[clang][analyzer] Ignore try-statements in UnreachableCode checker (#91675)

Fixes #90162

Author: sookach

clang/lib/StaticAnalyzer/Checkers/UnreachableCodeChecker.cpp

@@ -159,6 +159,8 @@ void UnreachableCodeChecker::checkEndAnalysis(ExplodedGraph &G,
       SL = DL.asLocation();
       if (SR.isInvalid() || !SL.isValid())
         continue;
+      if (isa<CXXTryStmt>(S))
+        continue;
     }
     else
       continue;
@@ -254,4 +256,4 @@ void ento::registerUnreachableCodeChecker(CheckerManager &mgr) {
 
 bool ento::shouldRegisterUnreachableCodeChecker(const CheckerManager &mgr) {
   return true;
-}
+}

clang/test/Analysis/unreachable-code-exceptions.cpp

@@ -0,0 +1,13 @@
+// RUN: %clang_analyze_cc1 -verify %s -fcxx-exceptions -fexceptions -analyzer-checker=core,alpha.deadcode.UnreachableCode
+
+// expected-no-diagnostics
+
+void foo();
+
+void fp_90162() {
+  try { // no-warning: The TryStmt shouldn't be unreachable.
+    foo();
+  } catch (int) {
+    foo(); // We assume that catch handlers are reachable.
+  }
+}