[yaml2obj][obj2yaml][objdump] Handle LoongArch COFF files

- handle IMAGE_FILE_MACHINE_LOONGARCH64 machine type
- handle LOONGARCH COFF relocations

This patch is inspired by Mips's pr llvm#112591.

Author: leecheechen

llvm/include/llvm/ObjectYAML/COFFYAML.h

@@ -179,6 +179,10 @@ struct ScalarEnumerationTraits<COFF::RelocationTypeAMD64> {
   static void enumeration(IO &IO, COFF::RelocationTypeAMD64 &Value);
 };
 
+template <> struct ScalarEnumerationTraits<COFF::RelocationTypesLoongArch> {
+  static void enumeration(IO &IO, COFF::RelocationTypesLoongArch &Value);
+};
+
 template <> struct ScalarEnumerationTraits<COFF::RelocationTypesMips> {
   static void enumeration(IO &IO, COFF::RelocationTypesMips &Value);
 };

llvm/lib/ObjectYAML/COFFYAML.cpp

@@ -80,6 +80,7 @@ void ScalarEnumerationTraits<COFF::MachineTypes>::enumeration(
   ECase(IMAGE_FILE_MACHINE_RISCV32);
   ECase(IMAGE_FILE_MACHINE_RISCV64);
   ECase(IMAGE_FILE_MACHINE_RISCV128);
+  ECase(IMAGE_FILE_MACHINE_LOONGARCH64);
   ECase(IMAGE_FILE_MACHINE_SH3);
   ECase(IMAGE_FILE_MACHINE_SH3DSP);
   ECase(IMAGE_FILE_MACHINE_SH4);
@@ -183,6 +184,24 @@ void ScalarEnumerationTraits<COFF::RelocationTypeAMD64>::enumeration(
   ECase(IMAGE_REL_AMD64_SSPAN32);
 }
 
+void ScalarEnumerationTraits<COFF::RelocationTypesLoongArch>::enumeration(
+    IO &IO, COFF::RelocationTypesLoongArch &Value) {
+  ECase(IMAGE_REL_LARCH_ABSOLUTE);
+  ECase(IMAGE_REL_LARCH_ADDR32);
+  ECase(IMAGE_REL_LARCH_ADDR32NB);
+  ECase(IMAGE_REL_LARCH_BRANCH26);
+  ECase(IMAGE_REL_LARCH_SECREL);
+  ECase(IMAGE_REL_LARCH_SECTION);
+  ECase(IMAGE_REL_LARCH_ADDR64);
+  ECase(IMAGE_REL_LARCH_ADDR_HI20);
+  ECase(IMAGE_REL_LARCH_ADDR_LO12);
+  ECase(IMAGE_REL_LARCH_ADDR64_LO20);
+  ECase(IMAGE_REL_LARCH_ADDR64_HI12);
+  ECase(IMAGE_REL_LARCH_BRANCH21);
+  ECase(IMAGE_REL_LARCH_BRANCH16);
+  ECase(IMAGE_REL_LARCH_REL32);
+}
+
 void ScalarEnumerationTraits<COFF::RelocationTypesMips>::enumeration(
     IO &IO, COFF::RelocationTypesMips &Value) {
   ECase(IMAGE_REL_MIPS_ABSOLUTE);
@@ -446,6 +465,10 @@ 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_LOONGARCH64) {
+    MappingNormalization<NType<COFF::RelocationTypesLoongArch>, 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);

llvm/test/tools/yaml2obj/COFF/basic-loongarch64.yaml

@@ -0,0 +1,39 @@
+# RUN: yaml2obj %s -o %t
+# RUN: llvm-readobj --file-headers --relocs %t | FileCheck %s
+# RUN: obj2yaml %t | FileCheck %s --check-prefix=ROUNDTRIP
+
+# CHECK: Format: COFF-LoongArch64
+# CHECK: Arch: loongarch64
+# CHECK: Machine: IMAGE_FILE_MACHINE_LOONGARCH64 (0x6264)
+# CHECK: Relocations [
+# CHECK:  Section (1) .text {
+# CHECK:    0x4 IMAGE_REL_LARCH_BRANCH26 main (0)
+# CHECK:  }
+# CHECK: ]
+
+# ROUNDTRIP:      Machine: IMAGE_FILE_MACHINE_LOONGARCH64
+# ROUNDTRIP:      Relocations:
+# ROUNDTRIP-NEXT: - VirtualAddress: 4
+# ROUNDTRIP-NEXT:   SymbolName:     main
+# ROUNDTRIP-NEXT:   Type:           IMAGE_REL_LARCH_BRANCH26
+
+--- !COFF
+header:
+  Machine:         IMAGE_FILE_MACHINE_LOONGARCH64
+sections:
+  - Name:            .text
+    Characteristics: [ IMAGE_SCN_CNT_CODE, IMAGE_SCN_MEM_EXECUTE, IMAGE_SCN_MEM_READ ]
+    VirtualSize:     12
+    SectionData:     000000000000000C00000000
+    Relocations:
+      - VirtualAddress:  4
+        SymbolName:      main
+        Type:            IMAGE_REL_LARCH_BRANCH26
+symbols:
+  - Name: main
+    Value: 0
+    SectionNumber: 1
+    SimpleType: IMAGE_SYM_TYPE_NULL
+    ComplexType: IMAGE_SYM_DTYPE_NULL
+    StorageClass: IMAGE_SYM_CLASS_EXTERNAL
+...