Deal with empty parameter names

Summary:
public
C++ allows for parameters with empty names (unused/default copy constructors). Make backend happy by assigning a non-empty
name to these variables

Reviewed By: jvillard

Differential Revision: D2895550

fb-gh-sync-id: b466397

facebook-clang-plugins

@@ -1 +1 @@
-Subproject commit df8dc4e093b0f8147e5d8dc06e3e5316ceac865a
+Subproject commit d07910830a3ccf56c10a4eaf9c8dcad23ecb4d9b

infer/src/clang/ast_expressions.ml

@@ -54,6 +54,7 @@ let empty_var_decl_info = {
   vdi_is_module_private = false;
   vdi_is_nrvo_variable = false;
   vdi_init_expr = None;
+  vdi_parm_index_in_function = None;
 }
 
 let stmt_info_with_fresh_pointer stmt_info = {

infer/src/clang/cFrontend_utils.ml

@@ -573,11 +573,19 @@ struct
     let type_name_crc = Some (CRC.crc16 type_name) in
     Procname.mangled_c_method class_name method_name type_name_crc
 
+  let get_var_name_string name_info var_decl_info =
+    let clang_name = Ast_utils.get_qualified_name name_info in
+    match clang_name, var_decl_info.Clang_ast_t.vdi_parm_index_in_function with
+    | "", Some index -> "__param_" ^ string_of_int index
+    | "", None -> assert false
+    | _ -> clang_name
+
   let mk_sil_var name decl_info_type_ptr_opt procname outer_procname =
     let name_string = Ast_utils.get_qualified_name name in
-    let simple_name = Mangled.from_string name_string  in
     match decl_info_type_ptr_opt with
     | Some (decl_info, type_ptr, var_decl_info, should_be_mangled) ->
+        let name_string = get_var_name_string name var_decl_info in
+        let simple_name = Mangled.from_string name_string in
         if var_decl_info.Clang_ast_t.vdi_is_global then
           let global_mangled_name =
             if var_decl_info.Clang_ast_t.vdi_is_static_local then
@@ -593,7 +601,7 @@ struct
           let mangled = CRC.crc16 (type_name ^ line_str) in
           let mangled_name = Mangled.mangled name_string mangled in
           Sil.mk_pvar mangled_name procname
-    | None -> Sil.mk_pvar simple_name procname
+    | None -> Sil.mk_pvar (Mangled.from_string name_string) procname
 
   let is_cpp_translation language =
     language = CFrontend_config.CPP || language = CFrontend_config.OBJCPP

infer/src/clang/cFrontend_utils.mli

@@ -179,6 +179,8 @@ sig
 
   val mk_class_field_name : Clang_ast_t.named_decl_info -> Ident.fieldname
 
+  val get_var_name_string : Clang_ast_t.named_decl_info -> Clang_ast_t.var_decl_info -> string
+
   val mk_sil_var : Clang_ast_t.named_decl_info -> var_info option -> Procname.t -> Procname.t ->
     Sil.pvar
 

infer/src/clang/cMethod_trans.ml

@@ -103,7 +103,7 @@ let get_parameters tenv function_method_decl_info =
   let par_to_ms_par par =
     match par with
     | Clang_ast_t.ParmVarDecl (decl_info, name_info, type_ptr, var_decl_info) ->
-        let name = name_info.Clang_ast_t.ni_name in
+        let name = General_utils.get_var_name_string name_info var_decl_info in
         (name, type_ptr)
     | _ -> assert false in
   let pars = IList.map par_to_ms_par (get_param_decls function_method_decl_info) in

infer/tests/codetoanalyze/cpp/frontend/methods/return_struct.cpp.dot

@@ -32,7 +32,7 @@ digraph iCFG {
 4 [label="4: Exit X_X \n  " color=yellow style=filled]
 	
 
-3 [label="3: Start X_X\nFormals:  this:class X * :void \nLocals:  \n   DECLARE_LOCALS(&return); [line 10]\n  NULLIFY(&,false); [line 10]\n  NULLIFY(&this,false); [line 10]\n " color=yellow style=filled]
+3 [label="3: Start X_X\nFormals:  this:class X * __param_0:void \nLocals:  \n   DECLARE_LOCALS(&return); [line 10]\n  NULLIFY(&__param_0,false); [line 10]\n  NULLIFY(&this,false); [line 10]\n " color=yellow style=filled]
 	
 
 	 3 -> 4 ;

infer/tests/codetoanalyze/cpp/frontend/types/functions.cpp

@@ -17,6 +17,10 @@ int fun_default_decl(int a, int b) {
   return a + b;
 }
 
+int fun_ignore_param(int a, int, int) {
+  return a;
+}
+
 void test() {
   fun_default(1, 2);
   fun_default(1);
@@ -25,3 +29,7 @@ void test() {
   fun_default_decl(6);
   fun_default_decl(6,6);
 }
+
+void test2() {
+  fun_ignore_param(1, 1, 1);
+}

infer/tests/codetoanalyze/cpp/frontend/types/functions.cpp.dot

@@ -1,31 +1,53 @@
 digraph iCFG {
-13 [label="13:  Call _fun_fun_default \n   n$4=_fun_fun_default(1:int ,2:int ) [line 21]\n  REMOVE_TEMPS(n$4); [line 21]\n " shape="box"]
+19 [label="19:  Call _fun_fun_ignore_param \n   n$0=_fun_fun_ignore_param(1:int ,1:int ,1:int ) [line 34]\n  REMOVE_TEMPS(n$0); [line 34]\n  APPLY_ABSTRACTION; [line 34]\n " shape="box"]
+	
+
+	 19 -> 18 ;
+18 [label="18: Exit test2 \n  " color=yellow style=filled]
+	
+
+17 [label="17: Start test2\nFormals: \nLocals:  \n   DECLARE_LOCALS(&return); [line 33]\n " color=yellow style=filled]
+	
+
+	 17 -> 19 ;
+16 [label="16:  Call _fun_fun_default \n   n$4=_fun_fun_default(1:int ,2:int ) [line 25]\n  REMOVE_TEMPS(n$4); [line 25]\n " shape="box"]
+	
+
+	 16 -> 15 ;
+15 [label="15:  Call _fun_fun_default \n   n$3=_fun_fun_default(1:int ,5:int ) [line 26]\n  REMOVE_TEMPS(n$3); [line 26]\n " shape="box"]
+	
+
+	 15 -> 14 ;
+14 [label="14:  Call _fun_fun_default \n   n$2=_fun_fun_default(3:int ,5:int ) [line 27]\n  REMOVE_TEMPS(n$2); [line 27]\n " shape="box"]
+	
+
+	 14 -> 13 ;
+13 [label="13:  Call _fun_fun_default_decl \n   n$1=_fun_fun_default_decl(6:int ,5:int ) [line 29]\n  REMOVE_TEMPS(n$1); [line 29]\n " shape="box"]
 	
 
 	 13 -> 12 ;
-12 [label="12:  Call _fun_fun_default \n   n$3=_fun_fun_default(1:int ,5:int ) [line 22]\n  REMOVE_TEMPS(n$3); [line 22]\n " shape="box"]
+12 [label="12:  Call _fun_fun_default_decl \n   n$0=_fun_fun_default_decl(6:int ,6:int ) [line 30]\n  REMOVE_TEMPS(n$0); [line 30]\n  APPLY_ABSTRACTION; [line 30]\n " shape="box"]
 	
 
 	 12 -> 11 ;
-11 [label="11:  Call _fun_fun_default \n   n$2=_fun_fun_default(3:int ,5:int ) [line 23]\n  REMOVE_TEMPS(n$2); [line 23]\n " shape="box"]
+11 [label="11: Exit test \n  " color=yellow style=filled]
 	
 
-	 11 -> 10 ;
+10 [label="10: Start test\nFormals: \nLocals:  \n   DECLARE_LOCALS(&return); [line 24]\n " color=yellow style=filled]
-10 [label="10:  Call _fun_fun_default_decl \n   n$1=_fun_fun_default_decl(6:int ,5:int ) [line 25]\n  REMOVE_TEMPS(n$1); [line 25]\n " shape="box"]
 	
 
-	 10 -> 9 ;
+	 10 -> 16 ;
-9 [label="9:  Call _fun_fun_default_decl \n   n$0=_fun_fun_default_decl(6:int ,6:int ) [line 26]\n  REMOVE_TEMPS(n$0); [line 26]\n  APPLY_ABSTRACTION; [line 26]\n " shape="box"]
+9 [label="9:  Return Stmt \n   n$0=*&a:int  [line 21]\n  *&return:int =n$0 [line 21]\n  REMOVE_TEMPS(n$0); [line 21]\n  NULLIFY(&a,false); [line 21]\n  APPLY_ABSTRACTION; [line 21]\n " shape="box"]
 	
 
 	 9 -> 8 ;
-8 [label="8: Exit test \n  " color=yellow style=filled]
+8 [label="8: Exit fun_ignore_param \n  " color=yellow style=filled]
 	
 
-7 [label="7: Start test\nFormals: \nLocals:  \n   DECLARE_LOCALS(&return); [line 20]\n " color=yellow style=filled]
+7 [label="7: Start fun_ignore_param\nFormals:  a:int  __param_1:int  __param_2:int \nLocals:  \n   DECLARE_LOCALS(&return); [line 20]\n  NULLIFY(&__param_1,false); [line 20]\n  NULLIFY(&__param_2,false); [line 20]\n " color=yellow style=filled]
 	
 
-	 7 -> 13 ;
+	 7 -> 9 ;
 6 [label="6:  Return Stmt \n   n$0=*&a:int  [line 17]\n  n$1=*&b:int  [line 17]\n  *&return:int =(n$0 + n$1) [line 17]\n  REMOVE_TEMPS(n$0,n$1); [line 17]\n  NULLIFY(&a,false); [line 17]\n  NULLIFY(&b,false); [line 17]\n  APPLY_ABSTRACTION; [line 17]\n " shape="box"]