[WebAssembly] Add a EM_WEBASSEMBLY value, and several bits of code that use it.

A request has been made to the official registry, but an official value is
not yet available. This patch uses a temporary value in order to support
development. When an official value is recieved, the value of EM_WEBASSEMBLY
will be updated.

llvm-svn: 257517

llvm/include/llvm/Object/ELFObjectFile.h

@@ -842,6 +842,8 @@ StringRef ELFObjectFile<ELFT>::getFileFormatName() const {
     case ELF::EM_SPARC:
     case ELF::EM_SPARC32PLUS:
       return "ELF32-sparc";
+    case ELF::EM_WEBASSEMBLY:
+      return "ELF32-wasm";
     default:
       return "ELF32-unknown";
     }
@@ -861,6 +863,8 @@ StringRef ELFObjectFile<ELFT>::getFileFormatName() const {
       return "ELF64-sparc";
     case ELF::EM_MIPS:
       return "ELF64-mips";
+    case ELF::EM_WEBASSEMBLY:
+      return "ELF64-wasm";
     default:
       return "ELF64-unknown";
     }
@@ -908,6 +912,12 @@ unsigned ELFObjectFile<ELFT>::getArch() const {
     return IsLittleEndian ? Triple::sparcel : Triple::sparc;
   case ELF::EM_SPARCV9:
     return Triple::sparcv9;
+  case ELF::EM_WEBASSEMBLY:
+    switch (EF.getHeader()->e_ident[ELF::EI_CLASS]) {
+    case ELF::ELFCLASS32: return Triple::wasm32;
+    case ELF::ELFCLASS64: return Triple::wasm64;
+    default: return Triple::UnknownArch;
+    }
 
   default:
     return Triple::UnknownArch;

llvm/include/llvm/Support/ELF.h

@@ -309,7 +309,12 @@ enum {
   EM_COOL          = 217, // iCelero CoolEngine
   EM_NORC          = 218, // Nanoradio Optimized RISC
   EM_CSR_KALIMBA   = 219, // CSR Kalimba architecture family
-  EM_AMDGPU        = 224  // AMD GPU architecture
+  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
 };
 
 // Object file classes.

llvm/lib/Object/ELF.cpp

@@ -91,6 +91,13 @@ StringRef getELFRelocationTypeName(uint32_t Machine, uint32_t Type) {
       break;
     }
     break;
+  case ELF::EM_WEBASSEMBLY:
+    switch (Type) {
+#include "llvm/Support/ELFRelocs/WebAssembly.def"
+    default:
+      break;
+    }
+    break;
   default:
     break;
   }

llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyELFObjectWriter.cpp

@@ -30,13 +30,10 @@ protected:
 };
 } // end anonymous namespace
 
-// FIXME: Use EM_NONE as a temporary hack. Should we decide to pursue ELF
-// writing seriously, we should email generic-abi@googlegroups.com and ask
-// for our own ELF code.
 WebAssemblyELFObjectWriter::WebAssemblyELFObjectWriter(bool Is64Bit,
                                                        uint8_t OSABI)
-    : MCELFObjectTargetWriter(Is64Bit, OSABI, ELF::EM_NONE,
-                              /*HasRelocationAddend=*/true) {}
+    : MCELFObjectTargetWriter(Is64Bit, OSABI, ELF::EM_WEBASSEMBLY,
+                              /*HasRelocationAddend=*/false) {}
 
 unsigned WebAssemblyELFObjectWriter::GetRelocType(const MCValue &Target,
                                                   const MCFixup &Fixup,

llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyTargetStreamer.h

@@ -16,6 +16,7 @@
 #ifndef LLVM_LIB_TARGET_WEBASSEMBLY_MCTARGETDESC_WEBASSEMBLYTARGETSTREAMER_H
 #define LLVM_LIB_TARGET_WEBASSEMBLY_MCTARGETDESC_WEBASSEMBLYTARGETSTREAMER_H
 
+#include "llvm/CodeGen/MachineValueType.h"
 #include "llvm/MC/MCStreamer.h"
 
 namespace llvm {

llvm/test/CodeGen/WebAssembly/func.ll

@@ -7,6 +7,7 @@ target triple = "wasm32-unknown-unknown"
 
 ; CHECK-LABEL: f0:
 ; CHECK: return{{$}}
+; CHECK: .endfunc{{$}}
 ; CHECK: .size f0,
 define void @f0() {
   ret void

llvm/tools/llvm-objdump/llvm-objdump.cpp

@@ -482,6 +482,23 @@ static std::error_code getRelocationValueString(const ELFObjectFile<ELFT> *Obj,
   case ELF::EM_MIPS:
     res = Target;
     break;
+  case ELF::EM_WEBASSEMBLY:
+    switch (type) {
+    case ELF::R_WEBASSEMBLY_DATA: {
+      std::string fmtbuf;
+      raw_string_ostream fmt(fmtbuf);
+      fmt << Target << (addend < 0 ? "" : "+") << addend;
+      fmt.flush();
+      Result.append(fmtbuf.begin(), fmtbuf.end());
+      break;
+    }
+    case ELF::R_WEBASSEMBLY_FUNCTION:
+      res = Target;
+      break;
+    default:
+      res = "Unknown";
+    }
+    break;
   default:
     res = "Unknown";
   }

llvm/tools/llvm-readobj/ELFDumper.cpp

@@ -708,7 +708,8 @@ static const EnumEntry<unsigned> ElfMachineType[] = {
   LLVM_READOBJ_ENUM_ENT(ELF, EM_VIDEOCORE5   ),
   LLVM_READOBJ_ENUM_ENT(ELF, EM_78KOR        ),
   LLVM_READOBJ_ENUM_ENT(ELF, EM_56800EX      ),
-  LLVM_READOBJ_ENUM_ENT(ELF, EM_AMDGPU       )
+  LLVM_READOBJ_ENUM_ENT(ELF, EM_AMDGPU       ),
+  LLVM_READOBJ_ENUM_ENT(ELF, EM_WEBASSEMBLY  ),
 };
 
 static const EnumEntry<unsigned> ElfSymbolBindings[] = {