[DB] Alawys use DB.source_file_to_abs_path to do actual filesystem operations

Summary:
Using DB.source_file_to_string may return relative path which may or may not be relative to current location.
I went through all calls to `DB.source_file_to_string` and fixed ones that used that output to open files

Reviewed By: jeremydubreil

Differential Revision: D4205407

fbshipit-source-id: b285b7e

infer/src/backend/inferconfig.ml

@@ -85,7 +85,7 @@ module FileContainsStringMatcher = struct
           DB.SourceFileMap.find source_file !source_map
         with Not_found ->
         try
-          let file_in = open_in (DB.source_file_to_string source_file) in
+          let file_in = open_in (DB.source_file_to_abs_path source_file) in
           let pattern_found = file_contains regexp file_in in
           close_in file_in;
           source_map := DB.SourceFileMap.add source_file pattern_found !source_map;

infer/src/backend/printer.ml

@@ -48,7 +48,7 @@ struct
       Some (Hashtbl.find hash fname)
     with Not_found ->
     try
-      let lines_arr = read_file (DB.source_file_to_string fname) in
+      let lines_arr = read_file (DB.source_file_to_abs_path fname) in
       Hashtbl.add hash fname lines_arr;
       Some lines_arr
     with exn when SymOp.exn_not_failure exn -> None

infer/src/harness/inhabit.ml

@@ -217,7 +217,7 @@ let create_dummy_harness_file harness_name =
 (* TODO (t3040429): fill this file up with Java-like code that matches the SIL *)
 let write_harness_to_file harness_instrs harness_file =
   let harness_file =
-    let harness_file_name = DB.source_file_to_string harness_file in
+    let harness_file_name = DB.source_file_to_abs_path harness_file in
     create_outfile harness_file_name in
   let pp_harness fmt = IList.iter (fun instr ->
       Format.fprintf fmt "%a\n" (Sil.pp_instr pe_text) instr) harness_instrs in

infer/src/java/jClasspath.ml

@@ -103,7 +103,7 @@ type file_entry =
 (* Open the source file and search for the package declaration.
    Only the case where the package is declared in a single line is supported *)
 let read_package_declaration source_file =
-  let path = DB.source_file_to_string source_file in
+  let path = DB.source_file_to_abs_path source_file in
   let file_in = open_in path in
   let remove_trailing_semicolon =
     Str.replace_first (Str.regexp ";") "" in