[libcxx-commits] [clang] [libcxx] [clang] Add -Wimplicit-fallthrough to -Wextra (PR #97926)
Max Coplan via libcxx-commits
libcxx-commits at lists.llvm.org
Fri Jul 26 15:03:42 PDT 2024
Max =?utf-8?b?8J+RqPCfj73igI3wn5K7?= Copl
Message-ID:
In-Reply-To: <llvm.org/llvm/llvm-project/pull/97926 at github.com>
https://github.com/vegerot updated https://github.com/llvm/llvm-project/pull/97926
>From eb83d32dcf26cf5a8f749400beaccf6688b9107d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Max=20=F0=9F=91=A8=F0=9F=8F=BD=E2=80=8D=F0=9F=92=BB=20Copl?=
=?UTF-8?q?an?= <mchcopl at gmail.com>
Date: Fri, 26 Jul 2024 14:56:12 -0700
Subject: [PATCH 1/2] [libcxx][regex] add [[clang::fallthrough]] to suppress
fallthrough warning
---
libcxx/include/regex | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/libcxx/include/regex b/libcxx/include/regex
index b814135121321..463fea1638454 100644
--- a/libcxx/include/regex
+++ b/libcxx/include/regex
@@ -3921,7 +3921,7 @@ _ForwardIterator basic_regex<_CharT, _Traits>::__parse_character_escape(
if (__hd == -1)
__throw_regex_error<regex_constants::error_escape>();
__sum = 16 * __sum + static_cast<unsigned>(__hd);
- // fallthrough
+ [[clang::fallthrough]];
case 'x':
++__first;
if (__first == __last)
>From cec4051cf50c29c4bf89db183afd8459578e70fa Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Max=20=F0=9F=91=A8=F0=9F=8F=BD=E2=80=8D=F0=9F=92=BB=20Copl?=
=?UTF-8?q?an?= <mchcopl at gmail.com>
Date: Sat, 6 Jul 2024 17:22:55 -0700
Subject: [PATCH 2/2] [clang] Add -Wimplicit-fallthrough to -Wextra
This patch adds -Wimplicit-fallthrough to -Wextra. GCC already includes it in -Wextra.
This patch also adds a test to check that -Wimplicit-fallthrough is included in -Wextra.
Note: This patch may regress performance when building with -Wextra.
This is because -Wextra requires forming a CFG for every function.
---
clang/include/clang/Basic/DiagnosticGroups.td | 1 +
clang/test/Sema/fallthrough-attr.c | 1 +
clang/test/SemaCXX/switch-implicit-fallthrough-macro.cpp | 1 +
3 files changed, 3 insertions(+)
diff --git a/clang/include/clang/Basic/DiagnosticGroups.td b/clang/include/clang/Basic/DiagnosticGroups.td
index 19c3f1e043349..2a307679c9283 100644
--- a/clang/include/clang/Basic/DiagnosticGroups.td
+++ b/clang/include/clang/Basic/DiagnosticGroups.td
@@ -1067,6 +1067,7 @@ def Extra : DiagGroup<"extra", [
StringConcatation,
FUseLdPath,
CastFunctionTypeMismatch,
+ ImplicitFallthrough,
]>;
def Most : DiagGroup<"most", [
diff --git a/clang/test/Sema/fallthrough-attr.c b/clang/test/Sema/fallthrough-attr.c
index de50ebf39d42f..6cc19136f30a7 100644
--- a/clang/test/Sema/fallthrough-attr.c
+++ b/clang/test/Sema/fallthrough-attr.c
@@ -2,6 +2,7 @@
// RUN: %clang_cc1 -fsyntax-only -std=gnu99 -verify -Wimplicit-fallthrough %s
// RUN: %clang_cc1 -fsyntax-only -std=c99 -verify -Wimplicit-fallthrough %s
// RUN: %clang_cc1 -fsyntax-only -std=c11 -verify -Wimplicit-fallthrough %s
+// RUN: %clang_cc1 -fsyntax-only -std=c11 -verify -Wextra %s
// RUN: %clang_cc1 -fsyntax-only -std=c2x -DC2X -verify -Wimplicit-fallthrough %s
int fallthrough_attribute_spelling(int n) {
diff --git a/clang/test/SemaCXX/switch-implicit-fallthrough-macro.cpp b/clang/test/SemaCXX/switch-implicit-fallthrough-macro.cpp
index 11df2cbfb53f0..cbbff1f1793b8 100644
--- a/clang/test/SemaCXX/switch-implicit-fallthrough-macro.cpp
+++ b/clang/test/SemaCXX/switch-implicit-fallthrough-macro.cpp
@@ -3,6 +3,7 @@
// RUN: %clang_cc1 -fsyntax-only -verify -std=c++1z -Wimplicit-fallthrough -DCLANG_PREFIX -DCOMMAND_LINE_FALLTHROUGH=[[clang::fallthrough]] %s
// RUN: %clang_cc1 -fsyntax-only -verify -std=c++1z -Wimplicit-fallthrough -DCOMMAND_LINE_FALLTHROUGH=[[clang::fallthrough]] %s
// RUN: %clang_cc1 -fsyntax-only -verify -std=c++1z -Wimplicit-fallthrough -DCOMMAND_LINE_FALLTHROUGH=[[fallthrough]] -DUNCHOSEN=[[clang::fallthrough]] %s
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++1z -Wextra -DCOMMAND_LINE_FALLTHROUGH=[[fallthrough]] -DUNCHOSEN=[[clang::fallthrough]] %s
int fallthrough_compatibility_macro_from_command_line(int n) {
switch (n) {
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