1 files changed, 82 insertions, 0 deletions
diff --git a/build2/prerequisite.cxx b/build2/prerequisite.cxx
new file mode 100644
index 0000000..6a31071
--- /dev/null
+++ b/build2/prerequisite.cxx
@@ -0,0 +1,82 @@
+// file      : build2/prerequisite.cxx -*- C++ -*-
+// copyright : Copyright (c) 2014-2015 Code Synthesis Ltd
+// license   : MIT; see accompanying LICENSE file
+
+#include <build2/prerequisite>
+
+#include <ostream>
+
+#include <build2/scope>
+#include <build2/target> // target_type
+#include <build2/context>
+#include <build2/diagnostics>
+
+using namespace std;
+
+namespace build2
+{
+  // prerequisite_key
+  //
+  ostream&
+  operator<< (ostream& os, const prerequisite_key& pk)
+  {
+    if (pk.proj != nullptr)
+      os << *pk.proj << '%';
+
+    // Don't print scope if we are project-qualified or the
+    // prerequisite's directory is absolute. In both these
+    // cases the scope is not used to resolve it to target.
+    //
+    else if (!pk.tk.dir->absolute ())
+    {
+      string s (diag_relative (pk.scope->out_path (), false));
+
+      if (!s.empty ())
+        os << s << ':';
+    }
+
+    return os << pk.tk;
+  }
+
+  // prerequisite_set
+  //
+  auto prerequisite_set::
+  insert (const std::string* proj,
+          const target_type& tt,
+          dir_path dir,
+          std::string name,
+          const std::string* ext,
+          scope& s,
+          tracer& trace) -> pair<prerequisite&, bool>
+  {
+    //@@ OPT: would be nice to somehow first check if this prerequisite is
+    //   already in the set before allocating a new instance.
+
+    // Find or insert.
+    //
+    auto r (emplace (proj, tt, move (dir), move (name), ext, s));
+    prerequisite& p (const_cast<prerequisite&> (*r.first));
+
+    // Update extension if the existing prerequisite has it unspecified.
+    //
+    if (p.ext != ext)
+    {
+      level5 ([&]{
+          diag_record r (trace);
+          r << "assuming prerequisite " << p << " is the same as the "
+            << "one with ";
+          if (ext == nullptr)
+            r << "unspecified extension";
+          else if (ext->empty ())
+            r << "no extension";
+          else
+            r << "extension " << *ext;
+        });
+
+      if (ext != nullptr)
+        p.ext = ext;
+    }
+
+    return pair<prerequisite&, bool> (p, r.second);
+  }
+}