[clang] [clang][analyzer] Fix the false positive ArgInitializedness warning on unnamed bit-field (PR #145066)

[Balazs Benics via cfe-commits]

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@@ -22,3 +29,21 @@ void pointee_uninit(void) {
 // checker, as described in the CallAndMessage comments!
 // CHECK: <key>issue_hash_content_of_line_in_context</key>
 // CHECK-SAME: <string>97a74322d64dca40aa57303842c745a1</string>
+
+typedef struct {
+  int i  :2;
+  int    :30;  // unnamed bit-field
+} B;
+
+extern void consume_B(B);
+
+void bitfield_B_init(void) {
+  B b1;
+  b1.i = 1; // b1 is initialized
+  consume_B(b1);
+}
+
+void bitfield_B_uninit(void) {
+  B b2;
+  consume_B(b2); // arg-init-warning{{Passed-by-value struct argument contains uninitialized data (e.g., field: 'i') [core.CallAndMessage]}}
+}
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steakhal wrote:

I think we could move this test to `clang/test/Analysis/uninit-const.c`.

https://github.com/llvm/llvm-project/pull/145066