[clang-tools-extra] 3365d62 - [clang-tidy] add new check readability-enum-initial-value (#86129)
via cfe-commits
cfe-commits at lists.llvm.org
Mon Apr 1 00:54:00 PDT 2024
Author: Congcong Cai
Date: 2024-04-01T15:53:57+08:00
New Revision: 3365d62179011aad6da3e4cbcb31044eec3462a2
URL: https://github.com/llvm/llvm-project/commit/3365d62179011aad6da3e4cbcb31044eec3462a2
DIFF: https://github.com/llvm/llvm-project/commit/3365d62179011aad6da3e4cbcb31044eec3462a2.diff
LOG: [clang-tidy] add new check readability-enum-initial-value (#86129)
Fixes: #85243.
Added:
clang-tools-extra/clang-tidy/readability/EnumInitialValueCheck.cpp
clang-tools-extra/clang-tidy/readability/EnumInitialValueCheck.h
clang-tools-extra/docs/clang-tidy/checks/readability/enum-initial-value.rst
clang-tools-extra/test/clang-tidy/checkers/readability/enum-initial-value.c
clang-tools-extra/test/clang-tidy/checkers/readability/enum-initial-value.cpp
Modified:
clang-tools-extra/clang-tidy/readability/CMakeLists.txt
clang-tools-extra/clang-tidy/readability/ReadabilityTidyModule.cpp
clang-tools-extra/docs/ReleaseNotes.rst
clang-tools-extra/docs/clang-tidy/checks/list.rst
Removed:
################################################################################
diff --git a/clang-tools-extra/clang-tidy/readability/CMakeLists.txt b/clang-tools-extra/clang-tidy/readability/CMakeLists.txt
index 5728c9970fb65d..dd772d69202548 100644
--- a/clang-tools-extra/clang-tidy/readability/CMakeLists.txt
+++ b/clang-tools-extra/clang-tidy/readability/CMakeLists.txt
@@ -17,6 +17,7 @@ add_clang_library(clangTidyReadabilityModule
DeleteNullPointerCheck.cpp
DuplicateIncludeCheck.cpp
ElseAfterReturnCheck.cpp
+ EnumInitialValueCheck.cpp
FunctionCognitiveComplexityCheck.cpp
FunctionSizeCheck.cpp
IdentifierLengthCheck.cpp
diff --git a/clang-tools-extra/clang-tidy/readability/EnumInitialValueCheck.cpp b/clang-tools-extra/clang-tidy/readability/EnumInitialValueCheck.cpp
new file mode 100644
index 00000000000000..8f2841c32259a2
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/readability/EnumInitialValueCheck.cpp
@@ -0,0 +1,200 @@
+//===--- EnumInitialValueCheck.cpp - clang-tidy ---------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "EnumInitialValueCheck.h"
+#include "../utils/LexerUtils.h"
+#include "clang/AST/Decl.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/ASTMatchers/ASTMatchers.h"
+#include "clang/Basic/Diagnostic.h"
+#include "clang/Basic/SourceLocation.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/SmallString.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang::tidy::readability {
+
+static bool isNoneEnumeratorsInitialized(const EnumDecl &Node) {
+ return llvm::all_of(Node.enumerators(), [](const EnumConstantDecl *ECD) {
+ return ECD->getInitExpr() == nullptr;
+ });
+}
+
+static bool isOnlyFirstEnumeratorInitialized(const EnumDecl &Node) {
+ bool IsFirst = true;
+ for (const EnumConstantDecl *ECD : Node.enumerators()) {
+ if ((IsFirst && ECD->getInitExpr() == nullptr) ||
+ (!IsFirst && ECD->getInitExpr() != nullptr))
+ return false;
+ IsFirst = false;
+ }
+ return !IsFirst;
+}
+
+static bool areAllEnumeratorsInitialized(const EnumDecl &Node) {
+ return llvm::all_of(Node.enumerators(), [](const EnumConstantDecl *ECD) {
+ return ECD->getInitExpr() != nullptr;
+ });
+}
+
+/// Check if \p Enumerator is initialized with a (potentially negated) \c
+/// IntegerLiteral.
+static bool isInitializedByLiteral(const EnumConstantDecl *Enumerator) {
+ const Expr *const Init = Enumerator->getInitExpr();
+ if (!Init)
+ return false;
+ return Init->isIntegerConstantExpr(Enumerator->getASTContext());
+}
+
+static void cleanInitialValue(DiagnosticBuilder &Diag,
+ const EnumConstantDecl *ECD,
+ const SourceManager &SM,
+ const LangOptions &LangOpts) {
+ const SourceRange InitExprRange = ECD->getInitExpr()->getSourceRange();
+ if (InitExprRange.isInvalid() || InitExprRange.getBegin().isMacroID() ||
+ InitExprRange.getEnd().isMacroID())
+ return;
+ std::optional<Token> EqualToken = utils::lexer::findNextTokenSkippingComments(
+ ECD->getLocation(), SM, LangOpts);
+ if (!EqualToken.has_value() ||
+ EqualToken.value().getKind() != tok::TokenKind::equal)
+ return;
+ const SourceLocation EqualLoc{EqualToken->getLocation()};
+ if (EqualLoc.isInvalid() || EqualLoc.isMacroID())
+ return;
+ Diag << FixItHint::CreateRemoval(EqualLoc)
+ << FixItHint::CreateRemoval(InitExprRange);
+ return;
+}
+
+namespace {
+
+AST_MATCHER(EnumDecl, isMacro) {
+ SourceLocation Loc = Node.getBeginLoc();
+ return Loc.isMacroID();
+}
+
+AST_MATCHER(EnumDecl, hasConsistentInitialValues) {
+ return isNoneEnumeratorsInitialized(Node) ||
+ isOnlyFirstEnumeratorInitialized(Node) ||
+ areAllEnumeratorsInitialized(Node);
+}
+
+AST_MATCHER(EnumDecl, hasZeroInitialValueForFirstEnumerator) {
+ const EnumDecl::enumerator_range Enumerators = Node.enumerators();
+ if (Enumerators.empty())
+ return false;
+ const EnumConstantDecl *ECD = *Enumerators.begin();
+ return isOnlyFirstEnumeratorInitialized(Node) &&
+ isInitializedByLiteral(ECD) && ECD->getInitVal().isZero();
+}
+
+/// Excludes bitfields because enumerators initialized with the result of a
+/// bitwise operator on enumeration values or any other expr that is not a
+/// potentially negative integer literal.
+/// Enumerations where it is not directly clear if they are used with
+/// bitmask, evident when enumerators are only initialized with (potentially
+/// negative) integer literals, are ignored. This is also the case when all
+/// enumerators are powers of two (e.g., 0, 1, 2).
+AST_MATCHER(EnumDecl, hasSequentialInitialValues) {
+ const EnumDecl::enumerator_range Enumerators = Node.enumerators();
+ if (Enumerators.empty())
+ return false;
+ const EnumConstantDecl *const FirstEnumerator = *Node.enumerator_begin();
+ llvm::APSInt PrevValue = FirstEnumerator->getInitVal();
+ if (!isInitializedByLiteral(FirstEnumerator))
+ return false;
+ bool AllEnumeratorsArePowersOfTwo = true;
+ for (const EnumConstantDecl *Enumerator : llvm::drop_begin(Enumerators)) {
+ const llvm::APSInt NewValue = Enumerator->getInitVal();
+ if (NewValue != ++PrevValue)
+ return false;
+ if (!isInitializedByLiteral(Enumerator))
+ return false;
+ PrevValue = NewValue;
+ AllEnumeratorsArePowersOfTwo &= NewValue.isPowerOf2();
+ }
+ return !AllEnumeratorsArePowersOfTwo;
+}
+
+} // namespace
+
+EnumInitialValueCheck::EnumInitialValueCheck(StringRef Name,
+ ClangTidyContext *Context)
+ : ClangTidyCheck(Name, Context),
+ AllowExplicitZeroFirstInitialValue(
+ Options.get("AllowExplicitZeroFirstInitialValue", true)),
+ AllowExplicitSequentialInitialValues(
+ Options.get("AllowExplicitSequentialInitialValues", true)) {}
+
+void EnumInitialValueCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
+ Options.store(Opts, "AllowExplicitZeroFirstInitialValue",
+ AllowExplicitZeroFirstInitialValue);
+ Options.store(Opts, "AllowExplicitSequentialInitialValues",
+ AllowExplicitSequentialInitialValues);
+}
+
+void EnumInitialValueCheck::registerMatchers(MatchFinder *Finder) {
+ Finder->addMatcher(
+ enumDecl(unless(isMacro()), unless(hasConsistentInitialValues()))
+ .bind("inconsistent"),
+ this);
+ if (!AllowExplicitZeroFirstInitialValue)
+ Finder->addMatcher(
+ enumDecl(hasZeroInitialValueForFirstEnumerator()).bind("zero_first"),
+ this);
+ if (!AllowExplicitSequentialInitialValues)
+ Finder->addMatcher(enumDecl(unless(isMacro()), hasSequentialInitialValues())
+ .bind("sequential"),
+ this);
+}
+
+void EnumInitialValueCheck::check(const MatchFinder::MatchResult &Result) {
+ if (const auto *Enum = Result.Nodes.getNodeAs<EnumDecl>("inconsistent")) {
+ DiagnosticBuilder Diag =
+ diag(Enum->getBeginLoc(),
+ "inital values in enum %0 are not consistent, consider explicit "
+ "initialization of all, none or only the first enumerator")
+ << Enum;
+ for (const EnumConstantDecl *ECD : Enum->enumerators())
+ if (ECD->getInitExpr() == nullptr) {
+ const SourceLocation EndLoc = Lexer::getLocForEndOfToken(
+ ECD->getLocation(), 0, *Result.SourceManager, getLangOpts());
+ if (EndLoc.isMacroID())
+ continue;
+ llvm::SmallString<8> Str{" = "};
+ ECD->getInitVal().toString(Str);
+ Diag << FixItHint::CreateInsertion(EndLoc, Str);
+ }
+ return;
+ }
+
+ if (const auto *Enum = Result.Nodes.getNodeAs<EnumDecl>("zero_first")) {
+ const EnumConstantDecl *ECD = *Enum->enumerator_begin();
+ const SourceLocation Loc = ECD->getLocation();
+ if (Loc.isInvalid() || Loc.isMacroID())
+ return;
+ DiagnosticBuilder Diag = diag(Loc, "zero initial value for the first "
+ "enumerator in %0 can be disregarded")
+ << Enum;
+ cleanInitialValue(Diag, ECD, *Result.SourceManager, getLangOpts());
+ return;
+ }
+ if (const auto *Enum = Result.Nodes.getNodeAs<EnumDecl>("sequential")) {
+ DiagnosticBuilder Diag =
+ diag(Enum->getBeginLoc(),
+ "sequential initial value in %0 can be ignored")
+ << Enum;
+ for (const EnumConstantDecl *ECD : llvm::drop_begin(Enum->enumerators()))
+ cleanInitialValue(Diag, ECD, *Result.SourceManager, getLangOpts());
+ return;
+ }
+}
+
+} // namespace clang::tidy::readability
diff --git a/clang-tools-extra/clang-tidy/readability/EnumInitialValueCheck.h b/clang-tools-extra/clang-tidy/readability/EnumInitialValueCheck.h
new file mode 100644
index 00000000000000..66087e4ee170da
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/readability/EnumInitialValueCheck.h
@@ -0,0 +1,38 @@
+//===--- EnumInitialValueCheck.h - clang-tidy -------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_ENUMINITIALVALUECHECK_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_ENUMINITIALVALUECHECK_H
+
+#include "../ClangTidyCheck.h"
+
+namespace clang::tidy::readability {
+
+/// Enforces consistent style for enumerators' initialization, covering three
+/// styles: none, first only, or all initialized explicitly.
+///
+/// For the user-facing documentation see:
+/// http://clang.llvm.org/extra/clang-tidy/checks/readability/enum-initial-value.html
+class EnumInitialValueCheck : public ClangTidyCheck {
+public:
+ EnumInitialValueCheck(StringRef Name, ClangTidyContext *Context);
+ void storeOptions(ClangTidyOptions::OptionMap &Opts) override;
+ void registerMatchers(ast_matchers::MatchFinder *Finder) override;
+ void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
+ std::optional<TraversalKind> getCheckTraversalKind() const override {
+ return TK_IgnoreUnlessSpelledInSource;
+ }
+
+private:
+ const bool AllowExplicitZeroFirstInitialValue;
+ const bool AllowExplicitSequentialInitialValues;
+};
+
+} // namespace clang::tidy::readability
+
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_ENUMINITIALVALUECHECK_H
diff --git a/clang-tools-extra/clang-tidy/readability/ReadabilityTidyModule.cpp b/clang-tools-extra/clang-tidy/readability/ReadabilityTidyModule.cpp
index bca2c425111f6c..376b84683df74e 100644
--- a/clang-tools-extra/clang-tidy/readability/ReadabilityTidyModule.cpp
+++ b/clang-tools-extra/clang-tidy/readability/ReadabilityTidyModule.cpp
@@ -22,6 +22,7 @@
#include "DeleteNullPointerCheck.h"
#include "DuplicateIncludeCheck.h"
#include "ElseAfterReturnCheck.h"
+#include "EnumInitialValueCheck.h"
#include "FunctionCognitiveComplexityCheck.h"
#include "FunctionSizeCheck.h"
#include "IdentifierLengthCheck.h"
@@ -92,6 +93,8 @@ class ReadabilityModule : public ClangTidyModule {
"readability-duplicate-include");
CheckFactories.registerCheck<ElseAfterReturnCheck>(
"readability-else-after-return");
+ CheckFactories.registerCheck<EnumInitialValueCheck>(
+ "readability-enum-initial-value");
CheckFactories.registerCheck<FunctionCognitiveComplexityCheck>(
"readability-function-cognitive-complexity");
CheckFactories.registerCheck<FunctionSizeCheck>(
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index 78b09d23d4427f..309b844615a121 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -123,6 +123,12 @@ New checks
Finds initializer lists for aggregate types that could be
written as designated initializers instead.
+- New :doc:`readability-enum-initial-value
+ <clang-tidy/checks/readability/enum-initial-value>` check.
+
+ Enforces consistent style for enumerators' initialization, covering three
+ styles: none, first only, or all initialized explicitly.
+
- New :doc:`readability-use-std-min-max
<clang-tidy/checks/readability/use-std-min-max>` check.
diff --git a/clang-tools-extra/docs/clang-tidy/checks/list.rst b/clang-tools-extra/docs/clang-tidy/checks/list.rst
index 79e81dd174e4f3..188a42bfddd383 100644
--- a/clang-tools-extra/docs/clang-tidy/checks/list.rst
+++ b/clang-tools-extra/docs/clang-tidy/checks/list.rst
@@ -352,6 +352,7 @@ Clang-Tidy Checks
:doc:`readability-delete-null-pointer <readability/delete-null-pointer>`, "Yes"
:doc:`readability-duplicate-include <readability/duplicate-include>`, "Yes"
:doc:`readability-else-after-return <readability/else-after-return>`, "Yes"
+ :doc:`readability-enum-initial-value <readability/enum-initial-value>`, "Yes"
:doc:`readability-function-cognitive-complexity <readability/function-cognitive-complexity>`,
:doc:`readability-function-size <readability/function-size>`,
:doc:`readability-identifier-length <readability/identifier-length>`,
diff --git a/clang-tools-extra/docs/clang-tidy/checks/readability/enum-initial-value.rst b/clang-tools-extra/docs/clang-tidy/checks/readability/enum-initial-value.rst
new file mode 100644
index 00000000000000..660efc1eaff3e5
--- /dev/null
+++ b/clang-tools-extra/docs/clang-tidy/checks/readability/enum-initial-value.rst
@@ -0,0 +1,75 @@
+.. title:: clang-tidy - readability-enum-initial-value
+
+readability-enum-initial-value
+==============================
+
+Enforces consistent style for enumerators' initialization, covering three
+styles: none, first only, or all initialized explicitly.
+
+When adding new enumerations, inconsistent initial value will cause potential
+enumeration value conflicts.
+
+In an enumeration, the following three cases are accepted.
+1. none of enumerators are explicit initialized.
+2. the first enumerator is explicit initialized.
+3. all of enumerators are explicit initialized.
+
+.. code-block:: c++
+
+ // valid, none of enumerators are initialized.
+ enum A {
+ e0,
+ e1,
+ e2,
+ };
+
+ // valid, the first enumerator is initialized.
+ enum A {
+ e0 = 0,
+ e1,
+ e2,
+ };
+
+ // valid, all of enumerators are initialized.
+ enum A {
+ e0 = 0,
+ e1 = 1,
+ e2 = 2,
+ };
+
+ // invalid, e1 is not explicit initialized.
+ enum A {
+ e0 = 0,
+ e1,
+ e2 = 2,
+ };
+
+Options
+-------
+
+.. option:: AllowExplicitZeroFirstInitialValue
+
+ If set to `false`, the first enumerator must not be explicitly initialized.
+ See examples below. Default is `true`.
+
+ .. code-block:: c++
+
+ enum A {
+ e0 = 0, // not allowed if AllowExplicitZeroFirstInitialValue is false
+ e1,
+ e2,
+ };
+
+
+.. option:: AllowExplicitSequentialInitialValues
+
+ If set to `false`, sequential initializations are not allowed.
+ See examples below. Default is `true`.
+
+ .. code-block:: c++
+
+ enum A {
+ e0 = 1, // not allowed if AllowExplicitSequentialInitialValues is false
+ e1 = 2,
+ e2 = 3,
+ };
diff --git a/clang-tools-extra/test/clang-tidy/checkers/readability/enum-initial-value.c b/clang-tools-extra/test/clang-tidy/checkers/readability/enum-initial-value.c
new file mode 100644
index 00000000000000..c66288cbe3e957
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/checkers/readability/enum-initial-value.c
@@ -0,0 +1,80 @@
+// RUN: %check_clang_tidy %s readability-enum-initial-value %t
+// RUN: %check_clang_tidy -check-suffix=ENABLE %s readability-enum-initial-value %t -- \
+// RUN: -config='{CheckOptions: { \
+// RUN: readability-enum-initial-value.AllowExplicitZeroFirstInitialValue: false, \
+// RUN: readability-enum-initial-value.AllowExplicitSequentialInitialValues: false, \
+// RUN: }}'
+
+enum EError {
+ // CHECK-MESSAGES: :[[@LINE-1]]:1: warning: inital values in enum 'EError' are not consistent
+ // CHECK-MESSAGES-ENABLE: :[[@LINE-2]]:1: warning: inital values in enum 'EError' are not consistent
+ EError_a = 1,
+ EError_b,
+ // CHECK-FIXES: EError_b = 2,
+ EError_c = 3,
+};
+
+enum ENone {
+ ENone_a,
+ ENone_b,
+ EENone_c,
+};
+
+enum EFirst {
+ EFirst_a = 1,
+ EFirst_b,
+ EFirst_c,
+};
+
+enum EAll {
+ EAll_a = 1,
+ EAll_b = 2,
+ EAll_c = 4,
+};
+
+#define ENUMERATOR_1 EMacro1_b
+enum EMacro1 {
+ // CHECK-MESSAGES: :[[@LINE-1]]:1: warning: inital values in enum 'EMacro1' are not consistent
+ // CHECK-MESSAGES-ENABLE: :[[@LINE-2]]:1: warning: inital values in enum 'EMacro1' are not consistent
+ EMacro1_a = 1,
+ ENUMERATOR_1,
+ // CHECK-FIXES: ENUMERATOR_1 = 2,
+ EMacro1_c = 3,
+};
+
+
+#define ENUMERATOR_2 EMacro2_b = 2
+enum EMacro2 {
+ // CHECK-MESSAGES: :[[@LINE-1]]:1: warning: inital values in enum 'EMacro2' are not consistent
+ // CHECK-MESSAGES-ENABLE: :[[@LINE-2]]:1: warning: inital values in enum 'EMacro2' are not consistent
+ EMacro2_a = 1,
+ ENUMERATOR_2,
+ EMacro2_c,
+ // CHECK-FIXES: EMacro2_c = 3,
+};
+
+enum EnumZeroFirstInitialValue {
+ EnumZeroFirstInitialValue_0 = 0,
+ // CHECK-MESSAGES-ENABLE: :[[@LINE-1]]:3: warning: zero initial value for the first enumerator in 'EnumZeroFirstInitialValue' can be disregarded
+ // CHECK-FIXES-ENABLE: EnumZeroFirstInitialValue_0 ,
+ EnumZeroFirstInitialValue_1,
+ EnumZeroFirstInitialValue_2,
+};
+
+enum EnumZeroFirstInitialValueWithComment {
+ EnumZeroFirstInitialValueWithComment_0 = /* == */ 0,
+ // CHECK-MESSAGES-ENABLE: :[[@LINE-1]]:3: warning: zero initial value for the first enumerator in 'EnumZeroFirstInitialValueWithComment' can be disregarded
+ // CHECK-FIXES-ENABLE: EnumZeroFirstInitialValueWithComment_0 /* == */ ,
+ EnumZeroFirstInitialValueWithComment_1,
+ EnumZeroFirstInitialValueWithComment_2,
+};
+
+enum EnumSequentialInitialValue {
+ // CHECK-MESSAGES-ENABLE: :[[@LINE-1]]:1: warning: sequential initial value in 'EnumSequentialInitialValue' can be ignored
+ EnumSequentialInitialValue_0 = 2,
+ // CHECK-FIXES-ENABLE: EnumSequentialInitialValue_0 = 2,
+ EnumSequentialInitialValue_1 = 3,
+ // CHECK-FIXES-ENABLE: EnumSequentialInitialValue_1 ,
+ EnumSequentialInitialValue_2 = 4,
+ // CHECK-FIXES-ENABLE: EnumSequentialInitialValue_2 ,
+};
diff --git a/clang-tools-extra/test/clang-tidy/checkers/readability/enum-initial-value.cpp b/clang-tools-extra/test/clang-tidy/checkers/readability/enum-initial-value.cpp
new file mode 100644
index 00000000000000..3c4ba970372a07
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/checkers/readability/enum-initial-value.cpp
@@ -0,0 +1,27 @@
+// RUN: %check_clang_tidy %s readability-enum-initial-value %t
+
+enum class EError {
+ // CHECK-MESSAGES: :[[@LINE-1]]:1: warning: inital values in enum 'EError' are not consistent
+ EError_a = 1,
+ EError_b,
+ // CHECK-FIXES: EError_b = 2,
+ EError_c = 3,
+};
+
+enum class ENone {
+ ENone_a,
+ ENone_b,
+ EENone_c,
+};
+
+enum class EFirst {
+ EFirst_a = 1,
+ EFirst_b,
+ EFirst_c,
+};
+
+enum class EAll {
+ EAll_a = 1,
+ EAll_b = 2,
+ EAll_c = 3,
+};
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