[cfe-commits] r79587 - in /cfe/trunk: lib/AST/DeclCXX.cpp lib/CodeGen/CGCXX.cpp test/CodeGenCXX/virt.cpp
Mike Stump
mrs at apple.com
Thu Aug 20 18:45:00 PDT 2009
Author: mrs
Date: Thu Aug 20 20:45:00 2009
New Revision: 79587
URL: http://llvm.org/viewvc/llvm-project?rev=79587&view=rev
Log:
We now support overriding base functions in vtables. WIP.
Modified:
cfe/trunk/lib/AST/DeclCXX.cpp
cfe/trunk/lib/CodeGen/CGCXX.cpp
cfe/trunk/test/CodeGenCXX/virt.cpp
Modified: cfe/trunk/lib/AST/DeclCXX.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/DeclCXX.cpp?rev=79587&r1=79586&r2=79587&view=diff
==============================================================================
--- cfe/trunk/lib/AST/DeclCXX.cpp (original)
+++ cfe/trunk/lib/AST/DeclCXX.cpp Thu Aug 20 20:45:00 2009
@@ -332,6 +332,8 @@
std::vector<const CXXMethodDecl *> *>
OverriddenMethodsMapTy;
+// FIXME: We hate static data. This doesn't survive PCH saving/loading, and
+// the vtable building code uses it at CG time.
static OverriddenMethodsMapTy *OverriddenMethods = 0;
void CXXMethodDecl::addOverriddenMethod(const CXXMethodDecl *MD) {
Modified: cfe/trunk/lib/CodeGen/CGCXX.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGCXX.cpp?rev=79587&r1=79586&r2=79587&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGCXX.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGCXX.cpp Thu Aug 20 20:45:00 2009
@@ -851,14 +851,19 @@
class VtableBuilder {
std::vector<llvm::Constant *> &methods;
llvm::Type *Ptr8Ty;
+ /// Class - The most derived class that this vtable is being built for.
const CXXRecordDecl *Class;
+ /// BLayout - Layout for the most derived class that this vtable is being
+ /// built for.
const ASTRecordLayout &BLayout;
llvm::SmallSet<const CXXRecordDecl *, 32> IndirectPrimary;
llvm::SmallSet<const CXXRecordDecl *, 32> SeenVBase;
llvm::Constant *rtti;
llvm::LLVMContext &VMContext;
CodeGenModule &CGM; // Per-module state.
-
+ /// Index - Maps a method decl into a vtable index. Useful for virtual
+ /// dispatch codegen.
+ llvm::DenseMap<const CXXMethodDecl *, int32_t> Index;
typedef CXXRecordDecl::method_iterator method_iter;
public:
VtableBuilder(std::vector<llvm::Constant *> &meth,
@@ -914,24 +919,69 @@
}
}
- void GenerateMethods(const CXXRecordDecl *RD) {
+ void StartNewTable() {
+ SeenVBase.clear();
+ }
+
+ inline uint32_t nottoobig(uint64_t t) {
+ assert(t < (uint32_t)-1ULL || "vtable too big");
+ return t;
+ }
+#if 0
+ inline uint32_t nottoobig(uint32_t t) {
+ return t;
+ }
+#endif
+
+ void AddMethod(const CXXMethodDecl *MD, int32_t FirstIndex) {
+ typedef CXXMethodDecl::method_iterator meth_iter;
+
llvm::Constant *m;
+ m = CGM.GetAddrOfFunction(GlobalDecl(MD), Ptr8Ty);
+ m = llvm::ConstantExpr::getBitCast(m, Ptr8Ty);
- for (method_iter mi = RD->method_begin(), me = RD->method_end(); mi != me;
- ++mi) {
- if (mi->isVirtual()) {
- m = CGM.GetAddrOfFunction(GlobalDecl(*mi));
- m = llvm::ConstantExpr::getBitCast(m, Ptr8Ty);
- methods.push_back(m);
+ // FIXME: Don't like the nested loops. For very large inheritance
+ // heirarchies we could have a table on the side with the final overridder
+ // and just replace each instance of an overridden method once. Would be
+ // nice to measure the cost/benefit on real code.
+
+ // If we can find a previously allocated slot for this, reuse it.
+ for (meth_iter mi = MD->begin_overridden_methods(),
+ e = MD->end_overridden_methods();
+ mi != e; ++mi) {
+ const CXXMethodDecl *OMD = *mi;
+ llvm::Constant *om;
+ om = CGM.GetAddrOfFunction(GlobalDecl(OMD), Ptr8Ty);
+ om = llvm::ConstantExpr::getBitCast(om, Ptr8Ty);
+
+ for (int32_t i = FirstIndex, e = nottoobig(methods.size()); i != e; ++i) {
+ // FIXME: begin_overridden_methods might be too lax, covariance */
+ if (methods[i] == om) {
+ methods[i] = m;
+ Index[MD] = i;
+ return;
+ }
}
}
+
+ // else allocate a new slot.
+ Index[MD] = methods.size();
+ methods.push_back(m);
+ }
+
+ void GenerateMethods(const CXXRecordDecl *RD, int32_t FirstIndex) {
+ for (method_iter mi = RD->method_begin(), me = RD->method_end(); mi != me;
+ ++mi)
+ if (mi->isVirtual())
+ AddMethod(*mi, FirstIndex);
}
void GenerateVtableForBase(const CXXRecordDecl *RD,
bool forPrimary,
bool VBoundary,
int64_t Offset,
- bool ForVirtualBase) {
+ bool ForVirtualBase,
+ int32_t FirstIndex) {
llvm::Constant *m = llvm::Constant::getNullValue(Ptr8Ty);
if (RD && !RD->isDynamicClass())
@@ -964,7 +1014,7 @@
IndirectPrimary.insert(PrimaryBase);
Top = false;
GenerateVtableForBase(PrimaryBase, true, PrimaryBaseWasVirtual|VBoundary,
- Offset, PrimaryBaseWasVirtual);
+ Offset, PrimaryBaseWasVirtual, FirstIndex);
}
if (Top) {
@@ -980,7 +1030,7 @@
}
// And add the virtuals for the class to the primary vtable.
- GenerateMethods(RD);
+ GenerateMethods(RD, FirstIndex);
// and then the non-virtual bases.
for (CXXRecordDecl::base_class_const_iterator i = RD->bases_begin(),
@@ -991,8 +1041,9 @@
cast<CXXRecordDecl>(i->getType()->getAs<RecordType>()->getDecl());
if (Base != PrimaryBase || PrimaryBaseWasVirtual) {
uint64_t o = Offset + Layout.getBaseClassOffset(Base);
- SeenVBase.clear();
- GenerateVtableForBase(Base, true, false, o, false);
+ StartNewTable();
+ FirstIndex = methods.size();
+ GenerateVtableForBase(Base, true, false, o, false, FirstIndex);
}
}
}
@@ -1006,9 +1057,10 @@
if (i->isVirtual() && !IndirectPrimary.count(Base)) {
// Mark it so we don't output it twice.
IndirectPrimary.insert(Base);
- SeenVBase.clear();
+ StartNewTable();
int64_t BaseOffset = BLayout.getVBaseClassOffset(Base);
- GenerateVtableForBase(Base, false, true, BaseOffset, true);
+ int32_t FirstIndex = methods.size();
+ GenerateVtableForBase(Base, false, true, BaseOffset, true, FirstIndex);
}
if (Base->getNumVBases())
GenerateVtableForVBases(Base, Class);
@@ -1034,7 +1086,7 @@
VtableBuilder b(methods, RD, CGM);
// First comes the vtables for all the non-virtual bases...
- b.GenerateVtableForBase(RD, true, false, 0, false);
+ b.GenerateVtableForBase(RD, true, false, 0, false, 0);
// then the vtables for all the virtual bases.
b.GenerateVtableForVBases(RD, RD);
Modified: cfe/trunk/test/CodeGenCXX/virt.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/virt.cpp?rev=79587&r1=79586&r2=79587&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenCXX/virt.cpp (original)
+++ cfe/trunk/test/CodeGenCXX/virt.cpp Thu Aug 20 20:45:00 2009
@@ -620,6 +620,36 @@
// CHECK-LP32-NEXT: .long 4294967276
// CHECK-LP32-NEXT: .long __ZTI8test10_D
+struct test11_B {
+ virtual void B1() { }
+ virtual void D() { }
+ virtual void B2() { }
+};
+
+struct test11_D : test11_B {
+ virtual void D1() { }
+ virtual void D() { }
+ virtual void D2() { }
+};
+
+// CHECK-LP32:__ZTV8test11_D:
+// CHECK-LP32-NEXT: .space 4
+// CHECK-LP32-NEXT: .long __ZTI8test11_D
+// CHECK-LP32-NEXT: .long __ZN8test11_B2B1Ev
+// CHECK-LP32-NEXT: .long __ZN8test11_D1DEv
+// CHECK-LP32-NEXT: .long __ZN8test11_B2B2Ev
+// CHECK-LP32-NEXT: .long __ZN8test11_D2D1Ev
+// CHECK-LP32-NEXT: .long __ZN8test11_D2D2Ev
+
+
+// CHECK-LP64:__ZTV8test11_D:
+// CHECK-LP64-NEXT: .space 8
+// CHECK-LP64-NEXT: .quad __ZTI8test11_D
+// CHECK-LP64-NEXT: .quad __ZN8test11_B2B1Ev
+// CHECK-LP64-NEXT: .quad __ZN8test11_D1DEv
+// CHECK-LP64-NEXT: .quad __ZN8test11_B2B2Ev
+// CHECK-LP64-NEXT: .quad __ZN8test11_D2D1Ev
+// CHECK-LP64-NEXT: .quad __ZN8test11_D2D2Ev
@@ -702,6 +732,7 @@
// CHECK-LP64-NEXT: .quad __ZN2D14bar5Ev
+test11_D d11;
test10_D d10;
test9_D d9;
test8_D d8;
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