[cfe-commits] r96137 - in /cfe/trunk: lib/CodeGen/CGVtable.cpp test/CodeGenCXX/vtable-layout.cpp
Anders Carlsson
andersca at mac.com
Sat Feb 13 16:16:19 PST 2010
Author: andersca
Date: Sat Feb 13 18:16:19 2010
New Revision: 96137
URL: http://llvm.org/viewvc/llvm-project?rev=96137&view=rev
Log:
Improve support for non-virtual 'this' pointer adjustments. With this, it should be possible to use the new vtable layout code for all class hierarchies that do not involve virtual bases.
Modified:
cfe/trunk/lib/CodeGen/CGVtable.cpp
cfe/trunk/test/CodeGenCXX/vtable-layout.cpp
Modified: cfe/trunk/lib/CodeGen/CGVtable.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGVtable.cpp?rev=96137&r1=96136&r2=96137&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGVtable.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGVtable.cpp Sat Feb 13 18:16:19 2010
@@ -136,9 +136,9 @@
SubobjectOffsetsMapTy &Offsets);
/// ComputeThisAdjustmentBaseOffset - Compute the base offset for adjusting
- /// the 'this' pointer from BaseRD to DerivedRD.
- BaseOffset ComputeThisAdjustmentBaseOffset(const CXXRecordDecl *BaseRD,
- const CXXRecordDecl *DerivedRD);
+ /// the 'this' pointer from the base subobject to the derived subobject.
+ BaseOffset ComputeThisAdjustmentBaseOffset(BaseSubobject BaseSubobject,
+ BaseSubobject Derived);
static void MergeSubobjectOffsets(const SubobjectOffsetsMapTy &NewOffsets,
SubobjectOffsetsMapTy &Offsets);
@@ -229,22 +229,11 @@
}
}
-static FinalOverriders::BaseOffset
-ComputeBaseOffset(ASTContext &Context, const CXXRecordDecl *BaseRD,
- const CXXRecordDecl *DerivedRD) {
- CXXBasePaths Paths(/*FindAmbiguities=*/false,
- /*RecordPaths=*/true, /*DetectVirtual=*/false);
-
- if (!const_cast<CXXRecordDecl *>(DerivedRD)->
- isDerivedFrom(const_cast<CXXRecordDecl *>(BaseRD), Paths)) {
- assert(false && "Class must be derived from the passed in base class!");
- return FinalOverriders::BaseOffset();
- }
-
+static FinalOverriders::BaseOffset
+ComputeBaseOffset(ASTContext &Context, const CXXRecordDecl *DerivedRD,
+ const CXXBasePath &Path) {
int64_t NonVirtualOffset = 0;
- const CXXBasePath &Path = Paths.front();
-
unsigned NonVirtualStart = 0;
const CXXRecordDecl *VirtualBase = 0;
@@ -280,6 +269,22 @@
// CharUnits.
return FinalOverriders::BaseOffset(DerivedRD, VirtualBase,
NonVirtualOffset / 8);
+
+}
+
+static FinalOverriders::BaseOffset
+ComputeBaseOffset(ASTContext &Context, const CXXRecordDecl *BaseRD,
+ const CXXRecordDecl *DerivedRD) {
+ CXXBasePaths Paths(/*FindAmbiguities=*/false,
+ /*RecordPaths=*/true, /*DetectVirtual=*/false);
+
+ if (!const_cast<CXXRecordDecl *>(DerivedRD)->
+ isDerivedFrom(const_cast<CXXRecordDecl *>(BaseRD), Paths)) {
+ assert(false && "Class must be derived from the passed in base class!");
+ return FinalOverriders::BaseOffset();
+ }
+
+ return ComputeBaseOffset(Context, DerivedRD, Paths.front());
}
static FinalOverriders::BaseOffset
@@ -337,9 +342,12 @@
}
FinalOverriders::BaseOffset
-FinalOverriders::ComputeThisAdjustmentBaseOffset(const CXXRecordDecl *BaseRD,
- const CXXRecordDecl *DerivedRD) {
- CXXBasePaths Paths(/*FindAmbiguities=*/false,
+FinalOverriders::ComputeThisAdjustmentBaseOffset(BaseSubobject Base,
+ BaseSubobject Derived) {
+ const CXXRecordDecl *BaseRD = Base.getBase();
+ const CXXRecordDecl *DerivedRD = Derived.getBase();
+
+ CXXBasePaths Paths(/*FindAmbiguities=*/true,
/*RecordPaths=*/true, /*DetectVirtual=*/true);
if (!const_cast<CXXRecordDecl *>(DerivedRD)->
@@ -350,10 +358,15 @@
assert(!Paths.getDetectedVirtual() && "FIXME: Handle virtual bases!");
- // FIXME: We need to go through all paths here, just not the first one.
- BaseOffset Offset = ComputeBaseOffset(Context, BaseRD, DerivedRD);
+ BaseOffset Offset;
+
+ // FIXME: This is not going to be enough with virtual bases.
+ // FIXME: We should not use / 8 here.
+ int64_t DerivedToBaseOffset =
+ (Base.getBaseOffset() - Derived.getBaseOffset()) / 8;
+
+ Offset.NonVirtualOffset = -DerivedToBaseOffset;
- Offset.NonVirtualOffset = -Offset.NonVirtualOffset;
return Offset;
}
@@ -380,8 +393,9 @@
for (unsigned I = 0, E = OffsetVector.size(); I != E; ++I) {
uint64_t Offset = OffsetVector[I];
+ BaseSubobject OverriddenSubobject = BaseSubobject(OverriddenRD, Offset);
BaseSubobjectMethodPairTy SubobjectAndMethod =
- std::make_pair(BaseSubobject(OverriddenRD, Offset), OverriddenMD);
+ std::make_pair(OverriddenSubobject, OverriddenMD);
OverriderInfo &Overrider = OverridersMap[SubobjectAndMethod];
@@ -402,8 +416,8 @@
// Check if we need a 'this' adjustment base offset as well.
if (Offset != NewBase.getBaseOffset()) {
BaseOffset ThisBaseOffset =
- ComputeThisAdjustmentBaseOffset(OverriddenMD->getParent(),
- NewMD->getParent());
+ ComputeThisAdjustmentBaseOffset(OverriddenSubobject,
+ NewBase);
assert(!ThisBaseOffset.isEmpty() &&
"Should not get an empty 'this' adjustment!");
@@ -921,7 +935,7 @@
// First, add the offset to top.
// FIXME: This is not going to be right for construction vtables.
- // FIXME: We should not use -8 here.
+ // FIXME: We should not use / 8 here.
int64_t OffsetToTop = -(int64_t)Base.getBaseOffset() / 8;
Components.push_back(VtableComponent::MakeOffsetToTop(OffsetToTop));
Modified: cfe/trunk/test/CodeGenCXX/vtable-layout.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/vtable-layout.cpp?rev=96137&r1=96136&r2=96137&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenCXX/vtable-layout.cpp (original)
+++ cfe/trunk/test/CodeGenCXX/vtable-layout.cpp Sat Feb 13 18:16:19 2010
@@ -279,4 +279,45 @@
};
void C::f() { }
-}
\ No newline at end of file
+}
+
+namespace Test7 {
+
+// Test that the D::f overrider for A::f have different 'this' pointer
+// adjustments in the two A base subobjects.
+
+struct A {
+ virtual void f();
+ int a;
+};
+
+struct B1 : A { };
+struct B2 : A { };
+
+struct C { virtual void c(); };
+
+// CHECK: Vtable for 'Test7::D' (10 entries).
+// CHECK-NEXT: 0 | offset_to_top (0)
+// CHECK-NEXT: 1 | Test7::D RTTI
+// CHECK-NEXT: -- (Test7::C, 0) vtable address --
+// CHECK-NEXT: -- (Test7::D, 0) vtable address --
+// CHECK-NEXT: 2 | void Test7::C::c()
+// CHECK-NEXT: 3 | void Test7::D::f()
+// CHECK-NEXT: 4 | offset_to_top (-8)
+// CHECK-NEXT: 5 | Test7::D RTTI
+// CHECK-NEXT: -- (Test7::A, 8) vtable address --
+// CHECK-NEXT: -- (Test7::B1, 8) vtable address --
+// CHECK-NEXT: 6 | void Test7::D::f()
+// CHECK-NEXT: [this adjustment: -8 non-virtual]
+// CHECK-NEXT: 7 | offset_to_top (-24)
+// CHECK-NEXT: 8 | Test7::D RTTI
+// CHECK-NEXT: -- (Test7::A, 24) vtable address --
+// CHECK-NEXT: -- (Test7::B2, 24) vtable address --
+// CHECK-NEXT: 9 | void Test7::D::f()
+// CHECK-NEXT: [this adjustment: -24 non-virtual]
+struct D : C, B1, B2 {
+ virtual void f();
+};
+void D::f() { }
+
+}
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