https://github.com/MaskRay created https://github.com/llvm/llvm-project/pull/76094
https://github.com/llvm/llvm-project/pull/75332 diagnosed narrowing involving const reference. Our depot has hundreds if not thousands of breakages (https://github.com/llvm/llvm-project/pull/75332#issuecomment-1864757240). Add a subgroup of -Wc++11-narrowing to help users gradually fix their issues without regressing the existing -Wc++11-narrowing diagnostics. >From 8413d1612ed324229683aae75a78907e3ce8c9ca Mon Sep 17 00:00:00 2001 From: Fangrui Song <i...@maskray.me> Date: Wed, 20 Dec 2023 10:57:15 -0800 Subject: [PATCH] [Sema] Add -Wc++11-narrowing-const-reference https://github.com/llvm/llvm-project/pull/75332 diagnosed narrowing involving const reference. Our depot has hundreds if not thousands of breakages (https://github.com/llvm/llvm-project/pull/75332#issuecomment-1864757240). Add a subgroup of -Wc++11-narrowing to help users gradually fix their issues without regressing the existing -Wc++11-narrowing diagnostics. --- clang/include/clang/Basic/DiagnosticGroups.td | 3 +- .../clang/Basic/DiagnosticSemaKinds.td | 11 +++++++ clang/lib/Sema/SemaInit.cpp | 31 +++++++++++++------ .../dcl.decl/dcl.init/dcl.init.list/p7-0x.cpp | 2 ++ clang/test/SemaCXX/GH63151.cpp | 3 +- 5 files changed, 39 insertions(+), 11 deletions(-) diff --git a/clang/include/clang/Basic/DiagnosticGroups.td b/clang/include/clang/Basic/DiagnosticGroups.td index 7cf347e92d9972..6765721ae7002c 100644 --- a/clang/include/clang/Basic/DiagnosticGroups.td +++ b/clang/include/clang/Basic/DiagnosticGroups.td @@ -348,7 +348,8 @@ def CXX98CompatPedantic : DiagGroup<"c++98-compat-pedantic", CXXPre20CompatPedantic, CXXPre23CompatPedantic]>; -def CXX11Narrowing : DiagGroup<"c++11-narrowing">; +def CXX11NarrowingConstReference : DiagGroup<"c++11-narrowing-const-reference">; +def CXX11Narrowing : DiagGroup<"c++11-narrowing", [CXX11NarrowingConstReference]>; def CXX11WarnInconsistentOverrideDestructor : DiagGroup<"inconsistent-missing-destructor-override">; diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td index c100041ca400f2..979f8990055142 100644 --- a/clang/include/clang/Basic/DiagnosticSemaKinds.td +++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td @@ -6158,12 +6158,23 @@ def err_illegal_initializer_type : Error<"illegal initializer type %0">; def ext_init_list_type_narrowing : ExtWarn< "type %0 cannot be narrowed to %1 in initializer list">, InGroup<CXX11Narrowing>, DefaultError, SFINAEFailure; +// *_narrowing_const_reference diagnostics are used by narrowing involving a +// const reference, to be controlled by -Wc++11-narrowing-const-reference. +def ext_init_list_type_narrowing_const_reference : ExtWarn< + "type %0 cannot be narrowed to %1 in initializer list">, + InGroup<CXX11NarrowingConstReference>, DefaultError, SFINAEFailure; def ext_init_list_variable_narrowing : ExtWarn< "non-constant-expression cannot be narrowed from type %0 to %1 in " "initializer list">, InGroup<CXX11Narrowing>, DefaultError, SFINAEFailure; +def ext_init_list_variable_narrowing_const_reference : ExtWarn< + "non-constant-expression cannot be narrowed from type %0 to %1 in " + "initializer list">, InGroup<CXX11NarrowingConstReference>, DefaultError, SFINAEFailure; def ext_init_list_constant_narrowing : ExtWarn< "constant expression evaluates to %0 which cannot be narrowed to type %1">, InGroup<CXX11Narrowing>, DefaultError, SFINAEFailure; +def ext_init_list_constant_narrowing_const_reference : ExtWarn< + "constant expression evaluates to %0 which cannot be narrowed to type %1">, + InGroup<CXX11NarrowingConstReference>, DefaultError, SFINAEFailure; def warn_init_list_type_narrowing : Warning< "type %0 cannot be narrowed to %1 in initializer list in C++11">, InGroup<CXX11Narrowing>, DefaultIgnore; diff --git a/clang/lib/Sema/SemaInit.cpp b/clang/lib/Sema/SemaInit.cpp index 0fbd87ce34db90..c21ab162320120 100644 --- a/clang/lib/Sema/SemaInit.cpp +++ b/clang/lib/Sema/SemaInit.cpp @@ -10410,40 +10410,53 @@ static void DiagnoseNarrowingInInitList(Sema &S, // No narrowing occurred. return; - case NK_Type_Narrowing: + case NK_Type_Narrowing: { // This was a floating-to-integer conversion, which is always considered a // narrowing conversion even if the value is a constant and can be // represented exactly as an integer. - S.Diag(PostInit->getBeginLoc(), NarrowingErrs(S.getLangOpts()) - ? diag::ext_init_list_type_narrowing - : diag::warn_init_list_type_narrowing) + auto T = EntityType.getNonReferenceType(); + S.Diag(PostInit->getBeginLoc(), + NarrowingErrs(S.getLangOpts()) + ? (T == EntityType + ? diag::ext_init_list_type_narrowing + : diag::ext_init_list_type_narrowing_const_reference) + : diag::warn_init_list_type_narrowing) << PostInit->getSourceRange() << PreNarrowingType.getLocalUnqualifiedType() - << EntityType.getNonReferenceType().getLocalUnqualifiedType(); + << T.getLocalUnqualifiedType(); break; + } - case NK_Constant_Narrowing: + case NK_Constant_Narrowing: { // A constant value was narrowed. + auto T = EntityType.getNonReferenceType(); S.Diag(PostInit->getBeginLoc(), NarrowingErrs(S.getLangOpts()) - ? diag::ext_init_list_constant_narrowing + ? (T == EntityType + ? diag::ext_init_list_constant_narrowing + : diag::ext_init_list_constant_narrowing_const_reference) : diag::warn_init_list_constant_narrowing) << PostInit->getSourceRange() << ConstantValue.getAsString(S.getASTContext(), ConstantType) << EntityType.getNonReferenceType().getLocalUnqualifiedType(); break; + } - case NK_Variable_Narrowing: + case NK_Variable_Narrowing: { // A variable's value may have been narrowed. + auto T = EntityType.getNonReferenceType(); S.Diag(PostInit->getBeginLoc(), NarrowingErrs(S.getLangOpts()) - ? diag::ext_init_list_variable_narrowing + ? (T == EntityType + ? diag::ext_init_list_variable_narrowing + : diag::ext_init_list_variable_narrowing_const_reference) : diag::warn_init_list_variable_narrowing) << PostInit->getSourceRange() << PreNarrowingType.getLocalUnqualifiedType() << EntityType.getNonReferenceType().getLocalUnqualifiedType(); break; } + } SmallString<128> StaticCast; llvm::raw_svector_ostream OS(StaticCast); diff --git a/clang/test/CXX/dcl.decl/dcl.init/dcl.init.list/p7-0x.cpp b/clang/test/CXX/dcl.decl/dcl.init/dcl.init.list/p7-0x.cpp index eac9ac0e827982..a3c115b409c71c 100644 --- a/clang/test/CXX/dcl.decl/dcl.init/dcl.init.list/p7-0x.cpp +++ b/clang/test/CXX/dcl.decl/dcl.init/dcl.init.list/p7-0x.cpp @@ -1,4 +1,6 @@ // RUN: %clang_cc1 -fsyntax-only -std=c++11 -triple x86_64-apple-macosx10.6.7 -verify %s +// These types do not involve const references, so -Wno-c++11-narrowing-const-reference does not suppress the errors. +// RUN: %clang_cc1 -fsyntax-only -std=c++11 -triple x86_64-apple-macosx10.6.7 -Wno-c++11-narrowing-const-reference -verify %s // Verify that narrowing conversions in initializer lists cause errors in C++0x // mode. diff --git a/clang/test/SemaCXX/GH63151.cpp b/clang/test/SemaCXX/GH63151.cpp index 2c7533ed88f3bb..dbbd583320222c 100644 --- a/clang/test/SemaCXX/GH63151.cpp +++ b/clang/test/SemaCXX/GH63151.cpp @@ -1,5 +1,5 @@ // RUN: %clang_cc1 -fsyntax-only -verify %s - +// RUN: %clang_cc1 -fsyntax-only -Wno-c++11-narrowing-const-reference -verify=allow %s struct A { A(const unsigned &x) {} }; @@ -9,4 +9,5 @@ void foo(int p) { A c { p }; // expected-error {{non-constant-expression cannot be narrowed from type 'int' to 'unsigned int' in initializer list}} A d { 0.5 }; // expected-error {{type 'double' cannot be narrowed to 'unsigned int' in initializer list}} // expected-warning@-1 {{implicit conversion from 'double' to 'unsigned int' changes value from 0.5 to 0}} + // allow-warning@-2 {{implicit conversion from 'double' to 'unsigned int' changes value from 0.5 to 0}} } _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
