[clang] [Clang][ASTMatchers] Make `hasConditionVariableStatement` support `for` loop, `while` loop and `switch` statement (PR #154298)

[Yanzuo Liu via cfe-commits]

https://github.com/zwuis updated https://github.com/llvm/llvm-project/pull/154298

>From 14102c2c5bbd5c4caa9049f87699cce82cdc4481 Mon Sep 17 00:00:00 2001
From: Yanzuo Liu <zwuis at outlook.com>
Date: Tue, 19 Aug 2025 17:29:18 +0800
Subject: [PATCH 1/2] Make `hasConditionVariableStatement` support `for` loop,
 `while` loop and `switch` statement

---
 clang/docs/ReleaseNotes.rst                   |  3 ++
 clang/include/clang/ASTMatchers/ASTMatchers.h | 17 ++++++----
 .../ASTMatchers/ASTMatchersNodeTest.cpp       | 33 +++++++++++++++++++
 .../ASTMatchers/ASTMatchersTraversalTest.cpp  | 15 ---------
 4 files changed, 47 insertions(+), 21 deletions(-)

diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index b86a9c437ffb1..7ca574d316250 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -322,6 +322,9 @@ AST Matchers
 - Add a boolean member ``IgnoreSystemHeaders`` to ``MatchFinderOptions``. This
   allows it to ignore nodes in system headers when traversing the AST.
 
+- ``hasConditionVariableStatement`` now supports ``for`` loop, ``while`` loop
+  and ``switch`` statement.
+
 clang-format
 ------------
 - Add ``SpaceInEmptyBraces`` option and set it to ``Always`` for WebKit style.
diff --git a/clang/include/clang/ASTMatchers/ASTMatchers.h b/clang/include/clang/ASTMatchers/ASTMatchers.h
index cbd931cabd806..787f4a9af0772 100644
--- a/clang/include/clang/ASTMatchers/ASTMatchers.h
+++ b/clang/include/clang/ASTMatchers/ASTMatchers.h
@@ -5661,8 +5661,8 @@ AST_POLYMORPHIC_MATCHER_P(hasInitStatement,
   return Init != nullptr && InnerMatcher.matches(*Init, Finder, Builder);
 }
 
-/// Matches the condition expression of an if statement, for loop,
-/// switch statement or conditional operator.
+/// Matches the condition expression of an if statement, for loop, while loop,
+/// do-while loop, switch statement or conditional operator.
 ///
 /// Example matches true (matcher = hasCondition(cxxBoolLiteral(equals(true))))
 /// \code
@@ -5739,16 +5739,21 @@ AST_POLYMORPHIC_MATCHER_P(equalsBoundNode,
   return Builder->removeBindings(Predicate);
 }
 
-/// Matches the condition variable statement in an if statement.
+/// Matches the condition variable statement in an if statement, for loop,
+/// while loop or switch statement.
 ///
 /// Given
 /// \code
 ///   if (A* a = GetAPointer()) {}
+///   for (; A* a = GetAPointer(); ) {}
 /// \endcode
 /// hasConditionVariableStatement(...)
-///   matches 'A* a = GetAPointer()'.
-AST_MATCHER_P(IfStmt, hasConditionVariableStatement,
-              internal::Matcher<DeclStmt>, InnerMatcher) {
+///   matches both 'A* a = GetAPointer()'.
+AST_POLYMORPHIC_MATCHER_P(hasConditionVariableStatement,
+                          AST_POLYMORPHIC_SUPPORTED_TYPES(IfStmt, ForStmt,
+                                                          WhileStmt,
+                                                          SwitchStmt),
+                          internal::Matcher<DeclStmt>, InnerMatcher) {
   const DeclStmt* const DeclarationStatement =
     Node.getConditionVariableDeclStmt();
   return DeclarationStatement != nullptr &&
diff --git a/clang/unittests/ASTMatchers/ASTMatchersNodeTest.cpp b/clang/unittests/ASTMatchers/ASTMatchersNodeTest.cpp
index b55928f7060da..d7df9cae01f33 100644
--- a/clang/unittests/ASTMatchers/ASTMatchersNodeTest.cpp
+++ b/clang/unittests/ASTMatchers/ASTMatchersNodeTest.cpp
@@ -1183,6 +1183,39 @@ TEST_P(ASTMatchersTest, AsmStatement) {
   EXPECT_TRUE(matches("void foo() { __asm(\"mov al, 2\"); }", asmStmt()));
 }
 
+TEST_P(ASTMatchersTest, HasConditionVariableStatement) {
+  if (!GetParam().isCXX()) {
+    // FIXME: Add a test for `hasConditionVariableStatement()` that does not
+    // depend on C++.
+    return;
+  }
+
+  StatementMatcher IfCondition =
+      ifStmt(hasConditionVariableStatement(declStmt()));
+
+  EXPECT_TRUE(matches("void x() { if (int* a = 0) {} }", IfCondition));
+  EXPECT_TRUE(notMatches("void x() { if (true) {} }", IfCondition));
+  EXPECT_TRUE(notMatches("void x() { int x; if ((x = 42)) {} }", IfCondition));
+
+  StatementMatcher SwitchCondition =
+      switchStmt(hasConditionVariableStatement(declStmt()));
+
+  EXPECT_TRUE(matches("void x() { switch (int a = 0) {} }", SwitchCondition));
+  if (GetParam().isCXX17OrLater()) {
+    EXPECT_TRUE(
+        notMatches("void x() { switch (int a = 0; a) {} }", SwitchCondition));
+  }
+
+  StatementMatcher ForCondition =
+      forStmt(hasConditionVariableStatement(declStmt()));
+
+  EXPECT_TRUE(matches("void x() { for (; int a = 0; ) {} }", ForCondition));
+  EXPECT_TRUE(notMatches("void x() { for (int a = 0; ; ) {} }", ForCondition));
+
+  EXPECT_TRUE(matches("void x() { while (int a = 0) {} }",
+                      whileStmt(hasConditionVariableStatement(declStmt()))));
+}
+
 TEST_P(ASTMatchersTest, HasCondition) {
   if (!GetParam().isCXX()) {
     // FIXME: Add a test for `hasCondition()` that does not depend on C++.
diff --git a/clang/unittests/ASTMatchers/ASTMatchersTraversalTest.cpp b/clang/unittests/ASTMatchers/ASTMatchersTraversalTest.cpp
index d58bc00c995e0..c0a03deb5b543 100644
--- a/clang/unittests/ASTMatchers/ASTMatchersTraversalTest.cpp
+++ b/clang/unittests/ASTMatchers/ASTMatchersTraversalTest.cpp
@@ -5142,21 +5142,6 @@ TEST(ForEachLambdaCapture, MatchExplicitCapturesOnly) {
       matcher, std::make_unique<VerifyIdIsBoundTo<LambdaCapture>>("LC", 1)));
 }
 
-TEST(HasConditionVariableStatement, DoesNotMatchCondition) {
-  EXPECT_TRUE(notMatches(
-    "void x() { if(true) {} }",
-    ifStmt(hasConditionVariableStatement(declStmt()))));
-  EXPECT_TRUE(notMatches(
-    "void x() { int x; if((x = 42)) {} }",
-    ifStmt(hasConditionVariableStatement(declStmt()))));
-}
-
-TEST(HasConditionVariableStatement, MatchesConditionVariables) {
-  EXPECT_TRUE(matches(
-    "void x() { if(int* a = 0) {} }",
-    ifStmt(hasConditionVariableStatement(declStmt()))));
-}
-
 TEST(ForEach, BindsOneNode) {
   EXPECT_TRUE(matchAndVerifyResultTrue("class C { int x; };",
                                        recordDecl(hasName("C"), forEach(fieldDecl(hasName("x")).bind("x"))),

>From 9e62f8d26ee638350c0d58b8f1eb475f761e83d1 Mon Sep 17 00:00:00 2001
From: Yanzuo Liu <zwuis at outlook.com>
Date: Tue, 19 Aug 2025 23:36:39 +0800
Subject: [PATCH 2/2] statement -> statements

Co-authored-by: Aaron Ballman <aaron at aaronballman.com>
---
 clang/docs/ReleaseNotes.rst | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 7ca574d316250..b6ad73edb6960 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -323,7 +323,7 @@ AST Matchers
   allows it to ignore nodes in system headers when traversing the AST.
 
 - ``hasConditionVariableStatement`` now supports ``for`` loop, ``while`` loop
-  and ``switch`` statement.
+  and ``switch`` statements.
 
 clang-format
 ------------