summaryrefslogtreecommitdiffstats
path: root/contrib/llvm/tools/clang/lib/CodeGen/MicrosoftVBTables.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'contrib/llvm/tools/clang/lib/CodeGen/MicrosoftVBTables.cpp')
-rw-r--r--contrib/llvm/tools/clang/lib/CodeGen/MicrosoftVBTables.cpp233
1 files changed, 0 insertions, 233 deletions
diff --git a/contrib/llvm/tools/clang/lib/CodeGen/MicrosoftVBTables.cpp b/contrib/llvm/tools/clang/lib/CodeGen/MicrosoftVBTables.cpp
deleted file mode 100644
index dabf52c..0000000
--- a/contrib/llvm/tools/clang/lib/CodeGen/MicrosoftVBTables.cpp
+++ /dev/null
@@ -1,233 +0,0 @@
-//===--- MicrosoftVBTables.cpp - Virtual Base Table Emission --------------===//
-//
-// The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This class generates data about MSVC virtual base tables.
-//
-//===----------------------------------------------------------------------===//
-
-#include "MicrosoftVBTables.h"
-#include "CodeGenModule.h"
-#include "CGCXXABI.h"
-
-namespace clang {
-namespace CodeGen {
-
-/// Holds intermediate data about a path to a vbptr inside a base subobject.
-struct VBTablePath {
- VBTablePath(const VBTableInfo &VBInfo)
- : VBInfo(VBInfo), NextBase(VBInfo.VBPtrSubobject.getBase()) { }
-
- /// All the data needed to build a vbtable, minus the GlobalVariable whose
- /// name we haven't computed yet.
- VBTableInfo VBInfo;
-
- /// Next base to use for disambiguation. Can be null if we've already
- /// disambiguated this path once.
- const CXXRecordDecl *NextBase;
-
- /// Path is not really a full path like a CXXBasePath. It holds the subset of
- /// records that need to be mangled into the vbtable symbol name in order to get
- /// a unique name.
- llvm::SmallVector<const CXXRecordDecl *, 1> Path;
-};
-
-VBTableBuilder::VBTableBuilder(CodeGenModule &CGM,
- const CXXRecordDecl *MostDerived)
- : CGM(CGM), MostDerived(MostDerived),
- DerivedLayout(CGM.getContext().getASTRecordLayout(MostDerived)) {}
-
-void VBTableBuilder::enumerateVBTables(VBTableVector &VBTables) {
- VBTablePathVector Paths;
- findUnambiguousPaths(MostDerived, BaseSubobject(MostDerived,
- CharUnits::Zero()), Paths);
- for (VBTablePathVector::iterator I = Paths.begin(), E = Paths.end();
- I != E; ++I) {
- VBTablePath *P = *I;
- P->VBInfo.GV = getAddrOfVBTable(P->VBInfo.ReusingBase, P->Path);
- VBTables.push_back(P->VBInfo);
- }
-}
-
-
-void VBTableBuilder::findUnambiguousPaths(const CXXRecordDecl *ReusingBase,
- BaseSubobject CurSubobject,
- VBTablePathVector &Paths) {
- size_t PathsStart = Paths.size();
- bool ReuseVBPtrFromBase = true;
- const CXXRecordDecl *CurBase = CurSubobject.getBase();
- const ASTRecordLayout &Layout = CGM.getContext().getASTRecordLayout(CurBase);
-
- // If this base has a vbptr, then we've found a path. These are not full
- // paths, so we don't use CXXBasePath.
- if (Layout.hasOwnVBPtr()) {
- ReuseVBPtrFromBase = false;
- VBTablePath *Info = new VBTablePath(
- VBTableInfo(ReusingBase, CurSubobject, /*GV=*/0));
- Paths.push_back(Info);
- }
-
- // Recurse onto any bases which themselves have virtual bases.
- for (CXXRecordDecl::base_class_const_iterator I = CurBase->bases_begin(),
- E = CurBase->bases_end(); I != E; ++I) {
- const CXXRecordDecl *Base = I->getType()->getAsCXXRecordDecl();
- if (!Base->getNumVBases())
- continue; // Bases without virtual bases have no vbptrs.
- CharUnits NextOffset;
- const CXXRecordDecl *NextReusingBase = Base;
- if (I->isVirtual()) {
- if (!VBasesSeen.insert(Base))
- continue; // Don't visit virtual bases twice.
- NextOffset = DerivedLayout.getVBaseClassOffset(Base);
- } else {
- NextOffset = (CurSubobject.getBaseOffset() +
- Layout.getBaseClassOffset(Base));
-
- // If CurBase didn't have a vbptr, then ReusingBase will reuse the vbptr
- // from the first non-virtual base with vbases for its vbptr.
- if (ReuseVBPtrFromBase) {
- NextReusingBase = ReusingBase;
- ReuseVBPtrFromBase = false;
- }
- }
-
- size_t NumPaths = Paths.size();
- findUnambiguousPaths(NextReusingBase, BaseSubobject(Base, NextOffset),
- Paths);
-
- // Tag paths through this base with the base itself. We might use it to
- // disambiguate.
- for (size_t I = NumPaths, E = Paths.size(); I != E; ++I)
- Paths[I]->NextBase = Base;
- }
-
- bool AmbiguousPaths = rebucketPaths(Paths, PathsStart);
- if (AmbiguousPaths)
- rebucketPaths(Paths, PathsStart, /*SecondPass=*/true);
-
-#ifndef NDEBUG
- // Check that the paths are in fact unique.
- for (size_t I = PathsStart + 1, E = Paths.size(); I != E; ++I) {
- assert(Paths[I]->Path != Paths[I - 1]->Path && "vbtable paths are not unique");
- }
-#endif
-}
-
-static bool pathCompare(VBTablePath *LHS, VBTablePath *RHS) {
- return LHS->Path < RHS->Path;
-}
-
-void VBTableBuilder::extendPath(VBTablePath *P, bool SecondPass) {
- assert(P->NextBase || SecondPass);
- if (P->NextBase) {
- P->Path.push_back(P->NextBase);
- P->NextBase = 0; // Prevent the path from being extended twice.
- }
-}
-
-bool VBTableBuilder::rebucketPaths(VBTablePathVector &Paths, size_t PathsStart,
- bool SecondPass) {
- // What we're essentially doing here is bucketing together ambiguous paths.
- // Any bucket with more than one path in it gets extended by NextBase, which
- // is usually the direct base of the inherited the vbptr. This code uses a
- // sorted vector to implement a multiset to form the buckets. Note that the
- // ordering is based on pointers, but it doesn't change our output order. The
- // current algorithm is designed to match MSVC 2012's names.
- // TODO: Implement MSVC 2010 or earlier names to avoid extra vbtable cruft.
- VBTablePathVector PathsSorted(&Paths[PathsStart], &Paths.back() + 1);
- std::sort(PathsSorted.begin(), PathsSorted.end(), pathCompare);
- bool AmbiguousPaths = false;
- for (size_t I = 0, E = PathsSorted.size(); I != E;) {
- // Scan forward to find the end of the bucket.
- size_t BucketStart = I;
- do {
- ++I;
- } while (I != E && PathsSorted[BucketStart]->Path == PathsSorted[I]->Path);
-
- // If this bucket has multiple paths, extend them all.
- if (I - BucketStart > 1) {
- AmbiguousPaths = true;
- for (size_t II = BucketStart; II != I; ++II)
- extendPath(PathsSorted[II], SecondPass);
- }
- }
- return AmbiguousPaths;
-}
-
-llvm::GlobalVariable *
-VBTableBuilder::getAddrOfVBTable(const CXXRecordDecl *ReusingBase,
- ArrayRef<const CXXRecordDecl *> BasePath) {
- // Caching at this layer is redundant with the caching in EnumerateVBTables().
-
- SmallString<256> OutName;
- llvm::raw_svector_ostream Out(OutName);
- MicrosoftMangleContext &Mangler =
- cast<MicrosoftMangleContext>(CGM.getCXXABI().getMangleContext());
- Mangler.mangleCXXVBTable(MostDerived, BasePath, Out);
- Out.flush();
- StringRef Name = OutName.str();
-
- llvm::ArrayType *VBTableType =
- llvm::ArrayType::get(CGM.IntTy, 1 + ReusingBase->getNumVBases());
-
- assert(!CGM.getModule().getNamedGlobal(Name) &&
- "vbtable with this name already exists: mangling bug?");
- llvm::GlobalVariable *VBTable =
- CGM.CreateOrReplaceCXXRuntimeVariable(Name, VBTableType,
- llvm::GlobalValue::ExternalLinkage);
- VBTable->setUnnamedAddr(true);
- return VBTable;
-}
-
-void VBTableInfo::EmitVBTableDefinition(
- CodeGenModule &CGM, const CXXRecordDecl *RD,
- llvm::GlobalVariable::LinkageTypes Linkage) const {
- assert(RD->getNumVBases() && ReusingBase->getNumVBases() &&
- "should only emit vbtables for classes with vbtables");
-
- const ASTRecordLayout &BaseLayout =
- CGM.getContext().getASTRecordLayout(VBPtrSubobject.getBase());
- const ASTRecordLayout &DerivedLayout =
- CGM.getContext().getASTRecordLayout(RD);
-
- SmallVector<llvm::Constant *, 4> Offsets(1 + ReusingBase->getNumVBases(), 0);
-
- // The offset from ReusingBase's vbptr to itself always leads.
- CharUnits VBPtrOffset = BaseLayout.getVBPtrOffset();
- Offsets[0] = llvm::ConstantInt::get(CGM.IntTy, -VBPtrOffset.getQuantity());
-
- MicrosoftVTableContext &Context = CGM.getMicrosoftVTableContext();
- for (CXXRecordDecl::base_class_const_iterator I = ReusingBase->vbases_begin(),
- E = ReusingBase->vbases_end(); I != E; ++I) {
- const CXXRecordDecl *VBase = I->getType()->getAsCXXRecordDecl();
- CharUnits Offset = DerivedLayout.getVBaseClassOffset(VBase);
- assert(!Offset.isNegative());
- // Make it relative to the subobject vbptr.
- Offset -= VBPtrSubobject.getBaseOffset() + VBPtrOffset;
- unsigned VBIndex = Context.getVBTableIndex(ReusingBase, VBase);
- assert(Offsets[VBIndex] == 0 && "The same vbindex seen twice?");
- Offsets[VBIndex] = llvm::ConstantInt::get(CGM.IntTy, Offset.getQuantity());
- }
-
- assert(Offsets.size() ==
- cast<llvm::ArrayType>(cast<llvm::PointerType>(GV->getType())
- ->getElementType())->getNumElements());
- llvm::ArrayType *VBTableType =
- llvm::ArrayType::get(CGM.IntTy, Offsets.size());
- llvm::Constant *Init = llvm::ConstantArray::get(VBTableType, Offsets);
- GV->setInitializer(Init);
-
- // Set the correct linkage.
- GV->setLinkage(Linkage);
-
- // Set the right visibility.
- CGM.setTypeVisibility(GV, RD, CodeGenModule::TVK_ForVTable);
-}
-
-} // namespace CodeGen
-} // namespace clang
OpenPOWER on IntegriCloud