Make all internal pointers convertible to ints

Summary:
public Prepare to use integers as pointers (as opposed to strings right now).
This should speed decl/type map lookup and there are no real downsides.

In order to preserve all knowledge we have right now, use following semantics for pointer values
clang pointer - its value is greater than 0
invalid pointer - its value is 0
internal pointer - its value is smaller than 0

Reviewed By: jvillard

Differential Revision: D2739419

fb-gh-sync-id: d264c28

infer/src/clang/ast_expressions.ml

@@ -61,41 +61,41 @@ let stmt_info_with_fresh_pointer stmt_info = {
   si_source_range = stmt_info.Clang_ast_t.si_source_range;
 }
 
-let get_constant_type_ptr s =
-  let pointer = CFrontend_config.type_pointer_prefix ^ s in
+let new_constant_type_ptr () =
+  let pointer = Ast_utils.get_fresh_pointer () in
   `Prebuilt pointer
 
 (* Whenever new type are added manually to the translation here, *)
 (* they should be added to the map in cTypes_decl too!! *)
 let create_int_type =
-  get_constant_type_ptr "int"
+  new_constant_type_ptr ()
 
 let create_void_type =
-  get_constant_type_ptr "void"
+  new_constant_type_ptr ()
 
 let create_void_star_type =
-  get_constant_type_ptr "void *"
+  new_constant_type_ptr ()
 
 let create_id_type =
-  get_constant_type_ptr CFrontend_config.id_cl
+  new_constant_type_ptr ()
 
 let create_nsarray_star_type =
-  get_constant_type_ptr (CFrontend_config.nsarray_cl ^ " *")
+  new_constant_type_ptr ()
 
 let create_char_star_type =
-  get_constant_type_ptr "char *"
+  new_constant_type_ptr ()
 
 let create_BOOL_type =
-  get_constant_type_ptr "signed char"
+  new_constant_type_ptr ()
 
 let create_unsigned_long_type =
-  get_constant_type_ptr "unsigned long"
+  new_constant_type_ptr ()
 
 let create_void_unsigned_long_type =
-  get_constant_type_ptr "void *(unsigned long)"
+  new_constant_type_ptr ()
 
 let create_void_void_type =
-  get_constant_type_ptr "void (void *)"
+  new_constant_type_ptr ()
 
 let create_class_type class_name = `ClassType class_name
 

infer/src/clang/cFrontend_config.ml

@@ -107,7 +107,7 @@ let init = "init"
 
 let temp_var = "infer"
 
-let pointer_prefix = "internal"
+let invalid_pointer = 0
 
 let void = "void"
 
@@ -157,8 +157,6 @@ let sil_types_map = ref Clang_ast_types.TypePointerMap.empty
 (* Map from enum constants pointers to their predecesor and their sil value *)
 let enum_map = ref Clang_ast_main.PointerMap.empty
 
-let type_pointer_prefix = "internal_type"
-
 let nsarray_cl = "NSArray"
 
 let infer = "infer"

infer/src/clang/cFrontend_config.mli

@@ -99,7 +99,7 @@ val init : string
 
 val temp_var : string
 
-val pointer_prefix : string
+val invalid_pointer : int
 
 val void : string
 
@@ -152,8 +152,6 @@ val sil_types_map : (Sil.typ Clang_ast_types.TypePointerMap.t) ref
 (** Map from enum constants pointers to their predecesor and their sil value *)
 val enum_map : (Clang_ast_t.pointer option * Sil.exp option) Clang_ast_main.PointerMap.t ref
 
-val type_pointer_prefix : string
-
 val nsarray_cl : string
 
 val infer : string

infer/src/clang/cFrontend_utils.ml

@@ -267,10 +267,11 @@ struct
 
   let get_fresh_pointer () =
     pointer_counter := !pointer_counter + 1;
-    CFrontend_config.pointer_prefix^(string_of_int (!pointer_counter))
+    let internal_pointer = -(!pointer_counter) in
+    string_of_int internal_pointer
 
   let get_invalid_pointer () =
-    CFrontend_config.pointer_prefix^("INVALID")
+    string_of_int CFrontend_config.invalid_pointer
 
   let type_from_unary_expr_or_type_trait_expr_info info =
     match info.Clang_ast_t.uttei_type_ptr with

infer/src/clang/cVar_decl.ml

@@ -16,7 +16,8 @@ open CFrontend_utils
 module L = Logging
 
 let is_custom_var_pointer pointer =
-  Utils.string_is_prefix CFrontend_config.pointer_prefix pointer
+  let pointer_int = int_of_string pointer in
+  pointer_int <= 0
 
 let is_captured procdesc vname =
   IList.exists