[Object] Support relocation resolver for CSKY

[zixuan-wu]

Summary

It enables relocation resolver for CSKY to pass some check-all test, and also add some test about dwarf relocs.

[zixuan-wu]

Is there any more part of code or test I should develop in this patch together?

[MaskRay]

llvm/test/DebugInfo/CSKY/eh-frame.s

2

2

Add a file-level comment about the purpose of the test.

[MaskRay]

llvm/lib/Object/RelocationResolver.cpp

502

Remove the variable.

[MaskRay]

[CSKY] Enable relocation resolver for CSKY

Perhaps [Object] Support relocation resolver for CSKY.

"Enable" conveys that something has been already implemented.

[zixuan-wu]

Address comments.

llvm/lib/Object/RelocationResolver.cpp

case ELF::R_RISCV_ADD64:
     return (A + (S + RA));
   case ELF::R_RISCV_SUB64:
     return (A - (S + RA));
   default:
     llvm_unreachable("Invalid relocation type");
   }
 }
 
+static bool supportsCSKY(uint64_t Type) {
+  switch (Type) {
+  case ELF::R_CKCORE_NONE:
+  case ELF::R_CKCORE_ADDR32:
+  case ELF::R_CKCORE_PCREL32:
+    return true;
+  default:
+    return false;
+  }
+}
+
+static uint64_t resolveCSKY(uint64_t Type, uint64_t Offset, uint64_t S,
+                            uint64_t LocData, int64_t Addend) {
+  switch (Type) {
+  case ELF::R_CKCORE_NONE:
+    return LocData;
+  case ELF::R_CKCORE_ADDR32:
+    return (S + Addend) & 0xFFFFFFFF;
+  case ELF::R_CKCORE_PCREL32:
+    return (S + Addend - Offset) & 0xFFFFFFFF;
+  default:
+    llvm_unreachable("Invalid relocation type");
+  }
+}
+
 static bool supportsCOFFX86(uint64_t Type) {
   switch (Type) {
   case COFF::IMAGE_REL_I386_SECREL:
   case COFF::IMAGE_REL_I386_DIR32:
     return true;
   default:
     return false;
   }
if (Obj.isCOFF()) {
     case Triple::msp430:
       return {supportsMSP430, resolveMSP430};
     case Triple::sparc:
       return {supportsSparc32, resolveSparc32};
     case Triple::hexagon:
       return {supportsHexagon, resolveHexagon};
     case Triple::riscv32:
       return {supportsRISCV, resolveRISCV};
+    case Triple::csky:
+      return {supportsCSKY, resolveCSKY};
     default:
       return {nullptr, nullptr};
     }
   } else if (Obj.isMachO()) {
     if (Obj.getArch() == Triple::x86_64)
       return {supportsMachOX86_64, resolveMachOX86_64};
     return {nullptr, nullptr};
   } else if (Obj.isWasm()) {

llvm/test/DebugInfo/CSKY/dwarf-csky-relocs.ll

+; RUN: llc -filetype=obj -mtriple=csky %s -o %t.o
+; RUN: llvm-readobj -r %t.o | FileCheck -check-prefix=READOBJ-RELOCS %s
+; RUN: llvm-objdump --source %t.o | FileCheck --check-prefix=OBJDUMP-SOURCE %s
+; RUN: llvm-dwarfdump --debug-info --debug-line %t.o | \
+; RUN:     FileCheck -check-prefix=DWARF-DUMP %s
+
+; Check that we actually have relocations, otherwise this is kind of pointless.
+; READOBJ-RELOCS:  Section ({{.*}}) .rela.debug_info {
+; READOBJ-RELOCS:    0x8 R_CKCORE_ADDR32 .debug_abbrev 0x0
+; READOBJ-RELOCS-NEXT:    0x11 R_CKCORE_ADDR32 .debug_str_offsets 0x8
+; READOBJ-RELOCS-NEXT:    0x15 R_CKCORE_ADDR32 .debug_line 0x0
+; READOBJ-RELOCS-NEXT:    0x1F R_CKCORE_ADDR32 .debug_addr 0x8
+; READOBJ-RELOCS:  Section ({{.*}}) .rela.debug_frame {
+; READOBJ-RELOCS:    0x18 R_CKCORE_ADDR32 .debug_frame 0x0
+; READOBJ-RELOCS-NEXT:    0x1C R_CKCORE_ADDR32 .text 0x0
+; READOBJ-RELOCS:  Section ({{.*}}) .rela.debug_line {
+; READOBJ-RELOCS:    0x22 R_CKCORE_ADDR32 .debug_line_str 0x0
+; READOBJ-RELOCS-NEXT: 0x31 R_CKCORE_ADDR32 .debug_line_str 0x2
+; READOBJ-RELOCS-NEXT: 0x46 R_CKCORE_ADDR32 .debug_line_str 0x16
+; READOBJ-RELOCS-NEXT: 0x4F R_CKCORE_ADDR32 .text 0x0
+
+; Check that we can print the source, even with relocations.
+; OBJDUMP-SOURCE: Disassembly of section .text:
+; OBJDUMP-SOURCE-EMPTY:
+; OBJDUMP-SOURCE-NEXT: 00000000 <main>:
+; OBJDUMP-SOURCE: ; {
+; OBJDUMP-SOURCE: ; return 0;
+
+; Check that we correctly dump the DWARF info, even with relocations.
+; DWARF-DUMP: DW_AT_name        ("dwarf-csky-relocs.c")
+; DWARF-DUMP: DW_AT_comp_dir    (".")
+; DWARF-DUMP: DW_AT_name      ("main")
+; DWARF-DUMP: DW_AT_decl_file ("{{.*}}dwarf-csky-relocs.c")
+; DWARF-DUMP: DW_AT_decl_line (2)
+; DWARF-DUMP: DW_AT_type      (0x00000032 "int")
+; DWARF-DUMP: DW_AT_name      ("int")
+; DWARF-DUMP: DW_AT_encoding  (DW_ATE_signed)
+; DWARF-DUMP: DW_AT_byte_size (0x04)
+
+; DWARF-DUMP: .debug_line contents:
+; DWARF-DUMP-NEXT: debug_line[0x00000000]
+; DWARF-DUMP-NEXT: Line table prologue:
+; DWARF-DUMP-NEXT:     total_length: 0x00000059
+; DWARF-DUMP-NEXT:           format: DWARF32
+; DWARF-DUMP-NEXT:          version: 5
+; DWARF-DUMP-NEXT:     address_size: 4
+; DWARF-DUMP-NEXT:  seg_select_size: 0
+; DWARF-DUMP-NEXT:  prologue_length: 0x0000003e
+; DWARF-DUMP-NEXT:  min_inst_length: 1
+; DWARF-DUMP-NEXT: max_ops_per_inst: 1
+; DWARF-DUMP-NEXT:  default_is_stmt: 1
+; DWARF-DUMP-NEXT:        line_base: -5
+; DWARF-DUMP-NEXT:       line_range: 14
+; DWARF-DUMP-NEXT:      opcode_base: 13
+; DWARF-DUMP-NEXT: standard_opcode_lengths[DW_LNS_copy] = 0
+; DWARF-DUMP-NEXT: standard_opcode_lengths[DW_LNS_advance_pc] = 1
+; DWARF-DUMP-NEXT: standard_opcode_lengths[DW_LNS_advance_line] = 1
+; DWARF-DUMP-NEXT: standard_opcode_lengths[DW_LNS_set_file] = 1
+; DWARF-DUMP-NEXT: standard_opcode_lengths[DW_LNS_set_column] = 1
+; DWARF-DUMP-NEXT: standard_opcode_lengths[DW_LNS_negate_stmt] = 0
+; DWARF-DUMP-NEXT: standard_opcode_lengths[DW_LNS_set_basic_block] = 0
+; DWARF-DUMP-NEXT: standard_opcode_lengths[DW_LNS_const_add_pc] = 0
+; DWARF-DUMP-NEXT: standard_opcode_lengths[DW_LNS_fixed_advance_pc] = 1
+; DWARF-DUMP-NEXT: standard_opcode_lengths[DW_LNS_set_prologue_end] = 0
+; DWARF-DUMP-NEXT: standard_opcode_lengths[DW_LNS_set_epilogue_begin] = 0
+; DWARF-DUMP-NEXT: standard_opcode_lengths[DW_LNS_set_isa] = 1
+; DWARF-DUMP-NEXT: include_directories[  0] = "."
+; DWARF-DUMP-NEXT: file_names[  0]:
+; DWARF-DUMP-NEXT:            name: "dwarf-csky-relocs.c"
+; DWARF-DUMP-NEXT:       dir_index: 0
+; DWARF-DUMP-NEXT:    md5_checksum: ba6dbc7dc09162edb18beacd8474bcd3
+; DWARF-DUMP-NEXT:          source: "int main()\n{\n    return 0;\n}\n"
+; DWARF-DUMP-EMPTY:
+; DWARF-DUMP-NEXT: Address            Line   Column File   ISA Discriminator Flags
+; DWARF-DUMP-NEXT: ------------------ ------ ------ ------ --- ------------- -------------
+; DWARF-DUMP-NEXT: 0x0000000000000000      2      0      0   0             0  is_stmt
+; DWARF-DUMP-NEXT: 0x000000000000000e      3      3      0   0             0  is_stmt prologue_end
+; DWARF-DUMP-NEXT: 0x000000000000001a      3      3      0   0             0  is_stmt end_sequence
+
+; ModuleID = 'dwarf-csky-relocs.c'
+source_filename = "dwarf-csky-relocs.c"
+target datalayout = "e-m:e-S32-p:32:32-i32:32:32-i64:32:32-f32:32:32-f64:32:32-v64:32:32-v128:32:32-a:0:32-Fi32-n32"
+target triple = "csky-unknown-linux"
+
+; Function Attrs: noinline nounwind optnone
+define dso_local i32 @main() #0 !dbg !9 {
+entry:
+  %retval = alloca i32, align 4
+  store i32 0, ptr %retval, align 4
+  ret i32 0, !dbg !14
+}
+
+attributes #0 = { noinline nounwind optnone "frame-pointer"="all" "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="ck810" "target-features"="+2e3,+3e7,+7e10,+cache,+dsp1e2,+dspe60,+e1,+e2,+edsp,+elrw,+hard-tp,+high-registers,+hwdiv,+mp,+mp1e2,+nvic,+trust" }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!2, !3, !4, !5, !6, !7}
+!llvm.ident = !{!8}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, splitDebugInlining: false, nameTableKind: None)
+!1 = !DIFile(filename: "dwarf-csky-relocs.c", directory: ".", checksumkind: CSK_MD5, checksum: "ba6dbc7dc09162edb18beacd8474bcd3", source: "int main()\0A{\0A    return 0;\0A}\0A")
+!2 = !{i32 7, !"Dwarf Version", i32 5}
+!3 = !{i32 2, !"Debug Info Version", i32 3}
+!4 = !{i32 1, !"wchar_size", i32 4}
+!5 = !{i32 7, !"PIC Level", i32 2}
+!6 = !{i32 7, !"PIE Level", i32 2}
+!7 = !{i32 7, !"frame-pointer", i32 2}
+!8 = !{!"clang"}
+!9 = distinct !DISubprogram(name: "main", scope: !1, file: !1, line: 2, type: !10, scopeLine: 2, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !13)
+!10 = !DISubroutineType(types: !11)
+!11 = !{!12}
+!12 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!13 = !{}
+!14 = !DILocation(line: 3, column: 3, scope: !9)

llvm/test/DebugInfo/CSKY/eh-frame.s

+// Test the bits of .eh_frame on CSKY that are already implemented correctly.
+
+# RUN: llvm-mc -filetype=obj -triple=csky %s | llvm-dwarfdump -eh-frame - \
+# RUN:    | FileCheck  %s
+
+func:
+  .cfi_startproc
+  jmp16 r15
+  .cfi_endproc
+
+# CHECK: 00000000 00000010 00000000 CIE
+# CHECK:   Version:               1
+# CHECK:   Augmentation:          "zR"
+# CHECK:   Code alignment factor: 1
+# CHECK:   Data alignment factor: -4
+# CHECK:   Return address column: 15
+# CHECK:   Augmentation data:     1B
+# CHECK:   DW_CFA_def_cfa: R14 +0
+
+# CHECK:   CFA=R14
+#
+# CHECK: 00000014 00000010 00000018 FDE cie=00000000 pc=00000000...00000002
+# CHECK:   DW_CFA_nop:
+# CHECK:   DW_CFA_nop:
+# CHECK:   DW_CFA_nop:
+# CHECK:   0x0: CFA=R14

llvm/test/DebugInfo/CSKY/lit.local.cfg

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