Create build script temporary directory on demand

4 files changed, 51 insertions, 11 deletions

diff --git a/libbuild2/test/script/parser.cxx b/libbuild2/test/script/parser.cxx
index c206e0a..f663c11 100644
--- a/libbuild2/test/script/parser.cxx
+++ b/libbuild2/test/script/parser.cxx
@@ -389,7 +389,7 @@ namespace build2
             //
             string& n (t.value);
 
-            if (n == "*" || n == "~" || n == "@" || digit (n))
+            if (special_variable (n))
               fail (t) << "attempt to set '" << n << "' variable directly";
 
             // Pre-enter the variables now while we are executing serially.
@@ -1598,6 +1598,14 @@ namespace build2
       // The rest.
       //
 
+      // When add a special variable don't forget to update lexer::word().
+      //
+      bool parser::
+      special_variable (const string& n) noexcept
+      {
+        return n == "*" || n == "~" || n == "@" || digit (n);
+      }
+
       lookup parser::
       lookup_variable (name&& qual, string&& name, const location& loc)
       {
diff --git a/libbuild2/test/script/parser.hxx b/libbuild2/test/script/parser.hxx
index 19d4f76..aa64943 100644
--- a/libbuild2/test/script/parser.hxx
+++ b/libbuild2/test/script/parser.hxx
@@ -91,12 +91,6 @@ namespace build2
         command_expr
         parse_command_line (token&, token_type&);
 
-        // Workaround for GCC 4.9 that fails to compile the base class
-        // protected member function call from a lambda defined in the derived
-        // class.
-        //
-        using build2::parser::apply_value_attributes;
-
         // Execute. Issue diagnostics and throw failed in case of an error.
         //
       public:
@@ -110,6 +104,12 @@ namespace build2
         void
         exec_scope_body ();
 
+        // Helpers.
+        //
+      public:
+        static bool
+        special_variable (const string&) noexcept;
+
         // Customization hooks.
         //
       protected:
diff --git a/libbuild2/test/script/script.cxx b/libbuild2/test/script/script.cxx
index b56da1b..34d4723 100644
--- a/libbuild2/test/script/script.cxx
+++ b/libbuild2/test/script/script.cxx
@@ -8,7 +8,7 @@
 #include <libbuild2/target.hxx>
 #include <libbuild2/algorithm.hxx>
 
-#include <libbuild2/script/parser.hxx> // parser::apply_value_attributes()
+#include <libbuild2/test/script/parser.hxx>
 
 using namespace std;
 
@@ -96,8 +96,16 @@ namespace build2
       }
 
       void scope::
-      set_variable (string&& nm, names&& val, const string& attrs)
+      set_variable (string&& nm,
+                    names&& val,
+                    const string& attrs,
+                    const location& ll)
       {
+        // Check if we are trying to modify any of the special variables.
+        //
+        if (parser::special_variable (nm))
+          fail (ll) << "attempt to set '" << nm << "' variable directly";
+
         // Set the variable value and attributes. Note that we need to aquire
         // unique lock before potentially changing the script's variable
         // pool. The obtained variable reference can safelly be used with no
@@ -118,7 +126,22 @@ namespace build2
           lhs.assign (move (val), &var);
         else
         {
-          build2::script::parser p (context);
+          // If there is an error in the attributes string, our diagnostics
+          // will look like this:
+          //
+          // <attributes>:1:1 error: unknown value attribute x
+          //   testscript:10:1 info: while parsing attributes '[x]'
+          //
+          // Note that the attributes parsing error is the only reason for a
+          // failure.
+          //
+          auto df = make_diag_frame (
+            [attrs, &ll](const diag_record& dr)
+            {
+              dr << info (ll) << "while parsing attributes '" << attrs << "'";
+            });
+
+          parser p (context);
           p.apply_value_attributes (&var,
                                     lhs,
                                     value (move (val)),
diff --git a/libbuild2/test/script/script.hxx b/libbuild2/test/script/script.hxx
index 7bdb2ac..6356501 100644
--- a/libbuild2/test/script/script.hxx
+++ b/libbuild2/test/script/script.hxx
@@ -91,8 +91,17 @@ namespace build2
 
         scope_state state = scope_state::unknown;
 
+        void
+        set_variable (string&& name,
+                      names&&,
+                      const string& attrs,
+                      const location&) override;
+
+        // Noop since the temporary directory is a working directory and so
+        // is created before the scope commands execution.
+        //
         virtual void
-        set_variable (string&& name, names&&, const string& attrs) override;
+        create_temp_dir () override {assert (false);};
 
         // Variables.
         //