Reimplement version::in_rule in terms of in::rule

Significantly, the version::in_rule rule now track changes to the substitution
values.

3 files changed, 25 insertions, 7 deletions

diff --git a/build2/in/init.cxx b/build2/in/init.cxx
index 337722a..a87f8b3 100644
--- a/build2/in/init.cxx
+++ b/build2/in/init.cxx
@@ -18,7 +18,7 @@ namespace build2
 {
   namespace in
   {
-    static const rule rule_;
+    static const rule rule_ ("in", "in");
 
     bool
     base_init (scope& rs,
diff --git a/build2/in/rule.cxx b/build2/in/rule.cxx
index de43e4d..6be2e71 100644
--- a/build2/in/rule.cxx
+++ b/build2/in/rule.cxx
@@ -55,7 +55,7 @@ namespace build2
 
       // Derive the file name.
       //
-      // If this is an executable with an uspecified extension, then default
+      // If this is an executable with an unspecified extension, then default
       // to no extension (i.e., a shell script).
       //
       t.derive_path (t.is_a<exe> () ? "" : nullptr);
@@ -187,7 +187,7 @@ namespace build2
 
       // First should come the rule name/version.
       //
-      if (dd.expect ("in 1") != nullptr)
+      if (dd.expect (rule_id_ + " 1") != nullptr)
         l4 ([&]{trace << "rule mismatch forcing update of " << t;});
 
       // Then the substitution symbol.
@@ -253,6 +253,9 @@ namespace build2
             //
             // <ln> <name> <hash>
             //
+            // Note that <name> can contain spaces (see the constraint check
+            // expressions in the version module).
+            //
             char* e (nullptr);
             uint64_t ln (strtoull (s->c_str (), &e, 10));
 
@@ -296,9 +299,9 @@ namespace build2
       }
 
       if (verb >= 2)
-        text << "in " << ip << " >" << tp;
+        text << program_ << ' ' << ip << " >" << tp;
       else if (verb)
-        text << "in " << ip;
+        text << program_ << ' ' << ip;
 
       // Read and process the file, one line at a time.
       //
diff --git a/build2/in/rule.hxx b/build2/in/rule.hxx
index a68e80c..17fbaed 100644
--- a/build2/in/rule.hxx
+++ b/build2/in/rule.hxx
@@ -16,11 +16,24 @@ namespace build2
   {
     // Preprocess an .in file.
     //
+    // Note that a derived rule can use the target data pad to cache data
+    // (e.g., in match()) to be used in substitute/lookup() calls.
+    //
     class rule: public build2::rule
     {
     public:
-      rule (char symbol = '$', bool strict = true)
-          : symbol_ (symbol), strict_ (strict) {}
+      // The rule id is used to form the rule name/version entry in depdb. The
+      // program argument is the pseudo-program name to use in the command
+      // line diagnostics.
+      //
+      rule (string rule_id,
+            string program,
+            char symbol = '$',
+            bool strict = true)
+          : rule_id_ (move (rule_id)),
+            program_ (move (program)),
+            symbol_ (symbol),
+            strict_ (strict) {}
 
       virtual bool
       match (action, target&, const string&) const override;
@@ -46,6 +59,8 @@ namespace build2
       perform_update (action, const target&) const;
 
     protected:
+      const string rule_id_;
+      const string program_;
       char symbol_;
       bool strict_;
     };