[clang-tidy] Check number of arguments to size/length in readability-container-size-empty

[PiotrZSL]

Verify that size/length methods are called with no arguments.

Closes #88203

[llvmbot]

@llvm/pr-subscribers-clang-tools-extra

@llvm/pr-subscribers-clang-tidy

Author: Piotr Zegar (PiotrZSL)

Changes

Verify that size/length methods are called with no arguments.

Closes #88203

---

Full diff: https://github.com/llvm/llvm-project/pull/93724.diff

3 Files Affected:

• (modified) clang-tools-extra/clang-tidy/readability/ContainerSizeEmptyCheck.cpp (+3-1)
• (modified) clang-tools-extra/docs/ReleaseNotes.rst (+4)
• (modified) clang-tools-extra/test/clang-tidy/checkers/readability/container-size-empty.cpp (+28)

diff --git a/clang-tools-extra/clang-tidy/readability/ContainerSizeEmptyCheck.cpp b/clang-tools-extra/clang-tidy/readability/ContainerSizeEmptyCheck.cpp
index 19307b4cdcbe3..bbc1b47b97ae6 100644
--- a/clang-tools-extra/clang-tidy/readability/ContainerSizeEmptyCheck.cpp
+++ b/clang-tools-extra/clang-tidy/readability/ContainerSizeEmptyCheck.cpp
@@ -150,6 +150,7 @@ void ContainerSizeEmptyCheck::registerMatchers(MatchFinder *Finder) {
 
   Finder->addMatcher(
       cxxMemberCallExpr(
+          argumentCountIs(0),
           on(expr(anyOf(hasType(ValidContainer),
                         hasType(pointsTo(ValidContainer)),
                         hasType(references(ValidContainer))))
@@ -163,7 +164,8 @@ void ContainerSizeEmptyCheck::registerMatchers(MatchFinder *Finder) {
       this);
 
   Finder->addMatcher(
-      callExpr(has(cxxDependentScopeMemberExpr(
+      callExpr(argumentCountIs(0),
+               has(cxxDependentScopeMemberExpr(
                        hasObjectExpression(
                            expr(anyOf(hasType(ValidContainer),
                                       hasType(pointsTo(ValidContainer)),
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index 3e3195f6f6813..a5d037d7fa036 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -363,6 +363,10 @@ Changes in existing checks
   <clang-tidy/checks/readability/const-return-type>` check to eliminate false
   positives when returning types with const not at the top level.
 
+- Improved :doc:`readability-container-size-empty
+  <clang-tidy/checks/readability/container-size-empty>` check to prevent false
+  positives when utilizing ``size`` or ``length`` methods that accept parameter.
+
 - Improved :doc:`readability-duplicate-include
   <clang-tidy/checks/readability/duplicate-include>` check by excluding include
   directives that form the filename using macro.
diff --git a/clang-tools-extra/test/clang-tidy/checkers/readability/container-size-empty.cpp b/clang-tools-extra/test/clang-tidy/checkers/readability/container-size-empty.cpp
index 84bdbd58b85e9..ecaf97fa348cc 100644
--- a/clang-tools-extra/test/clang-tidy/checkers/readability/container-size-empty.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/readability/container-size-empty.cpp
@@ -861,3 +861,31 @@ namespace PR72619 {
     if (0 >= s.size()) {}
   }
 }
+
+namespace PR88203 {
+  struct SS {
+    bool empty() const;
+    int size() const;
+    int length(int) const;
+  };
+
+  struct SU {
+    bool empty() const;
+    int size(int) const;
+    int length() const;
+  };
+
+  void f(const SS& s) {
+    if (0 == s.length(1)) {}
+    if (0 == s.size()) {}
+    // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: the 'empty' method should be used to check for emptiness instead of 'size' [readability-container-size-empty]
+    // CHECK-FIXES: {{^    }}if (s.empty()) {}{{$}}
+  }
+
+  void f(const SU& s) {
+    if (0 == s.size(1)) {}
+    if (0 == s.length()) {}
+    // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: the 'empty' method should be used to check for emptiness instead of 'length' [readability-container-size-empty]
+    // CHECK-FIXES: {{^    }}if (s.empty()) {}{{$}}
+  }
+}

[PiotrZSL]

I'm not 100% sure about release-notes entry. If it shouldn't say that check is restricted now to zero-argument size/length.

[5chmidti]

I'm not 100% sure about release-notes entry. If it shouldn't say that check is restricted now to zero-argument size/length.

I'd use the release note as it is. Or what is your concern with it?