This should be fixed now.
On Sat, Aug 10, 2019, 8:08 PM Gábor Horváth <xazax....@gmail.com> wrote:
> You are right!
>
> I will look into this tomorrow. If you think this is urgent feel free to
> revert the commits.
>
> Cheers,
> Gabor
>
> On Sat, Aug 10, 2019, 6:41 PM Nico Weber <tha...@chromium.org> wrote:
>
>> Hi Gabor,
>>
>> this makes clang warn on this program:
>>
>> $ cat test.cc
>> #include <algorithm>
>> #include <vector>
>>
>> struct S {
>> bool operator==(const S &rhs) const;
>> };
>>
>> const S &f(const std::vector<S> &v) {
>> const auto &it = std::find(v.rbegin(), v.rend(), S());
>> return *it;
>> }
>>
>>
>> $ out/gn/bin/clang -c test.cc -isysroot $(xcrun -show-sdk-path) -isystem
>> libcxx/include/ -Wall
>> test.cc:10:11: warning: returning reference to local temporary object
>> [-Wreturn-stack-address]
>> return *it;
>> ^~
>> test.cc:9:15: note: binding reference variable 'it' here
>> const auto &it = std::find(v.rbegin(), v.rend(), S());
>> ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> 1 warning generated.
>>
>>
>> Is the warning correct here? The `const auto &it` is lifetime-extended to
>> the end of the block, and *it should return a reference to an element in
>> the vector. Since the vector's passed in, this should be fine. Or am I
>> missing something?
>>
>> Thanks,
>> Nico
>>
>> On Fri, Aug 9, 2019 at 11:15 AM Gabor Horvath via cfe-commits <
>> cfe-commits@lists.llvm.org> wrote:
>>
>>> Author: xazax
>>> Date: Fri Aug 9 08:16:35 2019
>>> New Revision: 368446
>>>
>>> URL: http://llvm.org/viewvc/llvm-project?rev=368446&view=rev
>>> Log:
>>> More warnings regarding gsl::Pointer and gsl::Owner attributes
>>>
>>> Differential Revision: https://reviews.llvm.org/D65120
>>>
>>> Modified:
>>> cfe/trunk/lib/Sema/SemaInit.cpp
>>> cfe/trunk/test/Analysis/inner-pointer.cpp
>>> cfe/trunk/test/Sema/warn-lifetime-analysis-nocfg.cpp
>>>
>>> Modified: cfe/trunk/lib/Sema/SemaInit.cpp
>>> URL:
>>> http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaInit.cpp?rev=368446&r1=368445&r2=368446&view=diff
>>>
>>> ==============================================================================
>>> --- cfe/trunk/lib/Sema/SemaInit.cpp (original)
>>> +++ cfe/trunk/lib/Sema/SemaInit.cpp Fri Aug 9 08:16:35 2019
>>> @@ -6564,6 +6564,25 @@ template <typename T> static bool isReco
>>> return false;
>>> }
>>>
>>> +static bool shouldTrackImplicitObjectArg(const CXXMethodDecl *Callee) {
>>> + if (auto *Conv = dyn_cast_or_null<CXXConversionDecl>(Callee))
>>> + if (isRecordWithAttr<PointerAttr>(Conv->getConversionType()))
>>> + return true;
>>> + if (!Callee->getParent()->isInStdNamespace() ||
>>> !Callee->getIdentifier())
>>> + return false;
>>> + if (!isRecordWithAttr<PointerAttr>(Callee->getThisObjectType()) &&
>>> + !isRecordWithAttr<OwnerAttr>(Callee->getThisObjectType()))
>>> + return false;
>>> + if (!isRecordWithAttr<PointerAttr>(Callee->getReturnType()) &&
>>> + !Callee->getReturnType()->isPointerType())
>>> + return false;
>>> + return llvm::StringSwitch<bool>(Callee->getName())
>>> + .Cases("begin", "rbegin", "cbegin", "crbegin", true)
>>> + .Cases("end", "rend", "cend", "crend", true)
>>> + .Cases("c_str", "data", "get", true)
>>> + .Default(false);
>>> +}
>>> +
>>> static void handleGslAnnotatedTypes(IndirectLocalPath &Path, Expr *Call,
>>> LocalVisitor Visit) {
>>> auto VisitPointerArg = [&](const Decl *D, Expr *Arg) {
>>> @@ -6577,10 +6596,9 @@ static void handleGslAnnotatedTypes(Indi
>>> };
>>>
>>> if (auto *MCE = dyn_cast<CXXMemberCallExpr>(Call)) {
>>> - const FunctionDecl *Callee = MCE->getDirectCallee();
>>> - if (auto *Conv = dyn_cast_or_null<CXXConversionDecl>(Callee))
>>> - if (isRecordWithAttr<PointerAttr>(Conv->getConversionType()))
>>> - VisitPointerArg(Callee, MCE->getImplicitObjectArgument());
>>> + const auto *MD =
>>> cast_or_null<CXXMethodDecl>(MCE->getDirectCallee());
>>> + if (MD && shouldTrackImplicitObjectArg(MD))
>>> + VisitPointerArg(MD, MCE->getImplicitObjectArgument());
>>> return;
>>> }
>>>
>>>
>>> Modified: cfe/trunk/test/Analysis/inner-pointer.cpp
>>> URL:
>>> http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Analysis/inner-pointer.cpp?rev=368446&r1=368445&r2=368446&view=diff
>>>
>>> ==============================================================================
>>> --- cfe/trunk/test/Analysis/inner-pointer.cpp (original)
>>> +++ cfe/trunk/test/Analysis/inner-pointer.cpp Fri Aug 9 08:16:35 2019
>>> @@ -1,4 +1,5 @@
>>> -// RUN: %clang_analyze_cc1 -analyzer-checker=cplusplus.InnerPointer \
>>> +// RUN: %clang_analyze_cc1 -analyzer-checker=cplusplus.InnerPointer \
>>> +// RUN: -Wno-dangling -Wno-dangling-field -Wno-return-stack-address \
>>> // RUN: %s -analyzer-output=text -verify
>>>
>>> #include "Inputs/system-header-simulator-cxx.h"
>>>
>>> Modified: cfe/trunk/test/Sema/warn-lifetime-analysis-nocfg.cpp
>>> URL:
>>> http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/warn-lifetime-analysis-nocfg.cpp?rev=368446&r1=368445&r2=368446&view=diff
>>>
>>> ==============================================================================
>>> --- cfe/trunk/test/Sema/warn-lifetime-analysis-nocfg.cpp (original)
>>> +++ cfe/trunk/test/Sema/warn-lifetime-analysis-nocfg.cpp Fri Aug 9
>>> 08:16:35 2019
>>> @@ -2,7 +2,6 @@
>>> struct [[gsl::Owner(int)]] MyIntOwner {
>>> MyIntOwner();
>>> int &operator*();
>>> - int *c_str() const;
>>> };
>>>
>>> struct [[gsl::Pointer(int)]] MyIntPointer {
>>> @@ -52,16 +51,6 @@ long *ownershipTransferToRawPointer() {
>>> return t.releaseAsRawPointer(); // ok
>>> }
>>>
>>> -int *danglingRawPtrFromLocal() {
>>> - MyIntOwner t;
>>> - return t.c_str(); // TODO
>>> -}
>>> -
>>> -int *danglingRawPtrFromTemp() {
>>> - MyIntPointer p;
>>> - return p.toOwner().c_str(); // TODO
>>> -}
>>> -
>>> struct Y {
>>> int a[4];
>>> };
>>> @@ -103,6 +92,12 @@ MyIntPointer danglingGslPtrFromTemporary
>>> return MyIntOwner{}; // expected-warning {{returning address of local
>>> temporary object}}
>>> }
>>>
>>> +MyIntOwner makeTempOwner();
>>> +
>>> +MyIntPointer danglingGslPtrFromTemporary2() {
>>> + return makeTempOwner(); // expected-warning {{returning address of
>>> local temporary object}}
>>> +}
>>> +
>>> MyLongPointerFromConversion danglingGslPtrFromTemporaryConv() {
>>> return MyLongOwnerWithConversion{}; // expected-warning {{returning
>>> address of local temporary object}}
>>> }
>>> @@ -124,12 +119,52 @@ void initLocalGslPtrWithTempOwner() {
>>> global2 = MyLongOwnerWithConversion{}; // TODO ?
>>> }
>>>
>>> -struct IntVector {
>>> - int *begin();
>>> - int *end();
>>> +namespace std {
>>> +template <typename T>
>>> +struct basic_iterator {};
>>> +
>>> +template <typename T>
>>> +struct vector {
>>> + typedef basic_iterator<T> iterator;
>>> + iterator begin();
>>> + T *data();
>>> +};
>>> +
>>> +template<typename T>
>>> +struct basic_string {
>>> + const T *c_str() const;
>>> +};
>>> +
>>> +template<typename T>
>>> +struct unique_ptr {
>>> + T *get() const;
>>> };
>>> +}
>>>
>>> void modelIterators() {
>>> - int *it = IntVector{}.begin(); // TODO ?
>>> + std::vector<int>::iterator it = std::vector<int>().begin(); //
>>> expected-warning {{object backing the pointer will be destroyed at the end
>>> of the full-expression}}
>>> (void)it;
>>> }
>>> +
>>> +std::vector<int>::iterator modelIteratorReturn() {
>>> + return std::vector<int>().begin(); // expected-warning {{returning
>>> address of local temporary object}}
>>> +}
>>> +
>>> +const char *danglingRawPtrFromLocal() {
>>> + std::basic_string<char> s;
>>> + return s.c_str(); // expected-warning {{address of stack memory
>>> associated with local variable 's' returned}}
>>> +}
>>> +
>>> +const char *danglingRawPtrFromTemp() {
>>> + return std::basic_string<char>().c_str(); // expected-warning
>>> {{returning address of local temporary object}}
>>> +}
>>> +
>>> +std::unique_ptr<int> getUniquePtr();
>>> +
>>> +int *danglingUniquePtrFromTemp() {
>>> + return getUniquePtr().get(); // expected-warning {{returning address
>>> of local temporary object}}
>>> +}
>>> +
>>> +int *danglingUniquePtrFromTemp2() {
>>> + return std::unique_ptr<int>().get(); // expected-warning {{returning
>>> address of local temporary object}}
>>> +}
>>>
>>>
>>> _______________________________________________
>>> cfe-commits mailing list
>>> cfe-commits@lists.llvm.org
>>> https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
>>>
>>
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