[C++] Make QualifiedCppName.t reversed list

Summary: This representation is more natural and results in less `List.rev` calls.

Reviewed By: jberdine

Differential Revision: D4762629

fbshipit-source-id: 481cbe4

infer/src/IR/QualifiedCppName.re

@@ -8,30 +8,42 @@
  */
 open! IStd;
 
+/* internally it uses reversed list to store qualified name, for example: ["get", "shared_ptr<int>", "std"]*/
 type t = list string [@@deriving compare];
 
 let equal = [%compare.equal : t];
 
 let empty = [];
 
-let append_qualifier quals qual::qual => List.append quals [qual];
+let append_qualifier quals qual::qual => List.cons qual quals;
 
-let to_list quals => quals;
+let extract_last =
+  fun
+  | [last, ...rest] => Some (last, rest)
+  | [] => None;
 
-let of_list quals => quals;
+let to_list = List.rev;
+
+let to_rev_list = ident;
+
+let of_list = List.rev;
+
+let of_rev_list = ident;
 
 let cpp_separator = "::";
 
 /* This is simplistic and will give the wrong answer in some cases, eg
    "foo<bar::baz<goo>>::someMethod" will get parsed as ["foo<bar", "baz<goo>>",
    "someMethod"]. Avoid using it if possible */
-let of_qual_string = {
+let of_qual_string str => {
   let class_sep_regex = Str.regexp_string cpp_separator;
   /* wait until here to define the function so that [class_sep_regex] is only computed once */
-  Str.split class_sep_regex
+  Str.split class_sep_regex str |> List.rev
 };
 
-let to_qual_string = String.concat sep::cpp_separator;
+let to_separated_string quals sep::sep => List.rev quals |> String.concat sep::sep;
+
+let to_qual_string = to_separated_string sep::cpp_separator;
 
 let pp fmt quals => Format.fprintf fmt "%s" (to_qual_string quals);
 
@@ -39,7 +51,7 @@ let module Match = {
   type quals_matcher = Str.regexp;
   let matching_separator = "#";
   let regexp_string_of_qualifiers quals =>
-    Str.quote (String.concat sep::matching_separator quals) ^ "$";
+    Str.quote (to_separated_string sep::matching_separator quals) ^ "$";
   let qualifiers_list_matcher quals_list =>
     (
       if (List.is_empty quals_list) {
@@ -66,6 +78,6 @@ let module Match = {
       let no_template_name s => List.hd_exn (String.split on::'<' s);
       List.map f::no_template_name quals
     };
-    Str.string_match matcher (String.concat sep::matching_separator normalized_qualifiers) 0
+    Str.string_match matcher (to_separated_string sep::matching_separator normalized_qualifiers) 0
   };
 };

infer/src/IR/QualifiedCppName.rei

@@ -29,13 +29,25 @@ let to_qual_string: t => string;
 let append_qualifier: t => qual::string => t;
 
 
+/** returns last (innermost scope) qualifier and qualified name without last qualifier */
+let extract_last: t => option (string, t);
+
+
 /** returns list of qualifers */
 let to_list: t => list string;
 
 
+/** returns reversed list of qualifiers, ie innermost scope is the first element */
+let to_rev_list: t => list string;
+
+
 /** given list of qualifiers in normal order produce qualified name ["std", "move"] */
 let of_list: list string => t;
 
+
+/** given reversed list of qualifiers, produce qualified name (ie. ["move", "std"] for std::move )*/
+let of_rev_list: list string => t;
+
 let pp: Format.formatter => t => unit;
 
 /* Module to match qualified C++ procnames "fuzzily", that is up to namescapes and templating. In

infer/src/IR/Typ.re

@@ -911,7 +911,7 @@ let module Procname = {
   let to_filename pname => {
     /* filenames for clang procs are REVERSED qualifiers with '#' as separator */
     let get_qual_name_str pname =>
-      get_qualifiers pname |> QualifiedCppName.to_list |> List.rev |> String.concat sep::"#";
+      get_qualifiers pname |> QualifiedCppName.to_rev_list |> String.concat sep::"#";
     let proc_id =
       switch pname {
       | C {mangled} =>

infer/src/clang/cAst_utils.ml

@@ -19,7 +19,7 @@ type type_ptr_to_sil_type = Tenv.t -> Clang_ast_t.type_ptr -> Typ.t
 
 let sanitize_name = Str.global_replace (Str.regexp "[/ ]") "_"
 let get_qual_name qual_name_list =
-  List.rev_map ~f:sanitize_name qual_name_list |> QualifiedCppName.of_list
+  List.map ~f:sanitize_name qual_name_list |> QualifiedCppName.of_rev_list
 
 let get_qualified_name name_info =
   get_qual_name name_info.Clang_ast_t.ni_qual_name

infer/src/clang/cFrontend_decl.ml

@@ -139,16 +139,14 @@ struct
       QualifiedCppName.Match.of_fuzzy_qual_names Config.whitelisted_cpp_methods in
     let class_matcher =
       QualifiedCppName.Match.of_fuzzy_qual_names Config.whitelisted_cpp_classes in
-    fun qual_method_rev ->
+    fun qual_name ->
       (* either the method is explictely whitelisted, or the whole class is whitelisted *)
-      QualifiedCppName.Match.match_qualifiers method_matcher
-        (List.rev qual_method_rev |> QualifiedCppName.of_list) ||
-      match qual_method_rev with
-      | _::(_::_ as class_name_rev) ->
+      QualifiedCppName.Match.match_qualifiers method_matcher qual_name ||
+      match QualifiedCppName.extract_last qual_name with
+      | Some (_, class_qual_name) ->
           (* make sure the class name is not empty; in particular, it cannot be a C function *)
-          QualifiedCppName.Match.match_qualifiers class_matcher
-            (List.rev class_name_rev |> QualifiedCppName.of_list)
-      | _ ->
+          QualifiedCppName.Match.match_qualifiers class_matcher class_qual_name
+      | None ->
           false
 
   let should_translate_decl trans_unit_ctx dec decl_trans_context =
@@ -157,7 +155,7 @@ struct
     let translate_when_used = match dec with
       | Clang_ast_t.FunctionDecl (_, name_info, _, _)
       | Clang_ast_t.CXXMethodDecl (_, name_info, _, _, _) ->
-          is_whitelisted_cpp_method name_info.Clang_ast_t.ni_qual_name
+          is_whitelisted_cpp_method (CAst_utils.get_qualified_name name_info)
       | _ -> false in
     let translate_location =
       CLocation.should_translate_lib trans_unit_ctx source_range decl_trans_context