Support decl_stmt in switch stmt

Summary:
public
Add support for decl statements inside condition of switch statement

Reviewed By: ddino

Differential Revision: D2734213

fb-gh-sync-id: d60021d

infer/src/clang/cTrans.ml

@@ -1115,7 +1115,7 @@ struct
     let sil_loc = CLocation.get_sil_location stmt_info pln context in
     let open Clang_ast_t in
     match switch_stmt_list with
-    | [_; cond; CompoundStmt(stmt_info, stmt_list)] ->
+    | [decl_stmt; cond; CompoundStmt(stmt_info, stmt_list)] ->
         let trans_state_pri = PriorityNode.try_claim_priority_node trans_state stmt_info in
         let trans_state' ={ trans_state_pri with succ_nodes = []} in
         let res_trans_cond_tmp = instruction trans_state' cond in
@@ -1133,6 +1133,7 @@ struct
                                root_nodes = root_nodes;
                                leaf_nodes = [switch_special_cond_node]
                              } in
+        let res_trans_decl = declStmt_in_condition_trans trans_state decl_stmt res_trans_cond in
         let trans_state_no_pri = if PriorityNode.own_priority_node trans_state_pri.priority stmt_info then
             { trans_state_pri with priority = Free }
           else trans_state_pri in
@@ -1226,7 +1227,7 @@ struct
         let top_entry_point, top_prune_nodes = translate_and_connect_cases list_of_cases succ_nodes succ_nodes in
         let _ = connected_instruction (IList.rev pre_case_stmts) top_entry_point in
         Cfg.Node.set_succs_exn switch_special_cond_node top_prune_nodes [];
-        let top_nodes = res_trans_cond.root_nodes in
+        let top_nodes = res_trans_decl.root_nodes in
         IList.iter (fun n' -> Cfg.Node.append_instrs_temps n' [] res_trans_cond.ids) succ_nodes; (* succ_nodes will remove the temps *)
         { root_nodes = top_nodes; leaf_nodes = succ_nodes; ids = []; instrs = []; exps =[]}
     | _ -> assert false

infer/tests/codetoanalyze/cpp/frontend/nestedoperators/var_decl_inside_switch.cpp

@@ -0,0 +1,20 @@
+/*
+* Copyright (c) 2015 - present Facebook, Inc.
+* All rights reserved.
+*
+* This source code is licensed under the BSD style license found in the
+* LICENSE file in the root directory of this source tree. An additional grant
+* of patent rights can be found in the PATENTS file in the same directory.
+*/
+
+int get(int a) {
+  switch (int x = a) {
+    case 0:
+    case 1:
+    return 0;
+    case 2:
+    return 1;
+    default:
+    return x;
+  }
+}

infer/tests/codetoanalyze/cpp/frontend/nestedoperators/var_decl_inside_switch.cpp.dot

@@ -0,0 +1,60 @@
+digraph iCFG {
+14 [label="14: Prune (false branch) \n   PRUNE(((n$0 == 0) == 0), false); [line 12]\n " shape="invhouse"]
+	
+
+	 14 -> 11 ;
+	 14 -> 12 ;
+13 [label="13: Prune (true branch) \n   PRUNE(((n$0 == 0) != 0), true); [line 12]\n  APPLY_ABSTRACTION; [line 12]\n " shape="invhouse"]
+	
+
+	 13 -> 10 ;
+12 [label="12: Prune (false branch) \n   PRUNE(((n$0 == 1) == 0), false); [line 13]\n " shape="invhouse"]
+	
+
+	 12 -> 8 ;
+	 12 -> 9 ;
+11 [label="11: Prune (true branch) \n   PRUNE(((n$0 == 1) != 0), true); [line 13]\n  APPLY_ABSTRACTION; [line 13]\n " shape="invhouse"]
+	
+
+	 11 -> 10 ;
+10 [label="10:  Return Stmt \n   NULLIFY(&x,false); [line 14]\n  *&return:int =0 [line 14]\n  APPLY_ABSTRACTION; [line 14]\n " shape="box"]
+	
+
+	 10 -> 2 ;
+9 [label="9: Prune (false branch) \n   PRUNE(((n$0 == 2) == 0), false); [line 15]\n " shape="invhouse"]
+	
+
+	 9 -> 5 ;
+8 [label="8: Prune (true branch) \n   PRUNE(((n$0 == 2) != 0), true); [line 15]\n " shape="invhouse"]
+	
+
+	 8 -> 7 ;
+7 [label="7:  Return Stmt \n   NULLIFY(&x,false); [line 16]\n  *&return:int =1 [line 16]\n  APPLY_ABSTRACTION; [line 16]\n " shape="box"]
+	
+
+	 7 -> 2 ;
+6 [label="6:  Return Stmt \n   n$2=*&x:int  [line 18]\n  *&return:int =n$2 [line 18]\n  REMOVE_TEMPS(n$2); [line 18]\n  NULLIFY(&x,false); [line 18]\n  APPLY_ABSTRACTION; [line 18]\n " shape="box"]
+	
+
+	 6 -> 2 ;
+5 [label="5:  DefaultStmt_placeholder \n  " shape="box"]
+	
+
+	 5 -> 6 ;
+4 [label="4:  DeclStmt \n   n$1=*&a:int  [line 11]\n  *&x:int =n$1 [line 11]\n  REMOVE_TEMPS(n$1); [line 11]\n  NULLIFY(&a,false); [line 11]\n " shape="box"]
+	
+
+	 4 -> 3 ;
+3 [label="3:  Switch_stmt \n   n$0=*&x:int  [line 11]\n " shape="box"]
+	
+
+	 3 -> 13 ;
+	 3 -> 14 ;
+2 [label="2: Exit get \n   REMOVE_TEMPS(n$0); [line 20]\n " color=yellow style=filled]
+	
+
+1 [label="1: Start get\nFormals:  a:int \nLocals:  x:int  \n   DECLARE_LOCALS(&return,&x); [line 10]\n  NULLIFY(&x,false); [line 10]\n " color=yellow style=filled]
+	
+
+	 1 -> 4 ;
+}

infer/tests/frontend/cpp/NestedCPPOperatorsTest.java

@@ -48,4 +48,9 @@ public class NestedCPPOperatorsTest {
     frontendTest("var_decl_inside_for.cpp");
   }
 
+  @Test
+  public void testVarDeclInsideSwitchDotFilesMatch()
+      throws InterruptedException, IOException, InferException {
+    frontendTest("var_decl_inside_switch.cpp");
+  }
 }