[clang-tools-extra] [clang-tidy] New Option Invalid Enum Default Initialization (PR #159220)
Félix-Antoine Constantin via cfe-commits
cfe-commits at lists.llvm.org
Wed Sep 17 08:05:11 PDT 2025
https://github.com/felix642 updated https://github.com/llvm/llvm-project/pull/159220
>From 8177f228f3d428336d802139eebff70426067b5a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?F=C3=A9lix-Antoine=20Constantin?=
<felix-antoine.constantin at comact.com>
Date: Tue, 16 Sep 2025 21:10:25 -0400
Subject: [PATCH 1/2] =?UTF-8?q?[clang-tidy]=C2=A0New=20Option=20Invalid=20?=
=?UTF-8?q?Enum=20Default=20Initialization?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
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.
---
.../InvalidEnumDefaultInitializationCheck.cpp | 18 +++++-
.../InvalidEnumDefaultInitializationCheck.h | 4 ++
clang-tools-extra/docs/ReleaseNotes.rst | 4 ++
.../invalid-enum-default-initialization.rst | 5 ++
.../invalid-enum-default-initialization.cpp | 56 +++++++++++--------
5 files changed, 61 insertions(+), 26 deletions(-)
diff --git a/clang-tools-extra/clang-tidy/bugprone/InvalidEnumDefaultInitializationCheck.cpp b/clang-tools-extra/clang-tidy/bugprone/InvalidEnumDefaultInitializationCheck.cpp
index 1e657888b0fc0..55bcec27b1863 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 +90,22 @@ 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", "::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 b9b4f20d111fc..af4a97ae12cec 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:
+ const 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 3f403c42a168a..a678be2dbb4e9 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -219,6 +219,10 @@ 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 some 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..92a51d5ec0a31 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
@@ -70,3 +70,8 @@ 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
+
+.. option:: IgnoredContainers
+
+Semicolon-separated list of enums regexp 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..54e37fa32e187 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 %s bugprone-invalid-enum-default-initialization %t
+// RUN: %check_clang_tidy -std=c++17 %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 +140,16 @@ 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
>From d9f998b01e672aef35678b0649f1a500070ffd53 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?F=C3=A9lix-Antoine=20Constantin?=
<felix-antoine.constantin at comact.com>
Date: Wed, 17 Sep 2025 11:04:41 -0400
Subject: [PATCH 2/2] =?UTF-8?q?fixup!=20[clang-tidy]=C2=A0New=20Option=20I?=
=?UTF-8?q?nvalid=20Enum=20Default=20Initialization?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Code review
---
clang-tools-extra/docs/ReleaseNotes.rst | 2 +-
.../checks/bugprone/invalid-enum-default-initialization.rst | 6 +++---
.../bugprone/invalid-enum-default-initialization.cpp | 4 ++--
3 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index a678be2dbb4e9..f7eb616bef938 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -221,7 +221,7 @@ Changes in existing checks
- Improved :doc:`bugprone-invalid-enum-default-initialization
<clang-tidy/checks/bugprone/invalid-enum-default-initialization>` with new
- ``IgnoredEnums`` option to ignore some enums during analysis.
+ `IgnoredEnums` option to ignore some enums during analysis.
- Improved :doc:`bugprone-narrowing-conversions
<clang-tidy/checks/bugprone/narrowing-conversions>` check by fixing
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 92a51d5ec0a31..6db5c4a0e75f6 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
@@ -71,7 +71,7 @@ enum type) are set to 0.
struct Struct1 S1 = {1}; // warn: element 'b' is initialized to 0
-.. option:: IgnoredContainers
+.. option:: IgnoredEnums
-Semicolon-separated list of enums regexp for which this check won't be
-enforced. Default is `::std::errc`.
+ 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 54e37fa32e187..345f0d3857569 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
@@ -1,5 +1,5 @@
-// RUN: %check_clang_tidy -check-suffixes=,DEFAULT -std=c++17 %s bugprone-invalid-enum-default-initialization %t
-// RUN: %check_clang_tidy -std=c++17 %s bugprone-invalid-enum-default-initialization %t -- -config="{CheckOptions: {bugprone-invalid-enum-default-initialization.IgnoredEnums: '::MyEnum'}}"
+// 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,
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