[clang-tools-extra] [clang-tidy] Improve `readability-function-size`: count class member initializers as statements (PR #131669)
Baranov Victor via cfe-commits
cfe-commits at lists.llvm.org
Fri Jun 6 08:46:24 PDT 2025
https://github.com/vbvictor updated https://github.com/llvm/llvm-project/pull/131669
>From 2b4699fda6854235cf59c69d1bf511bd12799c43 Mon Sep 17 00:00:00 2001
From: Victor Baranov <bar.victor.2002 at gmail.com>
Date: Fri, 6 Jun 2025 18:46:11 +0300
Subject: [PATCH] [clang-tidy] count ctor-initializers as statements in
function-size check
---
.../readability/FunctionSizeCheck.cpp | 15 ++++-
.../readability/FunctionSizeCheck.h | 2 +
clang-tools-extra/docs/ReleaseNotes.rst | 5 ++
.../checks/readability/function-size.rst | 5 ++
.../function-size-no-member-init-as-stmts.cpp | 64 +++++++++++++++++++
.../checkers/readability/function-size.cpp | 50 +++++++++++++++
6 files changed, 140 insertions(+), 1 deletion(-)
create mode 100644 clang-tools-extra/test/clang-tidy/checkers/readability/function-size-no-member-init-as-stmts.cpp
diff --git a/clang-tools-extra/clang-tidy/readability/FunctionSizeCheck.cpp b/clang-tools-extra/clang-tidy/readability/FunctionSizeCheck.cpp
index 3313bcb39b7f3..8e3a2e306dbf7 100644
--- a/clang-tools-extra/clang-tidy/readability/FunctionSizeCheck.cpp
+++ b/clang-tools-extra/clang-tidy/readability/FunctionSizeCheck.cpp
@@ -108,6 +108,14 @@ class FunctionASTVisitor : public RecursiveASTVisitor<FunctionASTVisitor> {
return true;
}
+ bool TraverseConstructorInitializer(CXXCtorInitializer *Init) {
+ if (CountMemberInitAsStmt)
+ ++Info.Statements;
+
+ Base::TraverseConstructorInitializer(Init);
+ return true;
+ }
+
struct FunctionInfo {
unsigned Lines = 0;
unsigned Statements = 0;
@@ -120,6 +128,7 @@ class FunctionASTVisitor : public RecursiveASTVisitor<FunctionASTVisitor> {
llvm::BitVector TrackedParent;
unsigned StructNesting = 0;
unsigned CurrentNestingLevel = 0;
+ bool CountMemberInitAsStmt;
};
} // namespace
@@ -135,7 +144,9 @@ FunctionSizeCheck::FunctionSizeCheck(StringRef Name, ClangTidyContext *Context)
NestingThreshold(
Options.get("NestingThreshold", DefaultNestingThreshold)),
VariableThreshold(
- Options.get("VariableThreshold", DefaultVariableThreshold)) {}
+ Options.get("VariableThreshold", DefaultVariableThreshold)),
+ CountMemberInitAsStmt(
+ Options.get("CountMemberInitAsStmt", DefaultCountMemberInitAsStmt)) {}
void FunctionSizeCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
Options.store(Opts, "LineThreshold", LineThreshold);
@@ -144,6 +155,7 @@ void FunctionSizeCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
Options.store(Opts, "ParameterThreshold", ParameterThreshold);
Options.store(Opts, "NestingThreshold", NestingThreshold);
Options.store(Opts, "VariableThreshold", VariableThreshold);
+ Options.store(Opts, "CountMemberInitAsStmt", CountMemberInitAsStmt);
}
void FunctionSizeCheck::registerMatchers(MatchFinder *Finder) {
@@ -160,6 +172,7 @@ void FunctionSizeCheck::check(const MatchFinder::MatchResult &Result) {
FunctionASTVisitor Visitor;
Visitor.Info.NestingThreshold = NestingThreshold.value_or(-1);
+ Visitor.CountMemberInitAsStmt = CountMemberInitAsStmt;
Visitor.TraverseDecl(const_cast<FunctionDecl *>(Func));
auto &FI = Visitor.Info;
diff --git a/clang-tools-extra/clang-tidy/readability/FunctionSizeCheck.h b/clang-tools-extra/clang-tidy/readability/FunctionSizeCheck.h
index 106c69ff07393..f668ab18fea52 100644
--- a/clang-tools-extra/clang-tidy/readability/FunctionSizeCheck.h
+++ b/clang-tools-extra/clang-tidy/readability/FunctionSizeCheck.h
@@ -47,6 +47,7 @@ class FunctionSizeCheck : public ClangTidyCheck {
const std::optional<unsigned> ParameterThreshold;
const std::optional<unsigned> NestingThreshold;
const std::optional<unsigned> VariableThreshold;
+ const bool CountMemberInitAsStmt;
static constexpr std::optional<unsigned> DefaultLineThreshold = std::nullopt;
static constexpr std::optional<unsigned> DefaultStatementThreshold = 800U;
@@ -58,6 +59,7 @@ class FunctionSizeCheck : public ClangTidyCheck {
std::nullopt;
static constexpr std::optional<unsigned> DefaultVariableThreshold =
std::nullopt;
+ static constexpr bool DefaultCountMemberInitAsStmt = true;
};
} // namespace clang::tidy::readability
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index b7d0a223ce5bb..dc4a24b9d72e7 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -245,6 +245,11 @@ Changes in existing checks
tolerating fix-it breaking compilation when functions is used as pointers
to avoid matching usage of functions within the current compilation unit.
+- Improved :doc:`readability-function-size
+ <clang-tidy/checks/readability/function-size>` check by adding new option
+ `CountMemberInitAsStmt` that allows counting class member initializers in
+ constructors as statements.
+
- Improved :doc:`readability-math-missing-parentheses
<clang-tidy/checks/readability/math-missing-parentheses>` check by fixing
false negatives where math expressions are the operand of assignment operators
diff --git a/clang-tools-extra/docs/clang-tidy/checks/readability/function-size.rst b/clang-tools-extra/docs/clang-tidy/checks/readability/function-size.rst
index 133bd3e9c8cbe..253e7c483cb85 100644
--- a/clang-tools-extra/docs/clang-tidy/checks/readability/function-size.rst
+++ b/clang-tools-extra/docs/clang-tidy/checks/readability/function-size.rst
@@ -43,3 +43,8 @@ Options
The default is `none` (ignore the number of variables).
Please note that function parameters and variables declared in lambdas,
GNU Statement Expressions, and nested class inline functions are not counted.
+
+.. option:: CountMemberInitAsStmt
+
+ When `true`, count class member initializers in constructors as statements.
+ Default is `true`.
diff --git a/clang-tools-extra/test/clang-tidy/checkers/readability/function-size-no-member-init-as-stmts.cpp b/clang-tools-extra/test/clang-tidy/checkers/readability/function-size-no-member-init-as-stmts.cpp
new file mode 100644
index 0000000000000..2301b4c7dee40
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/checkers/readability/function-size-no-member-init-as-stmts.cpp
@@ -0,0 +1,64 @@
+// RUN: %check_clang_tidy %s readability-function-size %t -- \
+// RUN: -config='{CheckOptions: { \
+// RUN: readability-function-size.LineThreshold: 0, \
+// RUN: readability-function-size.StatementThreshold: 0, \
+// RUN: readability-function-size.BranchThreshold: 0, \
+// RUN: readability-function-size.ParameterThreshold: 5, \
+// RUN: readability-function-size.NestingThreshold: 2, \
+// RUN: readability-function-size.VariableThreshold: 1, \
+// RUN: readability-function-size.CountMemberInitAsStmt: false \
+// RUN: }}'
+
+// Bad formatting is intentional, don't run clang-format over the whole file!
+
+void foo1() {
+}
+
+void foo2() {;}
+// CHECK-MESSAGES: :[[@LINE-1]]:6: warning: function 'foo2' exceeds recommended size/complexity thresholds [readability-function-size]
+// CHECK-MESSAGES: :[[@LINE-2]]:6: note: 1 statements (threshold 0)
+
+struct A {
+ A(int c, int d) : a(0), b(c) { ; }
+ int a;
+ int b;
+};
+// CHECK-MESSAGES: :[[@LINE-4]]:3: warning: function 'A' exceeds recommended size/complexity thresholds [readability-function-size]
+// CHECK-MESSAGES: :[[@LINE-5]]:3: note: 1 statements (threshold 0)
+
+struct B {
+ B(int x, int y, int z) : a(x + y * z), b(), c_a(y, z) {
+ ;
+ }
+ int a;
+ int b;
+ A c_a;
+};
+// CHECK-MESSAGES: :[[@LINE-7]]:3: warning: function 'B' exceeds recommended size/complexity thresholds [readability-function-size]
+// CHECK-MESSAGES: :[[@LINE-8]]:3: note: 2 lines including whitespace and comments (threshold 0)
+// CHECK-MESSAGES: :[[@LINE-9]]:3: note: 1 statements (threshold 0)
+
+struct C : A, B {
+ // 0 statements
+ C() : A(0, 4), B(1, 2, 3) {}
+};
+
+template<typename T>
+struct TemplateC {
+ // 0 statements
+ TemplateC() : a(3) {}
+ T a;
+};
+
+template<typename T>
+struct TemplateD {
+ template<typename U>
+ TemplateD(U&& val) : member(val) {
+ ;
+ }
+
+ T member;
+};
+// CHECK-MESSAGES: :[[@LINE-6]]:3: warning: function 'TemplateD<T>' exceeds recommended size/complexity thresholds [readability-function-size]
+// CHECK-MESSAGES: :[[@LINE-7]]:3: note: 2 lines including whitespace and comments (threshold 0)
+// CHECK-MESSAGES: :[[@LINE-8]]:3: note: 1 statements (threshold 0)
diff --git a/clang-tools-extra/test/clang-tidy/checkers/readability/function-size.cpp b/clang-tools-extra/test/clang-tidy/checkers/readability/function-size.cpp
index 45b2604b43d03..fb846ce01803a 100644
--- a/clang-tools-extra/test/clang-tidy/checkers/readability/function-size.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/readability/function-size.cpp
@@ -319,3 +319,53 @@ void variables_16() {
// CHECK-MESSAGES: :[[@LINE-5]]:6: note: 3 lines including whitespace and comments (threshold 0)
// CHECK-MESSAGES: :[[@LINE-6]]:6: note: 4 statements (threshold 0)
// CHECK-MESSAGES: :[[@LINE-7]]:6: note: 2 variables (threshold 1)
+
+struct A {
+ A(int c, int d) : a(0), b(c) { ; }
+ int a;
+ int b;
+};
+// CHECK-MESSAGES: :[[@LINE-4]]:3: warning: function 'A' exceeds recommended size/complexity thresholds [readability-function-size]
+// CHECK-MESSAGES: :[[@LINE-5]]:3: note: 3 statements (threshold 0)
+
+struct B {
+ B(int x, int y, int z) : a(x + y * z), b(), c_a(y, z) {
+ ;
+ }
+ int a;
+ int b;
+ A c_a;
+};
+// CHECK-MESSAGES: :[[@LINE-7]]:3: warning: function 'B' exceeds recommended size/complexity thresholds [readability-function-size]
+// CHECK-MESSAGES: :[[@LINE-8]]:3: note: 2 lines including whitespace and comments (threshold 0)
+// CHECK-MESSAGES: :[[@LINE-9]]:3: note: 4 statements (threshold 0)
+
+struct C : A, B {
+ C() : A(0, 4), B(1, 2, 3) {}
+};
+// CHECK-MESSAGES: :[[@LINE-2]]:3: warning: function 'C' exceeds recommended size/complexity thresholds [readability-function-size]
+// CHECK-MESSAGES: :[[@LINE-3]]:3: note: 2 statements (threshold 0)
+
+template<typename T>
+struct TemplateC {
+ // 0 statements
+ TemplateC() : a(3) {}
+ T a;
+};
+// CHECK-MESSAGES: :[[@LINE-3]]:3: warning: function 'TemplateC<T>' exceeds recommended size/complexity thresholds [readability-function-size]
+// CHECK-MESSAGES: :[[@LINE-4]]:3: note: 1 statements (threshold 0)
+
+template<typename T>
+struct TemplateD {
+ template<typename U>
+ TemplateD(U&& val) : member(val) {
+ ;
+ }
+
+ T member;
+};
+// CHECK-MESSAGES: :[[@LINE-6]]:3: warning: function 'TemplateD<T>' exceeds recommended size/complexity thresholds [readability-function-size]
+// CHECK-MESSAGES: :[[@LINE-7]]:3: note: 2 lines including whitespace and comments (threshold 0)
+// CHECK-MESSAGES: :[[@LINE-8]]:3: note: 2 statements (threshold 0)
+
+
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