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[BOLT][NFC] Pass JumpTable to analyzeJumpTable #132110

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[BOLT][NFC] Pass JumpTable to analyzeJumpTable #132110

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6eea20e
[𝘀𝗽𝗿] initial version
aaupov Mar 19, 2025
627b1ac
untangle changes
aaupov Mar 20, 2025
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7 changes: 3 additions & 4 deletions bolt/include/bolt/Core/BinaryContext.h
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Original file line number Diff line number Diff line change
Expand Up @@ -584,14 +584,13 @@ class BinaryContext {
/// If \p NextJTAddress is different from zero, it is used as an upper
/// bound for jump table memory layout.
///
/// Optionally, populate \p Address from jump table entries. The entries
/// could be partially populated if the jump table detection fails.
/// If \p JT is set, populate it with jump table entries. The entries could be
/// partially populated if the jump table detection fails.
bool analyzeJumpTable(const uint64_t Address,
const JumpTable::JumpTableType Type,
const BinaryFunction &BF,
const uint64_t NextJTAddress = 0,
JumpTable::AddressesType *EntriesAsAddress = nullptr,
bool *HasEntryInFragment = nullptr) const;
JumpTable *JT = nullptr) const;

/// After jump table locations are established, this function will populate
/// their EntriesAsAddress based on memory contents.
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24 changes: 11 additions & 13 deletions bolt/lib/Core/BinaryContext.cpp
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Expand Up @@ -553,8 +553,7 @@ bool BinaryContext::analyzeJumpTable(const uint64_t Address,
const JumpTable::JumpTableType Type,
const BinaryFunction &BF,
const uint64_t NextJTAddress,
JumpTable::AddressesType *EntriesAsAddress,
bool *HasEntryInFragment) const {
JumpTable *JT) const {
// Target address of __builtin_unreachable.
const uint64_t UnreachableAddress = BF.getAddress() + BF.getSize();

Expand All @@ -571,11 +570,11 @@ bool BinaryContext::analyzeJumpTable(const uint64_t Address,
size_t TrimmedSize = 0;

auto addEntryAddress = [&](uint64_t EntryAddress, bool Unreachable = false) {
if (!EntriesAsAddress)
if (!JT)
return;
EntriesAsAddress->emplace_back(EntryAddress);
JT->EntriesAsAddress.emplace_back(EntryAddress);
if (!Unreachable)
TrimmedSize = EntriesAsAddress->size();
TrimmedSize = JT->EntriesAsAddress.size();
};

ErrorOr<const BinarySection &> Section = getSectionForAddress(Address);
Expand Down Expand Up @@ -676,17 +675,17 @@ bool BinaryContext::analyzeJumpTable(const uint64_t Address,
++NumRealEntries;
LLVM_DEBUG(dbgs() << formatv("OK: {0:x} real entry\n", Value));

if (TargetBF != &BF && HasEntryInFragment)
*HasEntryInFragment = true;
if (TargetBF != &BF && JT)
JT->IsSplit = true;
addEntryAddress(Value);
}

// Trim direct/normal jump table to exclude trailing unreachable entries that
// can collide with a function address.
if (Type == JumpTable::JTT_X86_64_ABS && EntriesAsAddress &&
TrimmedSize != EntriesAsAddress->size() &&
if (Type == JumpTable::JTT_X86_64_ABS && JT &&
TrimmedSize != JT->EntriesAsAddress.size() &&
getBinaryFunctionAtAddress(UnreachableAddress))
EntriesAsAddress->resize(TrimmedSize);
JT->EntriesAsAddress.resize(TrimmedSize);

// It's a jump table if the number of real entries is more than 1, or there's
// one real entry and one or more special targets. If there are only multiple
Expand All @@ -710,9 +709,8 @@ void BinaryContext::populateJumpTables() {
if (NextJTI != JTE)
NextJTAddress = NextJTI->second->getAddress();

const bool Success =
analyzeJumpTable(JT->getAddress(), JT->Type, *(JT->Parents[0]),
NextJTAddress, &JT->EntriesAsAddress, &JT->IsSplit);
const bool Success = analyzeJumpTable(
JT->getAddress(), JT->Type, *JT->Parents.front(), NextJTAddress, JT);
if (!Success) {
LLVM_DEBUG({
dbgs() << "failed to analyze ";
Expand Down
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