Merge branch 'llvm:main' into gh-101657

Author: ravindra-shinde2

.ci/monolithic-linux.sh

@@ -53,6 +53,7 @@ targets="${2}"
 lit_args="-v --xunit-xml-output ${BUILD_DIR}/test-results.xml --use-unique-output-file-name --timeout=1200 --time-tests"
 
 echo "--- cmake"
+export PIP_BREAK_SYSTEM_PACKAGES=1
 pip install -q -r "${MONOREPO_ROOT}"/mlir/python/requirements.txt
 pip install -q -r "${MONOREPO_ROOT}"/lldb/test/requirements.txt
 pip install -q -r "${MONOREPO_ROOT}"/.ci/requirements.txt

.github/workflows/containers/github-action-ci-windows/Dockerfile

@@ -108,7 +108,7 @@ RUN choco install -y handle
 
 RUN pip3 install pywin32 buildbot-worker==2.8.4
 
-ARG RUNNER_VERSION=2.322.0
+ARG RUNNER_VERSION=2.323.0
 ENV RUNNER_VERSION=$RUNNER_VERSION
 
 RUN powershell -Command \

.github/workflows/containers/github-action-ci/Dockerfile

@@ -95,7 +95,7 @@ WORKDIR /home/gha
 
 FROM ci-container as ci-container-agent
 
-ENV GITHUB_RUNNER_VERSION=2.322.0
+ENV GITHUB_RUNNER_VERSION=2.323.0
 
 RUN mkdir actions-runner && \
     cd actions-runner && \

.github/workflows/libcxx-build-and-test.yaml

@@ -197,10 +197,20 @@ jobs:
           os: macos-15
         - config: apple-configuration
           os: macos-15
+        # TODO: These jobs are intended to test back-deployment (building against ToT libc++ but running against an
+        #       older system-provided libc++.dylib). Doing this properly would require building the test suite on a
+        #       recent macOS using a recent Clang (hence recent Xcode), and then running the actual test suite on an
+        #       older mac. We could do that by e.g. sharing artifacts between the two jobs.
+        #
+        #       However, our Lit configuration currently doesn't provide a good way to do that in a batch, so our only
+        #       alternative is to actually build on the same host that we're going to run on. Sadly, that doesn't work
+        #       since older macOSes don't support newer Xcodes. For now, we run the "backdeployment" jobs on recent
+        #       macOS versions as a way to avoid rotting that configuration, but it doesn't provide a lot of additional
+        #       coverage.
         - config: apple-system
-          os: macos-13
+          os: macos-15
         - config: apple-system-hardened
-          os: macos-13
+          os: macos-15
     runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2

bolt/include/bolt/Core/Relocation.h

@@ -86,6 +86,9 @@ class Relocation {
   /// Adjust value depending on relocation type (make it PC relative or not).
   static uint64_t encodeValue(uint32_t Type, uint64_t Value, uint64_t PC);
 
+  /// Return true if there are enough bits to encode the relocation value.
+  static bool canEncodeValue(uint32_t Type, uint64_t Value, uint64_t PC);
+
   /// Extract current relocated value from binary contents. This is used for
   /// RISC architectures where values are encoded in specific bits depending
   /// on the relocation value. For X86, we limit to sign extending the value

bolt/lib/Core/BinaryFunction.cpp

@@ -1795,6 +1795,8 @@ bool BinaryFunction::scanExternalRefs() {
     // Create relocation for every fixup.
     for (const MCFixup &Fixup : Fixups) {
       std::optional<Relocation> Rel = BC.MIB->createRelocation(Fixup, *BC.MAB);
+      // Can be skipped in case of overlow during relocation value encoding.
+      Rel->setOptional();
       if (!Rel) {
         Success = false;
         continue;

bolt/lib/Core/BinarySection.cpp

@@ -12,6 +12,7 @@
 
 #include "bolt/Core/BinarySection.h"
 #include "bolt/Core/BinaryContext.h"
+#include "bolt/Utils/CommandLineOpts.h"
 #include "bolt/Utils/Utils.h"
 #include "llvm/MC/MCStreamer.h"
 #include "llvm/Support/CommandLine.h"
@@ -22,8 +23,8 @@ using namespace llvm;
 using namespace bolt;
 
 namespace opts {
-extern cl::opt<bool> PrintRelocations;
 extern cl::opt<bool> HotData;
+extern cl::opt<bool> PrintRelocations;
 } // namespace opts
 
 uint64_t BinarySection::Count = 0;
@@ -174,11 +175,30 @@ void BinarySection::flushPendingRelocations(raw_pwrite_stream &OS,
     OS.pwrite(Patch.Bytes.data(), Patch.Bytes.size(),
               SectionFileOffset + Patch.Offset);
 
+  uint64_t SkippedPendingRelocations = 0;
   for (Relocation &Reloc : PendingRelocations) {
     uint64_t Value = Reloc.Addend;
     if (Reloc.Symbol)
       Value += Resolver(Reloc.Symbol);
 
+    // Safely skip any optional pending relocation that cannot be encoded.
+    if (Reloc.isOptional() &&
+        !Relocation::canEncodeValue(Reloc.Type, Value,
+                                    SectionAddress + Reloc.Offset)) {
+
+      // A successful run of 'scanExternalRefs' means that all pending
+      // relocations are flushed. Otherwise, PatchEntries should run.
+      if (!opts::ForcePatch) {
+        BC.errs()
+            << "BOLT-ERROR: cannot encode relocation for symbol "
+            << Reloc.Symbol->getName()
+            << " as it is out-of-range. To proceed must use -force-patch\n";
+        exit(1);
+      }
+
+      ++SkippedPendingRelocations;
+      continue;
+    }
     Value = Relocation::encodeValue(Reloc.Type, Value,
                                     SectionAddress + Reloc.Offset);
 
@@ -197,6 +217,11 @@ void BinarySection::flushPendingRelocations(raw_pwrite_stream &OS,
   }
 
   clearList(PendingRelocations);
+
+  if (SkippedPendingRelocations > 0 && opts::Verbosity >= 1) {
+    BC.outs() << "BOLT-INFO: skipped " << SkippedPendingRelocations
+              << " out-of-range optional relocations\n";
+  }
 }
 
 BinarySection::~BinarySection() { updateContents(nullptr, 0); }

bolt/lib/Core/Relocation.cpp

@@ -271,6 +271,16 @@ static uint64_t encodeValueX86(uint32_t Type, uint64_t Value, uint64_t PC) {
   return Value;
 }
 
+static bool canEncodeValueAArch64(uint32_t Type, uint64_t Value, uint64_t PC) {
+  switch (Type) {
+  default:
+    llvm_unreachable("unsupported relocation");
+  case ELF::R_AARCH64_CALL26:
+  case ELF::R_AARCH64_JUMP26:
+    return isInt<28>(Value - PC);
+  }
+}
+
 static uint64_t encodeValueAArch64(uint32_t Type, uint64_t Value, uint64_t PC) {
   switch (Type) {
   default:
@@ -303,6 +313,16 @@ static uint64_t encodeValueAArch64(uint32_t Type, uint64_t Value, uint64_t PC) {
   return Value;
 }
 
+static uint64_t canEncodeValueRISCV(uint32_t Type, uint64_t Value,
+                                    uint64_t PC) {
+  switch (Type) {
+  default:
+    llvm_unreachable("unsupported relocation");
+  case ELF::R_RISCV_64:
+    return true;
+  }
+}
+
 static uint64_t encodeValueRISCV(uint32_t Type, uint64_t Value, uint64_t PC) {
   switch (Type) {
   default:
@@ -739,6 +759,19 @@ uint64_t Relocation::encodeValue(uint32_t Type, uint64_t Value, uint64_t PC) {
   }
 }
 
+bool Relocation::canEncodeValue(uint32_t Type, uint64_t Value, uint64_t PC) {
+  switch (Arch) {
+  default:
+    llvm_unreachable("Unsupported architecture");
+  case Triple::aarch64:
+    return canEncodeValueAArch64(Type, Value, PC);
+  case Triple::riscv64:
+    return canEncodeValueRISCV(Type, Value, PC);
+  case Triple::x86_64:
+    return true;
+  }
+}
+
 uint64_t Relocation::extractValue(uint32_t Type, uint64_t Contents,
                                   uint64_t PC) {
   switch (Arch) {

bolt/lib/Rewrite/RewriteInstance.cpp

@@ -2827,9 +2827,10 @@ void RewriteInstance::handleRelocation(const SectionRef &RelocatedSection,
     if (SymbolAddress == 0)
       ReferencedSymbol = BC->registerNameAtAddress(SymbolName, 0, 0, 0);
 
-    LLVM_DEBUG(dbgs() << "BOLT-DEBUG: forcing relocation against symbol "
-                      << ReferencedSymbol->getName() << " with addend "
-                      << Addend << '\n');
+    LLVM_DEBUG(
+        dbgs() << "BOLT-DEBUG: forcing relocation against symbol "
+               << (ReferencedSymbol ? ReferencedSymbol->getName() : "<none>")
+               << " with addend " << Addend << '\n');
   } else if (ReferencedBF) {
     ReferencedSymbol = ReferencedBF->getSymbol();
     uint64_t RefFunctionOffset = 0;

bolt/lib/Target/AArch64/AArch64MCSymbolizer.cpp

@@ -119,26 +119,39 @@ AArch64MCSymbolizer::adjustRelocation(const Relocation &Rel,
     // The ADRP+LDR sequence was converted into ADRP+ADD. We are looking at the
     // second instruction and have to use the relocation type for ADD.
     AdjustedRel.Type = ELF::R_AARCH64_ADD_ABS_LO12_NC;
-  } else {
-    // For instructions that reference GOT, ignore the referenced symbol and
-    // use value at the relocation site. FixRelaxationPass will look at
-    // instruction pairs and will perform necessary adjustments.
+    return AdjustedRel;
+  }
+
+  // ADRP is a special case since the linker can leave the instruction opcode
+  // intact and modify only the operand. We are doing our best to detect when
+  // such conversion has happened without looking at the next instruction.
+  //
+  // If we detect that a page referenced by the ADRP cannot belong to GOT, and
+  // that it matches the symbol from the relocation, then we can be certain
+  // that the linker converted the GOT reference into the local one. Otherwise,
+  // we leave the disambiguation resolution to FixRelaxationPass.
+  //
+  // Note that ADRP relaxation described above cannot happen for TLS relocation.
+  // Since TLS relocations may not even have a valid symbol (not supported by
+  // BOLT), we explicitly exclude them from the check.
+  if (BC.MIB->isADRP(Inst) && Rel.Addend == 0 && !Relocation::isTLS(Rel.Type)) {
     ErrorOr<uint64_t> SymbolValue = BC.getSymbolValue(*Rel.Symbol);
     assert(SymbolValue && "Symbol value should be set");
     const uint64_t SymbolPageAddr = *SymbolValue & ~0xfffULL;
 
-    // Check if defined symbol and GOT are on the same page. If they are not,
-    // disambiguate the operand.
-    if (BC.MIB->isADRP(Inst) && Rel.Addend == 0 &&
-        SymbolPageAddr == Rel.Value &&
+    if (SymbolPageAddr == Rel.Value &&
         !isPageAddressValidForGOT(SymbolPageAddr)) {
       AdjustedRel.Type = ELF::R_AARCH64_ADR_PREL_PG_HI21;
-    } else {
-      AdjustedRel.Symbol = BC.registerNameAtAddress("__BOLT_got_zero", 0, 0, 0);
-      AdjustedRel.Addend = Rel.Value;
+      return AdjustedRel;
     }
   }
 
+  // For instructions that reference GOT, ignore the referenced symbol and
+  // use value at the relocation site. FixRelaxationPass will look at
+  // instruction pairs and will perform necessary adjustments.
+  AdjustedRel.Symbol = BC.registerNameAtAddress("__BOLT_got_zero", 0, 0, 0);
+  AdjustedRel.Addend = Rel.Value;
+
   return AdjustedRel;
 }