[lld-macho] Use fewer indirections in UnwindInfo implementation

[int3]

Summary

The previous implementation of UnwindInfoSection materialized
all the compact unwind entries & applied their relocations, then parsed
the resulting data to generate the final unwind info. This design had
some unfortunate conseqeuences: since relocations can only be applied
after their referents have had addresses assigned, operations that need
to happen before address assignment must contort themselves. (See
D113582: [lld-macho] Support renaming of LSDA section and observe how this diff greatly simplifies it.)

Moreover, it made synthesizing new compact unwind entries awkward.
Handling PR50956 will require us to do this synthesis, and is the main
motivation behind this diff.

Previously, instead of generating a new CompactUnwindEntry directly, we
would have had to generate a ConcatInputSection with a number of
Relocs that would then get "flattened" into a CompactUnwindEntry.

This diff introduces an internal representation of CompactUnwindEntry
(the former CompactUnwindEntry has been renamed to
CompactUnwindLayout). The new CompactUnwindEntry stores references to
its personality symbol and LSDA section directly, without the use of
Reloc structs.

In addition to being easier to work with, this diff also allows us to
handle unwind info whose personality symbols are located in sections
placed after the __unwind_info.

[int3]

add comment

[int3]

lld/test/MachO/compact-unwind.s

95

it turns out that _my_personality below was keeping _foo and _bar alive as they were all part of the same section, and because I'd neglected to add .subsections_via_symbols to the test file. With _my_personality now in a different section, we need .no_dead_strip to keep these other functions alive.

[thakis]

https://llvm.org/PR50300 looks unrelated. Is that the right PR number?

[int3]

Ah I meant https://github.com/llvm/llvm-project/issues/50300. GH issues that originated from Bugzilla have to use the original Bugzilla bug number...

[oontvoo]

lld/MachO/UnwindInfoSection.cpp

107

IIRC, this was changed to Ptr (it was originally uint64_t) because of an overflow bug on 32-bit platforms ...

[int3]

lld/MachO/UnwindInfoSection.cpp

107

maybe you were thinking of D107035: [lld-macho] Change personalities entry type to Ptr to avoid overflowing uint32?

[oontvoo]

LG , except the duplicate structs but then I don't have a better suggestion /shrug

lld/MachO/UnwindInfoSection.cpp

98

It seems a little iffy to me that we need this additional struct ... (Would be great to have only one of these two...)

107

Ah, yes. :)

[int3]

lld/MachO/UnwindInfoSection.cpp

98

mm I further "simplify" it in D123277: [lld-macho][nfc] De-templatize UnwindInfoSection, lmk what you think :)

lld/MachO/InputFiles.cpp

for (auto it = isec->relocs.begin(); it != isec->relocs.end();) {
           continue;
         }
         add += sym->value;
         referentIsec = cast<ConcatInputSection>(sym->isec);
       } else {
         referentIsec =
             cast<ConcatInputSection>(r.referent.dyn_cast<InputSection *>());
       }
+      // Unwind info lives in __DATA, and finalization of __TEXT will occur
+      // before finalization of __DATA. Moreover, the finalization of unwind
+      // info depends on the exact addresses that it references. So it is safe
+      // for compact unwind to reference addresses in __TEXT, but not addresses
+      // in any other segment.
       if (referentIsec->getSegName() != segment_names::text)
         error(isec->getLocation(r.offset) + " references section " +
               referentIsec->getName() + " which is not in segment __TEXT");
       // The functionAddress relocations are typically section relocations.
       // However, unwind info operates on a per-symbol basis, so we search for
       // the function symbol here.
       auto symIt = llvm::lower_bound(
           referentIsec->symbols, add,

lld/MachO/UnwindInfoSection.cpp

 //
 // Refer to the definition of unwind_info_section_header in
 // compact_unwind_encoding.h for an overview of the format we are encoding
 // here.
 
 // TODO(gkm): prune __eh_frame entries superseded by __unwind_info, PR50410
 // TODO(gkm): how do we align the 2nd-level pages?
 
-template <class Ptr> struct CompactUnwindEntry {
+template <class Ptr> struct CompactUnwindLayout {
   Ptr functionAddress;
   uint32_t functionLength;
   compact_unwind_encoding_t encoding;
   Ptr personality;
   Ptr lsda;
 };
 
+struct CompactUnwindEntry {
+  uint64_t functionAddress;
+  uint32_t functionLength;
+  compact_unwind_encoding_t encoding;
+  Symbol *personality;
+  InputSection *lsda;
+};
+
 using EncodingMap = DenseMap<compact_unwind_encoding_t, size_t>;
 
 struct SecondLevelPage {
   uint32_t kind;
   size_t entryIndex;
   size_t entryCount;
   size_t byteCount;
   std::vector<compact_unwind_encoding_t> localEncodings;
   EncodingMap localEncodingIndexes;
 };
 
 template <class Ptr>
 class UnwindInfoSectionImpl final : public UnwindInfoSection {
 public:
   void prepareRelocations(ConcatInputSection *) override;
-  void relocateCompactUnwind(std::vector<CompactUnwindEntry<Ptr>> &);
-  Reloc *findLsdaReloc(ConcatInputSection *) const;
+  void relocateCompactUnwind(std::vector<CompactUnwindEntry> &);
   void encodePersonalities();
   void finalize() override;
   void writeTo(uint8_t *buf) const override;
 
 private:
   std::vector<std::pair<compact_unwind_encoding_t, size_t>> commonEncodings;
   EncodingMap commonEncodingIndexes;
   // The entries here will be in the same order as their originating symbols
   // in symbolsVec.
-  std::vector<CompactUnwindEntry<Ptr>> cuEntries;
+  std::vector<CompactUnwindEntry> cuEntries;
   // Indices into the cuEntries vector.
   std::vector<size_t> cuIndices;
-  // Indices of personality functions within the GOT.
-  std::vector<Ptr> personalities;
+  std::vector<Symbol *> personalities;
   SmallDenseMap<std::pair<InputSection *, uint64_t /* addend */>, Symbol *>
       personalityTable;
   // Indices into cuEntries for CUEs with a non-null LSDA.
   std::vector<size_t> entriesWithLsda;
   // Map of cuEntries index to an index within the LSDA array.
   DenseMap<size_t, uint32_t> lsdaIndex;
   std::vector<SecondLevelPage> secondLevelPages;
   uint64_t level2PagesOffset = 0;
void UnwindInfoSectionImpl<Ptr>::prepareRelocations(ConcatInputSection *isec) {
   for (size_t i = 0; i < isec->relocs.size(); ++i) {
     Reloc &r = isec->relocs[i];
     assert(target->hasAttr(r.type, RelocAttrBits::UNSIGNED));
 
     // Functions and LSDA entries always reside in the same object file as the
     // compact unwind entries that references them, and thus appear as section
     // relocs. There is no need to prepare them. We only prepare relocs for
     // personality functions.
-    if (r.offset % sizeof(CompactUnwindEntry<Ptr>) !=
-        offsetof(CompactUnwindEntry<Ptr>, personality))
+    if (r.offset != offsetof(CompactUnwindLayout<Ptr>, personality))
       continue;
 
     if (auto *s = r.referent.dyn_cast<Symbol *>()) {
       // Personality functions are nearly always system-defined (e.g.,
       // ___gxx_personality_v0 for C++) and relocated as dylib symbols.  When an
       // application provides its own personality function, it might be
       // referenced by an extern Defined symbol reloc, or a local section reloc.
       if (auto *defined = dyn_cast<Defined>(s)) {
if (auto *referentIsec = r.referent.dyn_cast<InputSection *>()) {
         in.got->addEntry(s);
       }
       r.referent = s;
       r.addend = 0;
     }
   }
 }
 
-// Unwind info lives in __DATA, and finalization of __TEXT will occur before
-// finalization of __DATA. Moreover, the finalization of unwind info depends on
-// the exact addresses that it references. So it is safe for compact unwind to
-// reference addresses in __TEXT, but not addresses in any other segment.
-static ConcatInputSection *
-checkTextSegment(InputSection *isec, InputSection *cuIsec, uint64_t off) {
-  if (isec->getSegName() != segment_names::text)
-    error(cuIsec->getLocation(off) + " references section " + isec->getName() +
-          " which is not in segment __TEXT");
-  // __TEXT should always contain ConcatInputSections.
-  return cast<ConcatInputSection>(isec);
-}
-
 // We need to apply the relocations to the pre-link compact unwind section
 // before converting it to post-link form. There should only be absolute
 // relocations here: since we are not emitting the pre-link CU section, there
 // is no source address to make a relative location meaningful.
 template <class Ptr>
 void UnwindInfoSectionImpl<Ptr>::relocateCompactUnwind(
-    std::vector<CompactUnwindEntry<Ptr>> &cuEntries) {
+    std::vector<CompactUnwindEntry> &cuEntries) {
   parallelForEachN(0, symbolsVec.size(), [&](size_t i) {
-    uint8_t *buf = reinterpret_cast<uint8_t *>(cuEntries.data()) +
-                   i * sizeof(CompactUnwindEntry<Ptr>);
+    CompactUnwindEntry &cu = cuEntries[i];
     const Defined *d = symbolsVec[i].second;
-    // Write the functionAddress.
-    writeAddress(buf, d->getVA(), sizeof(Ptr) == 8 ? 3 : 2);
+    cu.functionAddress = d->getVA();
     if (!d->unwindEntry)
       return;
 
-    // Write the rest of the CUE.
-    memcpy(buf + sizeof(Ptr), d->unwindEntry->data.data(),
-           d->unwindEntry->data.size());
+    auto buf = reinterpret_cast<const uint8_t *>(d->unwindEntry->data.data()) -
+               sizeof(Ptr);
+    cu.functionLength = support::endian::read32le(
+        buf + offsetof(CompactUnwindLayout<Ptr>, functionLength));
+    cu.encoding = support::endian::read32le(
+        buf + offsetof(CompactUnwindLayout<Ptr>, encoding));
     for (const Reloc &r : d->unwindEntry->relocs) {
-      uint64_t referentVA = 0;
-      if (auto *referentSym = r.referent.dyn_cast<Symbol *>()) {
-        if (!isa<Undefined>(referentSym)) {
-          if (auto *defined = dyn_cast<Defined>(referentSym))
-            checkTextSegment(defined->isec, d->unwindEntry, r.offset);
-          // At this point in the link, we may not yet know the final address of
-          // the GOT, so we just encode the index. We make it a 1-based index so
-          // that we can distinguish the null pointer case.
-          referentVA = referentSym->gotIndex + 1;
-        }
-      } else {
-        auto *referentIsec = r.referent.get<InputSection *>();
-        checkTextSegment(referentIsec, d->unwindEntry, r.offset);
-        referentVA = referentIsec->getVA(r.addend);
+      if (r.offset == offsetof(CompactUnwindLayout<Ptr>, personality)) {
+        cu.personality = r.referent.get<Symbol *>();
+      } else if (r.offset == offsetof(CompactUnwindLayout<Ptr>, lsda)) {
+        if (auto *referentSym = r.referent.dyn_cast<Symbol *>())
+          cu.lsda = cast<Defined>(referentSym)->isec;
+        else
+          cu.lsda = r.referent.get<InputSection *>();
       }
-      writeAddress(buf + r.offset, referentVA, r.length);
     }
   });
 }
 
 // There should only be a handful of unique personality pointers, so we can
 // encode them as 2-bit indices into a small array.
 template <class Ptr> void UnwindInfoSectionImpl<Ptr>::encodePersonalities() {
   for (size_t idx : cuIndices) {
-    CompactUnwindEntry<Ptr> &cu = cuEntries[idx];
-    if (cu.personality == 0)
+    CompactUnwindEntry &cu = cuEntries[idx];
+    if (cu.personality == nullptr)
       continue;
     // Linear search is fast enough for a small array.
     auto it = find(personalities, cu.personality);
     uint32_t personalityIndex; // 1-based index
     if (it != personalities.end()) {
       personalityIndex = std::distance(personalities.begin(), it) + 1;
     } else {
       personalities.push_back(cu.personality);
       personalityIndex = personalities.size();
     }
     cu.encoding |=
         personalityIndex << countTrailingZeros(
             static_cast<compact_unwind_encoding_t>(UNWIND_PERSONALITY_MASK));
   }
   if (personalities.size() > 3)
-    error("too many personalities (" + std::to_string(personalities.size()) +
+    error("too many personalities (" + Twine(personalities.size()) +
           ") for compact unwind to encode");
 }
 
 static bool canFoldEncoding(compact_unwind_encoding_t encoding) {
   // From compact_unwind_encoding.h:
   //  UNWIND_X86_64_MODE_STACK_IND:
   //  A "frameless" (RBP not used as frame pointer) function large constant
   //  stack size.  This case is like the previous, except the stack size is too
if ((target->cpuType == CPU_TYPE_X86_64 || target->cpuType == CPU_TYPE_X86) &&
     // FIXME: Consider passing in the two function addresses and getting
     // their two stack sizes off the `subq` and only returning false if they're
     // actually different.
     return false;
   }
   return true;
 }
 
-template <class Ptr>
-Reloc *
-UnwindInfoSectionImpl<Ptr>::findLsdaReloc(ConcatInputSection *isec) const {
-  if (isec == nullptr)
-    return nullptr;
-  auto it = llvm::find_if(isec->relocs, [](const Reloc &r) {
-    return r.offset % sizeof(CompactUnwindEntry<Ptr>) ==
-           offsetof(CompactUnwindEntry<Ptr>, lsda);
-  });
-  if (it == isec->relocs.end())
-    return nullptr;
-  return &*it;
-}
-
 // Scan the __LD,__compact_unwind entries and compute the space needs of
 // __TEXT,__unwind_info and __TEXT,__eh_frame.
 template <class Ptr> void UnwindInfoSectionImpl<Ptr>::finalize() {
   if (symbols.empty())
     return;
 
   // At this point, the address space for __TEXT,__text has been
   // assigned, so we can relocate the __LD,__compact_unwind entries
template <class Ptr> void UnwindInfoSectionImpl<Ptr>::finalize() {
   // (3) `foldWrite`
   auto foldWrite = cuIndices.begin();
   for (auto foldBegin = cuIndices.begin(); foldBegin < cuIndices.end();) {
     auto foldEnd = foldBegin;
     while (++foldEnd < cuIndices.end() &&
            cuEntries[*foldBegin].encoding == cuEntries[*foldEnd].encoding &&
            cuEntries[*foldBegin].personality ==
                cuEntries[*foldEnd].personality &&
-           canFoldEncoding(cuEntries[*foldEnd].encoding)) {
-      // In most cases, we can just compare the values of cuEntries[*].lsda.
-      // However, it is possible for -rename_section to cause the LSDA section
-      // (__gcc_except_tab) to be finalized after the unwind info section. In
-      // that case, we don't yet have unique addresses for the LSDA entries.
-      // So we check their relocations instead.
-      // FIXME: should we account for an LSDA at an absolute address? ld64 seems
-      // to support it, but it seems unlikely to be used in practice.
-      Reloc *lsda1 = findLsdaReloc(symbolsVec[*foldBegin].second->unwindEntry);
-      Reloc *lsda2 = findLsdaReloc(symbolsVec[*foldEnd].second->unwindEntry);
-      if (lsda1 == nullptr && lsda2 == nullptr)
-        continue;
-      if (lsda1 == nullptr || lsda2 == nullptr)
-        break;
-      if (lsda1->referent != lsda2->referent)
-        break;
-      if (lsda1->addend != lsda2->addend)
-        break;
-    }
+           cuEntries[*foldBegin].lsda == cuEntries[*foldEnd].lsda &&
+           canFoldEncoding(cuEntries[*foldEnd].encoding))
+      ;
     *foldWrite++ = *foldBegin;
     foldBegin = foldEnd;
   }
   cuIndices.erase(foldWrite, cuIndices.end());
 
   encodePersonalities();
 
   // Count frequencies of the folded encodings
uintptr_t functionAddressMax =
         cuEntries[idx].functionAddress + COMPRESSED_ENTRY_FUNC_OFFSET_MASK;
     size_t n = commonEncodings.size();
     size_t wordsRemaining =
         SECOND_LEVEL_PAGE_WORDS -
         sizeof(unwind_info_compressed_second_level_page_header) /
             sizeof(uint32_t);
     while (wordsRemaining >= 1 && i < cuIndices.size()) {
       idx = cuIndices[i];
-      const CompactUnwindEntry<Ptr> *cuPtr = &cuEntries[idx];
+      const CompactUnwindEntry *cuPtr = &cuEntries[idx];
       if (cuPtr->functionAddress >= functionAddressMax) {
         break;
       } else if (commonEncodingIndexes.count(cuPtr->encoding) ||
                  page.localEncodingIndexes.count(cuPtr->encoding)) {
         i++;
         wordsRemaining--;
       } else if (wordsRemaining >= 2 && n < COMPACT_ENCODINGS_MAX) {
         page.localEncodings.emplace_back(cuPtr->encoding);
if (i < cuIndices.size() &&
       i = page.entryIndex + page.entryCount;
     } else {
       page.kind = UNWIND_SECOND_LEVEL_COMPRESSED;
     }
   }
 
   for (size_t idx : cuIndices) {
     lsdaIndex[idx] = entriesWithLsda.size();
-    const Defined *d = symbolsVec[idx].second;
-    if (findLsdaReloc(d->unwindEntry))
+    if (cuEntries[idx].lsda)
       entriesWithLsda.push_back(idx);
   }
 
   // compute size of __TEXT,__unwind_info section
   level2PagesOffset = sizeof(unwind_info_section_header) +
                       commonEncodings.size() * sizeof(uint32_t) +
                       personalities.size() * sizeof(uint32_t) +
                       // The extra second-level-page entry is for the sentinel
void UnwindInfoSectionImpl<Ptr>::writeTo(uint8_t *buf) const {
   uip->indexCount = secondLevelPages.size() + 1;
 
   // Common encodings
   auto *i32p = reinterpret_cast<uint32_t *>(&uip[1]);
   for (const auto &encoding : commonEncodings)
     *i32p++ = encoding.first;
 
   // Personalities
-  for (Ptr personality : personalities)
-    *i32p++ =
-        in.got->addr + (personality - 1) * target->wordSize - in.header->addr;
+  for (const Symbol *personality : personalities)
+    *i32p++ = personality->getGotVA() - in.header->addr;
 
   // Level-1 index
   uint32_t lsdaOffset =
       uip->indexSectionOffset +
       uip->indexCount * sizeof(unwind_info_section_header_index_entry);
   uint64_t l2PagesOffset = level2PagesOffset;
   auto *iep = reinterpret_cast<unwind_info_section_header_index_entry *>(i32p);
   for (const SecondLevelPage &page : secondLevelPages) {
     size_t idx = cuIndices[page.entryIndex];
     iep->functionOffset = cuEntries[idx].functionAddress - in.header->addr;
     iep->secondLevelPagesSectionOffset = l2PagesOffset;
     iep->lsdaIndexArraySectionOffset =
         lsdaOffset + lsdaIndex.lookup(idx) *
                          sizeof(unwind_info_section_header_lsda_index_entry);
     iep++;
     l2PagesOffset += SECOND_LEVEL_PAGE_BYTES;
   }
   // Level-1 sentinel
-  const CompactUnwindEntry<Ptr> &cuEnd = cuEntries[cuIndices.back()];
+  const CompactUnwindEntry &cuEnd = cuEntries[cuIndices.back()];
   iep->functionOffset =
       cuEnd.functionAddress - in.header->addr + cuEnd.functionLength;
   iep->secondLevelPagesSectionOffset = 0;
   iep->lsdaIndexArraySectionOffset =
       lsdaOffset + entriesWithLsda.size() *
                        sizeof(unwind_info_section_header_lsda_index_entry);
   iep++;
 
   // LSDAs
   auto *lep =
       reinterpret_cast<unwind_info_section_header_lsda_index_entry *>(iep);
   for (size_t idx : entriesWithLsda) {
-    const CompactUnwindEntry<Ptr> &cu = cuEntries[idx];
-    const Defined *d = symbolsVec[idx].second;
-    if (Reloc *r = findLsdaReloc(d->unwindEntry)) {
-      uint64_t va;
-      if (auto *isec = r->referent.dyn_cast<InputSection *>()) {
-        va = isec->getVA(r->addend);
-      } else {
-        auto *sym = r->referent.get<Symbol *>();
-        va = sym->getVA() + r->addend;
-      }
-      lep->lsdaOffset = va - in.header->addr;
-    }
+    const CompactUnwindEntry &cu = cuEntries[idx];
+    lep->lsdaOffset = cu.lsda->getVA(/*off=*/0) - in.header->addr;
     lep->functionOffset = cu.functionAddress - in.header->addr;
     lep++;
   }
 
   // Level-2 pages
   auto *pp = reinterpret_cast<uint32_t *>(lep);
   for (const SecondLevelPage &page : secondLevelPages) {
     if (page.kind == UNWIND_SECOND_LEVEL_COMPRESSED) {
       uintptr_t functionAddressBase =
           cuEntries[cuIndices[page.entryIndex]].functionAddress;
       auto *p2p =
           reinterpret_cast<unwind_info_compressed_second_level_page_header *>(
               pp);
       p2p->kind = page.kind;
       p2p->entryPageOffset =
           sizeof(unwind_info_compressed_second_level_page_header);
       p2p->entryCount = page.entryCount;
       p2p->encodingsPageOffset =
           p2p->entryPageOffset + p2p->entryCount * sizeof(uint32_t);
       p2p->encodingsCount = page.localEncodings.size();
       auto *ep = reinterpret_cast<uint32_t *>(&p2p[1]);
       for (size_t i = 0; i < page.entryCount; i++) {
-        const CompactUnwindEntry<Ptr> &cue =
+        const CompactUnwindEntry &cue =
             cuEntries[cuIndices[page.entryIndex + i]];
         auto it = commonEncodingIndexes.find(cue.encoding);
         if (it == commonEncodingIndexes.end())
           it = page.localEncodingIndexes.find(cue.encoding);
         *ep++ = (it->second << COMPRESSED_ENTRY_FUNC_OFFSET_BITS) |
                 (cue.functionAddress - functionAddressBase);
       }
       if (!page.localEncodings.empty())
         memcpy(ep, page.localEncodings.data(),
                page.localEncodings.size() * sizeof(uint32_t));
     } else {
       auto *p2p =
           reinterpret_cast<unwind_info_regular_second_level_page_header *>(pp);
       p2p->kind = page.kind;
       p2p->entryPageOffset =
           sizeof(unwind_info_regular_second_level_page_header);
       p2p->entryCount = page.entryCount;
       auto *ep = reinterpret_cast<uint32_t *>(&p2p[1]);
       for (size_t i = 0; i < page.entryCount; i++) {
-        const CompactUnwindEntry<Ptr> &cue =
+        const CompactUnwindEntry &cue =
             cuEntries[cuIndices[page.entryIndex + i]];
         *ep++ = cue.functionAddress;
         *ep++ = cue.encoding;
       }
     }
     pp += SECOND_LEVEL_PAGE_WORDS;
   }
 }
 
 UnwindInfoSection *macho::makeUnwindInfoSection() {
   if (target->wordSize == 8)
     return make<UnwindInfoSectionImpl<uint64_t>>();
   else
     return make<UnwindInfoSectionImpl<uint32_t>>();
 }

lld/test/MachO/compact-unwind.s

 # RUN: llvm-objdump --macho --unwind-info %t/x86_64-empty-after-strip.dylib | \
 # RUN:   FileCheck %s --check-prefixes=NOUNWIND --allow-empty
 # NOUNWIND-NOT: Contents of __unwind_info section:
 
 #--- my-personality.s
 .globl _my_personality, _exception0
 .text
 .p2align 2
+.no_dead_strip _foo
 _foo:
   .cfi_startproc
 ## This will generate a section relocation.
   .cfi_personality 155, _my_personality
   .cfi_lsda 16, _exception0
   .cfi_def_cfa_offset 16
   ret
   .cfi_endproc
 
 .p2align 2
+.no_dead_strip _bar
 _bar:
   .cfi_startproc
 ## Check that we dedup references to the same statically-linked personality.
   .cfi_personality 155, _my_personality
   .cfi_lsda 16, _exception0
   .cfi_def_cfa_offset 16
   ret
   .cfi_endproc
 
+.data
 .p2align 2
 _my_personality:
   ret
 
 .section __TEXT,__gcc_except_tab
 _exception0:
   .space 1
 
+.subsections_via_symbols
+
 #--- main.s
 .globl _main, _quux, _my_personality, _exception1
 
 .text
 .p2align 2
 _main:
   .cfi_startproc
   .cfi_personality 155, ___gxx_personality_v0

lld/test/MachO/invalid/compact-unwind-bad-reloc.s

 # REQUIRES: x86
 # RUN: rm -rf %t; split-file %s %t
 # RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin19.0.0 %t/bad-function.s -o %t/bad-function.o
-# RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin19.0.0 %t/bad-personality.s -o %t/bad-personality.o
-# RUN: not %lld -lSystem -lc++ %t/bad-function.o -o %t 2>&1 | FileCheck %s -DFILE=%t/bad-function.o -D#OFF=0x0
-# RUN: not %lld -lSystem -lc++ %t/bad-personality.o -o %t 2>&1 | FileCheck %s -DFILE=%t/bad-personality.o -D#OFF=0x10
-# CHECK: error: [[FILE]]:(__compact_unwind+0x[[#%x,OFF]]) references section __data which is not in segment __TEXT
+# RUN: not %lld -lSystem -dylib -lc++ %t/bad-function.o -o /dev/null 2>&1 | FileCheck %s
+# CHECK: error: {{.*}}bad-function.o:(__compact_unwind+0x0) references section __data which is not in segment __TEXT
+# CHECK: error: {{.*}}bad-function.o:(__compact_unwind+0x20) references section __data which is not in segment __TEXT
 
 #--- bad-function.s
 .data
 _not_a_function:
   .cfi_startproc
   .cfi_personality 155, ___gxx_personality_v0
   .cfi_def_cfa_offset 16
   retq
   .cfi_endproc
 
-#--- bad-personality.s
-.globl _main, _not_a_function
-.text
-_main:
+_not_a_function_2:
   .cfi_startproc
-  .cfi_personality 155, _my_personality
+  .cfi_personality 155, ___gxx_personality_v0
   .cfi_def_cfa_offset 16
   retq
   .cfi_endproc
 
-.data
-.globl _my_personality
-_my_personality:
+.subsections_via_symbols