Implement tracing support

Also use to-relative path translation in diagnostics.

1 files changed, 19 insertions, 0 deletions

diff --git a/build/path b/build/path
index ccc1b85..92832a1 100644
--- a/build/path
+++ b/build/path
@@ -218,6 +218,16 @@ namespace build
     bool
     root () const;
 
+    // Return true if *this is a sub-path of the specified path (i.e.,
+    // the specified path is a prefix). Expects both paths to be
+    // normalized.
+    //
+    bool
+    sub (const basic_path& p) const
+    {
+      return path_.compare (0, p.path_.size (), p.path_) == 0;
+    }
+
   public:
     // Return the path without the directory part.
     //
@@ -249,6 +259,13 @@ namespace build
     basic_path
     base () const;
 
+    // Return a path relative to the specified path that is equivalent
+    // to *this. Throws invalid_path if a relative path cannot be derived
+    // (e.g., paths are on different drives on Windows).
+    //
+    basic_path
+    relative (basic_path) const;
+
   public:
     // Normalize the path. This includes collapsing the '.' and '..'
     // directories if possible, collapsing multiple directory
@@ -334,12 +351,14 @@ namespace build
     string_type path_;
   };
 
+  /*
   template <typename C>
   inline std::basic_ostream<C>&
   operator<< (std::basic_ostream<C>& os, basic_path<C> const& p)
   {
     return os << p.string ();
   }
+  */
 }
 
 #include <build/path.ixx>