https://github.com/AmrDeveloper created https://github.com/llvm/llvm-project/pull/118872
Starting from C++26 the array comparison warning should converted to an error. Fixes: #117859 >From 30eb50c2fff14d4f79b3f3bd2b36e511bcb2db27 Mon Sep 17 00:00:00 2001 From: AmrDeveloper <am...@programmer.net> Date: Thu, 5 Dec 2024 22:18:37 +0100 Subject: [PATCH] [Clang] Warning as error Array Comparisons from C++26 Starting from C++26 the array comparison warning should converted to an error. --- clang/docs/ReleaseNotes.rst | 3 +++ clang/include/clang/Basic/DiagnosticSemaKinds.td | 5 +++++ clang/lib/Sema/SemaExpr.cpp | 4 +++- clang/test/Sema/warn-stringcompare.c | 9 +++++---- clang/test/SemaCXX/warn-array-comparion.cpp | 6 ++++-- clang/test/SemaCXX/warn-self-comparisons.cpp | 2 ++ clang/www/cxx_status.html | 2 +- 7 files changed, 23 insertions(+), 8 deletions(-) diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index ad5ef2119d3654..6719cf42970ba4 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -428,6 +428,9 @@ New Compiler Flags - The ``-Warray-compare`` warning has been added to warn about array comparison on versions older than C++20. +- The ``-Warray-compare-cxx26`` warning has been added to warn about array comparison + starting from C++26, this warn is error by default. + Deprecated Compiler Flags ------------------------- diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td index 447358f0a5f382..0bf9303ba50f45 100644 --- a/clang/include/clang/Basic/DiagnosticSemaKinds.td +++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td @@ -10274,6 +10274,11 @@ def warn_array_comparison : Warning< "to compare array addresses, use unary '+' to decay operands to pointers">, InGroup<DiagGroup<"array-compare">>; +def warn_array_comparison_cxx26 : Warning< + "comparison between two arrays compare their addresses not their contents; " + "to compare array addresses, use unary '+' to decay operands to pointers">, + InGroup<DiagGroup<"array-compare-cxx26">>, DefaultError; + def warn_stringcompare : Warning< "result of comparison against %select{a string literal|@encode}0 is " "unspecified (use an explicit string comparison function instead)">, diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp index 4ffce2c1236610..14564b99de44c5 100644 --- a/clang/lib/Sema/SemaExpr.cpp +++ b/clang/lib/Sema/SemaExpr.cpp @@ -11843,7 +11843,9 @@ static void diagnoseTautologicalComparison(Sema &S, SourceLocation Loc, RHSStripped->getType()->isArrayType()) { auto IsDeprArrayComparionIgnored = S.getDiagnostics().isIgnored(diag::warn_depr_array_comparison, Loc); - auto DiagID = !S.getLangOpts().CPlusPlus20 || IsDeprArrayComparionIgnored + auto DiagID = S.getLangOpts().CPlusPlus26 + ? diag::warn_array_comparison_cxx26 + : !S.getLangOpts().CPlusPlus20 || IsDeprArrayComparionIgnored ? diag::warn_array_comparison : diag::warn_depr_array_comparison; S.Diag(Loc, DiagID) << LHS->getSourceRange() << RHS->getSourceRange() diff --git a/clang/test/Sema/warn-stringcompare.c b/clang/test/Sema/warn-stringcompare.c index 78145cf42578a4..93c2bc31fea0a3 100644 --- a/clang/test/Sema/warn-stringcompare.c +++ b/clang/test/Sema/warn-stringcompare.c @@ -1,5 +1,6 @@ // RUN: %clang_cc1 -x c -fsyntax-only -verify %s // RUN: %clang_cc1 -x c++ -fsyntax-only -verify=expected,cxx %s +// RUN: %clang_cc1 -x c++ -std=c++26 -fsyntax-only -verify=expected,cxx-26 %s #define DELIM "/" #define DOT "." @@ -15,15 +16,15 @@ void test(const char *d) { if (NULL == "/") return; if ("/" != DELIM) // expected-warning {{result of comparison against a string literal is unspecified (use an explicit string comparison function instead)}} - return; // cxx-warning@-1 {{comparison between two arrays}} + return; // cxx-warning@-1 {{comparison between two arrays}} cxx26-error@-1 {{comparison between two arrays compare their addresses not their contents}} if (DELIM == "/") // expected-warning {{result of comparison against a string literal is unspecified (use an explicit string comparison function instead)}} - return; // cxx-warning@-1 {{comparison between two arrays}} + return; // cxx-warning@-1 {{comparison between two arrays}} cxx26-error@-1 {{comparison between two arrays compare their addresses not their contents}} if (DELIM != NULL) return; if (NULL == DELIM) return; if (DOT != DELIM) // expected-warning {{result of comparison against a string literal is unspecified (use an explicit string comparison function instead)}} - return; // cxx-warning@-1 {{comparison between two arrays}} + return; // cxx-warning@-1 {{comparison between two arrays}} cxx26-error@-1 {{comparison between two arrays compare their addresses not their contents}} if (DELIM == DOT) // expected-warning {{result of comparison against a string literal is unspecified (use an explicit string comparison function instead)}} - return; // cxx-warning@-1 {{comparison between two arrays}} + return; // cxx-warning@-1 {{comparison between two arrays}} cxx26-error@-1 {{comparison between two arrays compare their addresses not their contents}} } diff --git a/clang/test/SemaCXX/warn-array-comparion.cpp b/clang/test/SemaCXX/warn-array-comparion.cpp index a6eaaab22fc16d..87b5c4fb91e3d7 100644 --- a/clang/test/SemaCXX/warn-array-comparion.cpp +++ b/clang/test/SemaCXX/warn-array-comparion.cpp @@ -1,6 +1,7 @@ // RUN: %clang_cc1 -std=c++17 -fsyntax-only -verify %s -verify=expected,not-cxx20 // RUN: %clang_cc1 -std=c++20 -fsyntax-only -Wno-deprecated-array-compare -verify %s -verify=expected,not-cxx20 // RUN: %clang_cc1 -std=c++20 -fsyntax-only -Wdeprecated -verify %s -verify=expected,cxx20 +// RUN: %clang_cc1 -std=c++26 -fsyntax-only -Wdeprecated -verify %s -verify=expected,cxx26 typedef struct { char str[16]; @@ -9,13 +10,14 @@ typedef struct { bool object_equal(const Object &obj1, const Object &obj2) { if (obj1.str != obj2.str) // not-cxx20-warning {{comparison between two arrays compare their addresses}} cxx20-warning {{comparison between two arrays is deprecated}} - return false; + return false; // cxx26-error@-1 {{comparison between two arrays compare their addresses not their contents}} if (obj1.id != obj2.id) // not-cxx20-warning {{comparison between two arrays compare their addresses}} cxx20-warning {{comparison between two arrays is deprecated}} - return false; + return false; // cxx26-error@-1 {{comparison between two arrays compare their addresses not their contents}} return true; } void foo(int (&array1)[2], int (&array2)[2]) { if (array1 == array2) { } // not-cxx20-warning {{comparison between two arrays compare their addresses}} cxx20-warning {{comparison between two arrays is deprecated}} + // cxx26-error@-1 {{comparison between two arrays compare their addresses not their contents}} } diff --git a/clang/test/SemaCXX/warn-self-comparisons.cpp b/clang/test/SemaCXX/warn-self-comparisons.cpp index 3847c2d918bf61..c7bb5fcc8fd00d 100644 --- a/clang/test/SemaCXX/warn-self-comparisons.cpp +++ b/clang/test/SemaCXX/warn-self-comparisons.cpp @@ -1,6 +1,8 @@ // RUN: %clang_cc1 -std=c++17 -fsyntax-only -verify %s -verify=expected,not-cxx20 // RUN: %clang_cc1 -std=c++20 -fsyntax-only -Wdeprecated -verify %s -verify=expected,cxx20 +// RUN: %clang_cc1 -std=c++26 -fsyntax-only -Wdeprecated -verify %s -verify=expected,cxx26 void f(int (&array1)[2], int (&array2)[2]) { if (array1 == array2) { } // not-cxx20-warning {{comparison between two arrays compare their addresses}} cxx20-warning {{comparison between two arrays is deprecated}} + // cxx26-error@-1 {{comparison between two arrays compare their addresses not their contents}} } diff --git a/clang/www/cxx_status.html b/clang/www/cxx_status.html index fdb9807b1168c7..839b66e7a082d3 100755 --- a/clang/www/cxx_status.html +++ b/clang/www/cxx_status.html @@ -239,7 +239,7 @@ <h2 id="cxx26">C++2c implementation status</h2> <tr> <td>Remove Deprecated Array Comparisons from C++26</td> <td><a href="https://wg21.link/P2865R6";>P2865R6</a></td> - <td class="none" align="center">No</td> + <td class="none" align="center">Clang 20</td> </tr> <tr> <td>Structured Bindings can introduce a Pack</td> _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits