Enforce config directives only appearing in project's root.build

3 files changed, 54 insertions, 39 deletions

diff --git a/libbuild2/file.cxx b/libbuild2/file.cxx
index fb5b68a..7fd3f78 100644
--- a/libbuild2/file.cxx
+++ b/libbuild2/file.cxx
@@ -159,8 +159,10 @@ namespace build2
     }
   }
 
+  using stage = parser::stage;
+
   static void
-  source (scope& root, scope& base, lexer& l, bool boot)
+  source (scope& root, scope& base, lexer& l, stage s)
   {
     tracer trace ("source");
 
@@ -170,7 +172,7 @@ namespace build2
     {
       l5 ([&]{trace << "sourcing " << fn;});
 
-      parser p (root.ctx, boot);
+      parser p (root.ctx, s);
       p.parse_buildfile (l, root, base);
     }
     catch (const io_error& e)
@@ -179,25 +181,25 @@ namespace build2
     }
   }
 
-  static void
+  static inline void
   source (scope& root,
           scope& base,
           istream& is,
           const path_name& in,
-          bool boot)
+          stage s)
   {
     lexer l (is, in);
-    source (root, base, l, boot);
+    source (root, base, l, s);
   }
 
   static void
-  source (scope& root, scope& base, const path& bf, bool boot)
+  source (scope& root, scope& base, const path& bf, stage s)
   {
     path_name fn (bf);
     try
     {
       ifdstream ifs;
-      return source (root, base, open_file_or_stdin (fn, ifs), fn, boot);
+      return source (root, base, open_file_or_stdin (fn, ifs), fn, s);
     }
     catch (const io_error& e)
     {
@@ -205,37 +207,43 @@ namespace build2
     }
   }
 
+  static bool
+  source_once (scope& root, scope& base, const path& bf, scope& once, stage s)
+  {
+    tracer trace ("source_once");
+
+    if (!once.buildfiles.insert (bf).second)
+    {
+      l5 ([&]{trace << "skipping already sourced " << bf;});
+      return false;
+    }
+
+    source (root, base, bf, s);
+    return true;
+  }
+
   void
   source (scope& root, scope& base, const path& bf)
   {
-    source (root, base, bf, false);
+    source (root, base, bf, stage::rest);
   }
 
   void
   source (scope& root, scope& base, istream& is, const path_name& in)
   {
-    source (root, base, is, in, false /* boot */);
+    source (root, base, is, in, stage::rest);
   }
 
   void
   source (scope& root, scope& base, lexer& l)
   {
-    source (root, base, l, false);
+    source (root, base, l, stage::rest);
   }
 
   bool
   source_once (scope& root, scope& base, const path& bf, scope& once)
   {
-    tracer trace ("source_once");
-
-    if (!once.buildfiles.insert (bf).second)
-    {
-      l5 ([&]{trace << "skipping already sourced " << bf;});
-      return false;
-    }
-
-    source (root, base, bf, false);
-    return true;
+    return source_once (root, base, bf, once, stage::rest);
   }
 
   // Source (once) pre-*.build (pre is true) or post-*.build (otherwise) hooks
@@ -243,7 +251,7 @@ namespace build2
   // must exist.
   //
   static void
-  source_hooks (scope& root, const dir_path& d, bool pre)
+  source_hooks (scope& root, const dir_path& d, stage s, 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
@@ -278,7 +286,7 @@ namespace build2
           fail << "unable to read buildfile " << f << ": " << e;
         }
 
-        source_once (root, root, f);
+        source_once (root, root, f, root, s);
       }
     }
     catch (const system_error& e)
@@ -799,7 +807,7 @@ namespace build2
         // root scope multiple time.
         //
         if (rs.buildfiles.insert (f).second)
-          source (rs, rs, f, true /* boot */);
+          source (rs, rs, f, stage::boot);
         else
           l5 ([&]{trace << "skipping already sourced " << f;});
 
@@ -1030,7 +1038,7 @@ namespace build2
       if (root.root_extra == nullptr)
         setup_root_extra (root, altn);
 
-      source_hooks (root, d, true /* pre */);
+      source_hooks (root, d, stage::boot, true /* pre */);
     }
   }
 
@@ -1042,7 +1050,7 @@ namespace build2
     dir_path d (out_root / root.root_extra->bootstrap_dir);
 
     if (exists (d))
-      source_hooks (root, d, false /* pre */);
+      source_hooks (root, d, stage::boot, false /* pre */);
   }
 
   bool
@@ -1268,9 +1276,9 @@ namespace build2
     dir_path hd (out_root / root.root_extra->root_dir);
     bool he (exists (hd));
 
-    if (he)         source_hooks (root, hd, true /* pre */);
-    if (exists (f)) source_once  (root, root, f);
-    if (he)         source_hooks (root, hd, false /* pre */);
+    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 */);
   }
 
   scope&
diff --git a/libbuild2/parser.cxx b/libbuild2/parser.cxx
index f20a4c4..fbf3bda 100644
--- a/libbuild2/parser.cxx
+++ b/libbuild2/parser.cxx
@@ -1655,12 +1655,13 @@ namespace build2
     // config [<var-attrs>] <var>[?=[<val-attrs>]<default-val>]
     //
 
-    // @@ TODO: enforce appears in root.build
+    // Make sure only appears in root.build.
     //
-    if (root_ != scope_)
-      fail (t) << "configuration variable in non-root scope";
+    if (stage_ != stage::root)
+      fail (t) << "configuration variable outside of project's "
+               << root_->root_extra->root_file;
 
-    // We enforce the config.<project> prefix.
+    // Enforce the config.<project> prefix.
     //
     // Note that this could be a subproject and it could be unnamed (e.g., the
     // tests subproject). The current thinking is to use hierarchical names
@@ -1982,7 +1983,7 @@ namespace build2
 
     bool optional (t.value.back () == '?');
 
-    if (optional && boot_)
+    if (optional && stage_ == stage::boot)
       fail (t) << "optional module in bootstrap";
 
     // The rest should be a list of module names. Parse them as names in the
@@ -2035,7 +2036,7 @@ namespace build2
       {
         assert (v.empty ()); // Module versioning not yet implemented.
 
-        if (boot_)
+        if (stage_ == stage::boot)
           boot_module (*root_, n, l);
         else
           init_module (*root_, *scope_, n, l, optional);
diff --git a/libbuild2/parser.hxx b/libbuild2/parser.hxx
index dd5cbda..ba707da 100644
--- a/libbuild2/parser.hxx
+++ b/libbuild2/parser.hxx
@@ -23,12 +23,18 @@ namespace build2
   class LIBBUILD2_SYMEXPORT parser
   {
   public:
-    // If boot is true, then we are parsing bootstrap.build and modules
-    // should only be bootstrapped.
+    // The project's loading stage during which the parsing is performed.
     //
+    enum class stage
+    {
+      boot,  // Parsing bootstrap.build (or bootstrap pre/post hooks).
+      root,  // Parsing root.build (or root pre/post hooks).
+      rest   // Parsing the rest (ordinary buildfiles, command line, etc).
+    };
+
     explicit
-    parser (context& c, bool boot = false)
-      : fail ("error", &path_), ctx (c), boot_ (boot) {}
+    parser (context& c, stage s = stage::rest)
+      : fail ("error", &path_), ctx (c), stage_ (s) {}
 
     // Issue diagnostics and throw failed in case of an error.
     //
@@ -699,9 +705,9 @@ namespace build2
 
   protected:
     context& ctx;
+    stage stage_;
 
     bool pre_parse_ = false;
-    bool boot_;
 
     const path_name* path_; // Current path name.
     lexer*           lexer_;