixedValue & 0xffff;
       break;
     }
-    macho::RelocationEntry MREPair;
-    MREPair.Word0 = Value;
-    MREPair.Word1 = ((0xffffff) |
-                     (Log2Size << 25) |
-                     (macho::RIT_Pair << 28));
+    MachO::any_relocation_info MREPair;
+    MREPair.r_word0 = Value;
+    MREPair.r_word1 = ((0xffffff              <<  0) |
+                       (Log2Size              << 25) |
+                       (MachO::ARM_RELOC_PAIR << 28));
 
-    Writer->addRelocation(Fragment->getParent(), MREPair);
+    Writer->addRelocation(nullptr, Fragment->getParent(), MREPair);
   }
 
-  Writer->addRelocation(Fragment->getParent(), MRE);
+  Writer->addRelocation(RelSymbol, Fragment->getParent(), MRE);
 }
 
-MCObjectWriter *llvm::createARMMachObjectWriter(raw_ostream &OS,
-                                                bool Is64Bit,
-                                                uint32_t CPUType,
+MCObjectWriter *llvm::createARMMachObjectWriter(raw_pwrite_stream &OS,
+                                                bool Is64Bit, uint32_t CPUType,
                                                 uint32_t CPUSubtype) {
   return createMachObjectWriter(new ARMMachObjectWriter(Is64Bit,
                                                         CPUType,