Commit 3822e3d5 authored by Vy Nguyen's avatar Vy Nguyen
Browse files

[lld-macho] Fix bug in handling unwind info from ld -r 

Two changess:
- Drop assertions that all symbols are in GOT
- Set allEntriesAreOmitted correctly

Related bug: 50812

Differential Revision: https://reviews.llvm.org/D105364
parent e5220104

lld/MachO/UnwindInfoSection.cpp

+8 −4
Original line number Diff line number Diff line
@@ -167,7 +167,12 @@ void UnwindInfoSectionImpl<Ptr>::prepareRelocations(ConcatInputSection *isec) { 
    assert(target->hasAttr(r.type, RelocAttrBits::UNSIGNED));



    if (r.offset % sizeof(CompactUnwindEntry<Ptr>) == 0) {

      if (auto *referentIsec = r.referent.dyn_cast<InputSection *>())

      InputSection *referentIsec;

      if (auto *isec = r.referent.dyn_cast<InputSection *>())

        referentIsec = isec;

      else

        referentIsec = cast<Defined>(r.referent.dyn_cast<Symbol *>())->isec;



      if (!cast<ConcatInputSection>(referentIsec)->shouldOmitFromOutput())

        allEntriesAreOmitted = false;

      continue;
@@ -257,7 +262,6 @@ relocateCompactUnwind(ConcatOutputSection *compactUnwindSection, 
      uint64_t referentVA = TombstoneValue<Ptr>;

      if (auto *referentSym = r.referent.dyn_cast<Symbol *>()) {

        if (!isa<Undefined>(referentSym)) {

          assert(referentSym->isInGot());

          if (auto *defined = dyn_cast<Defined>(referentSym))

            checkTextSegment(defined->isec);

          // At this point in the link, we may not yet know the final address of

lld/test/MachO/relocs-syms-not-in-got.s

0 → 100644
+101 −0
Original line number Diff line number Diff line 
# REQUIRES: x86

## These yaml files were  from an object file produced with 'ld -r', specifically:

##

##  // foo.s

## .text

## .globl _main

## _main:

##   .cfi_startproc

##   .cfi_def_cfa_offset 16

##   .cfi_endproc

##   nop

##

## llvm-mc -filetype=obj -triple=x86_64-apple-macos10.15 -o foo1.o foo.s

## ld -r -o foo.o foo1.o





# RUN: rm -rf %t; mkdir -p %t

# RUN: yaml2obj %s -o %t/foo.o

# RUN: %lld -o %t/a.out %t/foo.o



--- !mach-o

FileHeader:

  magic:           0xFEEDFACF

  cputype:         0x01000007

  cpusubtype:      0x00000003

  filetype:        0x00000001

  ncmds:           2

  sizeofcmds:      384

  flags:           0x00000000

  reserved:        0x00000000

LoadCommands:

  - cmd:             LC_SEGMENT_64

    cmdsize:         312

    segname:         ''

    vmaddr:          0

    vmsize:          64

    fileoff:         448

    filesize:        64

    maxprot:         7

    initprot:        7

    nsects:          2

    flags:           0

    Sections:

      - sectname:        __text

        segname:         __TEXT

        addr:            0x0000000000000000

        size:            1

        offset:          0x000001C0

        align:           0

        reloff:          0x00000000

        nreloc:          0

        flags:           0x80000400

        reserved1:       0x00000000

        reserved2:       0x00000000

        reserved3:       0x00000000

        content:         '90'

      - sectname:        __compact_unwind

        segname:         __LD

        addr:            0x0000000000000020

        size:            32

        offset:          0x000001E0

        align:           3

        reloff:          0x00000200

        nreloc:          1

        flags:           0x02000000

        reserved1:       0x00000000

        reserved2:       0x00000000

        reserved3:       0x00000000

        content:         '0000000000000000010000000000020200000000000000000000000000000000'

        relocations:

          - address:         0x00000000

            symbolnum:       1

            pcrel:           false

            length:          3

            extern:          true

            type:            0

            scattered:       false

            value:           0

  - cmd:             LC_SYMTAB

    cmdsize:         24

    symoff:          520

    nsyms:           2

    stroff:          552

    strsize:         24

LinkEditData:

  NameList:

    - n_strx:          8

      n_type:          0x0E

      n_sect:          2

      n_desc:          0

      n_value:         8

    - n_strx:          2

      n_type:          0x0F

      n_sect:          1

      n_desc:          32

      n_value:         0

  StringTable:

    - ' '

    - _main



...