diff options
| -rw-r--r-- | bolt/include/bolt/Core/BinaryContext.h | 10 | ||||
| -rw-r--r-- | bolt/lib/Core/BinaryContext.cpp | 32 | ||||
| -rw-r--r-- | bolt/lib/Core/BinaryFunction.cpp | 19 | ||||
| -rw-r--r-- | bolt/test/AArch64/constant-island-entry.s | 2 |
4 files changed, 37 insertions, 26 deletions
diff --git a/bolt/include/bolt/Core/BinaryContext.h b/bolt/include/bolt/Core/BinaryContext.h index 5cbc28fb38a3..085c0265de3e 100644 --- a/bolt/include/bolt/Core/BinaryContext.h +++ b/bolt/include/bolt/Core/BinaryContext.h @@ -932,6 +932,16 @@ public: std::pair<const MCSymbol *, uint64_t> handleAddressRef(uint64_t Address, BinaryFunction &BF, bool IsPCRel); + /// When \p Address inside function \p BF is a target of a control transfer + /// instruction (branch) from another function, return a corresponding symbol + /// that should be used by the branch. For example, main or secondary entry + /// point. + /// + /// If \p Address is an invalid destination, such as a constant island, return + /// nullptr and mark \p BF as ignored, since we cannot properly handle a + /// branch to a constant island. + MCSymbol *handleExternalBranchTarget(uint64_t Address, BinaryFunction &BF); + /// Analyze memory contents at the given \p Address and return the type of /// memory contents (such as a possible jump table). MemoryContentsType analyzeMemoryAt(uint64_t Address, BinaryFunction &BF); diff --git a/bolt/lib/Core/BinaryContext.cpp b/bolt/lib/Core/BinaryContext.cpp index c33540ada8a0..a383ced1712e 100644 --- a/bolt/lib/Core/BinaryContext.cpp +++ b/bolt/lib/Core/BinaryContext.cpp @@ -518,6 +518,23 @@ BinaryContext::handleAddressRef(uint64_t Address, BinaryFunction &BF, return std::make_pair(TargetSymbol, 0); } +MCSymbol *BinaryContext::handleExternalBranchTarget(uint64_t Address, + BinaryFunction &BF) { + if (BF.isInConstantIsland(Address)) { + BF.setIgnored(); + this->outs() << "BOLT-WARNING: ignoring entry point at address 0x" + << Twine::utohexstr(Address) + << " in constant island of function " << BF << '\n'; + return nullptr; + } + + const uint64_t Offset = Address - BF.getAddress(); + assert(Offset < BF.getSize() && + "Address should be inside the referenced function"); + + return Offset ? BF.addEntryPointAtOffset(Offset) : BF.getSymbol(); +} + MemoryContentsType BinaryContext::analyzeMemoryAt(uint64_t Address, BinaryFunction &BF) { if (!isX86()) @@ -1399,17 +1416,10 @@ void BinaryContext::processInterproceduralReferences() { << Function.getPrintName() << " and " << TargetFunction->getPrintName() << '\n'; } - if (uint64_t Offset = Address - TargetFunction->getAddress()) { - if (!TargetFunction->isInConstantIsland(Address)) { - TargetFunction->addEntryPointAtOffset(Offset); - } else { - TargetFunction->setIgnored(); - this->outs() << "BOLT-WARNING: Ignoring entry point at address 0x" - << Twine::utohexstr(Address) - << " in constant island of function " << *TargetFunction - << '\n'; - } - } + + // Create an extra entry point if needed. Can also render the target + // function ignored if the reference is invalid. + handleExternalBranchTarget(Address, *TargetFunction); continue; } diff --git a/bolt/lib/Core/BinaryFunction.cpp b/bolt/lib/Core/BinaryFunction.cpp index fbe186454351..ddaad6eef614 100644 --- a/bolt/lib/Core/BinaryFunction.cpp +++ b/bolt/lib/Core/BinaryFunction.cpp @@ -1697,21 +1697,12 @@ bool BinaryFunction::scanExternalRefs() { if (!TargetFunction || ignoreFunctionRef(*TargetFunction)) continue; - const uint64_t FunctionOffset = - TargetAddress - TargetFunction->getAddress(); - if (!TargetFunction->isInConstantIsland(TargetAddress)) { - BranchTargetSymbol = - FunctionOffset - ? TargetFunction->addEntryPointAtOffset(FunctionOffset) - : TargetFunction->getSymbol(); - } else { - TargetFunction->setIgnored(); - BC.outs() << "BOLT-WARNING: Ignoring entry point at address 0x" - << Twine::utohexstr(Address) - << " in constant island of function " << *TargetFunction - << '\n'; + // Get a reference symbol for the function when address is a valid code + // reference. + BranchTargetSymbol = + BC.handleExternalBranchTarget(TargetAddress, *TargetFunction); + if (!BranchTargetSymbol) continue; - } } // Can't find more references. Not creating relocations since we are not diff --git a/bolt/test/AArch64/constant-island-entry.s b/bolt/test/AArch64/constant-island-entry.s index 7f8449deea13..a82b876fde46 100644 --- a/bolt/test/AArch64/constant-island-entry.s +++ b/bolt/test/AArch64/constant-island-entry.s @@ -10,7 +10,7 @@ ## Skip caller to check the identical warning is triggered from ScanExternalRefs(). # RUN: llvm-bolt %t.exe -o %t.bolt -skip-funcs=caller 2>&1 | FileCheck %s -# CHECK: BOLT-WARNING: Ignoring entry point at address 0x{{[0-9a-f]+}} in constant island of function func +# CHECK: BOLT-WARNING: ignoring entry point at address 0x{{[0-9a-f]+}} in constant island of function func .globl func .type func, %function |