[clang-tools-extra] 042540a - [clang-tidy] New Option Invalid Enum Default Initialization (#159220)
via cfe-commits
cfe-commits at lists.llvm.org
Tue Sep 30 08:27:49 PDT 2025
Author: Félix-Antoine Constantin
Date: 2025-09-30T18:27:46+03:00
New Revision: 042540ab66e5ebee650e45ba6bfa4e68a045ff0a
URL: https://github.com/llvm/llvm-project/commit/042540ab66e5ebee650e45ba6bfa4e68a045ff0a
DIFF: https://github.com/llvm/llvm-project/commit/042540ab66e5ebee650e45ba6bfa4e68a045ff0a.diff
LOG: [clang-tidy] New Option Invalid Enum Default Initialization (#159220)
Added a new Option IgnoredEnums to bugprone invalid enum default
initialization to limit the scope of the analysis. This is needed to
remove warnings on enums like std::errc where the enum doesn't define a
value of 0, but is still used to check if some function calls like
std::from_chars are executed correctly.
The C++ Standard section 22.13.2 mentions the following : "[...] If the
member ec of the return value is such that the value is equal to the
value of a value-initialized errc, the conversion was successful [...]"
This means that a call to `std::errc{}` is clearly defined by the
standard and should not raise any warning under this check.
Added:
Modified:
clang-tools-extra/clang-tidy/bugprone/InvalidEnumDefaultInitializationCheck.cpp
clang-tools-extra/clang-tidy/bugprone/InvalidEnumDefaultInitializationCheck.h
clang-tools-extra/docs/ReleaseNotes.rst
clang-tools-extra/docs/clang-tidy/checks/bugprone/invalid-enum-default-initialization.rst
clang-tools-extra/test/clang-tidy/checkers/bugprone/invalid-enum-default-initialization.cpp
Removed:
################################################################################
diff --git a/clang-tools-extra/clang-tidy/bugprone/InvalidEnumDefaultInitializationCheck.cpp b/clang-tools-extra/clang-tidy/bugprone/InvalidEnumDefaultInitializationCheck.cpp
index 1e657888b0fc0..4fc1b3b99ece4 100644
--- a/clang-tools-extra/clang-tidy/bugprone/InvalidEnumDefaultInitializationCheck.cpp
+++ b/clang-tools-extra/clang-tidy/bugprone/InvalidEnumDefaultInitializationCheck.cpp
@@ -7,6 +7,8 @@
//===----------------------------------------------------------------------===//
#include "InvalidEnumDefaultInitializationCheck.h"
+#include "../utils/Matchers.h"
+#include "../utils/OptionsUtils.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/TypeVisitor.h"
#include "clang/ASTMatchers/ASTMatchFinder.h"
@@ -88,12 +90,24 @@ class FindEnumMember : public TypeVisitor<FindEnumMember, bool> {
InvalidEnumDefaultInitializationCheck::InvalidEnumDefaultInitializationCheck(
StringRef Name, ClangTidyContext *Context)
- : ClangTidyCheck(Name, Context) {}
+ : ClangTidyCheck(Name, Context),
+ IgnoredEnums(
+ utils::options::parseStringList(Options.get("IgnoredEnums", ""))) {
+ IgnoredEnums.emplace_back("::std::errc");
+}
+
+void InvalidEnumDefaultInitializationCheck::storeOptions(
+ ClangTidyOptions::OptionMap &Opts) {
+ Options.store(Opts, "IgnoredEnums",
+ utils::options::serializeStringList(IgnoredEnums));
+}
void InvalidEnumDefaultInitializationCheck::registerMatchers(
MatchFinder *Finder) {
- auto EnumWithoutZeroValue = enumType(
- hasDeclaration(enumDecl(isCompleteAndHasNoZeroValue()).bind("enum")));
+ auto EnumWithoutZeroValue = enumType(hasDeclaration(
+ enumDecl(isCompleteAndHasNoZeroValue(),
+ unless(matchers::matchesAnyListedName(IgnoredEnums)))
+ .bind("enum")));
auto EnumOrArrayOfEnum = qualType(hasUnqualifiedDesugaredType(
anyOf(EnumWithoutZeroValue,
arrayType(hasElementType(qualType(
diff --git a/clang-tools-extra/clang-tidy/bugprone/InvalidEnumDefaultInitializationCheck.h b/clang-tools-extra/clang-tidy/bugprone/InvalidEnumDefaultInitializationCheck.h
index 4f1a4a2a21af3..5e2662f642cd7 100644
--- a/clang-tools-extra/clang-tidy/bugprone/InvalidEnumDefaultInitializationCheck.h
+++ b/clang-tools-extra/clang-tidy/bugprone/InvalidEnumDefaultInitializationCheck.h
@@ -24,6 +24,10 @@ class InvalidEnumDefaultInitializationCheck : public ClangTidyCheck {
ClangTidyContext *Context);
void registerMatchers(ast_matchers::MatchFinder *Finder) override;
void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
+ void storeOptions(ClangTidyOptions::OptionMap &Opts) override;
+
+private:
+ std::vector<StringRef> IgnoredEnums;
};
} // namespace clang::tidy::bugprone
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index c3a6d2f9b2890..62e1987377989 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -253,6 +253,10 @@ Changes in existing checks
<clang-tidy/checks/bugprone/infinite-loop>` check by adding detection for
variables introduced by structured bindings.
+- Improved :doc:`bugprone-invalid-enum-default-initialization
+ <clang-tidy/checks/bugprone/invalid-enum-default-initialization>` with new
+ `IgnoredEnums` option to ignore specified enums during analysis.
+
- Improved :doc:`bugprone-narrowing-conversions
<clang-tidy/checks/bugprone/narrowing-conversions>` check by fixing
false positive from analysis of a conditional expression in C.
diff --git a/clang-tools-extra/docs/clang-tidy/checks/bugprone/invalid-enum-default-initialization.rst b/clang-tools-extra/docs/clang-tidy/checks/bugprone/invalid-enum-default-initialization.rst
index a3bd2b6d85c37..45cb878383a7d 100644
--- a/clang-tools-extra/docs/clang-tidy/checks/bugprone/invalid-enum-default-initialization.rst
+++ b/clang-tools-extra/docs/clang-tidy/checks/bugprone/invalid-enum-default-initialization.rst
@@ -19,6 +19,9 @@ The check emits a warning only if an ``enum`` variable is default-initialized
value of 0. The type can be a scoped or non-scoped ``enum``. Unions are not
handled by the check (if it contains a member of enumeration type).
+Note that the ``enum`` ``std::errc`` is always ignored because it is expected to
+be default initialized, despite not defining an enumerator with the value 0.
+
.. code-block:: c++
enum class Enum1: int {
@@ -70,3 +73,12 @@ enum type) are set to 0.
enum Enum1 Array3[2][2] = {{Enum1_A, Enum1_A}}; // warn: elements of second array are initialized to 0
struct Struct1 S1 = {1}; // warn: element 'b' is initialized to 0
+
+
+Options
+-------
+
+.. option:: IgnoredEnums
+
+ Semicolon-separated list of regexes specifying enums for which this check won't be
+ enforced. Default is `::std::errc`.
diff --git a/clang-tools-extra/test/clang-tidy/checkers/bugprone/invalid-enum-default-initialization.cpp b/clang-tools-extra/test/clang-tidy/checkers/bugprone/invalid-enum-default-initialization.cpp
index eb3d5632eaef7..85ff481aae301 100644
--- a/clang-tools-extra/test/clang-tidy/checkers/bugprone/invalid-enum-default-initialization.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/bugprone/invalid-enum-default-initialization.cpp
@@ -1,4 +1,5 @@
-// RUN: %check_clang_tidy -std=c++17 %s bugprone-invalid-enum-default-initialization %t
+// RUN: %check_clang_tidy -check-suffixes=,DEFAULT -std=c++17-or-later %s bugprone-invalid-enum-default-initialization %t
+// RUN: %check_clang_tidy -std=c++17-or-later %s bugprone-invalid-enum-default-initialization %t -- -config="{CheckOptions: {bugprone-invalid-enum-default-initialization.IgnoredEnums: '::MyEnum'}}"
enum class Enum0: int {
A = 0,
@@ -24,10 +25,10 @@ Enum0 E0_6{Enum0::B};
Enum1 E1_1{};
// CHECK-NOTES: :[[@LINE-1]]:11: warning: enum value of type 'Enum1' initialized with invalid value of 0, enum doesn't have a zero-value enumerator
-// CHECK-NOTES: :8:12: note: enum is defined here
+// CHECK-NOTES: :9:12: note: enum is defined here
Enum1 E1_2 = Enum1();
// CHECK-NOTES: :[[@LINE-1]]:14: warning: enum value of type 'Enum1' initialized with invalid value of 0, enum doesn't have a zero-value enumerator
-// CHECK-NOTES: :8:12: note: enum is defined here
+// CHECK-NOTES: :9:12: note: enum is defined here
Enum1 E1_3;
Enum1 E1_4{0};
Enum1 E1_5{Enum1::A};
@@ -35,44 +36,44 @@ Enum1 E1_6{Enum1::B};
Enum2 E2_1{};
// CHECK-NOTES: :[[@LINE-1]]:11: warning: enum value of type 'Enum2' initialized with invalid value of 0, enum doesn't have a zero-value enumerator
-// CHECK-NOTES: :13:6: note: enum is defined here
+// CHECK-NOTES: :14:6: note: enum is defined here
Enum2 E2_2 = Enum2();
// CHECK-NOTES: :[[@LINE-1]]:14: warning: enum value of type 'Enum2' initialized with invalid value of 0, enum doesn't have a zero-value enumerator
-// CHECK-NOTES: :13:6: note: enum is defined here
+// CHECK-NOTES: :14:6: note: enum is defined here
void f1() {
static Enum1 S; // FIMXE: warn for this?
Enum1 A;
Enum1 B = Enum1();
// CHECK-NOTES: :[[@LINE-1]]:13: warning: enum value of type 'Enum1' initialized with invalid value of 0, enum doesn't have a zero-value enumerator
- // CHECK-NOTES: :8:12: note: enum is defined here
+ // CHECK-NOTES: :9:12: note: enum is defined here
int C = int();
}
void f2() {
Enum1 A{};
// CHECK-NOTES: :[[@LINE-1]]:10: warning: enum value of type 'Enum1' initialized with invalid value of 0, enum doesn't have a zero-value enumerator
- // CHECK-NOTES: :8:12: note: enum is defined here
+ // CHECK-NOTES: :9:12: note: enum is defined here
Enum1 B = Enum1();
// CHECK-NOTES: :[[@LINE-1]]:13: warning: enum value of type 'Enum1' initialized with invalid value of 0, enum doesn't have a zero-value enumerator
- // CHECK-NOTES: :8:12: note: enum is defined here
+ // CHECK-NOTES: :9:12: note: enum is defined here
Enum1 C[5] = {{}};
// CHECK-NOTES: :[[@LINE-1]]:16: warning: enum value of type 'Enum1' initialized with invalid value of 0, enum doesn't have a zero-value enumerator
- // CHECK-NOTES: :8:12: note: enum is defined here
+ // CHECK-NOTES: :9:12: note: enum is defined here
// CHECK-NOTES: :[[@LINE-3]]:17: warning: enum value of type 'Enum1' initialized with invalid value of 0, enum doesn't have a zero-value enumerator
- // CHECK-NOTES: :8:12: note: enum is defined here
+ // CHECK-NOTES: :9:12: note: enum is defined here
Enum1 D[5] = {}; // FIMXE: warn for this?
// CHECK-NOTES: :[[@LINE-1]]:16: warning: enum value of type 'Enum1' initialized with invalid value of 0, enum doesn't have a zero-value enumerator
- // CHECK-NOTES: :8:12: note: enum is defined here
+ // CHECK-NOTES: :9:12: note: enum is defined here
}
struct S1 {
Enum1 E_1{};
// CHECK-NOTES: :[[@LINE-1]]:12: warning: enum value of type 'Enum1' initialized with invalid value of 0, enum doesn't have a zero-value enumerator
- // CHECK-NOTES: :8:12: note: enum is defined here
+ // CHECK-NOTES: :9:12: note: enum is defined here
Enum1 E_2 = Enum1();
// CHECK-NOTES: :[[@LINE-1]]:15: warning: enum value of type 'Enum1' initialized with invalid value of 0, enum doesn't have a zero-value enumerator
- // CHECK-NOTES: :8:12: note: enum is defined here
+ // CHECK-NOTES: :9:12: note: enum is defined here
Enum1 E_3;
Enum1 E_4;
Enum1 E_5;
@@ -80,10 +81,10 @@ struct S1 {
S1() :
E_3{},
// CHECK-NOTES: :[[@LINE-1]]:8: warning: enum value of type 'Enum1' initialized with invalid value of 0, enum doesn't have a zero-value enumerator
- // CHECK-NOTES: :8:12: note: enum is defined here
+ // CHECK-NOTES: :9:12: note: enum is defined here
E_4(),
// CHECK-NOTES: :[[@LINE-1]]:8: warning: enum value of type 'Enum1' initialized with invalid value of 0, enum doesn't have a zero-value enumerator
- // CHECK-NOTES: :8:12: note: enum is defined here
+ // CHECK-NOTES: :9:12: note: enum is defined here
E_5{Enum1::B}
{}
};
@@ -110,22 +111,22 @@ struct S5 {
S2 VarS2{};
// CHECK-NOTES: :[[@LINE-1]]:9: warning: enum value of type 'Enum1' initialized with invalid value of 0
-// CHECK-NOTES: :8:12: note: enum is defined here
+// CHECK-NOTES: :9:12: note: enum is defined here
// CHECK-NOTES: :[[@LINE-3]]:9: warning: enum value of type 'Enum2' initialized with invalid value of 0
-// CHECK-NOTES: :13:6: note: enum is defined here
+// CHECK-NOTES: :14:6: note: enum is defined here
S3 VarS3{};
// CHECK-NOTES: :[[@LINE-1]]:10: warning: enum value of type 'Enum1' initialized with invalid value of 0
-// CHECK-NOTES: :8:12: note: enum is defined here
+// CHECK-NOTES: :9:12: note: enum is defined here
// CHECK-NOTES: :[[@LINE-3]]:10: warning: enum value of type 'Enum2' initialized with invalid value of 0
-// CHECK-NOTES: :13:6: note: enum is defined here
+// CHECK-NOTES: :14:6: note: enum is defined here
S4 VarS4{};
// CHECK-NOTES: :[[@LINE-1]]:10: warning: enum value of type 'Enum1' initialized with invalid value of 0
-// CHECK-NOTES: :8:12: note: enum is defined here
+// CHECK-NOTES: :9:12: note: enum is defined here
// CHECK-NOTES: :[[@LINE-3]]:10: warning: enum value of type 'Enum2' initialized with invalid value of 0
-// CHECK-NOTES: :13:6: note: enum is defined here
+// CHECK-NOTES: :14:6: note: enum is defined here
S5 VarS5{};
// CHECK-NOTES: :[[@LINE-1]]:10: warning: enum value of type 'Enum1' initialized with invalid value of 0
-// CHECK-NOTES: :8:12: note: enum is defined here
+// CHECK-NOTES: :9:12: note: enum is defined here
enum class EnumFwd;
@@ -139,7 +140,25 @@ template<typename T>
struct Templ {
T Mem1{};
// CHECK-NOTES: :[[@LINE-1]]:9: warning: enum value of type 'Enum1' initialized with invalid value of 0
- // CHECK-NOTES: :8:12: note: enum is defined here
+ // CHECK-NOTES: :9:12: note: enum is defined here
};
Templ<Enum1> TemplVar;
+
+enum MyEnum {
+ A = 1,
+ B
+};
+
+MyEnum MyEnumVar{};
+// CHECK-NOTES-DEFAULT: :[[@LINE-1]]:17: warning: enum value of type 'MyEnum' initialized with invalid value of 0, enum doesn't have a zero-value enumerator
+// CHECK-NOTES-DEFAULT: :148:6: note: enum is defined here
+
+namespace std {
+ enum errc {
+ A = 1,
+ B
+ };
+}
+
+std::errc err{};
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