[co_return] Translate co_return as return in the frontend

Summary:
This diff translate the co_return as the normal return in the frontend, so that it can have an edge
to the exit node.

Reviewed By: jvillard

Differential Revision: D65275166

fbshipit-source-id: 785b1a2493fafd27894bea56479bcc185a570a15

infer/src/clang/cTrans.ml

@@ -4776,9 +4776,19 @@ module CTrans_funct (F : CModule_type.CFrontend) : CModule_type.CTranslation = s
 
 
   and coreturnStmt_trans trans_state stmt_info operand_opt promise_call_opt =
-    let args = Option.to_list operand_opt @ Option.to_list promise_call_opt in
-    call_function_with_args Procdesc.Node.ReturnStmt BuiltinDecl.__builtin_cxx_co_return trans_state
-      stmt_info StdTyp.void args
+    let sil_loc =
+      CLocation.location_of_stmt_info trans_state.context.translation_unit_context.source_file
+        stmt_info
+    in
+    PriorityNode.force_sequential sil_loc ReturnStmt trans_state stmt_info
+      ~mk_first_opt:(fun trans_state stmt_info ->
+        let args = Option.to_list operand_opt @ Option.to_list promise_call_opt in
+        Some
+          (call_function_with_args Procdesc.Node.ReturnStmt BuiltinDecl.__builtin_cxx_co_return
+             trans_state stmt_info StdTyp.void args ) )
+      ~mk_second:(fun trans_state stmt_info ->
+        returnStmt_trans trans_state stmt_info [Clang_ast_t.ReturnStmt (stmt_info, [])] )
+      ~mk_return:(fun ~fst ~snd:_ -> fst.return)
 
 
   and coroutineSuspendExpr_trans trans_state stmt_info expr_info cse_operand =

infer/tests/codetoanalyze/cpp/pulse-20/coro.cpp

@@ -87,7 +87,7 @@ Task<Request*> makeRequestToSink_bad() {
   co_return co_await co_get_something(request);
 }
 
-Task<std::string> optional_co_return_ok_FP() {
+Task<std::string> optional_co_return_ok() {
   std::optional<std::string> optional_field = std::nullopt;
   if (!optional_field.has_value()) {
     co_return "abc";

infer/tests/codetoanalyze/cpp/pulse-20/issues.exp

@@ -1,5 +1,4 @@
 codetoanalyze/cpp/pulse-20/coro.cpp, coro::do_coroutine_stuff_then_npe_bad, 5, NULLPTR_DEREFERENCE, no_bucket, ERROR, [is assigned to the null pointer,assigned,invalid access occurs here]
 codetoanalyze/cpp/pulse-20/coro.cpp, coro::FP_do_coroutine_stuff_then_npe_unless_semantics_accurate_bad, 6, NULLPTR_DEREFERENCE, no_bucket, ERROR, [is assigned to the null pointer,assigned,invalid access occurs here]
 codetoanalyze/cpp/pulse-20/coro.cpp, coro::makeRequestToSink_bad, 2, TAINT_ERROR, no_bucket, ERROR, [source of the taint here: value returned from `coro::makeRequest` with kind `SimpleSource`,in call to function `__builtin_cxx_co_await` with no summary,when calling `coro::co_get_something` here,flows to this sink: value passed as argument `#0` to `coro::requestSink` with kind `SimpleSink`], source: coro::makeRequest, sink: coro::requestSink, tainted expression: request
-codetoanalyze/cpp/pulse-20/coro.cpp, coro::optional_co_return_ok_FP, 5, OPTIONAL_EMPTY_ACCESS, no_bucket, ERROR, [in call to `std::optional::optional(=nullopt)` (modelled),is assigned an empty value,invalid access occurs here]
 codetoanalyze/cpp/pulse-20/std_exchange.cpp, std_exchange_semantics_bad, 6, NULLPTR_DEREFERENCE, no_bucket, ERROR, [is assigned to the null pointer,assigned,invalid access occurs here]