[clang] [ASTMatchers] fix captureVars assertion failure on capturesVariables (PR #76619)

[Ding Fei via cfe-commits]

https://github.com/danix800 updated https://github.com/llvm/llvm-project/pull/76619

>From 0ca1a2b2573d1f89a1b4d13cd43628a46c1e5c98 Mon Sep 17 00:00:00 2001
From: dingfei <fding at feysh.com>
Date: Sun, 31 Dec 2023 00:32:01 +0800
Subject: [PATCH] [ASTMatchers] fix captureVars assertion failure on
 capturesVariables

Matcher 'capturesVar' should check for capturesVariables() before
calling getCaptureVar() since it asserts this LambdaCapture does capture
a variable.

Fixes #76425
---
 clang/docs/ReleaseNotes.rst                         | 1 +
 clang/include/clang/ASTMatchers/ASTMatchers.h       | 2 ++
 clang/unittests/ASTMatchers/ASTMatchersNodeTest.cpp | 2 ++
 3 files changed, 5 insertions(+)

diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index abf15c8dc49d9e..8d9ccf789d9cb8 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -633,6 +633,7 @@ AST Matchers
 - Add ``isExplicitObjectMemberFunction``.
 - Fixed ``forEachArgumentWithParam`` and ``forEachArgumentWithParamType`` to
   not skip the explicit object parameter for operator calls.
+- Fixed captureVars assertion failure if not capturesVariables. (#GH76425)
 
 clang-format
 ------------
diff --git a/clang/include/clang/ASTMatchers/ASTMatchers.h b/clang/include/clang/ASTMatchers/ASTMatchers.h
index 2f71053d030f68..8a2bbfff9e9e6b 100644
--- a/clang/include/clang/ASTMatchers/ASTMatchers.h
+++ b/clang/include/clang/ASTMatchers/ASTMatchers.h
@@ -4961,6 +4961,8 @@ AST_MATCHER_P(LambdaExpr, hasAnyCapture, internal::Matcher<LambdaCapture>,
 /// capturesVar(hasName("x")) matches `x` and `x = 1`.
 AST_MATCHER_P(LambdaCapture, capturesVar, internal::Matcher<ValueDecl>,
               InnerMatcher) {
+  if (!Node.capturesVariable())
+    return false;
   auto *capturedVar = Node.getCapturedVar();
   return capturedVar && InnerMatcher.matches(*capturedVar, Finder, Builder);
 }
diff --git a/clang/unittests/ASTMatchers/ASTMatchersNodeTest.cpp b/clang/unittests/ASTMatchers/ASTMatchersNodeTest.cpp
index 0edc65162fbe3f..b76627cb9be637 100644
--- a/clang/unittests/ASTMatchers/ASTMatchersNodeTest.cpp
+++ b/clang/unittests/ASTMatchers/ASTMatchersNodeTest.cpp
@@ -2321,6 +2321,8 @@ TEST_P(ASTMatchersTest, LambdaCaptureTest_BindsToCaptureOfVarDecl) {
       matches("int main() { int cc; auto f = [=](){ return cc; }; }", matcher));
   EXPECT_TRUE(
       matches("int main() { int cc; auto f = [&](){ return cc; }; }", matcher));
+  EXPECT_TRUE(matches(
+      "void f(int a) { int cc[a]; auto f = [&](){ return cc;}; }", matcher));
 }
 
 TEST_P(ASTMatchersTest, LambdaCaptureTest_BindsToCaptureWithInitializer) {