Implement in-process package configuration

1 files changed, 118 insertions, 6 deletions

diff --git a/bpkg/pkg-build.cxx b/bpkg/pkg-build.cxx
index 2484880..4f5b423 100644
--- a/bpkg/pkg-build.cxx
+++ b/bpkg/pkg-build.cxx
@@ -1245,7 +1245,13 @@ namespace bpkg
               if (a.find ('=') == string::npos)
                 fail << "unexpected group argument '" << a << "'";
 
-              cvs.push_back (move (trim (a)));
+              trim (a);
+
+              if (a[0] == '!')
+                fail << "global override in package-specific configuration "
+                     << "variable '" << a << "'";
+
+              cvs.push_back (move (a));
             }
           }
 
@@ -5356,12 +5362,26 @@ namespace bpkg
     struct configure_package
     {
       reference_wrapper<build_package> pkg;
-      configure_prerequisites_result   res; // Unused for system package.
+
+      // These are unused for system packages.
+      //
+      configure_prerequisites_result   res;
+      build2::variable_overrides       ovrs;
     };
     vector<configure_package> configure_packages;
-
     configure_packages.reserve (build_pkgs.size ());
 
+    // While at it also collect global configuration variable overrides from
+    // each configure_prerequisites_result::config_variables and merge them
+    // into configure_global_vars.
+    //
+    // @@ TODO: Note that the current global override semantics is quite
+    //    broken in that we don't force reconfiguration of all the packages.
+    //
+#ifndef BPKG_OUTPROC_CONFIGURE
+    strings configure_global_vars;
+#endif
+
     // Return the "would be" state of packages that would be configured
     // by this stage.
     //
@@ -5557,11 +5577,97 @@ namespace bpkg
         }
 
         t.commit ();
+
+        if (verb >= 5 && !simulate && !cpr.config_variables.empty ())
+        {
+          diag_record dr (trace);
+
+          dr << sp->name << pdb << " configuration variables:";
+
+          for (const string& cv: cpr.config_variables)
+            dr << "\n  " << cv;
+        }
+
+        if (!simulate)
+        {
+#ifndef BPKG_OUTPROC_CONFIGURE
+          auto& gvs (configure_global_vars);
+
+          // Note that we keep global overrides in cpr.config_variables for
+          // diagnostics and skip them in var_override_function below.
+          //
+          for (const string& v: cpr.config_variables)
+          {
+            // Each package should have exactly the same set of global
+            // overrides by construction since we don't allow package-
+            // specific global overrides.
+            //
+            if (v[0] == '!')
+            {
+              if (find (gvs.begin (), gvs.end (), v) == gvs.end ())
+                gvs.push_back (v);
+            }
+          }
+#endif
+          // Add config.config.disfigure unless already disfigured (see the
+          // high-level pkg_configure() version for background).
+          //
+          if (ap == nullptr || !p.disfigure)
+          {
+            cpr.config_variables.push_back (
+              "config.config.disfigure='config." + sp->name.variable () + "**'");
+          }
+        }
       }
 
-      configure_packages.push_back (configure_package {p, move (cpr)});
+      configure_packages.push_back (configure_package {p, move (cpr), {}});
     }
 
+    // Reuse the build state to avoid reloading the dependencies over and over
+    // again. This is a valid optimization since we are configuring in the
+    // dependency-dependent order.
+    //
+    unique_ptr<build2::context> configure_ctx;
+
+#ifndef BPKG_OUTPROC_CONFIGURE
+    if (!simulate)
+    {
+      using build2::context;
+      using build2::variable_override;
+
+      function<context::var_override_function> vof (
+        [&configure_packages] (context& ctx, size_t& i)
+        {
+          for (configure_package& cp: configure_packages)
+          {
+            for (const string& v: cp.res.config_variables)
+            {
+              if (v[0] == '!') // Skip global overrides (see above).
+                continue;
+
+              pair<char, variable_override> p (
+                ctx.parse_variable_override (v, i++, false /* buildspec */));
+
+              variable_override& vo (p.second);
+
+              // @@ TODO: put absolute scope overrides into global_vars.
+              //
+              assert (!(p.first == '!' || (vo.dir && vo.dir->absolute ())));
+
+              cp.ovrs.push_back (move (vo));
+            }
+          }
+        });
+
+      configure_ctx = pkg_configure_context (
+        o, move (configure_global_vars), vof);
+
+      // Only global in configure_global_vars.
+      //
+      assert (configure_ctx->var_overrides.empty ());
+    }
+#endif
+
     if (progress)
     {
       prog_i = 0;
@@ -5606,7 +5712,8 @@ namespace bpkg
                          t,
                          sp,
                          move (cp.res),
-                         p.disfigure,
+                         configure_ctx,
+                         cp.ovrs,
                          simulate);
         }
         else // Dependent.
@@ -5616,7 +5723,8 @@ namespace bpkg
                          t,
                          sp,
                          move (cp.res),
-                         false /* disfigured */,
+                         configure_ctx,
+                         cp.ovrs,
                          simulate);
         }
       }
@@ -5643,6 +5751,10 @@ namespace bpkg
       }
     }
 
+#ifndef BPKG_OUTPROC_CONFIGURE
+    configure_ctx.reset (); // Free.
+#endif
+
     // Clear the progress if shown.
     //
     if (progress)