[yaml2obj][objdump] Handle IMAGE_FILE_MACHINE_R4000 machine type and MIPS COFF relocations

llvm-objdump can now parse MIPS COFF files.

Author: hpoussin

lld/COFF/Config.h

@@ -40,6 +40,7 @@ static const auto ARM64EC = llvm::COFF::IMAGE_FILE_MACHINE_ARM64EC;
 static const auto ARM64X = llvm::COFF::IMAGE_FILE_MACHINE_ARM64X;
 static const auto ARMNT = llvm::COFF::IMAGE_FILE_MACHINE_ARMNT;
 static const auto I386 = llvm::COFF::IMAGE_FILE_MACHINE_I386;
+static const auto MIPS = llvm::COFF::IMAGE_FILE_MACHINE_R4000;
 
 enum class ExportSource {
   Unset,

llvm/include/llvm/Object/WindowsMachineFlag.h

@@ -43,6 +43,8 @@ template <typename T> Triple::ArchType getMachineArchType(T machine) {
   case COFF::IMAGE_FILE_MACHINE_ARM64EC:
   case COFF::IMAGE_FILE_MACHINE_ARM64X:
     return llvm::Triple::ArchType::aarch64;
+  case COFF::IMAGE_FILE_MACHINE_R4000:
+    return llvm::Triple::ArchType::mipsel;
   default:
     return llvm::Triple::ArchType::UnknownArch;
   }

llvm/include/llvm/ObjectYAML/COFFYAML.h

@@ -179,6 +179,11 @@ struct ScalarEnumerationTraits<COFF::RelocationTypeAMD64> {
   static void enumeration(IO &IO, COFF::RelocationTypeAMD64 &Value);
 };
 
+template <>
+struct ScalarEnumerationTraits<COFF::RelocationTypesMips> {
+  static void enumeration(IO &IO, COFF::RelocationTypesMips &Value);
+};
+
 template <>
 struct ScalarEnumerationTraits<COFF::RelocationTypesARM> {
   static void enumeration(IO &IO, COFF::RelocationTypesARM &Value);

llvm/lib/Object/COFFObjectFile.cpp

@@ -1132,6 +1132,8 @@ StringRef COFFObjectFile::getFileFormatName() const {
     return "COFF-ARM64EC";
   case COFF::IMAGE_FILE_MACHINE_ARM64X:
     return "COFF-ARM64X";
+  case COFF::IMAGE_FILE_MACHINE_R4000:
+    return "COFF-R4000";
   default:
     return "COFF-<unknown arch>";
   }

llvm/lib/Object/WindowsMachineFlag.cpp

@@ -28,6 +28,8 @@ COFF::MachineTypes llvm::getMachineType(StringRef S) {
       .Case("arm64", COFF::IMAGE_FILE_MACHINE_ARM64)
       .Case("arm64ec", COFF::IMAGE_FILE_MACHINE_ARM64EC)
       .Case("arm64x", COFF::IMAGE_FILE_MACHINE_ARM64X)
+      .Case("mips", COFF::IMAGE_FILE_MACHINE_R4000) // also handle mips (big-endian) because we want to support '/machine:MIPS'
+      .Case("mipsel", COFF::IMAGE_FILE_MACHINE_R4000)
       .Default(COFF::IMAGE_FILE_MACHINE_UNKNOWN);
 }
 
@@ -45,6 +47,8 @@ StringRef llvm::machineToStr(COFF::MachineTypes MT) {
     return "x64";
   case COFF::IMAGE_FILE_MACHINE_I386:
     return "x86";
+  case COFF::IMAGE_FILE_MACHINE_R4000:
+    return "mipsel";
   default:
     llvm_unreachable("unknown machine type");
   }

llvm/lib/ObjectYAML/COFFYAML.cpp

@@ -183,6 +183,25 @@ void ScalarEnumerationTraits<COFF::RelocationTypeAMD64>::enumeration(
   ECase(IMAGE_REL_AMD64_SSPAN32);
 }
 
+void ScalarEnumerationTraits<COFF::RelocationTypesMips>::enumeration(
+    IO &IO, COFF::RelocationTypesMips &Value) {
+  ECase(IMAGE_REL_MIPS_ABSOLUTE);
+  ECase(IMAGE_REL_MIPS_REFHALF);
+  ECase(IMAGE_REL_MIPS_REFWORD);
+  ECase(IMAGE_REL_MIPS_JMPADDR);
+  ECase(IMAGE_REL_MIPS_REFHI);
+  ECase(IMAGE_REL_MIPS_REFLO);
+  ECase(IMAGE_REL_MIPS_GPREL);
+  ECase(IMAGE_REL_MIPS_LITERAL);
+  ECase(IMAGE_REL_MIPS_SECTION);
+  ECase(IMAGE_REL_MIPS_SECREL);
+  ECase(IMAGE_REL_MIPS_SECRELLO);
+  ECase(IMAGE_REL_MIPS_SECRELHI);
+  ECase(IMAGE_REL_MIPS_JMPADDR16);
+  ECase(IMAGE_REL_MIPS_REFWORDNB);
+  ECase(IMAGE_REL_MIPS_PAIR);
+}
+
 void ScalarEnumerationTraits<COFF::RelocationTypesARM>::enumeration(
     IO &IO, COFF::RelocationTypesARM &Value) {
   ECase(IMAGE_REL_ARM_ABSOLUTE);
@@ -427,6 +446,10 @@ void MappingTraits<COFFYAML::Relocation>::mapping(IO &IO,
     MappingNormalization<NType<COFF::RelocationTypeAMD64>, uint16_t> NT(
         IO, Rel.Type);
     IO.mapRequired("Type", NT->Type);
+  } else if (H.Machine == COFF::IMAGE_FILE_MACHINE_R4000) {
+    MappingNormalization<NType<COFF::RelocationTypesMips>, uint16_t> NT(
+        IO, Rel.Type);
+    IO.mapRequired("Type", NT->Type);
   } else if (H.Machine == COFF::IMAGE_FILE_MACHINE_ARMNT) {
     MappingNormalization<NType<COFF::RelocationTypesARM>, uint16_t> NT(
         IO, Rel.Type);

llvm/lib/ObjectYAML/CodeViewYAMLSymbols.cpp

@@ -171,6 +171,9 @@ void ScalarEnumerationTraits<RegisterId>::enumeration(IO &io, RegisterId &Reg) {
   case COFF::IMAGE_FILE_MACHINE_ARM64X:
     CpuType = CPUType::ARM64;
     break;
+  case COFF::IMAGE_FILE_MACHINE_R4000:
+    CpuType = CPUType::MIPSIII;
+    break;
   }
 
   if (CpuType)

llvm/test/Object/Inputs/COFF/mipsel.yaml

@@ -0,0 +1,8 @@
+!COFF
+header: !Header
+  Machine: IMAGE_FILE_MACHINE_R4000 # (0x166)
+  Characteristics: [ IMAGE_FILE_DEBUG_STRIPPED ]
+
+sections:
+
+symbols:

llvm/test/Object/objdump-section-content.test

@@ -39,3 +39,7 @@ Sections:
 
 # BSS: Contents of section .bss:
 # BSS-NEXT: <skipping contents of bss section at [12c8, 12cc)>
+
+# RUN: yaml2obj %p/Inputs/COFF/mipsel.yaml | llvm-objdump -s - | FileCheck %s --check-prefix=COFF-R4000
+
+# COFF-R4000: <stdin>:     file format coff-r4000