Index: llvm/lib/DebugInfo/DWARF/DWARFDebugFrame.cpp =================================================================== --- llvm/lib/DebugInfo/DWARF/DWARFDebugFrame.cpp +++ llvm/lib/DebugInfo/DWARF/DWARFDebugFrame.cpp @@ -380,7 +380,7 @@ uint64_t EndStructureOffset = Offset + Length; // The Id field's size depends on the DWARF format - Id = Data.getUnsigned(&Offset, (IsDWARF64 && !IsEH) ? 8 : 4); + Id = Data.getRelocatedValue((IsDWARF64 && !IsEH) ? 8 : 4, &Offset); bool IsCIE = ((IsDWARF64 && Id == DW64_CIE_ID) || Id == DW_CIE_ID || (IsEH && !Id)); Index: llvm/test/DebugInfo/debug-frame-cieid-reloc.test =================================================================== --- /dev/null +++ llvm/test/DebugInfo/debug-frame-cieid-reloc.test @@ -0,0 +1,45 @@ +# RUN: yaml2obj %s -o - | \ +# RUN: llvm-dwarfdump -debug-frame - | \ +# RUN: FileCheck %s + +## This checks that we resolve relocations when reading CIE pointers. +## The second FDE references the second CIE. The value for the CIE pointer +## field in the raw section data is 0, thus, to recover the real reference +## it is required to read the addend from the corresponding RELA relocation. + +# CHECK: .debug_frame contents: +# CHECK: 00000000 0000000c ffffffff CIE +# CHECK: 00000010 00000014 00000000 FDE cie=00000000 pc=00000000...00000001 +# CHECK: 00000028 0000000c ffffffff CIE +# CHECK: 00000038 00000014 00000028 FDE cie=00000028 pc=00000010...00000011 + +--- !ELF +FileHeader: + Class: ELFCLASS64 + Data: ELFDATA2LSB + Type: ET_REL + Machine: EM_X86_64 +Sections: + - Name: .debug_frame + Type: SHT_PROGBITS + AddressAlign: 0x0000000000000001 + Content: 0C000000FFFFFFFF02000178100000001400000000000000000000000000000001000000000000000C000000FFFFFFFF0200017810000000140000000000000010000000000000000100000000000000 + - Name: .rela.debug_frame + Type: SHT_RELA + Link: .symtab + AddressAlign: 0x0000000000000008 + EntSize: 0x0000000000000018 + Info: .debug_frame + Relocations: + - Offset: 0x0000000000000014 + Symbol: .debug_frame + Type: R_X86_64_32 + - Offset: 0x000000000000003C + Symbol: .debug_frame + Type: R_X86_64_32 + Addend: 40 +Symbols: + - Name: .debug_frame + Type: STT_SECTION + Section: .debug_frame +...