Don't emit structors for available_externally globals (PR19933)
[oota-llvm.git] / lib / MC / MCObjectFileInfo.cpp
index 26d2b61d5894f9cc1e1fd6f7552024df45ab6269..2a9bf6ade90ee22dd1ee5f5140b48f12f171edc9 100644 (file)
@@ -10,6 +10,7 @@
 #include "llvm/MC/MCObjectFileInfo.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/ADT/Triple.h"
+#include "llvm/MC/MCAsmInfo.h"
 #include "llvm/MC/MCContext.h"
 #include "llvm/MC/MCSection.h"
 #include "llvm/MC/MCSectionCOFF.h"
@@ -22,12 +23,13 @@ void MCObjectFileInfo::InitMachOMCObjectFileInfo(Triple T) {
   IsFunctionEHFrameSymbolPrivate = false;
   SupportsWeakOmittedEHFrame = false;
 
-  if (T.isOSDarwin() && T.getArch() == Triple::arm64)
+  if (T.isOSDarwin() &&
+      (T.getArch() == Triple::arm64 || T.getArch() == Triple::aarch64))
     SupportsCompactUnwindWithoutEHFrame = true;
 
   PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel
     | dwarf::DW_EH_PE_sdata4;
-  LSDAEncoding = FDEEncoding = FDECFIEncoding = dwarf::DW_EH_PE_pcrel;
+  LSDAEncoding = FDECFIEncoding = dwarf::DW_EH_PE_pcrel;
   TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
     dwarf::DW_EH_PE_sdata4;
 
@@ -150,7 +152,8 @@ void MCObjectFileInfo::InitMachOMCObjectFileInfo(Triple T) {
   COFFDebugSymbolsSection = nullptr;
 
   if ((T.isMacOSX() && !T.isMacOSXVersionLT(10, 6)) ||
-      (T.isOSDarwin() && T.getArch() == Triple::arm64)) {
+      (T.isOSDarwin() &&
+       (T.getArch() == Triple::arm64 || T.getArch() == Triple::aarch64))) {
     CompactUnwindSection =
       Ctx->getMachOSection("__LD", "__compact_unwind",
                            MachO::S_ATTR_DEBUG,
@@ -158,7 +161,7 @@ void MCObjectFileInfo::InitMachOMCObjectFileInfo(Triple T) {
 
     if (T.getArch() == Triple::x86_64 || T.getArch() == Triple::x86)
       CompactUnwindDwarfEHFrameOnly = 0x04000000;
-    else if (T.getArch() == Triple::arm64)
+    else if (T.getArch() == Triple::arm64 || T.getArch() == Triple::aarch64)
       CompactUnwindDwarfEHFrameOnly = 0x03000000;
   }
 
@@ -245,29 +248,40 @@ void MCObjectFileInfo::InitMachOMCObjectFileInfo(Triple T) {
 }
 
 void MCObjectFileInfo::InitELFMCObjectFileInfo(Triple T) {
-  if (T.getArch() == Triple::mips ||
-      T.getArch() == Triple::mipsel)
+  switch (T.getArch()) {
+  case Triple::mips:
+  case Triple::mipsel:
     FDECFIEncoding = dwarf::DW_EH_PE_sdata4;
-  else if (T.getArch() == Triple::mips64 ||
-           T.getArch() == Triple::mips64el)
+    break;
+  case Triple::mips64:
+  case Triple::mips64el:
     FDECFIEncoding = dwarf::DW_EH_PE_sdata8;
-  else
+    break;
+  default:
     FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
+    break;
+  }
 
-  if (T.getArch() == Triple::x86) {
+  switch (T.getArch()) {
+  case Triple::arm:
+  case Triple::armeb:
+  case Triple::thumb:
+  case Triple::thumbeb:
+    if (Ctx->getAsmInfo()->getExceptionHandlingType() == ExceptionHandling::ARM)
+      break;
+    // Fallthrough if not using EHABI
+  case Triple::x86:
     PersonalityEncoding = (RelocM == Reloc::PIC_)
      ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
      : dwarf::DW_EH_PE_absptr;
     LSDAEncoding = (RelocM == Reloc::PIC_)
       ? dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
       : dwarf::DW_EH_PE_absptr;
-    FDEEncoding = (RelocM == Reloc::PIC_)
-      ? dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
-      : dwarf::DW_EH_PE_absptr;
     TTypeEncoding = (RelocM == Reloc::PIC_)
      ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
      : dwarf::DW_EH_PE_absptr;
-  } else if (T.getArch() == Triple::x86_64) {
+    break;
+  case Triple::x86_64:
     if (RelocM == Reloc::PIC_) {
       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
         ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
@@ -275,7 +289,6 @@ void MCObjectFileInfo::InitELFMCObjectFileInfo(Triple T) {
       LSDAEncoding = dwarf::DW_EH_PE_pcrel |
         (CMModel == CodeModel::Small
          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
-      FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
         ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
@@ -285,13 +298,14 @@ void MCObjectFileInfo::InitELFMCObjectFileInfo(Triple T) {
         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
       LSDAEncoding = (CMModel == CodeModel::Small)
         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
-      FDEEncoding = dwarf::DW_EH_PE_udata4;
       TTypeEncoding = (CMModel == CodeModel::Small)
         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
     }
-  } else if (T.getArch() == Triple::aarch64 ||
-             T.getArch() == Triple::aarch64_be ||
-             T.getArch() == Triple::arm64) {
+    break;
+  case Triple::aarch64:
+  case Triple::aarch64_be:
+  case Triple::arm64:
+  case Triple::arm64_be:
     // The small model guarantees static code/data size < 4GB, but not where it
     // will be in memory. Most of these could end up >2GB away so even a signed
     // pc-relative 32-bit address is insufficient, theoretically.
@@ -299,65 +313,71 @@ void MCObjectFileInfo::InitELFMCObjectFileInfo(Triple T) {
       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
         dwarf::DW_EH_PE_sdata8;
       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata8;
-      FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
         dwarf::DW_EH_PE_sdata8;
     } else {
       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
       LSDAEncoding = dwarf::DW_EH_PE_absptr;
-      FDEEncoding = dwarf::DW_EH_PE_udata4;
       TTypeEncoding = dwarf::DW_EH_PE_absptr;
     }
-  } else if (T.getArch() == Triple::ppc64 || T.getArch() == Triple::ppc64le) {
+    break;
+  case Triple::mips:
+  case Triple::mipsel:
+    // MIPS uses indirect pointer to refer personality functions, so that the
+    // eh_frame section can be read-only.  DW.ref.personality will be generated
+    // for relocation.
+    PersonalityEncoding = dwarf::DW_EH_PE_indirect;
+    break;
+  case Triple::ppc64:
+  case Triple::ppc64le:
     PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
       dwarf::DW_EH_PE_udata8;
     LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8;
-    FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8;
     TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
       dwarf::DW_EH_PE_udata8;
-  } else if (T.getArch() == Triple::sparc) {
+    break;
+  case Triple::sparc:
     if (RelocM == Reloc::PIC_) {
       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
         dwarf::DW_EH_PE_sdata4;
-      FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
         dwarf::DW_EH_PE_sdata4;
     } else {
       LSDAEncoding = dwarf::DW_EH_PE_absptr;
       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
-      FDEEncoding = dwarf::DW_EH_PE_udata4;
       TTypeEncoding = dwarf::DW_EH_PE_absptr;
     }
-  } else if (T.getArch() == Triple::sparcv9) {
+    break;
+  case Triple::sparcv9:
     LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
     if (RelocM == Reloc::PIC_) {
       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
         dwarf::DW_EH_PE_sdata4;
-      FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
         dwarf::DW_EH_PE_sdata4;
     } else {
       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
-      FDEEncoding = dwarf::DW_EH_PE_udata4;
       TTypeEncoding = dwarf::DW_EH_PE_absptr;
     }
-  } else if (T.getArch() == Triple::systemz) {
+    break;
+  case Triple::systemz:
     // All currently-defined code models guarantee that 4-byte PC-relative
     // values will be in range.
     if (RelocM == Reloc::PIC_) {
       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
         dwarf::DW_EH_PE_sdata4;
       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
-      FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
         dwarf::DW_EH_PE_sdata4;
     } else {
       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
       LSDAEncoding = dwarf::DW_EH_PE_absptr;
-      FDEEncoding = dwarf::DW_EH_PE_absptr;
       TTypeEncoding = dwarf::DW_EH_PE_absptr;
     }
+    break;
+  default:
+    break;
   }
 
   // Solaris requires different flags for .eh_frame to seemingly every other
@@ -721,7 +741,7 @@ void MCObjectFileInfo::InitCOFFMCObjectFileInfo(Triple T) {
 
   DrectveSection =
     Ctx->getCOFFSection(".drectve",
-                        COFF::IMAGE_SCN_LNK_INFO,
+                        COFF::IMAGE_SCN_LNK_INFO | COFF::IMAGE_SCN_LNK_REMOVE,
                         SectionKind::getMetadata());
 
   PDataSection =
@@ -756,8 +776,8 @@ void MCObjectFileInfo::InitMCObjectFileInfo(StringRef TT, Reloc::Model relocm,
   IsFunctionEHFrameSymbolPrivate = true;
   SupportsCompactUnwindWithoutEHFrame = false;
 
-  PersonalityEncoding = LSDAEncoding = FDEEncoding = FDECFIEncoding =
-    TTypeEncoding = dwarf::DW_EH_PE_absptr;
+  PersonalityEncoding = LSDAEncoding = FDECFIEncoding = TTypeEncoding =
+      dwarf::DW_EH_PE_absptr;
 
   CompactUnwindDwarfEHFrameOnly = 0;
 
@@ -774,14 +794,15 @@ void MCObjectFileInfo::InitMCObjectFileInfo(StringRef TT, Reloc::Model relocm,
   // cellspu-apple-darwin. Perhaps we should fix in Triple?
   if ((Arch == Triple::x86 || Arch == Triple::x86_64 ||
        Arch == Triple::arm || Arch == Triple::thumb ||
-       Arch == Triple::arm64 ||
+       Arch == Triple::arm64 || Arch == Triple::aarch64 ||
        Arch == Triple::ppc || Arch == Triple::ppc64 ||
        Arch == Triple::UnknownArch) &&
       (T.isOSDarwin() || T.isOSBinFormatMachO())) {
     Env = IsMachO;
     InitMachOMCObjectFileInfo(T);
-  } else if ((Arch == Triple::x86 || Arch == Triple::x86_64) &&
-             T.getObjectFormat() != Triple::ELF && T.isOSWindows()) {
+  } else if ((Arch == Triple::x86 || Arch == Triple::x86_64 ||
+              Arch == Triple::arm || Arch == Triple::thumb) &&
+             (T.isOSWindows() && T.getObjectFormat() == Triple::COFF)) {
     Env = IsCOFF;
     InitCOFFMCObjectFileInfo(T);
   } else {