Share parser for loading root.build and pre/post hooks

1 files changed, 43 insertions, 25 deletions

diff --git a/libbuild2/file.cxx b/libbuild2/file.cxx
index 7fd3f78..613f095 100644
--- a/libbuild2/file.cxx
+++ b/libbuild2/file.cxx
@@ -159,10 +159,8 @@ namespace build2
     }
   }
 
-  using stage = parser::stage;
-
   static void
-  source (scope& root, scope& base, lexer& l, stage s)
+  source (parser& p, scope& root, scope& base, lexer& l)
   {
     tracer trace ("source");
 
@@ -171,8 +169,6 @@ namespace build2
     try
     {
       l5 ([&]{trace << "sourcing " << fn;});
-
-      parser p (root.ctx, s);
       p.parse_buildfile (l, root, base);
     }
     catch (const io_error& e)
@@ -182,24 +178,24 @@ namespace build2
   }
 
   static inline void
-  source (scope& root,
+  source (parser& p,
+          scope& root,
           scope& base,
           istream& is,
-          const path_name& in,
-          stage s)
+          const path_name& in)
   {
     lexer l (is, in);
-    source (root, base, l, s);
+    source (p, root, base, l);
   }
 
   static void
-  source (scope& root, scope& base, const path& bf, stage s)
+  source (parser& p, scope& root, scope& base, const path& bf)
   {
     path_name fn (bf);
     try
     {
       ifdstream ifs;
-      return source (root, base, open_file_or_stdin (fn, ifs), fn, s);
+      return source (p, root, base, open_file_or_stdin (fn, ifs), fn);
     }
     catch (const io_error& e)
     {
@@ -208,7 +204,11 @@ namespace build2
   }
 
   static bool
-  source_once (scope& root, scope& base, const path& bf, scope& once, stage s)
+  source_once (parser& p,
+               scope& root,
+               scope& base,
+               const path& bf,
+               scope& once)
   {
     tracer trace ("source_once");
 
@@ -218,32 +218,36 @@ namespace build2
       return false;
     }
 
-    source (root, base, bf, s);
+    source (p, root, base, bf);
     return true;
   }
 
   void
   source (scope& root, scope& base, const path& bf)
   {
-    source (root, base, bf, stage::rest);
+    parser p (root.ctx);
+    source (p, root, base, bf);
   }
 
   void
   source (scope& root, scope& base, istream& is, const path_name& in)
   {
-    source (root, base, is, in, stage::rest);
+    parser p (root.ctx);
+    source (p, root, base, is, in);
   }
 
   void
   source (scope& root, scope& base, lexer& l)
   {
-    source (root, base, l, stage::rest);
+    parser p (root.ctx);
+    source (p, root, base, l);
   }
 
   bool
   source_once (scope& root, scope& base, const path& bf, scope& once)
   {
-    return source_once (root, base, bf, once, stage::rest);
+    parser p (root.ctx);
+    return source_once (p, root, base, bf, once);
   }
 
   // Source (once) pre-*.build (pre is true) or post-*.build (otherwise) hooks
@@ -251,7 +255,7 @@ namespace build2
   // must exist.
   //
   static void
-  source_hooks (scope& root, const dir_path& d, stage s, bool pre)
+  source_hooks (parser& p, scope& root, const dir_path& d, bool pre)
   {
     // While we could have used the wildcard pattern matching functionality,
     // our needs are pretty basic and performance is quite important, so let's
@@ -286,7 +290,7 @@ namespace build2
           fail << "unable to read buildfile " << f << ": " << e;
         }
 
-        source_once (root, root, f, root, s);
+        source_once (p, root, root, f, root);
       }
     }
     catch (const system_error& e)
@@ -807,7 +811,10 @@ namespace build2
         // root scope multiple time.
         //
         if (rs.buildfiles.insert (f).second)
-          source (rs, rs, f, stage::boot);
+        {
+          parser p (rs.ctx, parser::stage::boot);
+          source (p, rs, rs, f);
+        }
         else
           l5 ([&]{trace << "skipping already sourced " << f;});
 
@@ -1038,7 +1045,8 @@ namespace build2
       if (root.root_extra == nullptr)
         setup_root_extra (root, altn);
 
-      source_hooks (root, d, stage::boot, true /* pre */);
+      parser p (root.ctx, parser::stage::boot);
+      source_hooks (p, root, d, true /* pre */);
     }
   }
 
@@ -1050,7 +1058,10 @@ namespace build2
     dir_path d (out_root / root.root_extra->bootstrap_dir);
 
     if (exists (d))
-      source_hooks (root, d, stage::boot, false /* pre */);
+    {
+      parser p (root.ctx, parser::stage::boot);
+      source_hooks (p, root, d, false /* pre */);
+    }
   }
 
   bool
@@ -1274,11 +1285,18 @@ namespace build2
     // with a post-bootstrap hook.
     //
     dir_path hd (out_root / root.root_extra->root_dir);
+
     bool he (exists (hd));
+    bool fe (exists (f));
+
+
+    // Reuse the parser to accumulate the configuration variable information.
+    //
+    parser p (root.ctx, parser::stage::root);
 
-    if (he)         source_hooks (root, hd, stage::root, true  /* pre */);
-    if (exists (f)) source_once  (root, root, f, root, stage::root);
-    if (he)         source_hooks (root, hd, stage::root, false /* pre */);
+    if (he) {source_hooks (p, root, hd, true  /* pre */); p.reset ();}
+    if (fe) {source_once (p, root, root, f, root);}
+    if (he) {p.reset (); source_hooks (p, root, hd, false /* pre */);}
   }
 
   scope&