Add ability to specify ad hoc recipe actions

We are reusing the buildspec syntax for that.

16 files changed, 284 insertions, 108 deletions

diff --git a/build2/b.cli b/build2/b.cli
index c6a4e3e..355e2d9 100644
--- a/build2/b.cli
+++ b/build2/b.cli
@@ -48,8 +48,9 @@ namespace build2
      omitted, then it defaults to \cb{perform}. If <operation> is omitted,
      then it defaults to the default operation for this meta-operation. For
      \cb{perform} it is \cb{update}. Finally, if <target> is omitted, then it
-     defaults to the current working directory. Some operations and
-     meta-operations may take additional <parameters>. For example:
+     defaults to the current working directory. A meta-operation on operation
+     is called an \i{action}. Some operations and meta-operations may take
+     additional <parameters>. For example:
 
      \
      $ b                       # perform(update(./))
diff --git a/build2/b.cxx b/build2/b.cxx
index fdd1b1c..bae40b6 100644
--- a/build2/b.cxx
+++ b/build2/b.cxx
@@ -28,13 +28,13 @@
 #include <libbuild2/dump.hxx>
 #include <libbuild2/file.hxx>
 #include <libbuild2/rule.hxx>
-#include <libbuild2/spec.hxx>
 #include <libbuild2/scope.hxx>
 #include <libbuild2/module.hxx>
 #include <libbuild2/target.hxx>
 #include <libbuild2/context.hxx>
 #include <libbuild2/variable.hxx>
 #include <libbuild2/algorithm.hxx>
+#include <libbuild2/buildspec.hxx>
 #include <libbuild2/operation.hxx>
 #include <libbuild2/filesystem.hxx>
 #include <libbuild2/diagnostics.hxx>
diff --git a/libbuild2/algorithm.cxx b/libbuild2/algorithm.cxx
index 0924540..6ea1e1f 100644
--- a/libbuild2/algorithm.cxx
+++ b/libbuild2/algorithm.cxx
@@ -335,20 +335,32 @@ namespace build2
       // the correct semantics.
 
       auto b (t.adhoc_recipes.begin ()), e (t.adhoc_recipes.end ());
-      auto i (find_if (b, e,
-                       [a, &t] (const adhoc_recipe& r)
-                       {
-                         return r.action == a &&
-                           r.rule->match (a, t, string () /* hint */, nullopt);
-                       }));
+      auto i (find_if (
+                b, e,
+                [a, &t] (const adhoc_recipe& r)
+                {
+                  auto& as (r.actions);
+                  return (find (as.begin (), as.end (), a) != as.end () &&
+                          r.rule->match (a, t, string () /* hint */, nullopt));
+                }));
 
       if (i == e)
-        i = find_if (b, e,
-                     [a, &t] (const adhoc_recipe& r)
-                     {
-                       return r.action != a &&
-                         r.rule->match (a, t, string () /* hint */, r.action);
-                     });
+        i = find_if (
+          b, e,
+          [a, &t] (const adhoc_recipe& r)
+          {
+            // See the adhoc_rule::match() documentation for details.
+            //
+            auto& as (r.actions);
+            if (find (as.begin (), as.end (), a) == as.end ())
+            {
+              for (auto ra: as)
+                if (r.rule->match (a, t, string () /* hint */, ra))
+                  return true;
+            }
+            return false;
+          });
+
       if (i != e)
         return &i->rule->rule_match;
     }
diff --git a/libbuild2/build/script/parser.cxx b/libbuild2/build/script/parser.cxx
index 72c99ad..274faf0 100644
--- a/libbuild2/build/script/parser.cxx
+++ b/libbuild2/build/script/parser.cxx
@@ -385,7 +385,7 @@ namespace build2
              << "the 'diag' recipe attribute";
 
           dr << info << "or provide custom low-verbosity diagnostics "
-             << " with the 'diag' builtin";
+             << "with the 'diag' builtin";
         };
 
         parse_names_result pr;
diff --git a/libbuild2/spec.cxx b/libbuild2/buildspec.cxx
index d1a39ab..bd580ca 100644
--- a/libbuild2/spec.cxx
+++ b/libbuild2/buildspec.cxx
@@ -1,7 +1,7 @@
-// file      : libbuild2/spec.cxx -*- C++ -*-
+// file      : libbuild2/buildspec.cxx -*- C++ -*-
 // license   : MIT; see accompanying LICENSE file
 
-#include <libbuild2/spec.hxx>
+#include <libbuild2/buildspec.hxx>
 
 #include <libbuild2/diagnostics.hxx>
 
diff --git a/libbuild2/spec.hxx b/libbuild2/buildspec.hxx
index d2ed609..b181d15 100644
--- a/libbuild2/spec.hxx
+++ b/libbuild2/buildspec.hxx
@@ -1,8 +1,8 @@
-// file      : libbuild2/spec.hxx -*- C++ -*-
+// file      : libbuild2/buildspec.hxx -*- C++ -*-
 // license   : MIT; see accompanying LICENSE file
 
-#ifndef LIBBUILD2_SPEC_HXX
-#define LIBBUILD2_SPEC_HXX
+#ifndef LIBBUILD2_BUILDSPEC_HXX
+#define LIBBUILD2_BUILDSPEC_HXX
 
 #include <libbuild2/types.hxx>
 #include <libbuild2/forward.hxx>
@@ -34,7 +34,7 @@ namespace build2
     bool forwarded = false;
   };
 
-  struct opspec: vector<targetspec>
+  struct opspec: small_vector<targetspec, 1>
   {
     opspec () = default;
     opspec (string n): name (move (n)) {}
@@ -43,7 +43,7 @@ namespace build2
     values params;
   };
 
-  struct metaopspec: vector<opspec>
+  struct metaopspec: small_vector<opspec, 1>
   {
     metaopspec () = default;
     metaopspec (string n): name (move (n)) {}
@@ -52,7 +52,7 @@ namespace build2
     values params;
   };
 
-  using buildspec = vector<metaopspec>;
+  using buildspec = small_vector<metaopspec, 1>;
 
   LIBBUILD2_SYMEXPORT ostream&
   operator<< (ostream&, const targetspec&);
@@ -67,4 +67,4 @@ namespace build2
   operator<< (ostream&, const buildspec&);
 }
 
-#endif // LIBBUILD2_SPEC_HXX
+#endif // LIBBUILD2_BUILDSPEC_HXX
diff --git a/libbuild2/config/operation.cxx b/libbuild2/config/operation.cxx
index 41d982b..6e28b0a 100644
--- a/libbuild2/config/operation.cxx
+++ b/libbuild2/config/operation.cxx
@@ -4,11 +4,11 @@
 #include <libbuild2/config/operation.hxx>
 
 #include <libbuild2/file.hxx>
-#include <libbuild2/spec.hxx>
 #include <libbuild2/scope.hxx>
 #include <libbuild2/target.hxx>
 #include <libbuild2/context.hxx>
 #include <libbuild2/algorithm.hxx>
+#include <libbuild2/buildspec.hxx>  // opspec
 #include <libbuild2/filesystem.hxx>
 #include <libbuild2/diagnostics.hxx>
 
diff --git a/libbuild2/dump.cxx b/libbuild2/dump.cxx
index 9f60900..11eb4b3 100644
--- a/libbuild2/dump.cxx
+++ b/libbuild2/dump.cxx
@@ -350,10 +350,21 @@ namespace build2
     //
     if (!t.adhoc_recipes.empty ())
     {
+      auto& re (*s.root_scope ()->root_extra);
+
       for (const adhoc_recipe r: t.adhoc_recipes)
       {
+        os << endl
+           << ind << '%';
+
+        r.rule->dump_attributes (os);
+
+        for (action a: r.actions)
+          os << ' ' << re.meta_operations[a.meta_operation ()]->name <<
+            '(' << re.operations[a.operation ()]->name << ')';
+
         os << endl;
-        r.rule->dump (os, ind); // @@ TODO: pass action(s).
+        r.rule->dump_text (os, ind);
       }
 
       used = true;
diff --git a/libbuild2/forward.hxx b/libbuild2/forward.hxx
index 4443610..94eb006 100644
--- a/libbuild2/forward.hxx
+++ b/libbuild2/forward.hxx
@@ -14,7 +14,7 @@ namespace build2
   //
   struct action;
 
-  // <libbuild2/spec.hxx>
+  // <libbuild2/buildspec.hxx>
   //
   struct opspec;
 
diff --git a/libbuild2/lexer.cxx b/libbuild2/lexer.cxx
index 7149d45..e50ec16 100644
--- a/libbuild2/lexer.cxx
+++ b/libbuild2/lexer.cxx
@@ -125,13 +125,13 @@ namespace build2
         //
         // 2. Recognizes comma.
         //
-        // 3. Treat newline as an ordinary space.
-        //
-        // Also note that we don't have buildspec attributes.
+        // Note that because we use this mode for both the command line
+        // buildspec and ad hoc recipe actions, we control the recognition of
+        // newlines as tokens via the auxiliary data.
         //
         s1 = " $(){},\t\n";
         s2 = "         ";
-        n = false;
+        n = (data != 0);
         break;
       }
     case lexer_mode::foreign:
diff --git a/libbuild2/parser.cxx b/libbuild2/parser.cxx
index d8baf06..6fb20fe 100644
--- a/libbuild2/parser.cxx
+++ b/libbuild2/parser.cxx
@@ -1046,11 +1046,12 @@ namespace build2
   {
     // Parse a recipe chain.
     //
-    // % [<attrs>]
+    // % [<attrs>] [<buildspec>]
     // [if|switch ...]
     // {{ [<lang> ...]
     //   ...
     // }}
+    // ...
     //
     // enter: start is percent or openining multi-curly-brace
     // leave: token past newline after last closing multi-curly-brace
@@ -1078,6 +1079,9 @@ namespace build2
       recipes.push_back (nullptr); // For missing else/default (see below).
 
       attributes as;
+      buildspec bs;
+      location bsloc;
+
       struct data
       {
         small_vector<shared_ptr<adhoc_rule>, 1>& recipes;
@@ -1085,7 +1089,9 @@ namespace build2
         bool&                                    clean;
         size_t                                   i;
         attributes&                              as;
-      } d {recipes, first, clean, i, as};
+        buildspec&                               bs;
+        const location&                          bsloc;
+      } d {recipes, first, clean, i, as, bs, bsloc};
 
       // Note that this function must be called at most once per iteration.
       //
@@ -1197,8 +1203,74 @@ namespace build2
               fail (d.as.loc) << "unknown recipe attribute " << a << endf;
           }
 
-          target_->adhoc_recipes.push_back (
-            adhoc_recipe {perform_update_id, move (ar)});
+          auto& ars (target_->adhoc_recipes);
+          ars.push_back (adhoc_recipe {{}, move (ar)});
+
+          // Translate each buildspec entry into action and add it into the
+          // target's ad hoc recipes entry.
+          //
+          const location& l (d.bsloc);
+
+          for (metaopspec& m: d.bs)
+          {
+            meta_operation_id mi (ctx.meta_operation_table.find (m.name));
+
+            if (mi == 0)
+              fail (l) << "unknown meta-operation " << m.name;
+
+            const meta_operation_info* mf (
+              root_->root_extra->meta_operations[mi]);
+
+            if (mf == nullptr)
+              fail (l) << "target " << *target_ << " does not support meta-"
+                       << "operation " << ctx.meta_operation_table[mi].name;
+
+            for (opspec& o: m)
+            {
+              operation_id oi;
+              if (o.name.empty ())
+              {
+                if (mf->operation_pre == nullptr)
+                  oi = update_id;
+                else
+                  // Calling operation_pre() to translate doesn't feel
+                  // appropriate here.
+                  //
+                  fail (l) << "default operation in recipe action";
+              }
+              else
+                oi = ctx.operation_table.find (o.name);
+
+              if (oi == 0)
+                fail (l) << "unknown operation " << o.name;
+
+              const operation_info* of (root_->root_extra->operations[oi]);
+
+              if (of == nullptr)
+                fail (l) << "target " << *target_ << " does not support "
+                         << "operation " << ctx.operation_table[oi];
+
+              // Note: for now always inner (see match_rule() for details).
+              //
+              action a (mi, oi);
+
+              // Check for duplicates.
+              //
+              if (find_if (
+                    ars.begin (), ars.end (),
+                    [a] (const adhoc_recipe& r)
+                    {
+                      auto& as (r.actions);
+                      return find (as.begin (), as.end (), a) != as.end ();
+                    }) != ars.end ())
+              {
+                fail (l) << "duplicate recipe for " << mf->name << '('
+                         << of->name << ')';
+              }
+
+              ars.back ().actions.push_back (a);
+            }
+          }
         }
 
         next (t, tt);
@@ -1210,6 +1282,11 @@ namespace build2
 
       if (tt == type::percent)
       {
+        // Similar code to parse_buildspec() except here we recognize
+        // attributes and newlines.
+        //
+        mode (lexer_mode::buildspec, '@', 1 /* recognize newline */);
+
         next_with_attributes (t, tt);
         attributes_push (t, tt, true /* standalone */);
 
@@ -1221,7 +1298,36 @@ namespace build2
         as = move (attributes_top ());
         attributes_pop ();
 
-        next_after_newline (t, tt, '%');
+        // Handle the buildspec.
+        //
+        // @@ TODO: diagnostics is a bit off ("operation or target").
+        //
+        if (tt != type::newline && tt != type::eos)
+        {
+          const location& l (bsloc = get_location (t));
+          bs = parse_buildspec_clause (t, tt);
+
+          // Verify we have no targets and assign default meta-operations.
+          //
+          // Note that here we don't bother with lifting operations to meta-
+          // operations like we do in the driver (this seems unlikely to be a
+          // pain point).
+          //
+          for (metaopspec& m: bs)
+          {
+            for (opspec& o: m)
+            {
+              if (!o.empty ())
+                fail (l) << "target in recipe action";
+            }
+
+            if (m.name.empty ())
+              m.name = "perform";
+          }
+        }
+
+        expire_mode ();
+        next_after_newline (t, tt, "recipe action");
 
         // See if this is if-else or switch.
         //
@@ -1259,6 +1365,14 @@ namespace build2
         // Fall through.
       }
 
+      // Default is perform(update).
+      //
+      if (bs.empty ())
+      {
+        bs.push_back (metaopspec ("perform"));
+        bs.back ().push_back (opspec ("update"));
+      }
+
       parse_block (t, tt, false /* skip */, "" /* kind */);
     }
 
@@ -6308,7 +6422,7 @@ namespace build2
     next (t, tt);
 
     buildspec r (tt != type::eos
-                 ? parse_buildspec_clause (t, tt, 0)
+                 ? parse_buildspec_clause (t, tt)
                  : buildspec ());
 
     if (tt != type::eos)
@@ -6437,8 +6551,8 @@ namespace build2
           }
         }
 
-        // No nested meta-operations means we should have a single
-        // metaopspec object with empty meta-operation name.
+        // No nested meta-operations means we should have a single metaopspec
+        // object with empty meta-operation name.
         //
         assert (nbs.size () == 1);
         const metaopspec& nmo (nbs.back ());
diff --git a/libbuild2/parser.hxx b/libbuild2/parser.hxx
index 88b4ad9..78c7d17 100644
--- a/libbuild2/parser.hxx
+++ b/libbuild2/parser.hxx
@@ -8,11 +8,11 @@
 #include <libbuild2/forward.hxx>
 #include <libbuild2/utility.hxx>
 
-#include <libbuild2/spec.hxx>
 #include <libbuild2/file.hxx>
 #include <libbuild2/lexer.hxx>
 #include <libbuild2/token.hxx>
 #include <libbuild2/variable.hxx>
+#include <libbuild2/buildspec.hxx>
 #include <libbuild2/diagnostics.hxx>
 
 #include <libbuild2/export.hxx>
@@ -496,7 +496,7 @@ namespace build2
     // Buildspec.
     //
     buildspec
-    parse_buildspec_clause (token&, token_type&, size_t);
+    parse_buildspec_clause (token&, token_type&, size_t = 0);
 
     // Customization hooks.
     //
diff --git a/libbuild2/recipe.hxx b/libbuild2/recipe.hxx
index efd184a..823f804 100644
--- a/libbuild2/recipe.hxx
+++ b/libbuild2/recipe.hxx
@@ -58,10 +58,8 @@ namespace build2
 
   struct adhoc_recipe
   {
-    // @@ TODO: maybe we should have a small vector of actions (for dump).
-    //
-    build2::action         action;
-    shared_ptr<adhoc_rule> rule;
+    small_vector<action, 1> actions;
+    shared_ptr<adhoc_rule>  rule;
   };
 }
 
diff --git a/libbuild2/rule.cxx b/libbuild2/rule.cxx
index 7ea6e68..0b9f066 100644
--- a/libbuild2/rule.cxx
+++ b/libbuild2/rule.cxx
@@ -333,6 +333,11 @@ namespace build2
     return true;
   }
 
+  void adhoc_rule::
+  dump_attributes (ostream&) const
+  {
+  }
+
   // Scope operation callback that cleans up recipe builds.
   //
   target_state adhoc_rule::
@@ -406,28 +411,23 @@ namespace build2
   }
 
   void adhoc_script_rule::
-  dump (ostream& os, string& ind) const
+  dump_attributes (ostream& os) const
   {
-    // Do we need the header?
-    //
-    // @@ TODO: for now we dump it as an attribute whether it was specified or
-    //    derived from the script. Maybe that's ok?
+    // For now we dump it as an attribute whether it was specified or derived
+    // from the script. Maybe that's ok (we use this in tests)?
     //
     if (script.diag_name)
     {
-      os << ind << '%';
-
-      if (script.diag_name)
-      {
-        os << " [";
-        os << "diag=";
-        to_stream (os, name (*script.diag_name), true /* quote */, '@');
-        os << ']';
-      }
-
-      os << endl;
+      os << " [";
+      os << "diag=";
+      to_stream (os, name (*script.diag_name), true /* quote */, '@');
+      os << ']';
     }
+  }
 
+  void adhoc_script_rule::
+  dump_text (ostream& os, string& ind) const
+  {
     os << ind << string (braces, '{') << endl;
     ind += "  ";
     script::dump (os, ind, script.lines);
@@ -807,7 +807,7 @@ namespace build2
   }
 
   void adhoc_cxx_rule::
-  dump (ostream& os, string& ind) const
+  dump_text (ostream& os, string& ind) const
   {
     // @@ TODO: indentation is multi-line recipes is off (would need to insert
     //          indentation after every newline).
diff --git a/libbuild2/rule.hxx b/libbuild2/rule.hxx
index a79eeed..c98c29e 100644
--- a/libbuild2/rule.hxx
+++ b/libbuild2/rule.hxx
@@ -153,8 +153,13 @@ namespace build2
     virtual bool
     match (action, target&, const string&) const override;
 
+    // Dump support.
+    //
+    virtual void
+    dump_attributes (ostream&) const;
+
     virtual void
-    dump (ostream&, string& indentation) const = 0;
+    dump_text (ostream&, string& indentation) const = 0;
 
     // Implementation details.
     //
@@ -188,14 +193,17 @@ namespace build2
     target_state
     default_action (action, const target&) const;
 
-    virtual void
-    dump (ostream&, string&) const override;
-
     adhoc_script_rule (const location& l, size_t b): adhoc_rule (l, b) {}
 
     virtual bool
     recipe_text (context&, const target&, string&&, attributes&) override;
 
+    virtual void
+    dump_attributes (ostream&) const override;
+
+    virtual void
+    dump_text (ostream&, string&) const override;
+
   public:
     using script_type = build::script::script;
 
@@ -245,9 +253,6 @@ namespace build2
     virtual recipe
     apply (action, target&) const override;
 
-    virtual void
-    dump (ostream&, string&) const override;
-
     adhoc_cxx_rule (const location&, size_t, uint64_t version);
 
     virtual bool
@@ -256,6 +261,9 @@ namespace build2
     virtual
     ~adhoc_cxx_rule () override;
 
+    virtual void
+    dump_text (ostream&, string&) const override;
+
   public:
     // Note that this recipe (rule instance) can be shared between multiple
     // targets which could all be matched in parallel.
diff --git a/tests/dependency/recipe/testscript b/tests/dependency/recipe/testscript
index b39abde..64947dd 100644
--- a/tests/dependency/recipe/testscript
+++ b/tests/dependency/recipe/testscript
@@ -17,7 +17,7 @@ dump alias{x}
 EOI
 <stdin>:5:1: dump:
 %  .+/alias\{x\}: .+/:alias\{z\}%
-  % [diag=echo]
+  % [diag=echo] perform(update)
   {{
     echo
   }}
@@ -34,7 +34,7 @@ dump alias{y}
 EOI
 <stdin>:5:1: dump:
 %  .+/alias\{y\}: .+/:alias\{z\}%
-  % [diag=echo]
+  % [diag=echo] perform(update)
   {{
     echo
   }}
@@ -44,7 +44,7 @@ EOE
 :
 $* <<EOI 2>>/~%EOE%
 alias{x}:
-%
+% update clean
 {{
   echo
 }}
@@ -52,7 +52,7 @@ dump alias{x}
 EOI
 <stdin>:6:1: dump:
 %  .+/alias\{x\}:%
-  % [diag=echo]
+  % [diag=echo] perform(update) perform(clean)
   {{
     echo
   }}
@@ -62,7 +62,7 @@ EOE
 :
 $* <<EOI 2>>/~%EOE%
 alias{x y}:
-%
+% perform(update clean)
 {{
   echo
 }}
@@ -70,7 +70,7 @@ dump alias{y}
 EOI
 <stdin>:6:1: dump:
 %  .+/alias\{y\}:%
-  % [diag=echo]
+  % [diag=echo] perform(update) perform(clean)
   {{
     echo
   }}
@@ -87,6 +87,7 @@ dump alias{x}
 EOI
 <stdin>:5:1: dump:
 %  .+/alias\{x\}:%
+  % perform(update)
   {{ c++ 1
     void f ();
   }}
@@ -109,7 +110,7 @@ EOI
   {
     var = x
   }
-  % [diag=echo]
+  % [diag=echo] perform(update)
   {{
     echo
   }}
@@ -132,7 +133,7 @@ EOI
   {
     var = x
   }
-  % [diag=echo]
+  % [diag=echo] perform(update)
   {{
     echo
   }}
@@ -145,7 +146,7 @@ alias{x}: alias{z}
 {
   var = x
 }
-%
+% perform(update)
 {{
   echo
 }}
@@ -156,7 +157,7 @@ EOI
   {
     var = x
   }
-  % [diag=echo]
+  % [diag=echo] perform(update)
   {{
     echo
   }}
@@ -169,7 +170,7 @@ alias{x y}:
 {
   var = x
 }
-%
+% perform(update)
 {{
   echo
 }}
@@ -180,7 +181,7 @@ EOI
   {
     var = x
   }
-  % [diag=echo]
+  % [diag=echo] perform(update)
   {{
     echo
   }}
@@ -193,18 +194,19 @@ alias{x}:
 {{
   echo
 }}
+% clean
 {{{
   cat
 }}}
 dump alias{x}
 EOI
-<stdin>:8:1: dump:
+<stdin>:9:1: dump:
 %  .+/alias\{x\}:%
-  % [diag=echo]
+  % [diag=echo] perform(update)
   {{
     echo
   }}
-  % [diag=cat]
+  % [diag=cat] perform(clean)
   {{{
     cat
   }}}
@@ -217,18 +219,19 @@ alias{x y}: alias{z}
 {{
   echo
 }}
+% clean
 {{{
   cat
 }}}
 dump alias{y}
 EOI
-<stdin>:8:1: dump:
+<stdin>:9:1: dump:
 %  .+/alias\{y\}: .+/:alias\{z\}%
-  % [diag=echo]
+  % [diag=echo] perform(update)
   {{
     echo
   }}
-  % [diag=cat]
+  % [diag=cat] perform(clean)
   {{{
     cat
   }}}
@@ -238,12 +241,12 @@ EOE
 :
 $* <<EOI 2>>/~%EOE%
 alias{x}: alias{z}
-
+% clean
 {{
   echo
 }}
 
-%
+% update
 {{{
   cat
 }}}
@@ -251,11 +254,11 @@ dump alias{x}
 EOI
 <stdin>:11:1: dump:
 %  .+/alias\{x\}: .+/:alias\{z\}%
-  % [diag=echo]
+  % [diag=echo] perform(clean)
   {{
     echo
   }}
-  % [diag=cat]
+  % [diag=cat] perform(update)
   {{{
     cat
   }}}
@@ -266,23 +269,24 @@ EOE
 $* <<EOI 2>>/~%EOE%
 alias{x y}:
 
+% clean
 {{
   echo
 }}
 
-%
+% update
 {{{
   cat
 }}}
 dump alias{y}
 EOI
-<stdin>:11:1: dump:
+<stdin>:12:1: dump:
 %  .+/alias\{y\}:%
-  % [diag=echo]
+  % [diag=echo] perform(clean)
   {{
     echo
   }}
-  % [diag=cat]
+  % [diag=cat] perform(update)
   {{{
     cat
   }}}
@@ -323,7 +327,7 @@ dump alias{x}
 EOI
 <stdin>:6:1: dump:
 !  .+/alias\{x\}:!
-  % [diag=gen]
+  % [diag=gen] perform(update)
   {{
     echo
   }}
@@ -341,7 +345,7 @@ dump alias{y}
 EOI
 <stdin>:6:1: dump:
 !  .+/alias\{y\}:!
-  % [diag=gen]
+  % [diag=gen] perform(update)
   {{
     echo
   }}
@@ -359,6 +363,33 @@ EOI
 <stdin>:3:1: error: expected recipe block instead of '{'
 EOE
 
+: duplicate-action-single
+:
+$* <<EOI 2>>EOE != 0
+alias{x}:
+% update perform(update)
+{{
+  echo
+}}
+EOI
+<stdin>:2:3: error: duplicate recipe for perform(update)
+EOE
+
+: duplicate-action-multiple
+:
+$* <<EOI 2>>EOE != 0
+alias{x}:
+{{
+  echo
+}}
+% perform(update)
+{{
+  echo
+}}
+EOI
+<stdin>:5:3: error: duplicate recipe for perform(update)
+EOE
+
 : diag
 :
 {
@@ -391,7 +422,7 @@ EOE
       dump alias{x}
       EOI
       %.{2}
-        % [diag=rm]
+        % [diag=rm] perform(update)
       %.{4}
       EOE
 
@@ -406,7 +437,7 @@ EOE
       dump alias{x}
       EOI
       %.{2}
-        % [diag=echo]
+        % [diag=echo] perform(update)
       %.{4}
       EOE
 
@@ -455,7 +486,7 @@ EOE
       dump alias{x}
       EOI
       %.{2}
-        % [diag=c++]
+        % [diag=c++] perform(update)
       %.{3}
       EOE
   }
@@ -477,7 +508,7 @@ EOE
         <stdin>:4:11: info: use the '\?' escape sequence if this is a wildcard pattern
         <stdin>:4:4: info: while deducing low-verbosity script diagnostics name
         info: consider specifying it explicitly with the 'diag' recipe attribute
-        info: or provide custom low-verbosity diagnostics  with the 'diag' builtin
+        info: or provide custom low-verbosity diagnostics with the 'diag' builtin
       EOE
 
     : empty
@@ -492,7 +523,7 @@ EOE
       EOI
       <stdin>:4:3: error: unable to deduce low-verbosity script diagnostics name
         info: consider specifying it explicitly with the 'diag' recipe attribute
-        info: or provide custom low-verbosity diagnostics  with the 'diag' builtin
+        info: or provide custom low-verbosity diagnostics with the 'diag' builtin
       EOE
 
     : process-path-typed
@@ -506,7 +537,7 @@ EOE
       EOI
       %<stdin>:3:4: error: unable to deduce low-verbosity script diagnostics name from process path .+%
         info: consider specifying it explicitly with the 'diag' recipe attribute
-        info: or provide custom low-verbosity diagnostics  with the 'diag' builtin
+        info: or provide custom low-verbosity diagnostics with the 'diag' builtin
       EOE
 
     : process-path-syntactic
@@ -521,7 +552,7 @@ EOE
       EOI
       %<stdin>:4:4: error: unable to deduce low-verbosity script diagnostics name from process path .+%
         info: consider specifying it explicitly with the 'diag' recipe attribute
-        info: or provide custom low-verbosity diagnostics  with the 'diag' builtin
+        info: or provide custom low-verbosity diagnostics with the 'diag' builtin
       EOE
 
     : target-no-name
@@ -541,7 +572,7 @@ EOE
         EOI
         %<stdin>:5:3: error: unable to deduce low-verbosity script diagnostics name from target .+/exe\{b\}%
           info: consider specifying it explicitly with the 'diag' recipe attribute
-          info: or provide custom low-verbosity diagnostics  with the 'diag' builtin
+          info: or provide custom low-verbosity diagnostics with the 'diag' builtin
         EOE
     }
 
@@ -557,7 +588,7 @@ EOE
       EOI
       <stdin>:4:3: error: unable to deduce low-verbosity script diagnostics name for program foo
         info: consider specifying it explicitly with the 'diag' recipe attribute
-        info: or provide custom low-verbosity diagnostics  with the 'diag' builtin
+        info: or provide custom low-verbosity diagnostics with the 'diag' builtin
       EOE
   }
 
@@ -577,7 +608,7 @@ EOE
       dump alias{x}
       EOI
       %.{2}
-        % [diag=foo]
+        % [diag=foo] perform(update)
       %.{5}
       EOE
 
@@ -596,6 +627,7 @@ EOE
       EOI
       %.
       %  .+alias\{x\}:%
+        % perform(update)
         {{
       %.{4}
       EOE