2 files changed, 55 insertions, 6 deletions

diff --git a/build2/b-options.cxx b/build2/b-options.cxx
index 8933a6a..cf2d9b5 100644
--- a/build2/b-options.cxx
+++ b/build2/b-options.cxx
@@ -217,6 +217,7 @@ namespace build2
     // argv_file_scanner
     //
     int argv_file_scanner::zero_argc_ = 0;
+    std::string argv_file_scanner::empty_string_;
 
     bool argv_file_scanner::
     more ()
@@ -290,7 +291,25 @@ namespace build2
       if (!more ())
         throw eos_reached ();
 
-      return args_.empty () ? base::peek () : args_.front ().c_str ();
+      return args_.empty () ? base::peek () : args_.front ().value.c_str ();
+    }
+
+    const std::string& argv_file_scanner::
+    peek_file ()
+    {
+      if (!more ())
+        throw eos_reached ();
+
+      return args_.empty () ? empty_string_ : *args_.front ().file;
+    }
+
+    std::size_t argv_file_scanner::
+    peek_line ()
+    {
+      if (!more ())
+        throw eos_reached ();
+
+      return args_.empty () ? 0 : args_.front ().line;
     }
 
     const char* argv_file_scanner::
@@ -303,7 +322,7 @@ namespace build2
         return base::next ();
       else
       {
-        hold_[i_ == 0 ? ++i_ : --i_].swap (args_.front ());
+        hold_[i_ == 0 ? ++i_ : --i_].swap (args_.front ().value);
         args_.pop_front ();
         return hold_[i_].c_str ();
       }
@@ -341,7 +360,12 @@ namespace build2
       if (!is.is_open ())
         throw file_io_failure (file);
 
-      while (!is.eof ())
+      files_.push_back (file);
+
+      arg a;
+      a.file = &*files_.rbegin ();
+
+      for (a.line = 1; !is.eof (); ++a.line)
       {
         string line;
         getline (is, line);
@@ -448,10 +472,12 @@ namespace build2
             continue;
           }
 
-          args_.push_back (s1);
+          a.value = s1;
+          args_.push_back (a);
         }
 
-        args_.push_back (s2);
+        a.value = s2;
+        args_.push_back (a);
       }
     }
 
diff --git a/build2/b-options.hxx b/build2/b-options.hxx
index 4b1852b..44777f7 100644
--- a/build2/b-options.hxx
+++ b/build2/b-options.hxx
@@ -12,6 +12,7 @@
 //
 // End prologue.
 
+#include <list>
 #include <deque>
 #include <iosfwd>
 #include <string>
@@ -341,6 +342,19 @@ namespace build2
       virtual void
       skip ();
 
+      // Return the file path if the peeked at argument came from a file and
+      // the empty string otherwise. The reference is guaranteed to be valid
+      // till the end of the scanner lifetime.
+      //
+      const std::string&
+      peek_file ();
+
+      // Return the 1-based line number if the peeked at argument came from
+      // a file and zero otherwise.
+      //
+      std::size_t
+      peek_line ();
+
       private:
       const option_info*
       find (const char*) const;
@@ -355,7 +369,15 @@ namespace build2
       const option_info* options_;
       std::size_t options_count_;
 
-      std::deque<std::string> args_;
+      struct arg
+      {
+        std::string value;
+        const std::string* file;
+        std::size_t line;
+      };
+
+      std::deque<arg> args_;
+      std::list<std::string> files_;
 
       // Circular buffer of two arguments.
       //
@@ -365,6 +387,7 @@ namespace build2
       bool skip_;
 
       static int zero_argc_;
+      static std::string empty_string_;
     };
 
     template <typename X>