Add support for parsing ARM symbol variants on ELF targets

ARM symbol variants are written with parens instead of @ like this:

  .word __GLOBAL_I_a(target1)

This commit adds support for parsing these symbol variants in
expressions. We introduce a new flag to MCAsmInfo that indicates the
parser should use parens to parse the symbol variant. The expression
parser is modified to look for symbol variants using parens instead
of @ when the corresponding MCAsmInfo flag is true.

The MCAsmInfo parens flag is enabled only for ARM on ELF.

By adding this flag to MCAsmInfo, we are able to get rid of
redundant ARM-specific symbol variants and use the generic variants
instead (e.g. VK_GOT instead of VK_ARM_GOT). We use the new
UseParensForSymbolVariant attribute in MCAsmInfo to correctly print
the symbol variants for arm.

To achive this we need to keep a handle to the MCAsmInfo in the
MCSymbolRefExpr class that we can check when printing the symbol
variant.

Updated Tests:
  Changed case of symbol variant to match the generic kind.
  test/CodeGen/ARM/tls-models.ll
  test/CodeGen/ARM/tls1.ll
  test/CodeGen/ARM/tls2.ll
  test/CodeGen/Thumb2/tls1.ll
  test/CodeGen/Thumb2/tls2.ll

PR18080

llvm-svn: 196424

4 files changed, 17 insertions, 14 deletions

diff --git a/llvm/lib/Target/ARM/ARMAsmPrinter.cpp b/llvm/lib/Target/ARM/ARMAsmPrinter.cpp
index 720c9b0111d..8e28a98277d 100644
--- a/llvm/lib/Target/ARM/ARMAsmPrinter.cpp
+++ b/llvm/lib/Target/ARM/ARMAsmPrinter.cpp
@@ -756,11 +756,11 @@ static MCSymbolRefExpr::VariantKind
 getModifierVariantKind(ARMCP::ARMCPModifier Modifier) {
   switch (Modifier) {
   case ARMCP::no_modifier: return MCSymbolRefExpr::VK_None;
-  case ARMCP::TLSGD:       return MCSymbolRefExpr::VK_ARM_TLSGD;
-  case ARMCP::TPOFF:       return MCSymbolRefExpr::VK_ARM_TPOFF;
-  case ARMCP::GOTTPOFF:    return MCSymbolRefExpr::VK_ARM_GOTTPOFF;
-  case ARMCP::GOT:         return MCSymbolRefExpr::VK_ARM_GOT;
-  case ARMCP::GOTOFF:      return MCSymbolRefExpr::VK_ARM_GOTOFF;
+  case ARMCP::TLSGD:       return MCSymbolRefExpr::VK_TLSGD;
+  case ARMCP::TPOFF:       return MCSymbolRefExpr::VK_TPOFF;
+  case ARMCP::GOTTPOFF:    return MCSymbolRefExpr::VK_GOTTPOFF;
+  case ARMCP::GOT:         return MCSymbolRefExpr::VK_GOT;
+  case ARMCP::GOTOFF:      return MCSymbolRefExpr::VK_GOTOFF;
   }
   llvm_unreachable("Invalid ARMCPModifier!");
 }
diff --git a/llvm/lib/Target/ARM/ARMMCInstLower.cpp b/llvm/lib/Target/ARM/ARMMCInstLower.cpp
index 1cc987ce99d..c8306277590 100644
--- a/llvm/lib/Target/ARM/ARMMCInstLower.cpp
+++ b/llvm/lib/Target/ARM/ARMMCInstLower.cpp
@@ -50,7 +50,7 @@ MCOperand ARMAsmPrinter::GetSymbolRef(const MachineOperand &MO,
   }
 
   case ARMII::MO_PLT:
-    Expr = MCSymbolRefExpr::Create(Symbol, MCSymbolRefExpr::VK_ARM_PLT,
+    Expr = MCSymbolRefExpr::Create(Symbol, MCSymbolRefExpr::VK_PLT,
                                    OutContext);
     break;
   }
diff --git a/llvm/lib/Target/ARM/MCTargetDesc/ARMELFObjectWriter.cpp b/llvm/lib/Target/ARM/MCTargetDesc/ARMELFObjectWriter.cpp
index f98bbd204c7..72ac6e22e8d 100644
--- a/llvm/lib/Target/ARM/MCTargetDesc/ARMELFObjectWriter.cpp
+++ b/llvm/lib/Target/ARM/MCTargetDesc/ARMELFObjectWriter.cpp
@@ -166,9 +166,9 @@ unsigned ARMELFObjectWriter::GetRelocTypeInner(const MCValue &Target,
       case MCSymbolRefExpr::VK_None:
         Type = ELF::R_ARM_REL32;
         break;
-      case MCSymbolRefExpr::VK_ARM_TLSGD:
+      case MCSymbolRefExpr::VK_TLSGD:
         llvm_unreachable("unimplemented");
-      case MCSymbolRefExpr::VK_ARM_GOTTPOFF:
+      case MCSymbolRefExpr::VK_GOTTPOFF:
         Type = ELF::R_ARM_TLS_IE32;
         break;
       }
@@ -176,7 +176,7 @@ unsigned ARMELFObjectWriter::GetRelocTypeInner(const MCValue &Target,
     case ARM::fixup_arm_blx:
     case ARM::fixup_arm_uncondbl:
       switch (Modifier) {
-      case MCSymbolRefExpr::VK_ARM_PLT:
+      case MCSymbolRefExpr::VK_PLT:
         Type = ELF::R_ARM_PLT32;
         break;
       default:
@@ -223,22 +223,22 @@ unsigned ARMELFObjectWriter::GetRelocTypeInner(const MCValue &Target,
       case MCSymbolRefExpr::VK_ARM_NONE:
         Type = ELF::R_ARM_NONE;
         break;
-      case MCSymbolRefExpr::VK_ARM_GOT:
+      case MCSymbolRefExpr::VK_GOT:
         Type = ELF::R_ARM_GOT_BREL;
         break;
-      case MCSymbolRefExpr::VK_ARM_TLSGD:
+      case MCSymbolRefExpr::VK_TLSGD:
         Type = ELF::R_ARM_TLS_GD32;
         break;
-      case MCSymbolRefExpr::VK_ARM_TPOFF:
+      case MCSymbolRefExpr::VK_TPOFF:
         Type = ELF::R_ARM_TLS_LE32;
         break;
-      case MCSymbolRefExpr::VK_ARM_GOTTPOFF:
+      case MCSymbolRefExpr::VK_GOTTPOFF:
         Type = ELF::R_ARM_TLS_IE32;
         break;
       case MCSymbolRefExpr::VK_None:
         Type = ELF::R_ARM_ABS32;
         break;
-      case MCSymbolRefExpr::VK_ARM_GOTOFF:
+      case MCSymbolRefExpr::VK_GOTOFF:
         Type = ELF::R_ARM_GOTOFF32;
         break;
       case MCSymbolRefExpr::VK_ARM_TARGET1:
diff --git a/llvm/lib/Target/ARM/MCTargetDesc/ARMMCAsmInfo.cpp b/llvm/lib/Target/ARM/MCTargetDesc/ARMMCAsmInfo.cpp
index 714142123d9..b2a71a87061 100644
--- a/llvm/lib/Target/ARM/MCTargetDesc/ARMMCAsmInfo.cpp
+++ b/llvm/lib/Target/ARM/MCTargetDesc/ARMMCAsmInfo.cpp
@@ -54,4 +54,7 @@ ARMELFMCAsmInfo::ARMELFMCAsmInfo() {
   // Exceptions handling
   if (EnableARMEHABI)
     ExceptionsType = ExceptionHandling::ARM;
+
+  // foo(plt) instead of foo@plt
+  UseParensForSymbolVariant = true;
 }