[clang] e6393ee - Canonicalize declaration pointers when forming APValues.
Nico Weber via cfe-commits
cfe-commits at lists.llvm.org
Fri Sep 4 07:36:20 PDT 2020
Actually in 2a03f270d69cf1079feb029f84727288e217588a
On Fri, Sep 4, 2020 at 10:27 AM Nico Weber <thakis at chromium.org> wrote:
> Test added in 85a9f6512a3cff797f1964c36c59d53e97a680c4
>
> On Fri, Sep 4, 2020 at 10:14 AM Nico Weber <thakis at chromium.org> wrote:
>
>> To keep the bots greener over the long weekend, I went ahead and reverted
>> this for now in 7b0332389afd705f46b02fcf87ec3414b8dece34. I'll add a test
>> for this.
>>
>> On Fri, Sep 4, 2020 at 10:11 AM Nico Weber <thakis at chromium.org> wrote:
>>
>>> Hi Richard,
>>>
>>> this breaks Wunreachable-code which now ignore "weak" on redeclarations:
>>>
>>> thakis at thakis:~/src/llvm-project$ cat foo.cc
>>> extern "C" void foo(void);
>>> extern "C" __attribute__((weak)) decltype(foo) foo;
>>>
>>> void g(), h();
>>> void f() {
>>> if (foo)
>>> return g();
>>> h();
>>> }
>>> thakis at thakis:~/src/llvm-project$ out/gn/bin/clang -Wunreachable-code
>>> -c foo.cc
>>> foo.cc:8:5: warning: code will never be executed [-Wunreachable-code]
>>> h();
>>> ^
>>>
>>> This seems to be a somewhat common pattern for calling new functions.
>>>
>>> (Chromium bug: https://crbug.com/1125102)
>>>
>>> On Thu, Sep 3, 2020 at 6:35 PM Richard Smith via cfe-commits <
>>> cfe-commits at lists.llvm.org> wrote:
>>>
>>>>
>>>> Author: Richard Smith
>>>> Date: 2020-09-03T15:35:12-07:00
>>>> New Revision: e6393ee813178e9d3306b8e3c6949a4f32f8a2cb
>>>>
>>>> URL:
>>>> https://github.com/llvm/llvm-project/commit/e6393ee813178e9d3306b8e3c6949a4f32f8a2cb
>>>> DIFF:
>>>> https://github.com/llvm/llvm-project/commit/e6393ee813178e9d3306b8e3c6949a4f32f8a2cb.diff
>>>>
>>>> LOG: Canonicalize declaration pointers when forming APValues.
>>>>
>>>> References to different declarations of the same entity aren't different
>>>> values, so shouldn't have different representations.
>>>>
>>>> Added:
>>>>
>>>>
>>>> Modified:
>>>> clang/include/clang/AST/APValue.h
>>>> clang/lib/AST/APValue.cpp
>>>> clang/lib/AST/ExprConstant.cpp
>>>> clang/test/CXX/dcl.dcl/dcl.spec/dcl.constexpr/p9.cpp
>>>> clang/test/OpenMP/ordered_messages.cpp
>>>>
>>>> Removed:
>>>>
>>>>
>>>>
>>>>
>>>> ################################################################################
>>>> diff --git a/clang/include/clang/AST/APValue.h
>>>> b/clang/include/clang/AST/APValue.h
>>>> index 87e4bd7f84c1..485e6c2602cf 100644
>>>> --- a/clang/include/clang/AST/APValue.h
>>>> +++ b/clang/include/clang/AST/APValue.h
>>>> @@ -174,6 +174,7 @@ class APValue {
>>>> return !(LHS == RHS);
>>>> }
>>>> friend llvm::hash_code hash_value(const LValueBase &Base);
>>>> + friend struct llvm::DenseMapInfo<LValueBase>;
>>>>
>>>> private:
>>>> PtrTy Ptr;
>>>> @@ -201,8 +202,7 @@ class APValue {
>>>>
>>>> public:
>>>> LValuePathEntry() : Value() {}
>>>> - LValuePathEntry(BaseOrMemberType BaseOrMember)
>>>> - :
>>>> Value{reinterpret_cast<uintptr_t>(BaseOrMember.getOpaqueValue())} {}
>>>> + LValuePathEntry(BaseOrMemberType BaseOrMember);
>>>> static LValuePathEntry ArrayIndex(uint64_t Index) {
>>>> LValuePathEntry Result;
>>>> Result.Value = Index;
>>>>
>>>> diff --git a/clang/lib/AST/APValue.cpp b/clang/lib/AST/APValue.cpp
>>>> index 2a8834b4db0c..7531229654cf 100644
>>>> --- a/clang/lib/AST/APValue.cpp
>>>> +++ b/clang/lib/AST/APValue.cpp
>>>> @@ -38,7 +38,7 @@ static_assert(
>>>> "Type is insufficiently aligned");
>>>>
>>>> APValue::LValueBase::LValueBase(const ValueDecl *P, unsigned I,
>>>> unsigned V)
>>>> - : Ptr(P), Local{I, V} {}
>>>> + : Ptr(P ? cast<ValueDecl>(P->getCanonicalDecl()) : nullptr),
>>>> Local{I, V} {}
>>>> APValue::LValueBase::LValueBase(const Expr *P, unsigned I, unsigned V)
>>>> : Ptr(P), Local{I, V} {}
>>>>
>>>> @@ -82,13 +82,19 @@ bool operator==(const APValue::LValueBase &LHS,
>>>> const APValue::LValueBase &RHS) {
>>>> if (LHS.Ptr != RHS.Ptr)
>>>> return false;
>>>> - if (LHS.is<TypeInfoLValue>())
>>>> + if (LHS.is<TypeInfoLValue>() || LHS.is<DynamicAllocLValue>())
>>>> return true;
>>>> return LHS.Local.CallIndex == RHS.Local.CallIndex &&
>>>> LHS.Local.Version == RHS.Local.Version;
>>>> }
>>>> }
>>>>
>>>> +APValue::LValuePathEntry::LValuePathEntry(BaseOrMemberType
>>>> BaseOrMember) {
>>>> + if (const Decl *D = BaseOrMember.getPointer())
>>>> + BaseOrMember.setPointer(D->getCanonicalDecl());
>>>> + Value = reinterpret_cast<uintptr_t>(BaseOrMember.getOpaqueValue());
>>>> +}
>>>> +
>>>> namespace {
>>>> struct LVBase {
>>>> APValue::LValueBase Base;
>>>> @@ -113,14 +119,16 @@ APValue::LValueBase::operator bool () const {
>>>>
>>>> clang::APValue::LValueBase
>>>> llvm::DenseMapInfo<clang::APValue::LValueBase>::getEmptyKey() {
>>>> - return clang::APValue::LValueBase(
>>>> - DenseMapInfo<const ValueDecl*>::getEmptyKey());
>>>> + clang::APValue::LValueBase B;
>>>> + B.Ptr = DenseMapInfo<const ValueDecl*>::getEmptyKey();
>>>> + return B;
>>>> }
>>>>
>>>> clang::APValue::LValueBase
>>>> llvm::DenseMapInfo<clang::APValue::LValueBase>::getTombstoneKey() {
>>>> - return clang::APValue::LValueBase(
>>>> - DenseMapInfo<const ValueDecl*>::getTombstoneKey());
>>>> + clang::APValue::LValueBase B;
>>>> + B.Ptr = DenseMapInfo<const ValueDecl*>::getTombstoneKey();
>>>> + return B;
>>>> }
>>>>
>>>> namespace clang {
>>>> @@ -757,8 +765,10 @@ void APValue::MakeMemberPointer(const ValueDecl
>>>> *Member, bool IsDerivedMember,
>>>> assert(isAbsent() && "Bad state change");
>>>> MemberPointerData *MPD = new ((void*)(char*)Data.buffer)
>>>> MemberPointerData;
>>>> Kind = MemberPointer;
>>>> - MPD->MemberAndIsDerivedMember.setPointer(Member);
>>>> + MPD->MemberAndIsDerivedMember.setPointer(
>>>> + Member ? cast<ValueDecl>(Member->getCanonicalDecl()) : nullptr);
>>>> MPD->MemberAndIsDerivedMember.setInt(IsDerivedMember);
>>>> MPD->resizePath(Path.size());
>>>> - memcpy(MPD->getPath(), Path.data(), Path.size()*sizeof(const
>>>> CXXRecordDecl*));
>>>> + for (unsigned I = 0; I != Path.size(); ++I)
>>>> + MPD->getPath()[I] = Path[I]->getCanonicalDecl();
>>>> }
>>>>
>>>> diff --git a/clang/lib/AST/ExprConstant.cpp
>>>> b/clang/lib/AST/ExprConstant.cpp
>>>> index e8f132dd4803..8e43b62662ee 100644
>>>> --- a/clang/lib/AST/ExprConstant.cpp
>>>> +++ b/clang/lib/AST/ExprConstant.cpp
>>>> @@ -1978,18 +1978,11 @@ static bool HasSameBase(const LValue &A, const
>>>> LValue &B) {
>>>> return false;
>>>>
>>>> if (A.getLValueBase().getOpaqueValue() !=
>>>> - B.getLValueBase().getOpaqueValue()) {
>>>> - const Decl *ADecl = GetLValueBaseDecl(A);
>>>> - if (!ADecl)
>>>> - return false;
>>>> - const Decl *BDecl = GetLValueBaseDecl(B);
>>>> - if (!BDecl || ADecl->getCanonicalDecl() !=
>>>> BDecl->getCanonicalDecl())
>>>> - return false;
>>>> - }
>>>> + B.getLValueBase().getOpaqueValue())
>>>> + return false;
>>>>
>>>> - return IsGlobalLValue(A.getLValueBase()) ||
>>>> - (A.getLValueCallIndex() == B.getLValueCallIndex() &&
>>>> - A.getLValueVersion() == B.getLValueVersion());
>>>> + return A.getLValueCallIndex() == B.getLValueCallIndex() &&
>>>> + A.getLValueVersion() == B.getLValueVersion();
>>>> }
>>>>
>>>> static void NoteLValueLocation(EvalInfo &Info, APValue::LValueBase
>>>> Base) {
>>>> @@ -3108,7 +3101,8 @@ static bool evaluateVarDeclInit(EvalInfo &Info,
>>>> const Expr *E,
>>>>
>>>> // If we're currently evaluating the initializer of this
>>>> declaration, use that
>>>> // in-flight value.
>>>> - if (Info.EvaluatingDecl.dyn_cast<const ValueDecl*>() == VD) {
>>>> + if (declaresSameEntity(Info.EvaluatingDecl.dyn_cast<const ValueDecl
>>>> *>(),
>>>> + VD)) {
>>>> Result = Info.EvaluatingDeclValue;
>>>> return true;
>>>> }
>>>>
>>>> diff --git a/clang/test/CXX/dcl.dcl/dcl.spec/dcl.constexpr/p9.cpp
>>>> b/clang/test/CXX/dcl.dcl/dcl.spec/dcl.constexpr/p9.cpp
>>>> index 8d51dbde7177..3720b277af7a 100644
>>>> --- a/clang/test/CXX/dcl.dcl/dcl.spec/dcl.constexpr/p9.cpp
>>>> +++ b/clang/test/CXX/dcl.dcl/dcl.spec/dcl.constexpr/p9.cpp
>>>> @@ -24,11 +24,10 @@ constexpr double &ni3; // expected-error
>>>> {{declaration of reference variable 'ni
>>>>
>>>> constexpr int nc1 = i; // expected-error {{constexpr variable 'nc1'
>>>> must be initialized by a constant expression}} expected-note {{read of
>>>> non-const variable 'i' is not allowed in a constant expression}}
>>>> constexpr C nc2 = C(); // expected-error {{cannot have non-literal
>>>> type 'const C'}}
>>>> -int &f(); // expected-note {{declared here}}
>>>> +int &f(); // expected-note 2{{declared here}}
>>>> constexpr int &nc3 = f(); // expected-error {{constexpr variable 'nc3'
>>>> must be initialized by a constant expression}} expected-note
>>>> {{non-constexpr function 'f' cannot be used in a constant expression}}
>>>> constexpr int nc4(i); // expected-error {{constexpr variable 'nc4'
>>>> must be initialized by a constant expression}} expected-note {{read of
>>>> non-const variable 'i' is not allowed in a constant expression}}
>>>> constexpr C nc5((C())); // expected-error {{cannot have non-literal
>>>> type 'const C'}}
>>>> -int &f(); // expected-note {{here}}
>>>> constexpr int &nc6(f()); // expected-error {{constexpr variable 'nc6'
>>>> must be initialized by a constant expression}} expected-note
>>>> {{non-constexpr function 'f'}}
>>>>
>>>> struct pixel {
>>>>
>>>> diff --git a/clang/test/OpenMP/ordered_messages.cpp
>>>> b/clang/test/OpenMP/ordered_messages.cpp
>>>> index f6b9dbd6d27f..8a3a86443eb8 100644
>>>> --- a/clang/test/OpenMP/ordered_messages.cpp
>>>> +++ b/clang/test/OpenMP/ordered_messages.cpp
>>>> @@ -16,6 +16,9 @@ void xxx(int argc) {
>>>> }
>>>>
>>>> int foo();
>>>> +#if __cplusplus >= 201103L
>>>> +// expected-note at -2 {{declared here}}
>>>> +#endif
>>>>
>>>> template <class T>
>>>> T foo() {
>>>> @@ -176,7 +179,7 @@ T foo() {
>>>>
>>>> int foo() {
>>>> #if __cplusplus >= 201103L
>>>> -// expected-note at -2 2 {{declared here}}
>>>> +// expected-note at -2 {{declared here}}
>>>> #endif
>>>> int k;
>>>> #pragma omp for ordered
>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>> cfe-commits mailing list
>>>> cfe-commits at lists.llvm.org
>>>> https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
>>>>
>>>
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