The ELF relocation record format is different for N64

which many Mips 64 ABIs use than for O64 which many 
if not all other target ABIs use.

Most architectures have the following 64 bit relocation record format:

  typedef struct
  {
    Elf64_Addr   r_offset; /* Address of reference */
    Elf64_Xword  r_info;   /* Symbol index and type of relocation */
  } Elf64_Rel;

  typedef struct
  {
    Elf64_Addr    r_offset;
    Elf64_Xword   r_info;
    Elf64_Sxword  r_addend;
  } Elf64_Rela;

Whereas N64 has the following format:

  typedef struct
  {
    Elf64_Addr    r_offset;/* Address of reference */
    Elf64_Word  r_sym;     /* Symbol index */
    Elf64_Byte  r_ssym;    /* Special symbol */
    Elf64_Byte  r_type3;   /* Relocation type */
    Elf64_Byte  r_type2;   /* Relocation type */
    Elf64_Byte  r_type;    /* Relocation type */
  } Elf64_Rel;

  typedef struct
  {
    Elf64_Addr    r_offset;/* Address of reference */
    Elf64_Word  r_sym;     /* Symbol index */
    Elf64_Byte  r_ssym;    /* Special symbol */
    Elf64_Byte  r_type3;   /* Relocation type */
    Elf64_Byte  r_type2;   /* Relocation type */
    Elf64_Byte  r_type;    /* Relocation type */
    Elf64_Sxword  r_addend;
  } Elf64_Rela;

The structure is the same size, but the r_info data element 
is now 5 separate elements. Besides the content aspects, 
endian byte reordering will be different for the area with 
each element being endianized separately.

I treat this as generic and continue to pass r_type as 
an integer masking and unmasking the byte sized N64 
values for N64 mode. I've implemented this and it causes no 
affect on other current targets.

This passes make check.

Jack


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159299 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 24 insertions, 12 deletions

diff --git a/lib/MC/ELFObjectWriter.cpp b/lib/MC/ELFObjectWriter.cpp
index 7b166fb56c..7203b9a4bf 100644
--- a/lib/MC/ELFObjectWriter.cpp
+++ b/lib/MC/ELFObjectWriter.cpp
@@ -1061,11 +1061,19 @@ void ELFObjectWriter::WriteRelocationsFragment(const MCAssembler &Asm,
       entry.Index += LocalSymbolData.size();
     if (is64Bit()) {
       String64(*F, entry.r_offset);
+      if (TargetObjectWriter->isN64()) {
+        String32(*F, entry.Index);
 
-      struct ELF::Elf64_Rela ERE64;
-      ERE64.setSymbolAndType(entry.Index, entry.Type);
-      String64(*F, ERE64.r_info);
-
+        String8(*F, TargetObjectWriter->getRSsym(entry.Type));
+        String8(*F, TargetObjectWriter->getRType3(entry.Type));
+        String8(*F, TargetObjectWriter->getRType2(entry.Type));
+        String8(*F, TargetObjectWriter->getRType(entry.Type));
+      }
+      else {
+        struct ELF::Elf64_Rela ERE64;
+        ERE64.setSymbolAndType(entry.Index, entry.Type);
+        String64(*F, ERE64.r_info);
+      }
       if (hasRelocationAddend())
         String64(*F, entry.r_addend);
     } else {
diff --git a/lib/MC/MCELFObjectTargetWriter.cpp b/lib/MC/MCELFObjectTargetWriter.cpp
index 171ab4d9bf..6eb6914f4b 100644
--- a/lib/MC/MCELFObjectTargetWriter.cpp
+++ b/lib/MC/MCELFObjectTargetWriter.cpp
@@ -15,9 +15,11 @@ using namespace llvm;
 MCELFObjectTargetWriter::MCELFObjectTargetWriter(bool Is64Bit_,
                                                  uint8_t OSABI_,
                                                  uint16_t EMachine_,
-                                                 bool HasRelocationAddend_)
+                                                 bool HasRelocationAddend_,
+                                                 bool IsN64_)
   : OSABI(OSABI_), EMachine(EMachine_),
-    HasRelocationAddend(HasRelocationAddend_), Is64Bit(Is64Bit_) {
+    HasRelocationAddend(HasRelocationAddend_), Is64Bit(Is64Bit_),
+    IsN64(IsN64_){
 }
 
 /// Default e_flags = 0
diff --git a/lib/Target/Mips/MCTargetDesc/MipsELFObjectWriter.cpp b/lib/Target/Mips/MCTargetDesc/MipsELFObjectWriter.cpp
index d76f8c7c5f..91cd7dce36 100644
--- a/lib/Target/Mips/MCTargetDesc/MipsELFObjectWriter.cpp
+++ b/lib/Target/Mips/MCTargetDesc/MipsELFObjectWriter.cpp
@@ -34,7 +34,7 @@ namespace {
 
   class MipsELFObjectWriter : public MCELFObjectTargetWriter {
   public:
-    MipsELFObjectWriter(bool _is64Bit, uint8_t OSABI);
+    MipsELFObjectWriter(bool _is64Bit, uint8_t OSABI, bool _isN64);
 
     virtual ~MipsELFObjectWriter();
 
@@ -52,9 +52,11 @@ namespace {
   };
 }
 
-MipsELFObjectWriter::MipsELFObjectWriter(bool _is64Bit, uint8_t OSABI)
+MipsELFObjectWriter::MipsELFObjectWriter(bool _is64Bit, uint8_t OSABI,
+                                         bool _isN64)
   : MCELFObjectTargetWriter(_is64Bit, OSABI, ELF::EM_MIPS,
-                            /*HasRelocationAddend*/ false) {}
+                            /*HasRelocationAddend*/ false,
+                            /*IsN64*/ _isN64) {}
 
 MipsELFObjectWriter::~MipsELFObjectWriter() {}
 
@@ -149,7 +151,6 @@ unsigned MipsELFObjectWriter::GetRelocType(const MCValue &Target,
     Type = ELF::R_MIPS_PC16;
     break;
   }
-
   return Type;
 }
 
@@ -184,7 +185,7 @@ static int CompareOffset(const RelEntry &R0, const RelEntry &R1) {
 
 void MipsELFObjectWriter::sortRelocs(const MCAssembler &Asm,
                                      std::vector<ELFRelocationEntry> &Relocs) {
-  // Call the defualt function first. Relocations are sorted in descending
+  // Call the default function first. Relocations are sorted in descending
   // order of r_offset.
   MCELFObjectTargetWriter::sortRelocs(Asm, Relocs);
 
@@ -244,6 +245,7 @@ MCObjectWriter *llvm::createMipsELFObjectWriter(raw_ostream &OS,
                                                 uint8_t OSABI,
                                                 bool IsLittleEndian,
                                                 bool Is64Bit) {
-  MCELFObjectTargetWriter *MOTW = new MipsELFObjectWriter(Is64Bit, OSABI);
+  MCELFObjectTargetWriter *MOTW = new MipsELFObjectWriter(Is64Bit, OSABI,
+                                                (Is64Bit) ? true : false);
   return createELFObjectWriter(MOTW, OS, IsLittleEndian);
 }