Rework extension handling logic

We no longer support hxx{vector.}. Rather, the target type can decide,
e.g., based on a config variable, whether to append an extension. Also,
in the future we may support a syntax to specify that this is a complete
name, e.g., hxx{'vector'}.

7 files changed, 55 insertions, 64 deletions

diff --git a/build/cxx/rule.cxx b/build/cxx/rule.cxx
index 8d2c0b2..26ad213 100644
--- a/build/cxx/rule.cxx
+++ b/build/cxx/rule.cxx
@@ -208,6 +208,10 @@ namespace build
             // extension. Here we can assume the name part is a valid
             // filesystem name.
             //
+            // Note that if the file has no extension, we record an empty
+            // extension rather than NULL (which would signify that the
+            // extension needs to be added).
+            //
             path d (file.directory ());
             string n (file.leaf ().base ().string ());
             const char* es (file.extension ());
diff --git a/build/parser.cxx b/build/parser.cxx
index 1cb0684..d1f3d8a 100644
--- a/build/parser.cxx
+++ b/build/parser.cxx
@@ -242,12 +242,12 @@ namespace build
 
               // Extract extension.
               //
-              string::size_type j (n.rfind ('.'));
+              string::size_type j (path::traits::find_extension (n));
 
               if (j != string::npos)
               {
-                e = &extension_pool.find (n.c_str () + j + 1);
-                n.resize (j);
+                e = &extension_pool.find (n.c_str () + j);
+                n.resize (j - 1);
               }
             }
 
@@ -318,12 +318,12 @@ namespace build
 
               // Extract extension.
               //
-              string::size_type j (n.rfind ('.'));
+              string::size_type j (path::traits::find_extension (n));
 
               if (j != string::npos)
               {
-                e = &extension_pool.find (n.c_str () + j + 1);
-                n.resize (j);
+                e = &extension_pool.find (n.c_str () + j);
+                n.resize (j - 1);
               }
             }
 
diff --git a/build/path b/build/path
index 8eb560b..9b3668d 100644
--- a/build/path
+++ b/build/path
@@ -74,6 +74,33 @@ namespace build
       return string_type::npos;
     }
 
+    static size_type
+    find_extension (string_type const& s)
+    {
+      size_type i (s.size ());
+
+      for (; i > 0; --i)
+      {
+        C c (s[i - 1]);
+
+        if (c == '.')
+          break;
+
+        if (is_separator (c))
+        {
+          i = 0;
+          break;
+        }
+      }
+
+      // Weed out paths like ".txt" (and "/.txt") and "txt.".
+      //
+      if (i > 1 && !is_separator (s[i - 2]) && i != s.size ())
+        return i - 1;
+      else
+        return string_type::npos;
+    }
+
     static int
     compare (string_type const& l, string_type const& r)
     {
diff --git a/build/path.ixx b/build/path.ixx
index f742060..60d3bc3 100644
--- a/build/path.ixx
+++ b/build/path.ixx
@@ -57,6 +57,22 @@ namespace build
     return *this;
   }
 
+  template <typename C>
+  inline basic_path<C> basic_path<C>::
+  base () const
+  {
+    size_type p (traits::find_extension (path_));
+    return p != string_type::npos ? basic_path (path_.c_str (), p) : *this;
+  }
+
+  template <typename C>
+  inline const C* basic_path<C>::
+  extension () const
+  {
+    size_type p (traits::find_extension (path_));
+    return p != string_type::npos ? path_.c_str () + p + 1 : nullptr;
+  }
+
 #ifndef _WIN32
   template <typename C>
   inline typename basic_path<C>::string_type basic_path<C>::
diff --git a/build/path.txx b/build/path.txx
index f576870..881dc17 100644
--- a/build/path.txx
+++ b/build/path.txx
@@ -34,62 +34,6 @@ namespace build
       : basic_path ();
   }
 
-  template <typename C>
-  basic_path<C> basic_path<C>::
-  base () const
-  {
-    size_type i (path_.size ());
-
-    for (; i > 0; --i)
-    {
-      if (path_[i - 1] == '.')
-        break;
-
-      if (traits::is_separator (path_[i - 1]))
-      {
-        i = 0;
-        break;
-      }
-    }
-
-    // Weed out paths like ".txt" and "/.txt"
-    //
-    if (i > 1 && !traits::is_separator (path_[i - 2]))
-    {
-      return basic_path (path_.c_str (), i - 1);
-    }
-    else
-      return *this;
-  }
-
-  template <typename C>
-  const C* basic_path<C>::
-  extension () const
-  {
-    size_type i (path_.size ());
-
-    for (; i > 0; --i)
-    {
-      if (path_[i - 1] == '.')
-        break;
-
-      if (traits::is_separator (path_[i - 1]))
-      {
-        i = 0;
-        break;
-      }
-    }
-
-    // Weed out paths like ".txt" and "/.txt"
-    //
-    if (i > 1 && !traits::is_separator (path_[i - 2]))
-    {
-      return path_.c_str () + i;
-    }
-    else
-      return nullptr;
-  }
-
 #ifdef _WIN32
   template <typename C>
   typename basic_path<C>::string_type basic_path<C>::
diff --git a/build/prerequisite.cxx b/build/prerequisite.cxx
index 8d86392..71bde5f 100644
--- a/build/prerequisite.cxx
+++ b/build/prerequisite.cxx
@@ -46,7 +46,7 @@ namespace build
 
       os << p.name;
 
-      if (p.ext != nullptr)
+      if (p.ext != nullptr && !p.ext->empty ())
         os << '.' << *p.ext;
 
       os << '}';
diff --git a/build/target.cxx b/build/target.cxx
index 31a7f59..7a40c61 100644
--- a/build/target.cxx
+++ b/build/target.cxx
@@ -38,7 +38,7 @@ namespace build
 
     os << t.name;
 
-    if (t.ext != nullptr)
+    if (t.ext != nullptr && !t.ext->empty ())
       os << '.' << *t.ext;
 
     os << '}';