Fix undefined behavior in the Mips backend.

[oota-llvm.git] / lib / Target / X86 / X86ELFWriterInfo.cpp

diff --git a/lib/Target/X86/X86ELFWriterInfo.cpp b/lib/Target/X86/X86ELFWriterInfo.cpp
index 315118f61091c255a48b6ea501b770dd2a2074d8..c1a49a764614dd0c8b354c9a3a9576e36d9b8ba6 100644 (file)
--- a/lib/Target/X86/X86ELFWriterInfo.cpp
+++ b/lib/Target/X86/X86ELFWriterInfo.cpp
@@ -14,6 +14,8 @@
 #include "X86ELFWriterInfo.h"
 #include "X86Relocations.h"
 #include "llvm/Function.h"
+#include "llvm/Support/ELF.h"
+#include "llvm/Support/ErrorHandling.h"
 #include "llvm/Target/TargetData.h"
 #include "llvm/Target/TargetMachine.h"
 
@@ -23,9 +25,8 @@ using namespace llvm;
 //  Implementation of the X86ELFWriterInfo class
 //===----------------------------------------------------------------------===//
 
-X86ELFWriterInfo::X86ELFWriterInfo(TargetMachine &TM)
-  : TargetELFWriterInfo(TM) {
-    bool is64Bit = TM.getTargetData()->getPointerSizeInBits() == 64;
+X86ELFWriterInfo::X86ELFWriterInfo(bool is64Bit_, bool isLittleEndian_)
+  : TargetELFWriterInfo(is64Bit_, isLittleEndian_) {
     EMachine = is64Bit ? EM_X86_64 : EM_386;
   }
 
@@ -35,50 +36,112 @@ unsigned X86ELFWriterInfo::getRelocationType(unsigned MachineRelTy) const {
   if (is64Bit) {
     switch(MachineRelTy) {
     case X86::reloc_pcrel_word:
-      return R_X86_64_PC32;
+      return ELF::R_X86_64_PC32;
     case X86::reloc_absolute_word:
-      return R_X86_64_32;
+      return ELF::R_X86_64_32;
+    case X86::reloc_absolute_word_sext:
+      return ELF::R_X86_64_32S;
     case X86::reloc_absolute_dword:
-      return R_X86_64_64;
+      return ELF::R_X86_64_64;
     case X86::reloc_picrel_word:
     default:
-      assert(0 && "unknown relocation type");
+      llvm_unreachable("unknown x86_64 machine relocation type");
     }
   } else {
     switch(MachineRelTy) {
     case X86::reloc_pcrel_word:
-      return R_386_PC32;
+      return ELF::R_386_PC32;
     case X86::reloc_absolute_word:
-      return R_386_32;
+      return ELF::R_386_32;
+    case X86::reloc_absolute_word_sext:
     case X86::reloc_absolute_dword:
     case X86::reloc_picrel_word:
     default:
-      assert(0 && "unknown relocation type");
+      llvm_unreachable("unknown x86 machine relocation type");
     }
   }
-  return 0;
 }
 
-unsigned X86ELFWriterInfo::getFunctionAlignment(const Function *F) const {
-  unsigned FnAlign = 4;
-
-  if (F->hasFnAttr(Attribute::OptimizeForSize))
-    FnAlign = 1;
-
-  if (F->getAlignment())
-    FnAlign = Log2_32(F->getAlignment());
+long int X86ELFWriterInfo::getDefaultAddendForRelTy(unsigned RelTy,
+                                                    long int Modifier) const {
+  if (is64Bit) {
+    switch(RelTy) {
+    case ELF::R_X86_64_PC32: return Modifier - 4;
+    case ELF::R_X86_64_32:
+    case ELF::R_X86_64_32S:
+    case ELF::R_X86_64_64:
+      return Modifier;
+    default:
+      llvm_unreachable("unknown x86_64 relocation type");
+    }
+  } else {
+    switch(RelTy) {
+    case ELF::R_386_PC32: return Modifier - 4;
+    case ELF::R_386_32: return Modifier;
+    default:
+      llvm_unreachable("unknown x86 relocation type");
+    }
+  }
+}
 
-  return (1 << FnAlign);
+unsigned X86ELFWriterInfo::getRelocationTySize(unsigned RelTy) const {
+  if (is64Bit) {
+    switch(RelTy) {
+    case ELF::R_X86_64_PC32:
+    case ELF::R_X86_64_32:
+    case ELF::R_X86_64_32S:
+        return 32;
+    case ELF::R_X86_64_64:
+        return 64;
+    default:
+      llvm_unreachable("unknown x86_64 relocation type");
+    }
+  } else {
+    switch(RelTy) {
+    case ELF::R_386_PC32:
+    case ELF::R_386_32:
+        return 32;
+    default:
+      llvm_unreachable("unknown x86 relocation type");
+    }
+  }
 }
 
-long int X86ELFWriterInfo::getAddendForRelTy(unsigned RelTy) const {
+bool X86ELFWriterInfo::isPCRelativeRel(unsigned RelTy) const {
   if (is64Bit) {
     switch(RelTy) {
-    case R_X86_64_PC32: return -4;
-      break;
+    case ELF::R_X86_64_PC32:
+        return true;
+    case ELF::R_X86_64_32:
+    case ELF::R_X86_64_32S:
+    case ELF::R_X86_64_64:
+        return false;
     default:
-      assert(0 && "unknown x86 relocation type");
+      llvm_unreachable("unknown x86_64 relocation type");
+    }
+  } else {
+    switch(RelTy) {
+    case ELF::R_386_PC32:
+        return true;
+    case ELF::R_386_32:
+        return false;
+    default:
+      llvm_unreachable("unknown x86 relocation type");
     }
   }
-  return 0;
+}
+
+unsigned X86ELFWriterInfo::getAbsoluteLabelMachineRelTy() const {
+  return is64Bit ?
+    X86::reloc_absolute_dword : X86::reloc_absolute_word;
+}
+
+long int X86ELFWriterInfo::computeRelocation(unsigned SymOffset,
+                                             unsigned RelOffset,
+                                             unsigned RelTy) const {
+
+  if (RelTy == ELF::R_X86_64_PC32 || RelTy == ELF::R_386_PC32)
+    return SymOffset - (RelOffset + 4);
+
+  llvm_unreachable("computeRelocation unknown for this relocation type");
 }