Add support for dry run mode for build script runner

3 files changed, 23 insertions, 18 deletions

diff --git a/libbuild2/build/script/runner.cxx b/libbuild2/build/script/runner.cxx
index 94f1394..0be55a5 100644
--- a/libbuild2/build/script/runner.cxx
+++ b/libbuild2/build/script/runner.cxx
@@ -29,10 +29,25 @@ namespace build2
            size_t li,
            const location& ll)
       {
-        if (verb >= 2)
-          text << expr;
+        if (verb >= 3)
+          text << ":  " << expr;
 
-        build2::script::run (env, expr, li, ll);
+        // Run the expression if we are not in the dry run mode or if it
+        // executes the set builtin and print the expression otherwise, unless
+        // it is already printed or the verbosity level is lower than 2.
+        //
+        // @@ Should we also run expressions that execute the exit builtin in
+        //    the dry run mode?
+        //
+        if (!env.context.dry_run ||
+            find_if (expr.begin (), expr.end (),
+                     [] (const expr_term& et)
+                     {
+                       return et.pipe.back ().program.string () == "set";
+                     }) != expr.end ())
+          build2::script::run (env, expr, li, ll);
+        else if (verb == 2)
+          text << expr;
       }
 
       bool default_runner::
@@ -40,8 +55,8 @@ namespace build2
               const command_expr& expr,
               size_t li, const location& ll)
       {
-        if (verb >= 2)
-          text << expr;
+        if (verb >= 3)
+          text << ": ?" << expr;
 
         return build2::script::run_if (env, expr, li, ll);
       }
diff --git a/libbuild2/build/script/script.hxx b/libbuild2/build/script/script.hxx
index 8569a1f..9ada56f 100644
--- a/libbuild2/build/script/script.hxx
+++ b/libbuild2/build/script/script.hxx
@@ -22,6 +22,7 @@ namespace build2
       using build2::script::line_type;
       using build2::script::redirect;
       using build2::script::redirect_type;
+      using build2::script::expr_term;
       using build2::script::command_expr;
 
       // Notes:
diff --git a/libbuild2/rule.cxx b/libbuild2/rule.cxx
index 9df5f67..49cb8f3 100644
--- a/libbuild2/rule.cxx
+++ b/libbuild2/rule.cxx
@@ -579,19 +579,8 @@ namespace build2
     {
       build::script::parser p (ctx);
       build::script::environment e (script, t);
-
-      if (!ctx.dry_run)
-      {
-        build::script::default_runner r;
-        p.execute (e, r);
-      }
-      else
-      {
-        //@@ TODO:
-        //
-        //build::script::print_runner r;
-        //p.execute (e, r);
-      }
+      build::script::default_runner r;
+      p.execute (e, r);
     }
 
     return target_state::changed;