[lanai] Add ELF enum value and relocations

[jpienaar]

Summary

Add ELF enum value and relocations for Lanai backed.

General Lanai backend discussion on llvm-dev thread "[RFC] Lanai backend" (http://lists.llvm.org/pipermail/llvm-dev/2016-February/095118.html).

[jyknight]

include/llvm/MC/MCExpr.h

294 ↗

(On Diff #47270)

It looks like half the backends put target specific expr kinds in a subclass of MCTargetExpr, instead of in here. I'm not sure, but maybe that's the way you're supposed to do it now?

include/llvm/Object/RelocVisitor.h

324

No call to getELFAddend needed here?

lib/MC/MCExpr.cpp

316 ↗

(On Diff #47270)

This, in particular, seems an unfortunate consequence of not using a LanaiMCExpr: a very generic name, assigned a target-specific variant.

[jpienaar]

Moved MCExpr changes to subclass of MCTargetExpr and use that instead in the backend.

[jpienaar]

Good suggestion on subclassing instead.

[eliben]

include/llvm/Support/ELFRelocs/Lanai.def

6

Would this be a good place for a few lines of comments explaining each relocation type?

[jpienaar]

include/llvm/Support/ELFRelocs/Lanai.def

6

Looking at the other backends, the relocation types are not normally documented in ELFRelocs/X.def. Rather the explanation of relocation types is commonly done in lib/Target/X/MCTargetDesc/XFixupKinds.h.

[echristo]

One inline comment. Are there any more testcases to test RelocToApply, readobj, etc?

-eric

include/llvm/Support/ELF.h

322

Add the extra comma at the end here...

[t.p.northover]

include/llvm/Object/RelocVisitor.h

323

What's the user of this function? It appears to be untested.

include/llvm/Support/ELFRelocs/Lanai.def

6

Fixups aren't usually in 1-1 correspondence with relocations. Normally relocs are documented in a platform's ABI document, but I Lanai's intending to do it in-tree isn't it?

If so, this file looks like a reasonable place since they're all together here.

test/Object/Lanai/yaml2obj-elf-lanai-rel.yaml

6

The other relocs should probably be tested too. It'd be good to test the actual numbers as well, if Lanai has any ABI stability expectations.

[jpienaar]

Addressed comments, added readobj and dwarfdump tests.

[jpienaar]

Updated, thanks

include/llvm/Object/RelocVisitor.h

323

It is used by dwarfdump. Adding test for it.

[t.p.northover]

Thanks, this looks fine now.

Tim.

[jpienaar]

Thanks, if none of the other reviewers have an objection, I'll submit this tomorrow.

[echristo]

It's good. Go ahead. :)

include/llvm/Object/ELFObjectFile.h

     case ELF::EM_X86_64:
       return "ELF32-x86-64";
     case ELF::EM_ARM:
       return (IsLittleEndian ? "ELF32-arm-little" : "ELF32-arm-big");
     case ELF::EM_AVR:
       return "ELF32-avr";
     case ELF::EM_HEXAGON:
       return "ELF32-hexagon";
+    case ELF::EM_LANAI:
+      return "ELF32-lanai";
     case ELF::EM_MIPS:
       return "ELF32-mips";
     case ELF::EM_PPC:
       return "ELF32-ppc";
     case ELF::EM_SPARC:
     case ELF::EM_SPARC32PLUS:
       return "ELF32-sparc";
     case ELF::EM_WEBASSEMBLY:

   case ELF::EM_AARCH64:
     return Triple::aarch64;
   case ELF::EM_ARM:
     return Triple::arm;
   case ELF::EM_AVR:
     return Triple::avr;
   case ELF::EM_HEXAGON:
     return Triple::hexagon;
+  case ELF::EM_LANAI:
+    return Triple::lanai;
   case ELF::EM_MIPS:
     switch (EF.getHeader()->e_ident[ELF::EI_CLASS]) {
     case ELF::ELFCLASS32:
       return IsLittleEndian ? Triple::mipsel : Triple::mips;
     case ELF::ELFCLASS64:
       return IsLittleEndian ? Triple::mips64el : Triple::mips64;
     default:
       report_fatal_error("Invalid ELFCLASS!");

include/llvm/Object/RelocVisitor.h

       case Triple::armeb:
         switch (RelocType) {
         default:
           HasError = true;
           return RelocToApply();
         case llvm::ELF::R_ARM_ABS32:
           return visitELF_ARM_ABS32(R, Value);
         }
+      case Triple::lanai:
+        switch (RelocType) {
+        case llvm::ELF::R_LANAI_32:
+          return visitELF_Lanai_32(R, Value);
+        default:
+          HasError = true;
+          return RelocToApply();
+        }
       case Triple::mipsel:
       case Triple::mips:
         switch (RelocType) {
         case llvm::ELF::R_MIPS_32:
           return visitELF_MIPS_32(R, Value);
         default:
           HasError = true;
           return RelocToApply();

 
   /// PPC32 ELF
   RelocToApply visitELF_PPC_ADDR32(RelocationRef R, uint64_t Value) {
     int64_t Addend = getELFAddend(R);
     uint32_t Res = (Value + Addend) & 0xFFFFFFFF;
     return RelocToApply(Res, 4);
   }
 
+  /// Lanai ELF
+  RelocToApply visitELF_Lanai_32(RelocationRef R, uint64_t Value) {
+    int64_t Addend = getELFAddend(R);
+    uint32_t Res = (Value + Addend) & 0xFFFFFFFF;
+    return RelocToApply(Res, 4);
+  }
+
   /// MIPS ELF
   RelocToApply visitELF_MIPS_32(RelocationRef R, uint64_t Value) {
     uint32_t Res = Value & 0xFFFFFFFF;
     return RelocToApply(Res, 4);
   }
 
   /// MIPS64 ELF
   RelocToApply visitELF_MIPS64_32(RelocationRef R, uint64_t Value) {

include/llvm/Support/ELF.h

   EM_NORC          = 218, // Nanoradio Optimized RISC
   EM_CSR_KALIMBA   = 219, // CSR Kalimba architecture family
   EM_AMDGPU        = 224, // AMD GPU architecture
 
   // A request has been made to the maintainer of the official registry for
   // such numbers for an official value for WebAssembly. As soon as one is
   // allocated, this enum will be updated to use it.
   EM_WEBASSEMBLY   = 0x4157, // WebAssembly architecture
+
+  // A request has been made to the maintainer of the official registry for
+  // an official value for Lanai. As soon as one is allocated, this enum will be
+  // updated to use it.
+  EM_LANAI         = 0x8123  // Lanai 32-bit processor
 };
 
 // Object file classes.
 enum {
   ELFCLASSNONE = 0,
   ELFCLASS32 = 1, // 32-bit object file
   ELFCLASS64 = 2  // 64-bit object file
 };

   SHN_HEXAGON_SCOMMON_8   = 0xff04        // Double-word-size access
 };
 
 // ELF Relocation types for Hexagon
 enum {
 #include "ELFRelocs/Hexagon.def"
 };
 
+// ELF Relocation type for Lanai.
+enum {
+#include "ELFRelocs/Lanai.def"
+};
+
 // ELF Relocation types for S390/zSeries
 enum {
 #include "ELFRelocs/SystemZ.def"
 };
 
 // ELF Relocation type for Sparc.
 enum {
 #include "ELFRelocs/Sparc.def"

include/llvm/Support/ELFRelocs/Lanai.def

+
+#ifndef ELF_RELOC
+#error "ELF_RELOC must be defined"
+#endif
+
+ELF_RELOC(R_LANAI_NONE,        0)
+ELF_RELOC(R_LANAI_21,          1)
+ELF_RELOC(R_LANAI_21_F,        2)
+ELF_RELOC(R_LANAI_25,          3)
+ELF_RELOC(R_LANAI_32,          4)
+ELF_RELOC(R_LANAI_HI16,        5)
+ELF_RELOC(R_LANAI_LO16,        6)

lib/MC/MCObjectFileInfo.cpp

       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;
       TTypeEncoding = dwarf::DW_EH_PE_absptr;
     }
     break;
+  case Triple::lanai:
+    LSDAEncoding = dwarf::DW_EH_PE_absptr;
+    PersonalityEncoding = dwarf::DW_EH_PE_absptr;
+    TTypeEncoding = dwarf::DW_EH_PE_absptr;
+    break;
   case Triple::mips:
   case Triple::mipsel:
   case Triple::mips64:
   case Triple::mips64el:
     // MIPS uses indirect pointer to refer personality functions and types, so
     // that the eh_frame section can be read-only. DW.ref.personality will be
     // generated for relocation.
     PersonalityEncoding = dwarf::DW_EH_PE_indirect;

lib/Object/ELF.cpp

     break;
   case ELF::EM_HEXAGON:
     switch (Type) {
 #include "llvm/Support/ELFRelocs/Hexagon.def"
     default:
       break;
     }
     break;
+  case ELF::EM_LANAI:
+    switch (Type) {
+#include "llvm/Support/ELFRelocs/Lanai.def"
+    default:
+      break;
+    }
+    break;
   case ELF::EM_PPC:
     switch (Type) {
 #include "llvm/Support/ELFRelocs/PowerPC.def"
     default:
       break;
     }
     break;
   case ELF::EM_PPC64:

lib/Object/ELFYAML.cpp

   ECase(EM_COREA_2ND)
   ECase(EM_ARC_COMPACT2)
   ECase(EM_OPEN8)
   ECase(EM_RL78)
   ECase(EM_VIDEOCORE5)
   ECase(EM_78KOR)
   ECase(EM_56800EX)
   ECase(EM_AMDGPU)
+  ECase(EM_LANAI)
 #undef ECase
 }
 
 void ScalarEnumerationTraits<ELFYAML::ELF_ELFCLASS>::enumeration(
     IO &IO, ELFYAML::ELF_ELFCLASS &Value) {
 #define ECase(X) IO.enumCase(Value, #X, ELF::X);
   // Since the semantics of ELFCLASSNONE is "invalid", just don't accept it
   // here.

 #include "llvm/Support/ELFRelocs/i386.def"
     break;
   case ELF::EM_AARCH64:
 #include "llvm/Support/ELFRelocs/AArch64.def"
     break;
   case ELF::EM_ARM:
 #include "llvm/Support/ELFRelocs/ARM.def"
     break;
+  case ELF::EM_LANAI:
+#include "llvm/Support/ELFRelocs/Lanai.def"
+    break;
   default:
     llvm_unreachable("Unsupported architecture");
   }
 #undef ELF_RELOC
 }
 
 void ScalarEnumerationTraits<ELFYAML::MIPS_AFL_REG>::enumeration(
     IO &IO, ELFYAML::MIPS_AFL_REG &Value) {

test/Object/Lanai/lit.local.cfg

+if not 'Lanai' in config.root.targets:
+    config.unsupported = True

test/Object/Lanai/yaml2obj-elf-lanai-rel.yaml

+# RUN: yaml2obj -format=elf %s > %t
+# RUN: llvm-readobj -r %t | FileCheck %s
+
+# CHECK:      Relocations [
+# CHECK-NEXT:   Section (2) .rel.text {
+# CHECK-NEXT:     0x0 R_LANAI_32 main 0x0
+# CHECK-NEXT:   }
+# CHECK-NEXT: ]
+
+FileHeader:
+  Class:           ELFCLASS32
+  Data:            ELFDATA2LSB
+  Type:            ET_REL
+  Machine:         EM_LANAI
+Sections:
+  - Type:            SHT_PROGBITS
+    Name:            .text
+    Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
+    AddressAlign:    0x04
+    Content:         0000000000000000
+  - Type:            SHT_REL
+    Name:            .rel.text
+    Link:            .symtab
+    Info:            .text
+    AddressAlign:    0x04
+    Relocations:
+      - Offset:          0
+        Symbol:          main
+        Type:            R_LANAI_32
+
+Symbols:
+  Local:
+    - Name:            .text
+      Type:            STT_SECTION
+      Section:         .text
+
+  Global:
+    - Name:            main
+      Type:            STT_FUNC
+      Section:         .text
+      Size:            0x08