Optimize internal scope implementation

5 files changed, 64 insertions, 70 deletions

diff --git a/libbuild2/cc/common.hxx b/libbuild2/cc/common.hxx
index 6e36f8e..7d8424f 100644
--- a/libbuild2/cc/common.hxx
+++ b/libbuild2/cc/common.hxx
@@ -180,14 +180,16 @@ namespace build2
       bool modules;                 // x.features.modules
       bool symexport;               // x.features.symexport
 
-      const string* internal_scope; // x.internal.scope
-      const scope*  internal_scope_current;
+      enum class internal_scope {current, base, root, bundle, strong, weak};
 
-      const strings* c_internal_libs; // cc.internal.libs
-      const strings* x_internal_libs; // x.internal.libs
+      optional<internal_scope> iscope; // x.internal.scope
+      const scope*             iscope_current;
 
       const scope*
-      effective_internal_scope (const scope& bs) const;
+      effective_iscope (const scope& bs) const;
+
+      const strings* c_ilibs; // cc.internal.libs
+      const strings* x_ilibs; // x.internal.libs
 
       build2::cc::importable_headers* importable_headers;
 
@@ -250,7 +252,7 @@ namespace build2
             const string& env_cs,
             bool fm,
             bool fs,
-            const string* ints, const scope* intsc,
+            optional<internal_scope> is, const scope* isc,
             const strings* cils, const strings* xils,
             const dir_paths& sld,
             const dir_paths& shd,
@@ -274,8 +276,8 @@ namespace build2
             env_checksum (env_cs),
             modules (fm),
             symexport (fs),
-            internal_scope (ints), internal_scope_current (intsc),
-            c_internal_libs (cils), x_internal_libs (xils),
+            iscope (is), iscope_current (isc),
+            c_ilibs (cils), x_ilibs (xils),
             importable_headers (nullptr),
             sys_lib_dirs (sld), sys_hdr_dirs (shd), sys_mod_dirs (smd),
             sys_lib_dirs_mode (slm), sys_hdr_dirs_mode (shm),
diff --git a/libbuild2/cc/common.ixx b/libbuild2/cc/common.ixx
index ce28890..417efbd 100644
--- a/libbuild2/cc/common.ixx
+++ b/libbuild2/cc/common.ixx
@@ -6,29 +6,22 @@ namespace build2
   namespace cc
   {
     inline const scope* data::
-    effective_internal_scope (const scope& bs) const
+    effective_iscope (const scope& bs) const
     {
-      if (internal_scope == nullptr)
-        return nullptr;
-      else
+      if (iscope)
       {
-        const string& s (*internal_scope);
-
-        if (s == "current")
-          return internal_scope_current;
-        else if (s == "base")
-          return &bs;
-        else if (s == "root")
-          return bs.root_scope ();
-        else if (s == "bundle")
-          return bs.bundle_scope ();
-        else if (s == "strong")
-          return bs.strong_scope ();
-        else if (s == "weak")
-          return bs.weak_scope ();
-        else
-          return nullptr;
+        switch (*iscope)
+        {
+        case internal_scope::current: return iscope_current;
+        case internal_scope::base:    return &bs;
+        case internal_scope::root:    return bs.root_scope ();
+        case internal_scope::bundle:  return bs.bundle_scope ();
+        case internal_scope::strong:  return bs.strong_scope ();
+        case internal_scope::weak:    return bs.weak_scope ();
+        }
       }
+
+      return nullptr;
     }
   }
 }
diff --git a/libbuild2/cc/compile-rule.cxx b/libbuild2/cc/compile-rule.cxx
index 9149f0c..c6ecf5e 100644
--- a/libbuild2/cc/compile-rule.cxx
+++ b/libbuild2/cc/compile-rule.cxx
@@ -509,22 +509,21 @@ namespace build2
           // are outside of the internal scope provided the library is not
           // whitelisted.
           //
-          auto whitelist = [&l] (const strings* pats)
+          auto whitelist = [&l] (const strings& pats)
           {
-            return (pats != nullptr &&
-                    find_if (pats->begin (), pats->end (),
+            return find_if (pats.begin (), pats.end (),
                             [&l] (const string& pat)
                             {
                               return path_match (l.name, pat);
-                            }) != pats->end ());
+                            }) != pats.end ();
           };
 
           const scope* is (d.is);
 
-          if (is != nullptr && whitelist (c_internal_libs))
+          if (is != nullptr && c_ilibs != nullptr && whitelist (*c_ilibs))
             is = nullptr;
 
-          if (is != nullptr && whitelist (x_internal_libs))
+          if (is != nullptr && x_ilibs != nullptr && whitelist (*x_ilibs))
             is = nullptr;
 
           for (auto i (ops->begin ()), e (ops->end ()); i != e; ++i)
@@ -654,10 +653,7 @@ namespace build2
                             const scope& bs,
                             action a, const file& l, bool la, linfo li) const
     {
-      const scope* is (isystem (*this)
-                       ? effective_internal_scope (bs)
-                       : nullptr);
-
+      const scope* is (isystem (*this) ? effective_iscope (bs) : nullptr);
       append_library_options (ls, args, bs, is, a, l, la, li, nullptr);
     }
 
@@ -667,10 +663,10 @@ namespace build2
                             const scope& bs,
                             action a, const target& t, linfo li) const
     {
-      auto internal_scope = [this, &bs, is = optional<const scope*> ()] () mutable
+      auto iscope = [this, &bs, is = optional<const scope*> ()] () mutable
       {
         if (!is)
-          is = isystem (*this) ? effective_internal_scope (bs) : nullptr;
+          is = isystem (*this) ? effective_iscope (bs) : nullptr;
 
         return *is;
       };
@@ -698,7 +694,7 @@ namespace build2
           {
             append_library_options (ls,
                                     args,
-                                    bs, internal_scope (),
+                                    bs, iscope (),
                                     a, *f, la, li,
                                     &lc);
           }
diff --git a/libbuild2/cc/module.cxx b/libbuild2/cc/module.cxx
index 117c8c9..871cfb6 100644
--- a/libbuild2/cc/module.cxx
+++ b/libbuild2/cc/module.cxx
@@ -473,17 +473,18 @@ namespace build2
       // Note also that we only update x.internal.scope (and not cc.*) to
       // reflect the effective value.
       //
+      const string* iscope_str (nullptr);
       {
         if (lookup l = lookup_config (rs, config_x_internal_scope))       // 1
         {
-          internal_scope = &cast<string> (l);
+          iscope_str = &cast<string> (l);
 
-          if (*internal_scope == "current")
+          if (*iscope_str == "current")
             fail << "'current' value in " << config_x_internal_scope;
         }
         else if (lookup l = rs["config.cc.internal.scope"])               // 2
         {
-          internal_scope = &cast<string> (l);
+          iscope_str = &cast<string> (l);
         }
         else                                                              // 3
         {
@@ -495,31 +496,31 @@ namespace build2
             //
             bool xl (cast_false<bool> (as[string (x) + ".config.loaded"]));
             if (xl)
-              internal_scope = cast_null<string> (as[x_internal_scope]);
+              iscope_str = cast_null<string> (as[x_internal_scope]);
 
-            if (internal_scope == nullptr)
+            if (iscope_str == nullptr)
             {
               if (xl || cast_false<bool> (as["cc.core.config.loaded"]))
-                internal_scope = cast_null<string> (as["cc.internal.scope"]);
+                iscope_str = cast_null<string> (as["cc.internal.scope"]);
             }
 
-            if (internal_scope != nullptr && *internal_scope == "current")
-              internal_scope_current = &as;
+            if (iscope_str != nullptr && *iscope_str == "current")
+              iscope_current = &as;
           }
         }
 
         lookup l;
-        if (internal_scope == nullptr)
+        if (iscope_str == nullptr)
         {
-          internal_scope = cast_null<string> (l = rs[x_internal_scope]);  // 4
+          iscope_str = cast_null<string> (l = rs[x_internal_scope]);      // 4
 
-          if (internal_scope == nullptr)
-            internal_scope = cast_null<string> (rs["cc.internal.scope"]); // 5
+          if (iscope_str == nullptr)
+            iscope_str = cast_null<string> (rs["cc.internal.scope"]);     // 5
         }
 
-        if (internal_scope != nullptr)
+        if (iscope_str != nullptr)
         {
-          const string& s (*internal_scope);
+          const string& s (*iscope_str);
 
           // Assign effective.
           //
@@ -528,17 +529,18 @@ namespace build2
 
           if (s == "current")
           {
-            if (internal_scope_current == nullptr)
-              internal_scope_current = &rs;
+            iscope = internal_scope::current;
+
+            if (iscope_current == nullptr)
+              iscope_current = &rs;
           }
-          else if (s == "base" ||
-                   s == "root" ||
-                   s == "bundle" ||
-                   s == "strong" ||
-                   s == "weak")
-            ;
+          else if (s == "base")   iscope = internal_scope::base;
+          else if (s == "root")   iscope = internal_scope::root;
+          else if (s == "bundle") iscope = internal_scope::bundle;
+          else if (s == "strong") iscope = internal_scope::strong;
+          else if (s == "weak")   iscope = internal_scope::weak;
           else if (s == "global")
-            internal_scope = nullptr; // Nothing to translate;
+            ; // Nothing to translate;
           else
             fail << "invalid " << x_internal_scope << " value '" << s << "'";
         }
@@ -789,14 +791,14 @@ namespace build2
         auto& incs (hdr_dirs.first);
         auto& libs (lib_dirs.first);
 
-        if (verb >= 3 && internal_scope != nullptr)
+        if (verb >= 3 && iscope)
         {
           dr << "\n  int scope  ";
 
-          if (*internal_scope == "current")
-            dr << internal_scope_current->out_path ();
+          if (*iscope == internal_scope::current)
+            dr << iscope_current->out_path ();
           else
-            dr << *internal_scope;
+            dr << *iscope_str;
         }
 
         if (verb >= 3 && !mods.empty ())
diff --git a/libbuild2/cc/module.hxx b/libbuild2/cc/module.hxx
index 5c68482..df7fc70 100644
--- a/libbuild2/cc/module.hxx
+++ b/libbuild2/cc/module.hxx
@@ -63,8 +63,9 @@ namespace build2
 
       // Cached x.internal.scope value.
       //
-      const string* internal_scope = nullptr;
-      const scope*  internal_scope_current = nullptr;
+      using internal_scope = data::internal_scope;
+      optional<internal_scope> iscope;
+      const scope*             iscope_current;
 
       // Temporary storage for data::sys_*_dirs_*.
       //