Pass const scope& where modification should not happen

11 files changed, 65 insertions, 49 deletions

diff --git a/build2/cc/common b/build2/cc/common
index c11e733..06df4c3 100644
--- a/build2/cc/common
+++ b/build2/cc/common
@@ -184,7 +184,7 @@ namespace build2
       //
     public:
       void
-      process_libraries (scope&,
+      process_libraries (const scope&,
                          lorder,
                          const dir_paths&,
                          file&,
@@ -210,7 +210,7 @@ namespace build2
 
     private:
       file&
-      resolve_library (scope&,
+      resolve_library (const scope&,
                        name,
                        lorder,
                        const dir_paths&,
@@ -222,10 +222,10 @@ namespace build2
                       const prerequisite_key&) const;
 
       dir_paths
-      extract_library_dirs (scope&) const;
+      extract_library_dirs (const scope&) const;
 
       bool
-      pkgconfig_extract (scope&,
+      pkgconfig_extract (const scope&,
                          bin::lib&,
                          bin::liba*,
                          bin::libs*,
diff --git a/build2/cc/common.cxx b/build2/cc/common.cxx
index aa0a45b..e7b26a1 100644
--- a/build2/cc/common.cxx
+++ b/build2/cc/common.cxx
@@ -46,7 +46,7 @@ namespace build2
     //
     void common::
     process_libraries (
-      scope& top_bs,
+      const scope& top_bs,
       lorder top_lo,
       const dir_paths& top_sysd,
       file& l,
@@ -183,7 +183,7 @@ namespace build2
         proc_lib (&l, p, s);
       }
 
-      scope& bs (t == nullptr || cc ? top_bs : l.base_scope ());
+      const scope& bs (t == nullptr || cc ? top_bs : l.base_scope ());
       optional<lorder> lo;                       // Calculate lazily.
       const dir_paths* sysd (nullptr);           // Resolve lazily.
 
@@ -386,7 +386,7 @@ namespace build2
     // that's the only way to guarantee it will be up-to-date.
     //
     file& common::
-    resolve_library (scope& s,
+    resolve_library (const scope& s,
                      name n,
                      lorder lo,
                      const dir_paths& sysd,
@@ -657,7 +657,7 @@ namespace build2
         //
         if (cid == "msvc")
         {
-          scope& rs (*p.scope->root_scope ());
+          const scope& rs (*p.scope->root_scope ());
           const process_path& ld (cast<process_path> (rs["bin.ld.path"]));
 
           if (s == nullptr && !sn.empty ())
@@ -821,7 +821,7 @@ namespace build2
     }
 
     dir_paths common::
-    extract_library_dirs (scope& bs) const
+    extract_library_dirs (const scope& bs) const
     {
       dir_paths r;
 
diff --git a/build2/cc/compile b/build2/cc/compile
index 11b3919..b6fc7d6 100644
--- a/build2/cc/compile
+++ b/build2/cc/compile
@@ -40,10 +40,10 @@ namespace build2
 
     private:
       void
-      append_lib_options (scope&, cstrings&, target&, lorder) const;
+      append_lib_options (const scope&, cstrings&, target&, lorder) const;
 
       void
-      hash_lib_options (scope&, sha256&, target&, lorder) const;
+      hash_lib_options (const scope&, sha256&, target&, lorder) const;
 
       // Mapping of include prefixes (e.g., foo in <foo/bar>) for auto-
       // generated headers to directories where they will be generated.
@@ -61,15 +61,15 @@ namespace build2
       append_prefixes (prefix_map&, target&, const variable&) const;
 
       void
-      append_lib_prefixes (scope&, prefix_map&, target&, lorder) const;
+      append_lib_prefixes (const scope&, prefix_map&, target&, lorder) const;
 
       prefix_map
-      build_prefix_map (scope&, target&, lorder) const;
+      build_prefix_map (const scope&, target&, lorder) const;
 
       // Reverse-lookup target type from extension.
       //
       const target_type*
-      map_extension (scope&, const string&, const string&) const;
+      map_extension (const scope&, const string&, const string&) const;
 
       // Header dependency injection.
       //
diff --git a/build2/cc/compile.cxx b/build2/cc/compile.cxx
index bc35272..2176b82 100644
--- a/build2/cc/compile.cxx
+++ b/build2/cc/compile.cxx
@@ -76,7 +76,10 @@ namespace build2
     // (first one is cc.export.*) recursively, prerequisite libraries first.
     //
     void compile::
-    append_lib_options (scope& bs, cstrings& args, target& t, lorder lo) const
+    append_lib_options (const scope& bs,
+                        cstrings& args,
+                        target& t,
+                        lorder lo) const
     {
       auto opt = [&args, this] (file& l, const string& t, bool com, bool exp)
       {
@@ -117,7 +120,7 @@ namespace build2
     }
 
     void compile::
-    hash_lib_options (scope& bs, sha256& cs, target& t, lorder lo) const
+    hash_lib_options (const scope& bs, sha256& cs, target& t, lorder lo) const
     {
       auto opt = [&cs, this] (file& l, const string& t, bool com, bool exp)
       {
@@ -156,7 +159,10 @@ namespace build2
     // recursively, prerequisite libraries first.
     //
     void compile::
-    append_lib_prefixes (scope& bs, prefix_map& m, target& t, lorder lo) const
+    append_lib_prefixes (const scope& bs,
+                         prefix_map& m,
+                         target& t,
+                         lorder lo) const
     {
       auto opt = [&m, this] (file& l, const string& t, bool com, bool exp)
       {
@@ -199,8 +205,8 @@ namespace build2
       file& t (static_cast<file&> (xt));
       const match_data& md (t.data<match_data> ());
 
-      scope& bs (t.base_scope ());
-      scope& rs (*bs.root_scope ());
+      const scope& bs (t.base_scope ());
+      const scope& rs (*bs.root_scope ());
       otype ct (compile_type (t));
 
       // Derive file name from target name.
@@ -405,7 +411,7 @@ namespace build2
     // Reverse-lookup target type from extension.
     //
     const target_type* compile::
-    map_extension (scope& s, const string& n, const string& e) const
+    map_extension (const scope& s, const string& n, const string& e) const
     {
       // We will just have to try all of the possible ones, in the "most
       // likely to match" order.
@@ -442,7 +448,7 @@ namespace build2
       // "imported as installed" library), then it can't possibly
       // generate any headers for us.
       //
-      scope* rs (t.base_scope ().root_scope ());
+      const scope* rs (t.base_scope ().root_scope ());
       if (rs == nullptr)
         return;
 
@@ -526,7 +532,9 @@ namespace build2
     }
 
     auto compile::
-    build_prefix_map (scope& bs, target& t, lorder lo) const -> prefix_map
+    build_prefix_map (const scope& bs,
+                      target& t,
+                      lorder lo) const -> prefix_map
     {
       prefix_map m;
 
@@ -737,8 +745,8 @@ namespace build2
             info << "while extracting header dependencies from " << src;
           }));
 
-      scope& bs (t.base_scope ());
-      scope& rs (*bs.root_scope ());
+      const scope& bs (t.base_scope ());
+      const scope& rs (*bs.root_scope ());
 
       // Initialize lazily, only if required.
       //
@@ -937,8 +945,8 @@ namespace build2
           //
           dir_path out;
 
-          scope& bs (scopes.find (d));
-          if (scope* rs = bs.root_scope ())
+          const scope& bs (scopes.find (d));
+          if (const scope* rs = bs.root_scope ())
           {
             tt = map_extension (bs, n, e);
 
@@ -1403,8 +1411,8 @@ namespace build2
           return p.second;
       }
 
-      scope& bs (t.base_scope ());
-      scope& rs (*bs.root_scope ());
+      const scope& bs (t.base_scope ());
+      const scope& rs (*bs.root_scope ());
 
       otype ct (compile_type (t));
       lorder lo (link_order (bs, ct));
diff --git a/build2/cc/link b/build2/cc/link
index 5f28204..d1b0e7a 100644
--- a/build2/cc/link
+++ b/build2/cc/link
@@ -71,13 +71,13 @@ namespace build2
       // Library handling.
       //
       void
-      append_libraries (strings&, file&, bool, scope&, lorder) const;
+      append_libraries (strings&, file&, bool, const scope&, lorder) const;
 
       void
-      hash_libraries (sha256&, file&, bool, scope&, lorder) const;
+      hash_libraries (sha256&, file&, bool, const scope&, lorder) const;
 
       void
-      rpath_libraries (strings&, target&, scope&, lorder, bool) const;
+      rpath_libraries (strings&, target&, const scope&, lorder, bool) const;
 
       // Windows rpath emulation (windows-rpath.cxx).
       //
@@ -93,13 +93,13 @@ namespace build2
       using windows_dlls = std::set<windows_dll>;
 
       timestamp
-      windows_rpath_timestamp (file&, scope&, lorder) const;
+      windows_rpath_timestamp (file&, const scope&, lorder) const;
 
       windows_dlls
-      windows_rpath_dlls (file&, scope&, lorder) const;
+      windows_rpath_dlls (file&, const scope&, lorder) const;
 
       void
-      windows_rpath_assembly (file&, scope&, lorder,
+      windows_rpath_assembly (file&, const scope&, lorder,
                               const string&,
                               timestamp,
                               bool) const;
diff --git a/build2/cc/link.cxx b/build2/cc/link.cxx
index 6de294a..d85faed 100644
--- a/build2/cc/link.cxx
+++ b/build2/cc/link.cxx
@@ -322,8 +322,8 @@ namespace build2
 
       file& t (static_cast<file&> (xt));
 
-      scope& bs (t.base_scope ());
-      scope& rs (*bs.root_scope ());
+      const scope& bs (t.base_scope ());
+      const scope& rs (*bs.root_scope ());
 
       otype lt (link_type (t));
       lorder lo (link_order (bs, lt));
@@ -657,7 +657,7 @@ namespace build2
     void link::
     append_libraries (strings& args,
                       file& l, bool la,
-                      scope& bs, lorder lo) const
+                      const scope& bs, lorder lo) const
     {
       // Note: lack of the "small function object" optimization will really
       // kill us here since we are called in a loop.
@@ -704,7 +704,11 @@ namespace build2
     }
 
     void link::
-    hash_libraries (sha256& cs, file& l, bool la, scope& bs, lorder lo) const
+    hash_libraries (sha256& cs,
+                    file& l,
+                    bool la,
+                    const scope& bs,
+                    lorder lo) const
     {
       bool win (tclass == "windows");
 
@@ -747,7 +751,9 @@ namespace build2
 
     void link::
     rpath_libraries (strings& args,
-                     target& t, scope& bs, lorder lo,
+                     target& t,
+                     const scope& bs,
+                     lorder lo,
                      bool for_install) const
     {
       // Use -rpath-link on targets that support it (Linux, *BSD). Note
@@ -887,8 +893,8 @@ namespace build2
 
       file& t (static_cast<file&> (xt));
 
-      scope& bs (t.base_scope ());
-      scope& rs (*bs.root_scope ());
+      const scope& bs (t.base_scope ());
+      const scope& rs (*bs.root_scope ());
 
       otype lt (link_type (t));
       lorder lo (link_order (bs, lt));
diff --git a/build2/cc/pkgconfig.cxx b/build2/cc/pkgconfig.cxx
index 6c8159f..d32cd61 100644
--- a/build2/cc/pkgconfig.cxx
+++ b/build2/cc/pkgconfig.cxx
@@ -37,7 +37,7 @@ namespace build2
     // search_library() POV.
     //
     bool common::
-    pkgconfig_extract (scope& s,
+    pkgconfig_extract (const scope& s,
                        lib& lt,
                        liba* at,
                        libs* st,
diff --git a/build2/cc/utility b/build2/cc/utility
index b481202..050b645 100644
--- a/build2/cc/utility
+++ b/build2/cc/utility
@@ -37,7 +37,7 @@ namespace build2
     // same directory have to have the same link order.
     //
     lorder
-    link_order (scope& base, otype);
+    link_order (const scope& base, otype);
 
     // Given the link order return the library member (liba or libs) to link.
     //
diff --git a/build2/cc/utility.cxx b/build2/cc/utility.cxx
index f8a0afc..5c5d1fe 100644
--- a/build2/cc/utility.cxx
+++ b/build2/cc/utility.cxx
@@ -18,7 +18,7 @@ namespace build2
     using namespace bin;
 
     lorder
-    link_order (scope& bs, otype ot)
+    link_order (const scope& bs, otype ot)
     {
       // Initialize to suppress 'may be used uninitialized' warning produced
       // by MinGW GCC 5.4.0.
diff --git a/build2/cc/windows-manifest.cxx b/build2/cc/windows-manifest.cxx
index 44d8f7b..b0b0feb 100644
--- a/build2/cc/windows-manifest.cxx
+++ b/build2/cc/windows-manifest.cxx
@@ -43,7 +43,7 @@ namespace build2
     {
       tracer trace (x, "windows_manifest");
 
-      scope& rs (t.root_scope ());
+      const scope& rs (t.root_scope ());
 
       const char* pa (windows_manifest_arch (cast<string> (rs[x_target_cpu])));
 
diff --git a/build2/cc/windows-rpath.cxx b/build2/cc/windows-rpath.cxx
index 35d83cc..00911d4 100644
--- a/build2/cc/windows-rpath.cxx
+++ b/build2/cc/windows-rpath.cxx
@@ -46,7 +46,7 @@ namespace build2
     // adding to the assembly or timestamp_nonexistent if there aren't any.
     //
     timestamp link::
-    windows_rpath_timestamp (file& t, scope& bs, lorder lo) const
+    windows_rpath_timestamp (file& t, const scope& bs, lorder lo) const
     {
       timestamp r (timestamp_nonexistent);
 
@@ -116,7 +116,9 @@ namespace build2
     // duplicates).
     //
     auto link::
-    windows_rpath_dlls (file& t, scope& bs, lorder lo) const -> windows_dlls
+    windows_rpath_dlls (file& t,
+                        const scope& bs,
+                        lorder lo) const -> windows_dlls
     {
       windows_dlls r;
 
@@ -204,7 +206,7 @@ namespace build2
     //
     void link::
     windows_rpath_assembly (file& t,
-                            scope& bs,
+                            const scope& bs,
                             lorder lo,
                             const string& tcpu,
                             timestamp ts,
@@ -276,7 +278,7 @@ namespace build2
             << "                    processorArchitecture='" << pa << "'\n"
             << "                    version='0.0.0.0'/>\n";
 
-        scope& as (*t.root_scope ().weak_scope ()); // Amalgamation scope.
+        const scope& as (*t.root_scope ().weak_scope ()); // Amalgamation.
 
         auto link = [&as, &ad] (const path& f, const path& l)
         {