merge main into amd-staging (llvm#935)

Author: ronlieb

bolt/include/bolt/Core/BinaryContext.h

@@ -537,6 +537,17 @@ class BinaryContext {
   BinaryFunction *createInjectedBinaryFunction(const std::string &Name,
                                                bool IsSimple = true);
 
+  /// Patch the original binary contents at address \p Address with a sequence
+  /// of instructions from the \p Instructions list. The callee is responsible
+  /// for checking that the sequence doesn't cross any function or section
+  /// boundaries.
+  ///
+  /// Optional \p Name can be assigned to the patch. The name will be emitted to
+  /// the symbol table at \p Address.
+  BinaryFunction *createInstructionPatch(uint64_t Address,
+                                         InstructionListType &Instructions,
+                                         const Twine &Name = "");
+
   std::vector<BinaryFunction *> &getInjectedBinaryFunctions() {
     return InjectedBinaryFunctions;
   }

bolt/include/bolt/Passes/PatchEntries.h

@@ -26,8 +26,6 @@ class PatchEntries : public BinaryFunctionPass {
   struct Patch {
     const MCSymbol *Symbol;
     uint64_t Address;
-    uint64_t FileOffset;
-    BinarySection *Section;
   };
 
 public:

bolt/lib/Core/BinaryContext.cpp

@@ -2400,6 +2400,32 @@ BinaryContext::createInjectedBinaryFunction(const std::string &Name,
   return BF;
 }
 
+BinaryFunction *BinaryContext::createInstructionPatch(
+    uint64_t Address, InstructionListType &Instructions, const Twine &Name) {
+  ErrorOr<BinarySection &> Section = getSectionForAddress(Address);
+  assert(Section && "cannot get section for patching");
+  assert(Section->hasSectionRef() && Section->isText() &&
+         "can only patch input file code sections");
+
+  const uint64_t FileOffset =
+      Section->getInputFileOffset() + Address - Section->getAddress();
+
+  std::string PatchName = Name.str();
+  if (PatchName.empty()) {
+    // Assign unique name to the patch.
+    static uint64_t N = 0;
+    PatchName = "__BP_" + std::to_string(N++);
+  }
+
+  BinaryFunction *PBF = createInjectedBinaryFunction(PatchName);
+  PBF->setOutputAddress(Address);
+  PBF->setFileOffset(FileOffset);
+  PBF->setOriginSection(&Section.get());
+  PBF->addBasicBlock()->addInstructions(Instructions);
+
+  return PBF;
+}
+
 std::pair<size_t, size_t>
 BinaryContext::calculateEmittedSize(BinaryFunction &BF, bool FixBranches) {
   // Adjust branch instruction to match the current layout.

bolt/lib/Passes/PatchEntries.cpp

@@ -83,9 +83,8 @@ Error PatchEntries::runOnFunctions(BinaryContext &BC) {
         return false;
       }
 
-      PendingPatches.emplace_back(Patch{Symbol, Function.getAddress() + Offset,
-                                        Function.getFileOffset() + Offset,
-                                        Function.getOriginSection()});
+      PendingPatches.emplace_back(
+          Patch{Symbol, Function.getAddress() + Offset});
       NextValidByte = Offset + PatchSize;
       if (NextValidByte > Function.getMaxSize()) {
         if (opts::Verbosity >= 1)
@@ -118,16 +117,12 @@ Error PatchEntries::runOnFunctions(BinaryContext &BC) {
     }
 
     for (Patch &Patch : PendingPatches) {
-      BinaryFunction *PatchFunction = BC.createInjectedBinaryFunction(
+      // Add instruction patch to the binary.
+      InstructionListType Instructions;
+      BC.MIB->createLongTailCall(Instructions, Patch.Symbol, BC.Ctx.get());
+      BinaryFunction *PatchFunction = BC.createInstructionPatch(
+          Patch.Address, Instructions,
           NameResolver::append(Patch.Symbol->getName(), ".org.0"));
-      // Force the function to be emitted at the given address.
-      PatchFunction->setOutputAddress(Patch.Address);
-      PatchFunction->setFileOffset(Patch.FileOffset);
-      PatchFunction->setOriginSection(Patch.Section);
-
-      InstructionListType Seq;
-      BC.MIB->createLongTailCall(Seq, Patch.Symbol, BC.Ctx.get());
-      PatchFunction->addBasicBlock()->addInstructions(Seq);
 
       // Verify the size requirements.
       uint64_t HotSize, ColdSize;

bolt/test/X86/Inputs/define_bar.s

@@ -1,5 +1,5 @@
 # Mocks a vtable object weak def in the C++ stdlib.
-  .data.rel.ro
+  .section .data.rel.ro,"aw"
   .weak bar
   .type bar, %object
 bar:

clang/lib/AST/ByteCode/Descriptor.cpp

@@ -367,10 +367,12 @@ Descriptor::Descriptor(const DeclTy &D, PrimType Type, MetadataSize MD,
 }
 
 /// Arrays of composite elements.
-Descriptor::Descriptor(const DeclTy &D, const Descriptor *Elem, MetadataSize MD,
+Descriptor::Descriptor(const DeclTy &D, const Type *SourceTy,
+                       const Descriptor *Elem, MetadataSize MD,
                        unsigned NumElems, bool IsConst, bool IsTemporary,
                        bool IsMutable)
-    : Source(D), ElemSize(Elem->getAllocSize() + sizeof(InlineDescriptor)),
+    : Source(D), SourceType(SourceTy),
+      ElemSize(Elem->getAllocSize() + sizeof(InlineDescriptor)),
       Size(ElemSize * NumElems), MDSize(MD.value_or(0)),
       AllocSize(std::max<size_t>(alignof(void *), Size) + MDSize),
       ElemDesc(Elem), IsConst(IsConst), IsMutable(IsMutable),
@@ -410,6 +412,8 @@ Descriptor::Descriptor(const DeclTy &D)
 }
 
 QualType Descriptor::getType() const {
+  if (SourceType)
+    return QualType(SourceType, 0);
   if (const auto *D = asValueDecl())
     return D->getType();
   if (const auto *T = dyn_cast_if_present<TypeDecl>(asDecl()))

clang/lib/AST/ByteCode/Descriptor.h

@@ -124,6 +124,7 @@ struct Descriptor final {
 private:
   /// Original declaration, used to emit the error message.
   const DeclTy Source;
+  const Type *SourceType = nullptr;
   /// Size of an element, in host bytes.
   const unsigned ElemSize;
   /// Size of the storage, in host bytes.
@@ -186,8 +187,9 @@ struct Descriptor final {
              bool IsTemporary, UnknownSize);
 
   /// Allocates a descriptor for an array of composites.
-  Descriptor(const DeclTy &D, const Descriptor *Elem, MetadataSize MD,
-             unsigned NumElems, bool IsConst, bool IsTemporary, bool IsMutable);
+  Descriptor(const DeclTy &D, const Type *SourceTy, const Descriptor *Elem,
+             MetadataSize MD, unsigned NumElems, bool IsConst, bool IsTemporary,
+             bool IsMutable);
 
   /// Allocates a descriptor for an array of composites of unknown size.
   Descriptor(const DeclTy &D, const Descriptor *Elem, MetadataSize MD,

clang/lib/AST/ByteCode/DynamicAllocator.cpp

@@ -57,8 +57,10 @@ Block *DynamicAllocator::allocate(const Descriptor *ElementDesc,
   assert(ElementDesc->getMetadataSize() == 0);
   // Create a new descriptor for an array of the specified size and
   // element type.
+  // FIXME: Pass proper element type.
   const Descriptor *D = allocateDescriptor(
-      ElementDesc->asExpr(), ElementDesc, Descriptor::InlineDescMD, NumElements,
+      ElementDesc->asExpr(), nullptr, ElementDesc, Descriptor::InlineDescMD,
+      NumElements,
       /*IsConst=*/false, /*IsTemporary=*/false, /*IsMutable=*/false);
   return allocate(D, EvalID, AllocForm);
 }

clang/lib/AST/ByteCode/Program.cpp

@@ -419,7 +419,7 @@ Descriptor *Program::createDescriptor(const DeclTy &D, const Type *Ty,
         unsigned ElemSize = ElemDesc->getAllocSize() + sizeof(InlineDescriptor);
         if (std::numeric_limits<unsigned>::max() / ElemSize <= NumElems)
           return {};
-        return allocateDescriptor(D, ElemDesc, MDSize, NumElems, IsConst,
+        return allocateDescriptor(D, Ty, ElemDesc, MDSize, NumElems, IsConst,
                                   IsTemporary, IsMutable);
       }
     }

clang/unittests/AST/ByteCode/toAPValue.cpp

@@ -254,3 +254,69 @@ TEST(ToAPValue, MemberPointers) {
     ASSERT_EQ(A.getKind(), APValue::MemberPointer);
   }
 }
+
+/// Compare outputs between the two interpreters.
+TEST(ToAPValue, Comparison) {
+  constexpr char Code[] =
+      "constexpr int GI = 12;\n"
+      "constexpr const int *PI = &GI;\n"
+      "struct S{int a; };\n"
+      "constexpr S GS[] = {{}, {}};\n"
+      "constexpr const S* OS = GS + 1;\n"
+      "constexpr S DS = *OS;\n"
+      "constexpr int IA[2][2][2] = {{{1, 2}, {3, 4}}, {{5, 6}, {7, 8}}};\n"
+      "constexpr const int *PIA = IA[1][1];\n";
+
+  for (const char *Arg : {"", "-fexperimental-new-constant-interpreter"}) {
+    auto AST = tooling::buildASTFromCodeWithArgs(Code, {Arg});
+
+    auto getDecl = [&](const char *Name) -> const VarDecl * {
+      auto Nodes =
+          match(valueDecl(hasName(Name)).bind("var"), AST->getASTContext());
+      assert(Nodes.size() == 1);
+      const auto *D = Nodes[0].getNodeAs<ValueDecl>("var");
+      assert(D);
+      return cast<VarDecl>(D);
+    };
+
+    {
+      const VarDecl *GIDecl = getDecl("GI");
+      const APValue *V = GIDecl->evaluateValue();
+      ASSERT_TRUE(V->isInt());
+    }
+
+    {
+      const VarDecl *GIDecl = getDecl("GI");
+      const VarDecl *PIDecl = getDecl("PI");
+      const APValue *V = PIDecl->evaluateValue();
+      ASSERT_TRUE(V->isLValue());
+      ASSERT_TRUE(V->hasLValuePath());
+      ASSERT_EQ(V->getLValueBase().get<const ValueDecl *>(), GIDecl);
+      ASSERT_EQ(V->getLValuePath().size(), 0u);
+    }
+
+    {
+      const APValue *V = getDecl("OS")->evaluateValue();
+      ASSERT_TRUE(V->isLValue());
+      ASSERT_EQ(V->getLValueOffset().getQuantity(), (unsigned)sizeof(int));
+      ASSERT_TRUE(V->hasLValuePath());
+      ASSERT_EQ(V->getLValuePath().size(), 1u);
+      ASSERT_EQ(V->getLValuePath()[0].getAsArrayIndex(), 1u);
+    }
+
+    {
+      const APValue *V = getDecl("DS")->evaluateValue();
+      ASSERT_TRUE(V->isStruct());
+    }
+    {
+      const APValue *V = getDecl("PIA")->evaluateValue();
+      ASSERT_TRUE(V->isLValue());
+      ASSERT_TRUE(V->hasLValuePath());
+      ASSERT_EQ(V->getLValuePath().size(), 3u);
+      ASSERT_EQ(V->getLValuePath()[0].getAsArrayIndex(), 1u);
+      ASSERT_EQ(V->getLValuePath()[1].getAsArrayIndex(), 1u);
+      ASSERT_EQ(V->getLValuePath()[2].getAsArrayIndex(), 0u);
+      ASSERT_EQ(V->getLValueOffset().getQuantity(), (unsigned)sizeof(int) * 6);
+    }
+  }
+}