exposes git commit ID in the bap version (#1071)

* adds a build-id oasis variable

* try with `with` param

* play with var

* wip

* don't fail if we are not in a git repo

* edited description

* uses add_variable instead of var_define

* no error message in case is not a git repo

* catch all the exceptions

* search for .git

Author: gitoleg

lib/bap_main/bap_main.ml

@@ -1161,6 +1161,9 @@ let init
       List.partition_map result ~f:(function
           | Ok p -> `Fst p
           | Error (p,e) -> `Snd (p,e)) in
+    let version = match Bap_main_config.build_id with
+      | "" -> version
+      | id -> sprintf "%s+%s" version id in
     if List.is_empty failures
     then match Grammar.eval argv
                  ?name ~version ?env ?help:out

lib/bap_main/bap_main_config.ml.ab

@@ -28,3 +28,4 @@ let suffix_program = "$suffix_program"
 let debug = "$debug"
 let profile = "$profile"
 let standard_library = "$standard_library"
+let build_id = "$build_id"

oasis/main.setup.ml.in

@@ -0,0 +1,14 @@
+
+let () =
+  add_variable "build_id"
+    ~doc:"Adds a build id to bap version"
+    ~define:(function
+        | Some x -> x
+        | None ->
+          try
+            if Sys.file_exists ".git" && Sys.is_directory ".git" then
+              OASISExec.run_read_one_line ~ctxt
+                ~f_exit_code:ignore
+                "git" ["rev-parse"; "--verify"; "--quiet"; "--short=7"; "HEAD"; ]
+            else ""
+          with _ -> "")