tbaeder created this revision.
tbaeder added reviewers: aaron.ballman, erichkeane, tahonermann, shafik.
Herald added a project: All.
tbaeder requested review of this revision.
Herald added a project: clang.
Herald added a subscriber: cfe-commits.
@aaron.ballman Not sure if this (the added early return) is all you meant when
you talked about virtual destructors.
I also wasn't sure about the added `getOverridingFunction()` - I think
`isDerivedFrom(..., paths)` is what I should be using, but that seemed
excessively hard to use.
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D142630
Files:
clang/lib/AST/Interp/ByteCodeExprGen.cpp
clang/lib/AST/Interp/Context.cpp
clang/lib/AST/Interp/Context.h
clang/lib/AST/Interp/Function.h
clang/lib/AST/Interp/Interp.h
clang/lib/AST/Interp/InterpState.h
clang/test/AST/Interp/records.cpp
Index: clang/test/AST/Interp/records.cpp
===================================================================
--- clang/test/AST/Interp/records.cpp
+++ clang/test/AST/Interp/records.cpp
@@ -1,8 +1,10 @@
// RUN: %clang_cc1 -fexperimental-new-constant-interpreter -verify %s
// RUN: %clang_cc1 -fexperimental-new-constant-interpreter -std=c++14 -verify %s
+// RUN: %clang_cc1 -fexperimental-new-constant-interpreter -std=c++20 -verify %s
// RUN: %clang_cc1 -fexperimental-new-constant-interpreter -triple i686 -verify %s
// RUN: %clang_cc1 -verify=ref %s
// RUN: %clang_cc1 -verify=ref -std=c++14 %s
+// RUN: %clang_cc1 -verify=ref -std=c++20 %s
// RUN: %clang_cc1 -verify=ref -triple i686 %s
struct BoolPair {
@@ -286,6 +288,7 @@
};
namespace DeriveFailures {
+#if __cplusplus < 202002L
struct Base { // ref-note 2{{declared here}}
int Val;
};
@@ -301,10 +304,12 @@
// ref-note {{in call to 'Derived(12)'}} \
// ref-note {{declared here}} \
// expected-error {{must be initialized by a constant expression}}
+
static_assert(D.Val == 0, ""); // ref-error {{not an integral constant expression}} \
// ref-note {{initializer of 'D' is not a constant expression}} \
// expected-error {{not an integral constant expression}} \
// expected-note {{read of object outside its lifetime}}
+#endif
struct AnotherBase {
int Val;
@@ -354,3 +359,82 @@
static_assert(getS(true).a == 12, "");
static_assert(getS(false).a == 13, "");
};
+
+#if __cplusplus >= 202002L
+namespace VirtualCalls {
+namespace Obvious {
+
+ class A {
+ public:
+ constexpr A(){}
+ constexpr virtual int foo() {
+ return 3;
+ }
+ };
+ class B : public A {
+ public:
+ constexpr int foo() override {
+ return 6;
+ }
+ };
+
+ constexpr int getFooB(bool b) {
+ A *a;
+ A myA;
+ B myB;
+
+ if (b)
+ a = &myA;
+ else
+ a = &myB;
+
+ return a->foo();
+ }
+ static_assert(getFooB(true) == 3, "");
+ static_assert(getFooB(false) == 6, "");
+}
+
+namespace MultipleBases {
+ class A {
+ public:
+ constexpr virtual int getInt() const { return 10; }
+ };
+ class B {
+ public:
+ };
+ class C : public A, public B {
+ public:
+ constexpr int getInt() const override { return 20; }
+ };
+
+ constexpr int callGetInt(const A& a) { return a.getInt(); }
+ static_assert(callGetInt(C()) == 20, "");
+ static_assert(callGetInt(A()) == 10, "");
+}
+
+namespace Destructors {
+ class Base {
+ public:
+ int i;
+ constexpr Base(int &i) : i(i) {i++;}
+ constexpr virtual ~Base() {i--;}
+ };
+
+ class Derived : public Base {
+ public:
+ constexpr Derived(int &i) : Base(i) {}
+ constexpr virtual ~Derived() {i--;}
+ };
+
+ constexpr int test() {
+ int i = 0;
+ Derived d(i);
+ return i;
+ }
+ static_assert(test() == 1);
+}
+
+
+
+};
+#endif
Index: clang/lib/AST/Interp/InterpState.h
===================================================================
--- clang/lib/AST/Interp/InterpState.h
+++ clang/lib/AST/Interp/InterpState.h
@@ -86,6 +86,8 @@
return M ? M->getSource(F, PC) : F->getSource(PC);
}
+ Context &getContext() const { return Ctx; }
+
private:
/// AST Walker state.
State &Parent;
Index: clang/lib/AST/Interp/Interp.h
===================================================================
--- clang/lib/AST/Interp/Interp.h
+++ clang/lib/AST/Interp/Interp.h
@@ -1509,6 +1509,22 @@
if (S.checkingPotentialConstantExpression())
return false;
+
+ // For a virtual call, we need to get the right function here.
+ if (Func->isVirtual()) {
+ // Our ThisPtr has the decl of the right type at this point,
+ // so we just need to find the function to call.
+ const CXXRecordDecl *DynamicDecl =
+ ThisPtr.getDeclDesc()->getType()->getAsCXXRecordDecl();
+ const CXXRecordDecl *StaticDecl =
+ cast<CXXRecordDecl>(Func->getParentDecl());
+ const CXXMethodDecl *InitialFunction =
+ cast<CXXMethodDecl>(Func->getDecl());
+ const CXXMethodDecl *Overrider = S.getContext().getOverridingFunction(
+ DynamicDecl, StaticDecl, InitialFunction);
+ if (Overrider != InitialFunction)
+ Func = S.P.getFunction(Overrider);
+ }
}
if (!CheckCallable(S, PC, Func))
Index: clang/lib/AST/Interp/Function.h
===================================================================
--- clang/lib/AST/Interp/Function.h
+++ clang/lib/AST/Interp/Function.h
@@ -130,6 +130,13 @@
/// Checks if the function is a constructor.
bool isConstructor() const { return isa<CXXConstructorDecl>(F); }
+ /// Returns the parent record decl, if any.
+ const CXXRecordDecl *getParentDecl() const {
+ if (const auto *MD = dyn_cast<CXXMethodDecl>(F))
+ return MD->getParent();
+ return nullptr;
+ }
+
/// Checks if the function is fully done compiling.
bool isFullyCompiled() const { return IsFullyCompiled; }
Index: clang/lib/AST/Interp/Context.h
===================================================================
--- clang/lib/AST/Interp/Context.h
+++ clang/lib/AST/Interp/Context.h
@@ -61,6 +61,11 @@
/// Classifies an expression.
std::optional<PrimType> classify(QualType T) const;
+ const CXXMethodDecl *
+ getOverridingFunction(const CXXRecordDecl *DynamicDecl,
+ const CXXRecordDecl *StaticDecl,
+ const CXXMethodDecl *InitialFunction);
+
private:
/// Runs a function.
bool Run(State &Parent, Function *Func, APValue &Result);
Index: clang/lib/AST/Interp/Context.cpp
===================================================================
--- clang/lib/AST/Interp/Context.cpp
+++ clang/lib/AST/Interp/Context.cpp
@@ -152,3 +152,38 @@
});
return false;
}
+
+// TODO: Virtual bases?
+const CXXMethodDecl *
+Context::getOverridingFunction(const CXXRecordDecl *DynamicDecl,
+ const CXXRecordDecl *StaticDecl,
+ const CXXMethodDecl *InitialFunction) {
+
+ const CXXRecordDecl *CurRecord = DynamicDecl;
+ const CXXMethodDecl *FoundFunction = InitialFunction;
+ for (;;) {
+ const CXXMethodDecl *Overrider =
+ FoundFunction->getCorrespondingMethodDeclaredInClass(CurRecord, false);
+ if (Overrider)
+ return Overrider;
+
+ // Common case of only one base class.
+ if (CurRecord->getNumBases() == 1) {
+ CurRecord = CurRecord->bases_begin()->getType()->getAsCXXRecordDecl();
+ continue;
+ }
+
+ // Otherwise, go to the base class that will lead to the StaticDecl.
+ for (const CXXBaseSpecifier &Spec : CurRecord->bases()) {
+ const CXXRecordDecl *Base = Spec.getType()->getAsCXXRecordDecl();
+ if (Base == StaticDecl || Base->isDerivedFrom(StaticDecl)) {
+ CurRecord = Base;
+ break;
+ }
+ }
+ }
+
+ llvm_unreachable(
+ "Couldn't find an overriding function in the class hierarchy?");
+ return nullptr;
+}
Index: clang/lib/AST/Interp/ByteCodeExprGen.cpp
===================================================================
--- clang/lib/AST/Interp/ByteCodeExprGen.cpp
+++ clang/lib/AST/Interp/ByteCodeExprGen.cpp
@@ -2047,6 +2047,8 @@
if (!this->emitCall(DtorFunc, SourceInfo{}))
return false;
}
+ if (Dtor->isVirtual())
+ return this->emitPopPtr(SourceInfo{});
}
for (const Record::Base &Base : llvm::reverse(R->bases())) {
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