[clang] [clang][analyzer] Correct SMT Layer for _BitInt cases refutations (PR #143310)

[Balazs Benics via cfe-commits]

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@@ -0,0 +1,23 @@
+// RUN: %clang_cc1 -analyze -analyzer-checker=core -w -DNO_CROSSCHECK -verify %s
+// RUN: %clang_cc1 -analyze -analyzer-checker=core -w -analyzer-config crosscheck-with-z3=true -verify %s
+// REQUIRES: z3
+
+// The SMTConv layer did not comprehend _BitInt types (because this was an
+// evolved feature) and was crashing due to needed updates in 2 places.
+// Analysis is expected to find these cases using _BitInt without crashing.
+
+_BitInt(35) a;
+int b;
+void c() {
+  int d;
+  if (a)
+    b = d; // expected-warning{{Assigned value is uninitialized [core.uninitialized.Assign]}}
+}
+
+int *d;
+_BitInt(3) e;
+void f() {
+  int g;
+  d = &g;
+  e ?: 0; // expected-warning{{Address of stack memory associated with local variable 'g' is still referred to by the global variable 'd' upon returning to the caller.  This will be a dangling reference [core.StackAddressEscape]}}
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steakhal wrote:

Here if I'm not mistaken, the only thing we need is some bug report. Thus we could swap the bug into a warnIfReached to create one report. That should allow simplifications to this test, including the use of the global variable.

https://github.com/llvm/llvm-project/pull/143310