[bxl] delete all infer env vars in buck subprocess

Summary: Buck2 sometimes executes actions locally. This means that Infer-set environment variables affect local actions, but not remote ones. In the case of the BXL integration this actually makes Infer capture fail when run locally. This diff explicitly unsets the Infer environment variables inside the buck process.

Reviewed By: martintrojer

Differential Revision: D50850658

fbshipit-source-id: 104efba0391789dda006cc1ee22d7a34b0774896

infer/src/base/CommandLineOption.ml

@@ -19,15 +19,17 @@ let manpage_s_notes = "NOTES"
 
 let is_env_var_set v = Option.value (Option.map (Sys.getenv v) ~f:(String.equal "1")) ~default:false
 
+let infer_cwd_env_var = "INFER_CWD"
+
 (** The working directory of the initial invocation of infer, to which paths passed as command line
     options are relative. *)
 let init_work_dir, is_originator =
-  match Sys.getenv "INFER_CWD" with
+  match Sys.getenv infer_cwd_env_var with
   | Some dir ->
       (dir, false)
   | None ->
       let real_cwd = Utils.realpath (Sys.getcwd ()) in
-      Unix.putenv ~key:"INFER_CWD" ~data:real_cwd ;
+      Unix.putenv ~key:infer_cwd_env_var ~data:real_cwd ;
       (real_cwd, true)
 
 

infer/src/base/CommandLineOption.mli

@@ -214,6 +214,9 @@ val mk_subcommand :
     (otherwise the command is considered internal). [on_unknown_arg] is the action taken on unknown
     anonymous arguments; it is `Reject by default. *)
 
+val infer_cwd_env_var : string
+(** environment variable pointing to the originator's process results directory *)
+
 val args_env_var : string
 (** environment variable use to pass arguments from parent to child processes *)
 

infer/src/integration/Buck.ml

@@ -35,6 +35,10 @@ let store_args_in_file ~identifier args =
   else args
 
 
+let infer_vars_to_kill =
+  CommandLineOption.[infer_cwd_env_var; args_env_var; strict_mode_env_var; inferconfig_path_arg]
+
+
 (** Wrap a call to buck while (i) logging standard error to our standard error in real time; (ii)
     redirecting standard out to a file, the contents of which are returned; (iii) protect the child
     process from [SIGQUIT].
@@ -44,7 +48,7 @@ let store_args_in_file ~identifier args =
     To achieve this we need to do two things: (i) tell the JVM not to use signals, meaning it leaves
     the default handler for [SIGQUIT] in place; (ii) uninstall the default handler for [SIGQUIT]
     because now that the JVM doesn't touch it, it will lead to process death. *)
-let wrap_buck_call ?(extend_env = []) version ~label cmd =
+let wrap_buck_call ?(extend_env = []) ?(kill_infer_env_vars = false) version ~label cmd =
   let is_buck2 = match (version : version) with V1 -> false | V2 -> true in
   let stdout_file =
     let prefix = Printf.sprintf "%s_%s" (if is_buck2 then "buck2" else "buck") label in
@@ -65,8 +69,8 @@ let wrap_buck_call ?(extend_env = []) version ~label cmd =
       (* Uninstall the default handler for [SIGQUIT]. *)
       Printf.sprintf "trap '' SIGQUIT ; %s" cmd_with_output
   in
-  let env =
-    if is_buck2 then `Extend []
+  let env_vars =
+    if is_buck2 then []
     else
       let explicit_buck_java_heap_size =
         Option.map Config.buck_java_heap_size_gb ~f:(fun size -> Printf.sprintf "-Xmx%dG" size)
@@ -82,7 +86,14 @@ let wrap_buck_call ?(extend_env = []) version ~label cmd =
       in
       L.environment_info "Buck: setting %s to '%s'@\n" buck_extra_java_args_env_var
         new_buck_extra_java_args ;
-      `Extend ((buck_extra_java_args_env_var, new_buck_extra_java_args) :: extend_env)
+      (buck_extra_java_args_env_var, new_buck_extra_java_args) :: extend_env
+  in
+  let env =
+    if kill_infer_env_vars then
+      `Override
+        ( List.map infer_vars_to_kill ~f:(fun var -> (var, None))
+        @ List.map env_vars ~f:(fun (lhs, rhs) -> (lhs, Some rhs)) )
+    else `Extend env_vars
   in
   L.debug Capture Quiet "Running buck command '%s'@." command ;
   let Unix.Process_info.{stdin; stdout; stderr; pid} =

infer/src/integration/Buck.mli

@@ -23,7 +23,12 @@ module Target : sig
 end
 
 val wrap_buck_call :
-  ?extend_env:(string * string) list -> version -> label:string -> string list -> string list
+     ?extend_env:(string * string) list
+  -> ?kill_infer_env_vars:bool
+  -> version
+  -> label:string
+  -> string list
+  -> string list
 (** Wrap a call to buck while (i) logging standard error to our standard error in real time; (ii)
     redirecting standard out to a file, the contents of which are returned; (iii) protect the child
     process from [SIGQUIT].
@@ -32,7 +37,8 @@ val wrap_buck_call :
     [(variable, value)] that will extend the environment of the subprocess; [label] is appended to
     [buck_] to make the prefix of the temporary file storing the standard output of the command, for
     quick identification; [cmd] is a list of strings making up the shell command to execute; the
-    return value is the standard output of the command split on newlines. *)
+    return value is the standard output of the command split on newlines. If [kill_infer_env_vars]
+    is true then all Infer environment variables will be unset in the child process.Absint *)
 
 val config : BuckMode.t -> version -> string list
 (** return list of string parameters of the form

infer/src/integration/BxlCapture.ml

@@ -32,7 +32,8 @@ let run_capture buck2_build_cmd =
   L.debug Capture Quiet "Processed buck2 bxl command '%a'@\n" (Pp.seq F.pp_print_string)
     buck2_build_cmd ;
   let infer_deps_lines =
-    Buck.wrap_buck_call ~extend_env:[] V2 ~label:"build" ("buck2" :: buck2_build_cmd)
+    Buck.wrap_buck_call ~extend_env:[] ~kill_infer_env_vars:true V2 ~label:"build"
+      ("buck2" :: buck2_build_cmd)
     |> List.fold ~init:[] ~f:(traverse ~root:Config.buck2_root (Visited.create 11))
     |> List.dedup_and_sort ~compare:String.compare
   in