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.
Function pointers can be compared for (in)equality but, but LE, GE, LT,
and GT opcodes should emit an error and abort.
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D149154
Files:
clang/lib/AST/Interp/FunctionPointer.h
clang/lib/AST/Interp/Interp.h
clang/lib/AST/Interp/Opcodes.td
clang/test/AST/Interp/functions.cpp
Index: clang/test/AST/Interp/functions.cpp
===================================================================
--- clang/test/AST/Interp/functions.cpp
+++ clang/test/AST/Interp/functions.cpp
@@ -178,6 +178,31 @@
static_assert(s.fp == nullptr, ""); // zero-initialized function pointer.
}
+namespace Comparison {
+ void f(), g();
+ constexpr void (*pf)() = &f, (*pg)() = &g;
+
+ constexpr bool u13 = pf < pg; // ref-warning {{ordered comparison of function pointers}} \
+ // ref-error {{must be initialized by a constant expression}} \
+ // ref-note {{comparison between '&f' and '&g' has unspecified value}} \
+ // expected-warning {{ordered comparison of function pointers}} \
+ // expected-error {{must be initialized by a constant expression}} \
+ // expected-note {{comparison between '&f' and '&g' has unspecified value}}
+
+ constexpr bool u14 = pf < (void(*)())nullptr; // ref-warning {{ordered comparison of function pointers}} \
+ // ref-error {{must be initialized by a constant expression}} \
+ // ref-note {{comparison between '&f' and 'nullptr' has unspecified value}} \
+ // expected-warning {{ordered comparison of function pointers}} \
+ // expected-error {{must be initialized by a constant expression}} \
+ // expected-note {{comparison between '&f' and 'nullptr' has unspecified value}}
+
+
+
+ static_assert(pf != pg, "");
+ static_assert(pf == &f, "");
+ static_assert(pg == &g, "");
+}
+
}
struct F {
Index: clang/lib/AST/Interp/Opcodes.td
===================================================================
--- clang/lib/AST/Interp/Opcodes.td
+++ clang/lib/AST/Interp/Opcodes.td
@@ -94,7 +94,7 @@
}
def ComparableTypeClass : TypeClass {
- let Types = !listconcat(AluTypeClass.Types, [Ptr], [Float]);
+ let Types = !listconcat(AluTypeClass.Types, [Ptr], [Float], [FnPtr]);
}
class SingletonTypeClass<Type Ty> : TypeClass {
Index: clang/lib/AST/Interp/Interp.h
===================================================================
--- clang/lib/AST/Interp/Interp.h
+++ clang/lib/AST/Interp/Interp.h
@@ -637,6 +637,32 @@
return CmpHelper<T>(S, OpPC, Fn);
}
+/// Function pointers cannot be compared in an ordered way.
+template <>
+inline bool CmpHelper<FunctionPointer>(InterpState &S, CodePtr OpPC,
+ CompareFn Fn) {
+ const auto &RHS = S.Stk.pop<FunctionPointer>();
+ const auto &LHS = S.Stk.pop<FunctionPointer>();
+
+ std::string LS =
+ LHS.toAPValue().getAsString(S.getCtx(), LHS.getType(S.getCtx()));
+ std::string RS =
+ RHS.toAPValue().getAsString(S.getCtx(), RHS.getType(S.getCtx()));
+ const SourceInfo &Loc = S.Current->getSource(OpPC);
+ S.FFDiag(Loc, diag::note_constexpr_pointer_comparison_unspecified)
+ << LS << RS;
+ return false;
+}
+
+template <>
+inline bool CmpHelperEQ<FunctionPointer>(InterpState &S, CodePtr OpPC,
+ CompareFn Fn) {
+ const auto &RHS = S.Stk.pop<FunctionPointer>();
+ const auto &LHS = S.Stk.pop<FunctionPointer>();
+ S.Stk.push<Boolean>(Boolean::from(Fn(LHS.compare(RHS))));
+ return true;
+}
+
template <>
inline bool CmpHelper<Pointer>(InterpState &S, CodePtr OpPC, CompareFn Fn) {
using BoolT = PrimConv<PT_Bool>::T;
Index: clang/lib/AST/Interp/FunctionPointer.h
===================================================================
--- clang/lib/AST/Interp/FunctionPointer.h
+++ clang/lib/AST/Interp/FunctionPointer.h
@@ -6,6 +6,7 @@
#include "Function.h"
#include "Primitives.h"
#include "clang/AST/APValue.h"
+#include "clang/AST/ASTContext.h"
namespace clang {
namespace interp {
@@ -38,6 +39,13 @@
OS << ")";
}
+ QualType getType(const ASTContext &Ctx) const {
+ if (!Func)
+ return Ctx.NullPtrTy;
+
+ return Func->getDecl()->getType();
+ }
+
ComparisonCategoryResult compare(const FunctionPointer &RHS) const {
if (Func == RHS.Func)
return ComparisonCategoryResult::Equal;
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
