Author: Richard Smith Date: 2021-03-05T15:53:10-08:00 New Revision: abbe42d8b5e4e0f3a30adbf232c693712cf2899c
URL: https://github.com/llvm/llvm-project/commit/abbe42d8b5e4e0f3a30adbf232c693712cf2899c DIFF: https://github.com/llvm/llvm-project/commit/abbe42d8b5e4e0f3a30adbf232c693712cf2899c.diff LOG: PR49260: Improve diagnostics for no matching 'operator new'. Fix duplicate diagnostic for an over-aligned allocation with no matching function, and add custom diagnostic for the case where the non-allocating placement new was intended but <new> was not included. Added: Modified: clang/include/clang/Basic/DiagnosticSemaKinds.td clang/lib/Sema/SemaExprCXX.cpp clang/test/SemaCXX/new-delete.cpp clang/test/SemaCXX/std-align-val-t-in-operator-new.cpp Removed: ################################################################################ diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td index 1ffc9884013d..9247426b3a88 100644 --- a/clang/include/clang/Basic/DiagnosticSemaKinds.td +++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td @@ -7188,6 +7188,9 @@ def err_need_header_before_typeid : Error< "you need to include <typeinfo> before using the 'typeid' operator">; def err_need_header_before_ms_uuidof : Error< "you need to include <guiddef.h> before using the '__uuidof' operator">; +def err_need_header_before_placement_new : Error< + "no matching %0 function for non-allocating placement new expression; " + "include <new>">; def err_ms___leave_not_in___try : Error< "'__leave' statement not in __try block">; def err_uuidof_without_guid : Error< diff --git a/clang/lib/Sema/SemaExprCXX.cpp b/clang/lib/Sema/SemaExprCXX.cpp index a708ccd58dd4..42537019df0e 100644 --- a/clang/lib/Sema/SemaExprCXX.cpp +++ b/clang/lib/Sema/SemaExprCXX.cpp @@ -2458,12 +2458,27 @@ static bool resolveAllocationOverload( } if (Diagnose) { - PartialDiagnosticAt PD(R.getNameLoc(), S.PDiag(diag::err_ovl_no_viable_function_in_call) - << R.getLookupName() << Range); + // If this is an allocation of the form 'new (p) X' for some object + // pointer p (or an expression that will decay to such a pointer), + // diagnose the missing inclusion of <new>. + if (!R.isClassLookup() && Args.size() == 2 && + (Args[1]->getType()->isObjectPointerType() || + Args[1]->getType()->isArrayType())) { + S.Diag(R.getNameLoc(), diag::err_need_header_before_placement_new) + << R.getLookupName() << Range; + // Listing the candidates is unlikely to be useful; skip it. + return true; + } - // If we have aligned candidates, only note the align_val_t candidates - // from AlignedCandidates and the non-align_val_t candidates from - // Candidates. + // Finish checking all candidates before we note any. This checking can + // produce additional diagnostics so can't be interleaved with our + // emission of notes. + // + // For an aligned allocation, separately check the aligned and unaligned + // candidates with their respective argument lists. + SmallVector<OverloadCandidate*, 32> Cands; + SmallVector<OverloadCandidate*, 32> AlignedCands; + llvm::SmallVector<Expr*, 4> AlignedArgs; if (AlignedCandidates) { auto IsAligned = [](OverloadCandidate &C) { return C.Function->getNumParams() > 1 && @@ -2471,17 +2486,26 @@ static bool resolveAllocationOverload( }; auto IsUnaligned = [&](OverloadCandidate &C) { return !IsAligned(C); }; - // This was an overaligned allocation, so list the aligned candidates - // first. - Args.insert(Args.begin() + 1, AlignArg); - AlignedCandidates->NoteCandidates(PD, S, OCD_AllCandidates, Args, "", - R.getNameLoc(), IsAligned); - Args.erase(Args.begin() + 1); - Candidates.NoteCandidates(PD, S, OCD_AllCandidates, Args, "", R.getNameLoc(), - IsUnaligned); + AlignedArgs.reserve(Args.size() + 1); + AlignedArgs.push_back(Args[0]); + AlignedArgs.push_back(AlignArg); + AlignedArgs.append(Args.begin() + 1, Args.end()); + AlignedCands = AlignedCandidates->CompleteCandidates( + S, OCD_AllCandidates, AlignedArgs, R.getNameLoc(), IsAligned); + + Cands = Candidates.CompleteCandidates(S, OCD_AllCandidates, Args, + R.getNameLoc(), IsUnaligned); } else { - Candidates.NoteCandidates(PD, S, OCD_AllCandidates, Args); + Cands = Candidates.CompleteCandidates(S, OCD_AllCandidates, Args, + R.getNameLoc()); } + + S.Diag(R.getNameLoc(), diag::err_ovl_no_viable_function_in_call) + << R.getLookupName() << Range; + if (AlignedCandidates) + AlignedCandidates->NoteCandidates(S, AlignedArgs, AlignedCands, "", + R.getNameLoc()); + Candidates.NoteCandidates(S, Args, Cands, "", R.getNameLoc()); } return true; diff --git a/clang/test/SemaCXX/new-delete.cpp b/clang/test/SemaCXX/new-delete.cpp index 2fc917ce7488..b26aba1296eb 100644 --- a/clang/test/SemaCXX/new-delete.cpp +++ b/clang/test/SemaCXX/new-delete.cpp @@ -32,10 +32,10 @@ inline void *operator new(size_t) { // no warning, due to __attribute__((used)) } // PR5823 -void* operator new(const size_t); // expected-note 2 {{candidate}} -void* operator new(size_t, int*); // expected-note 3 {{candidate}} -void* operator new(size_t, float*); // expected-note 3 {{candidate}} -void* operator new(size_t, S); // expected-note 2 {{candidate}} +void* operator new(const size_t); // expected-note {{candidate}} +void* operator new(size_t, int*); // expected-note 2{{candidate}} +void* operator new(size_t, float*); // expected-note 2{{candidate}} +void* operator new(size_t, S); // expected-note {{candidate}} struct foo { }; @@ -130,7 +130,7 @@ void bad_news(int *ip) (void)new (0, 0) int; // expected-error {{no matching function for call to 'operator new'}} (void)new (0L) int; // expected-error {{call to 'operator new' is ambiguous}} // This must fail, because the member version shouldn't be found. - (void)::new ((S*)0) U; // expected-error {{no matching function for call to 'operator new'}} + (void)::new ((S*)0) U; // expected-error {{no matching 'operator new' function for non-allocating placement new expression; include <new>}} // This must fail, because any member version hides all global versions. (void)new U; // expected-error {{no matching function for call to 'operator new'}} (void)new (int[]); // expected-error {{array size must be specified in new expression with no initializer}} @@ -143,6 +143,14 @@ void bad_news(int *ip) #endif } +void no_matching_placement_new() { + struct X { int n; }; + __attribute__((aligned(__alignof(X)))) unsigned char buffer[sizeof(X)]; + (void)new(buffer) X; // expected-error {{no matching 'operator new' function for non-allocating placement new expression; include <new>}} + (void)new(+buffer) X; // expected-error {{no matching 'operator new' function for non-allocating placement new expression; include <new>}} + (void)new(&buffer) X; // expected-error {{no matching 'operator new' function for non-allocating placement new expression; include <new>}} +} + void good_deletes() { delete (int*)0; diff --git a/clang/test/SemaCXX/std-align-val-t-in-operator-new.cpp b/clang/test/SemaCXX/std-align-val-t-in-operator-new.cpp index c743c15b4127..9c34cb8e0d50 100644 --- a/clang/test/SemaCXX/std-align-val-t-in-operator-new.cpp +++ b/clang/test/SemaCXX/std-align-val-t-in-operator-new.cpp @@ -21,7 +21,7 @@ enum align_val_t { #endif } // namespace std -void *operator new(std::size_t count, std::align_val_t al) __attribute__((alloc_align(2))); +void *operator new(std::size_t count, std::align_val_t al) __attribute__((alloc_align(2))); // #1 #define OVERALIGNED alignas(__STDCPP_DEFAULT_NEW_ALIGNMENT__ * 2) @@ -55,3 +55,29 @@ void *alloc_overaligned_struct_with_extra_255_alignment(int align) { std::align_val_t align_variable(int align) { return std::align_val_t(align); } std::align_val_t align_align16() { return std::align_val_t(16); } std::align_val_t align_align15() { return std::align_val_t(15); } + +struct X {}; +void *operator new(std::size_t, X); // #2 +void *operator new(std::size_t, std::align_val_t, X); // #3 +// FIXME: Consider improving notes 1 and 3 here to say that these are aligned +// allocation functions and the type is not over-aligned. +X *p = new (123) X; // expected-error {{no matching function}} +// expected-note@#1 {{no known conversion from 'int' to 'std::align_val_t' for 2nd argument}} +// expected-note@#2 {{no known conversion from 'int' to 'X' for 2nd argument}} +// expected-note@#3 {{requires 3 arguments}} +// expected-note@* {{requires 1 argument, but 2 were provided}} (builtin) + +#ifdef __cpp_aligned_new +struct alignas(__STDCPP_DEFAULT_NEW_ALIGNMENT__ * 2) Y {}; +Y *q = new (123) Y; // expected-error {{no matching function}} +// expected-note@#1 {{requires 2 arguments, but 3 were provided}} +// expected-note@#2 {{no known conversion from 'int' to 'X' for 2nd argument}} +// expected-note@#3 {{no known conversion from 'int' to 'X' for 3rd argument}} +// expected-note@* {{requires 1 argument, but 2 were provided}} (builtin) +#endif + +X *r = new (std::align_val_t(32), 123) X; // expected-error {{no matching function}} +// expected-note@#1 {{requires 2 arguments, but 3 were provided}} +// expected-note@#2 {{requires 2 arguments, but 3 were provided}} +// expected-note@#3 {{no known conversion from 'int' to 'X' for 3rd argument}} +// expected-note@* {{requires 1 argument, but 3 were provided}} (builtin) _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
