Author: higher-performance Date: 2024-10-15T13:41:52-07:00 New Revision: dd47920ce97e7db1ddeec34acdd9cb0ca7dcd7c4
URL: https://github.com/llvm/llvm-project/commit/dd47920ce97e7db1ddeec34acdd9cb0ca7dcd7c4 DIFF: https://github.com/llvm/llvm-project/commit/dd47920ce97e7db1ddeec34acdd9cb0ca7dcd7c4.diff LOG: Make [[clang::lifetimebound]] work for expressions coming from default arguments (#112047) Fixes #68596. Added: Modified: clang/include/clang/Basic/DiagnosticSemaKinds.td clang/lib/Sema/CheckExprLifetime.cpp clang/test/SemaCXX/attr-lifetimebound.cpp Removed: ################################################################################ diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td index e78acc8dc8c57b..e9111394bcd398 100644 --- a/clang/include/clang/Basic/DiagnosticSemaKinds.td +++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td @@ -10124,6 +10124,8 @@ def note_lambda_capture_initializer : Note< " via initialization of lambda capture %0}1">; def note_init_with_default_member_initializer : Note< "initializing field %0 with default member initializer">; +def note_init_with_default_argument : Note< + "initializing parameter %0 with default argument">; // Check for initializing a member variable with the address or a reference to // a constructor parameter. diff --git a/clang/lib/Sema/CheckExprLifetime.cpp b/clang/lib/Sema/CheckExprLifetime.cpp index 9b3894767d8629..8caeae5fcf9f8e 100644 --- a/clang/lib/Sema/CheckExprLifetime.cpp +++ b/clang/lib/Sema/CheckExprLifetime.cpp @@ -198,6 +198,7 @@ struct IndirectLocalPathEntry { GslReferenceInit, GslPointerInit, GslPointerAssignment, + DefaultArg, } Kind; Expr *E; union { @@ -609,15 +610,22 @@ static void visitFunctionCallArguments(IndirectLocalPath &Path, Expr *Call, for (unsigned I = 0, N = std::min<unsigned>(Callee->getNumParams(), Args.size()); I != N; ++I) { + Expr *Arg = Args[I]; + RevertToOldSizeRAII RAII(Path); + if (auto *DAE = dyn_cast<CXXDefaultArgExpr>(Arg)) { + Path.push_back( + {IndirectLocalPathEntry::DefaultArg, DAE, DAE->getParam()}); + Arg = DAE->getExpr(); + } if (CheckCoroCall || Callee->getParamDecl(I)->hasAttr<LifetimeBoundAttr>()) - VisitLifetimeBoundArg(Callee->getParamDecl(I), Args[I]); + VisitLifetimeBoundArg(Callee->getParamDecl(I), Arg); else if (EnableGSLAnalysis && I == 0) { // Perform GSL analysis for the first argument if (shouldTrackFirstArgument(Callee)) { - VisitGSLPointerArg(Callee, Args[0]); + VisitGSLPointerArg(Callee, Arg); } else if (auto *Ctor = dyn_cast<CXXConstructExpr>(Call); Ctor && shouldTrackFirstArgumentForConstructor(Ctor)) { - VisitGSLPointerArg(Ctor->getConstructor(), Args[0]); + VisitGSLPointerArg(Ctor->getConstructor(), Arg); } } } @@ -1060,6 +1068,9 @@ static SourceRange nextPathEntryRange(const IndirectLocalPath &Path, unsigned I, if (!Path[I].Capture->capturesVariable()) continue; return Path[I].E->getSourceRange(); + + case IndirectLocalPathEntry::DefaultArg: + return cast<CXXDefaultArgExpr>(Path[I].E)->getUsedLocation(); } } return E->getSourceRange(); @@ -1370,7 +1381,7 @@ static void checkExprLifetimeImpl(Sema &SemaRef, break; } - case IndirectLocalPathEntry::LambdaCaptureInit: + case IndirectLocalPathEntry::LambdaCaptureInit: { if (!Elem.Capture->capturesVariable()) break; // FIXME: We can't easily tell apart an init-capture from a nested @@ -1383,6 +1394,16 @@ static void checkExprLifetimeImpl(Sema &SemaRef, << nextPathEntryRange(Path, I + 1, L); break; } + + case IndirectLocalPathEntry::DefaultArg: { + const auto *DAE = cast<CXXDefaultArgExpr>(Elem.E); + const ParmVarDecl *Param = DAE->getParam(); + SemaRef.Diag(Param->getDefaultArgRange().getBegin(), + diag::note_init_with_default_argument) + << Param << nextPathEntryRange(Path, I + 1, L); + break; + } + } } // We didn't lifetime-extend, so don't go any further; we don't need more diff --git a/clang/test/SemaCXX/attr-lifetimebound.cpp b/clang/test/SemaCXX/attr-lifetimebound.cpp index bdc58171917375..d04bbb32433fb5 100644 --- a/clang/test/SemaCXX/attr-lifetimebound.cpp +++ b/clang/test/SemaCXX/attr-lifetimebound.cpp @@ -107,6 +107,37 @@ namespace std { using std::operator""s; using std::operator""sv; +namespace default_args { + using IntArray = int[]; + const int *defaultparam1(const int &def1 [[clang::lifetimebound]] = 0); // #def1 + const int &defaultparam_array([[clang::lifetimebound]] const int *p = IntArray{1, 2, 3}); // #def2 + struct A { + A(const char *, const int &def3 [[clang::lifetimebound]] = 0); // #def3 + }; + const int &defaultparam2(const int &def4 [[clang::lifetimebound]] = 0); // #def4 + const int &defaultparam3(const int &def5 [[clang::lifetimebound]] = defaultparam2(), const int &def6 [[clang::lifetimebound]] = 0); // #def5 #def6 + std::string_view defaultparam4(std::string_view s [[clang::lifetimebound]] = std::string()); // #def7 + + const int *test_default_args() { + const int *c = defaultparam1(); // expected-warning {{temporary whose address is used as value of local variable 'c' will be destroyed at the end of the full-expression}} expected-note@#def1 {{initializing parameter 'def1' with default argument}} + A a = A(""); // expected-warning {{temporary whose address is used as value of local variable 'a' will be destroyed at the end of the full-expression}} expected-note@#def3 {{initializing parameter 'def3' with default argument}} + const int &s = defaultparam2(); // expected-warning {{temporary bound to local reference 's' will be destroyed at the end of the full-expression}} expected-note@#def4 {{initializing parameter 'def4' with default argument}} + const int &t = defaultparam3(); // expected-warning {{temporary bound to local reference 't' will be destroyed at the end of the full-expression}} expected-note@#def4 {{initializing parameter 'def4' with default argument}} expected-note@#def5 {{initializing parameter 'def5' with default argument}} expected-warning {{temporary bound to local reference 't' will be destroyed at the end of the full-expression}} expected-note@#def6 {{initializing parameter 'def6' with default argument}} + const int &u = defaultparam_array(); // expected-warning {{temporary bound to local reference 'u' will be destroyed at the end of the full-expression}} expected-note@#def2 {{initializing parameter 'p' with default argument}} + int local; + const int &v = defaultparam2(local); // no warning + const int &w = defaultparam2(1); // expected-warning {{temporary bound to local reference 'w' will be destroyed at the end of the full-expression}} + if (false) { + return &defaultparam2(); // expected-warning {{returning address of local temporary object}} + } + if (false) { + return &defaultparam2(0); // expected-warning {{returning address of local temporary object}} expected-note@#def4 {{initializing parameter 'def4' with default argument}} + } + std::string_view sv = defaultparam4(); // expected-warning {{temporary whose address is used as value of local variable 'sv' will be destroyed at the end of the full-expression}} expected-note@#def7 {{initializing parameter 's' with default argument}} + return nullptr; + } +} // namespace default_args + namespace p0936r0_examples { std::string_view s = "foo"s; // expected-warning {{temporary}} _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
