[clang] [WebKit Checkers] Make TrivialFunctionAnalysis recognize std::array::operator[] as trivial (PR #113377)

[Rashmi Mudduluru via cfe-commits]

https://github.com/t-rasmud created https://github.com/llvm/llvm-project/pull/113377

TFA wasn't recognizing `__libcpp_verbose_abort` as trivial causing `std::array::operator[]` also not being recongnized as trivial.

>From 9e21b0f2f0968a5f8810c797913318884dcc8c7b Mon Sep 17 00:00:00 2001
From: Rashmi Mudduluru <r_mudduluru at apple.com>
Date: Tue, 22 Oct 2024 13:16:30 -0700
Subject: [PATCH] [WebKit Checkers] Make TrivialFunctionAnalysis recognize
 std::array::operator[] as trivial

TFA wasn't recognizing `__libcpp_verbose_abort` as trivial causing `std::array::operator[]` also not being recongnized as trivial.
---
 .../Checkers/WebKit/PtrTypesSemantics.cpp     |  3 +-
 .../WebKit/uncounted-obj-arg-std-array.cpp    | 33 +++++++++++++++++++
 2 files changed, 35 insertions(+), 1 deletion(-)
 create mode 100644 clang/test/Analysis/Checkers/WebKit/uncounted-obj-arg-std-array.cpp

diff --git a/clang/lib/StaticAnalyzer/Checkers/WebKit/PtrTypesSemantics.cpp b/clang/lib/StaticAnalyzer/Checkers/WebKit/PtrTypesSemantics.cpp
index e043806eadd6ac..71440e6d08a1c9 100644
--- a/clang/lib/StaticAnalyzer/Checkers/WebKit/PtrTypesSemantics.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/WebKit/PtrTypesSemantics.cpp
@@ -414,7 +414,8 @@ class TrivialFunctionAnalysisVisitor
         Name == "isMainThreadOrGCThread" || Name == "isMainRunLoop" ||
         Name == "isWebThread" || Name == "isUIThread" ||
         Name == "mayBeGCThread" || Name == "compilerFenceForCrash" ||
-        Name == "bitwise_cast" || Name.find("__builtin") == 0)
+        Name == "bitwise_cast" || Name.find("__builtin") == 0 ||
+        Name == "__libcpp_verbose_abort")
       return true;
 
     return IsFunctionTrivial(Callee);
diff --git a/clang/test/Analysis/Checkers/WebKit/uncounted-obj-arg-std-array.cpp b/clang/test/Analysis/Checkers/WebKit/uncounted-obj-arg-std-array.cpp
new file mode 100644
index 00000000000000..43c76c0b0793a8
--- /dev/null
+++ b/clang/test/Analysis/Checkers/WebKit/uncounted-obj-arg-std-array.cpp
@@ -0,0 +1,33 @@
+// RUN: %clang_analyze_cc1 -analyzer-checker=alpha.webkit.UncountedCallArgsChecker -verify %s
+// expected-no-diagnostics
+
+#include "mock-types.h"
+
+using size_t = __typeof(sizeof(int));
+namespace std{
+template <class T, size_t N>
+class array {
+  T elements[N];
+  
+  public:
+  T& operator[](unsigned i) { return elements[i]; }
+  constexpr const T* data() const noexcept {
+     return elements;
+  }
+
+};
+}
+
+class ArrayClass {
+public:
+    typedef std::array<std::array<double, 4>, 4> Matrix;
+    double e() { return matrix[3][0]; }
+    Matrix matrix;
+};
+
+class AnotherClass {
+    Ref<ArrayClass> matrix;
+    void test() {
+      double val[] = { matrix->e(), matrix->e() };
+    }
+};