[IR] Save defined and declared procedure attributes in different files.

Summary:
Declared and defined procedure attributes are now saved in different files (hashed_name.decl.attr and hashname.attr).
We always try to load using the filename of defined procedure attributes first,
and fall back to loading the file for declared ones if it does not exist.
The logic for replacing an existing file stays the same, with one extra thing:
when a file for a defined attribute is written, the one for the declared one
is deleted if it exists.

At the end of a capture, either a declared or a defined file exist, but not both.
The reason for this change is that when captures of different subprojects are
merged together, it can happen that a link gets created to a declared attributes
file even though a defined one exists, so the body of the procedure will not be analyzed.
After this diff, both links will be created, and the defined one will be loaded
by the back-end.

Reviewed By: dulmarod

Differential Revision: D4037423

fbshipit-source-id: 74fb7e6

infer/src/IR/AttributesTable.re

@@ -16,17 +16,16 @@ let module L = Logging;
 /** Module to manage the table of attributes. */
 let serializer: Serialization.serializer ProcAttributes.t = Serialization.create_serializer Serialization.attributes_key;
 
-let attributes_filename pname => {
-  let pname_file = Procname.to_filename pname;
-  pname_file ^ ".attr"
-};
+let attributes_filename defined::defined pname_file =>
+  pname_file ^ (defined ? ".attr" : ".decl.attr");
 
 
 /** path to the .attr file for the given procedure in the current results directory */
-let res_dir_attr_filename pname => {
-  let attr_fname = attributes_filename pname;
+let res_dir_attr_filename defined::defined pname => {
+  let pname_file = Procname.to_filename pname;
+  let attr_fname = attributes_filename defined::defined pname_file;
   let bucket_dir = {
-    let base = Filename.chop_extension attr_fname;
+    let base = pname_file;
     let len = String.length base;
     if (len < 2) {
       Filename.current_dir_name
@@ -41,12 +40,33 @@ let res_dir_attr_filename pname => {
   filename
 };
 
+/* Load the proc attribute for the defined filename if it exists,
+   otherwise try to load the declared filename. */
+let load_defined_first proc_name => {
+  let attributes_file defined => res_dir_attr_filename defined::defined proc_name;
+  let attr = Serialization.from_file serializer (attributes_file true);
+  attr != None ? attr : Serialization.from_file serializer (attributes_file false)
+};
+
+/* Write a proc attributes to file.
+   If defined, delete the declared file if it exists. */
+let write_and_delete proc_name (proc_attributes: ProcAttributes.t) => {
+  let attributes_file defined => res_dir_attr_filename defined::defined proc_name;
+  Serialization.to_file serializer (attributes_file proc_attributes.is_defined) proc_attributes;
+  if proc_attributes.is_defined {
+    let fname_declared = DB.filename_to_string (attributes_file false);
+    if (Sys.file_exists fname_declared) {
+      try (Unix.unlink fname_declared) {
+      | Unix.Unix_error _ => ()
+      }
+    }
+  }
+};
+
 let store_attributes (proc_attributes: ProcAttributes.t) => {
   let proc_name = proc_attributes.proc_name;
-  let attributes_file = res_dir_attr_filename proc_name;
   let should_write =
-    not (DB.file_exists attributes_file) || (
-      switch (Serialization.from_file serializer attributes_file) {
+    switch (load_defined_first proc_name) {
     | None => true
     | Some proc_attributes_on_disk =>
       let higher_rank_than_on_disk () =>
@@ -56,10 +76,9 @@ let store_attributes (proc_attributes: ProcAttributes.t) => {
       /* Only overwrite the attribute file if the procedure becomes defined
          or its associated file has higher rank (alphabetically) than on disk. */
       becomes_defined || higher_rank_than_on_disk ()
-      }
-    );
+    };
   if should_write {
-    Serialization.to_file serializer attributes_file proc_attributes
+    write_and_delete proc_name proc_attributes
   }
 };
 
@@ -68,12 +87,11 @@ let attr_tbl = Procname.Hash.create 16;
 let load_attributes proc_name =>
   try (Procname.Hash.find attr_tbl proc_name) {
   | Not_found =>
-    let attributes_file = res_dir_attr_filename proc_name;
-    let attr = Serialization.from_file serializer attributes_file;
-    if (attr != None) {
-      Procname.Hash.add attr_tbl proc_name attr
+    let proc_attributes = load_defined_first proc_name;
+    if (proc_attributes != None) {
+      Procname.Hash.add attr_tbl proc_name proc_attributes
     };
-    attr
+    proc_attributes
   };