Attached. With the functional part of your change reverted and this applied, the modified tests still pass except
error: 'note' diagnostics expected but not seen: File /usr/local/google/home/richardsmith/llvm-git-1/src/tools/clang/test/Analysis/nullptr.cpp Line 128: 'p' initialized to a null pointer value error: 'note' diagnostics seen but not expected: File /usr/local/google/home/richardsmith/llvm-git-1/src/tools/clang/test/Analysis/nullptr.cpp Line 128: 'p' declared without an initial value ... which seems accurate (but perhaps not useful). On Fri, 14 Dec 2018 at 14:47, Richard Smith <rich...@metafoo.co.uk> wrote: > I have a patch I put together a while back as an attempt to fix a > different bug, that creates a new CastKind for this operation (didn't work > out there, but it might do so here). I'll dig it out and mail it to you in > case it's a useful starting point. > > On Fri, 14 Dec 2018 at 14:42, Keane, Erich via cfe-commits < > cfe-commits@lists.llvm.org> wrote: > >> Alright, no problem. I’ll push a revert in a few minutes and give it >> another try. Perhaps I can suppress the creation of a CK_LValueToRValue in >> the case where it’s a read from nullptr_t >> >> >> >> >> >> *From:* Richard Smith [mailto:rich...@metafoo.co.uk] >> *Sent:* Friday, December 14, 2018 2:41 PM >> *To:* Keane, Erich <erich.ke...@intel.com> >> *Cc:* cfe-commits <cfe-commits@lists.llvm.org> >> *Subject:* Re: r349201 - Add extension to always default-initialize >> nullptr_t. >> >> >> >> Sorry, I was late with my review comment. I think this is the wrong way >> to approach this problem. This does not "fix all situations where nullptr_t >> would seem uninitialized", and it makes our AST representation lose source >> fidelity. >> >> >> >> On Fri, 14 Dec 2018 at 14:25, Erich Keane via cfe-commits < >> cfe-commits@lists.llvm.org> wrote: >> >> Author: erichkeane >> Date: Fri Dec 14 14:22:29 2018 >> New Revision: 349201 >> >> URL: http://llvm.org/viewvc/llvm-project?rev=349201&view=rev >> Log: >> Add extension to always default-initialize nullptr_t. >> >> Core issue 1013 suggests that having an uninitialied std::nullptr_t be >> UB is a bit foolish, since there is only a single valid value. This DR >> reports that DR616 fixes it, which does so by making lvalue-to-rvalue >> conversions from nullptr_t be equal to nullptr. >> >> However, just implementing that results in warnings/etc in many places. >> In order to fix all situations where nullptr_t would seem uninitialized, >> this patch instead (as an otherwise transparent extension) default >> initializes uninitialized VarDecls of nullptr_t. >> >> Differential Revision: https://reviews.llvm.org/D53713 >> >> Change-Id: I84d72a9290054fa55341e8cbdac43c8e7f25b885 >> >> Added: >> cfe/trunk/test/SemaCXX/nullptr_t-init.cpp (with props) >> Modified: >> cfe/trunk/lib/Sema/SemaInit.cpp >> cfe/trunk/test/Analysis/nullptr.cpp >> cfe/trunk/test/SemaCXX/ast-print-crash.cpp >> >> Modified: cfe/trunk/lib/Sema/SemaInit.cpp >> URL: >> http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaInit.cpp?rev=349201&r1=349200&r2=349201&view=diff >> >> ============================================================================== >> --- cfe/trunk/lib/Sema/SemaInit.cpp (original) >> +++ cfe/trunk/lib/Sema/SemaInit.cpp Fri Dec 14 14:22:29 2018 >> @@ -4881,6 +4881,13 @@ static void TryDefaultInitialization(Sem >> return; >> } >> >> + // As an extension, and to fix Core issue 1013, zero initialize >> nullptr_t. >> + // Since there is only 1 valid value of nullptr_t, we can just use >> that. >> + if (DestType->isNullPtrType()) { >> + Sequence.AddZeroInitializationStep(Entity.getType()); >> + return; >> + } >> + >> // - otherwise, no initialization is performed. >> >> // If a program calls for the default initialization of an object of >> >> Modified: cfe/trunk/test/Analysis/nullptr.cpp >> URL: >> http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Analysis/nullptr.cpp?rev=349201&r1=349200&r2=349201&view=diff >> >> ============================================================================== >> --- cfe/trunk/test/Analysis/nullptr.cpp (original) >> +++ cfe/trunk/test/Analysis/nullptr.cpp Fri Dec 14 14:22:29 2018 >> @@ -125,21 +125,16 @@ struct Type { >> }; >> >> void shouldNotCrash() { >> - decltype(nullptr) p; // expected-note{{'p' declared without an initial >> value}} >> - if (getSymbol()) // expected-note {{Assuming the condition is false}} >> - // expected-note@-1{{Taking false branch}} >> - // expected-note@-2{{Assuming the condition is >> false}} >> - // expected-note@-3{{Taking false branch}} >> - // expected-note@-4{{Assuming the condition is true}} >> - // expected-note@-5{{Taking true branch}} >> - invokeF(p); // expected-warning{{1st function call argument is an >> uninitialized value}} >> - // expected-note@-1{{1st function call argument is an >> uninitialized value}} >> + decltype(nullptr) p; // expected-note{{'p' initialized to a null >> pointer value}} >> if (getSymbol()) // expected-note {{Assuming the condition is false}} >> // expected-note@-1{{Taking false branch}} >> // expected-note@-2{{Assuming the condition is true}} >> // expected-note@-3{{Taking true branch}} >> - invokeF(nullptr); // expected-note {{Calling 'invokeF'}} >> - // expected-note@-1{{Passing null pointer value >> via 1st parameter 'x'}} >> + invokeF(p); // expected-note{{Passing null pointer value via 1st >> parameter 'x'}} >> + // expected-note@-1{{Calling 'invokeF'}} >> + if (getSymbol()) // expected-note {{Assuming the condition is false}} >> + // expected-note@-1{{Taking false branch}} >> + invokeF(nullptr); >> if (getSymbol()) { // expected-note {{Assuming the condition is >> true}} >> // expected-note@-1{{Taking true branch}} >> X *xx = Type().x; // expected-note {{Null pointer value stored to >> field 'x'}} >> >> Modified: cfe/trunk/test/SemaCXX/ast-print-crash.cpp >> URL: >> http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/ast-print-crash.cpp?rev=349201&r1=349200&r2=349201&view=diff >> >> ============================================================================== >> --- cfe/trunk/test/SemaCXX/ast-print-crash.cpp (original) >> +++ cfe/trunk/test/SemaCXX/ast-print-crash.cpp Fri Dec 14 14:22:29 2018 >> @@ -7,6 +7,6 @@ >> >> // CHECK: struct { >> // CHECK-NEXT: } dont_crash_on_syntax_error; >> -// CHECK-NEXT: decltype(nullptr) p; >> +// CHECK-NEXT: decltype(nullptr) p(/*implicit*/(decltype(nullptr))0); >> struct { >> } dont_crash_on_syntax_error /* missing ; */ decltype(nullptr) p; >> >> Added: cfe/trunk/test/SemaCXX/nullptr_t-init.cpp >> URL: >> http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/nullptr_t-init.cpp?rev=349201&view=auto >> >> ============================================================================== >> --- cfe/trunk/test/SemaCXX/nullptr_t-init.cpp (added) >> +++ cfe/trunk/test/SemaCXX/nullptr_t-init.cpp Fri Dec 14 14:22:29 2018 >> @@ -0,0 +1,10 @@ >> +// RUN: %clang_cc1 -fsyntax-only -verify -std=c++11 -ffreestanding >> -Wuninitialized %s >> +// expected-no-diagnostics >> +typedef decltype(nullptr) nullptr_t; >> + >> +// Ensure no 'uninitialized when used here' warnings (Wuninitialized), >> for >> +// nullptr_t always-initialized extension. >> +nullptr_t default_init() { >> + nullptr_t a; >> + return a; >> +} >> >> Propchange: cfe/trunk/test/SemaCXX/nullptr_t-init.cpp >> >> ------------------------------------------------------------------------------ >> svn:eol-style = native >> >> Propchange: cfe/trunk/test/SemaCXX/nullptr_t-init.cpp >> >> ------------------------------------------------------------------------------ >> svn:keywords = "Author Date Id Rev URL" >> >> Propchange: cfe/trunk/test/SemaCXX/nullptr_t-init.cpp >> >> ------------------------------------------------------------------------------ >> svn:mime-type = text/plain >> >> >> _______________________________________________ >> cfe-commits mailing list >> cfe-commits@lists.llvm.org >> http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits >> >> _______________________________________________ >> cfe-commits mailing list >> cfe-commits@lists.llvm.org >> http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits >> >
nullptr-lval-to-rval.patch
Description: Binary data
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