[lld-macho] Fix bug in CUE folding that resulted in wrong unwind table.
PR/59070
Differential Revision: https://reviews.llvm.org/D138320
diff --git a/lld/MachO/UnwindInfoSection.cpp b/lld/MachO/UnwindInfoSection.cpp
index b83aa89..6a58b51 100644
--- a/lld/MachO/UnwindInfoSection.cpp
+++ b/lld/MachO/UnwindInfoSection.cpp
@@ -179,6 +179,9 @@
DenseMap<size_t, uint32_t> lsdaIndex;
std::vector<SecondLevelPage> secondLevelPages;
uint64_t level2PagesOffset = 0;
+ // The highest-address function plus its size. The unwinder needs this to
+ // determine the address range that is covered by unwind info.
+ uint64_t cueEndBoundary = 0;
};
UnwindInfoSection::UnwindInfoSection()
@@ -458,6 +461,10 @@
return cuEntries[a].functionAddress < cuEntries[b].functionAddress;
});
+ // Record the ending boundary before we fold the entries.
+ cueEndBoundary = cuEntries[cuIndices.back()].functionAddress +
+ cuEntries[cuIndices.back()].functionLength;
+
// Fold adjacent entries with matching encoding+personality and without LSDA
// We use three iterators on the same cuIndices to fold in-situ:
// (1) `foldBegin` is the first of a potential sequence of matching entries
@@ -631,6 +638,9 @@
for (const Symbol *personality : personalities)
*i32p++ = personality->getGotVA() - in.header->addr;
+ // FIXME: LD64 checks and warns aboutgaps or overlapse in cuEntries address
+ // ranges. We should do the same too
+
// Level-1 index
uint32_t lsdaOffset =
uip->indexSectionOffset +
@@ -648,9 +658,10 @@
l2PagesOffset += SECOND_LEVEL_PAGE_BYTES;
}
// Level-1 sentinel
- const CompactUnwindEntry &cuEnd = cuEntries[cuIndices.back()];
- iep->functionOffset =
- cuEnd.functionAddress - in.header->addr + cuEnd.functionLength;
+ // XXX(vyng): Note that LD64 adds +1 here.
+ // Unsure whether it's a bug or it's their workaround for something else.
+ // See comments from https://reviews.llvm.org/D138320.
+ iep->functionOffset = cueEndBoundary - in.header->addr;
iep->secondLevelPagesSectionOffset = 0;
iep->lsdaIndexArraySectionOffset =
lsdaOffset + entriesWithLsda.size() *
