Fold translated *.std options into compiler mode options

This way they are accessible in ad hoc recipes.

8 files changed, 35 insertions, 55 deletions

diff --git a/libbuild2/c/init.cxx b/libbuild2/c/init.cxx
index 7760808..38ee3d2 100644
--- a/libbuild2/c/init.cxx
+++ b/libbuild2/c/init.cxx
@@ -36,23 +36,23 @@ namespace build2
       explicit
       config_module (config_data&& d): cc::config_module (move (d)) {}
 
-      virtual strings
+      virtual void
       translate_std (const compiler_info&,
                      const target_triplet&,
                      scope&,
+                     strings&,
                      const string*) const override;
     };
 
     using cc::module;
 
-    strings config_module::
+    void config_module::
     translate_std (const compiler_info& ci,
                    const target_triplet&,
                    scope& rs,
+                   strings& mode,
                    const string* v) const
     {
-      strings r;
-
       switch (ci.class_)
       {
       case compiler_class::msvc:
@@ -116,13 +116,11 @@ namespace build2
             else if (*v == "90") o += "c90";
             else o += *v; // In case the user specifies `gnuNN` or some such.
 
-            r.push_back (move (o));
+            mode.insert (mode.begin (), move (o));
           }
           break;
         }
       }
-
-      return r;
     }
 
     static const char* const hinters[] = {"cxx", nullptr};
@@ -340,8 +338,6 @@ namespace build2
         cast<strings>        (rs[cm.x_mode]),
         cast<target_triplet> (rs[cm.x_target]),
 
-        cm.tstd,
-
         false, // No C modules yet.
         false, // No __symexport support since no modules.
 
diff --git a/libbuild2/cc/common.hxx b/libbuild2/cc/common.hxx
index 6df1ab0..781fcf5 100644
--- a/libbuild2/cc/common.hxx
+++ b/libbuild2/cc/common.hxx
@@ -155,8 +155,6 @@ namespace build2
       const string& tsys;           // x.target.system
       const string& tclass;         // x.target.class
 
-      const strings& tstd;          // Translated x_std value (options).
-
       bool modules;                 // x.features.modules
       bool symexport;               // x.features.symexport
 
@@ -218,7 +216,6 @@ namespace build2
             const process_path& path,
             const strings& mode,
             const target_triplet& tgt,
-            const strings& std,
             bool fm,
             bool fs,
             const dir_paths& sld,
@@ -239,7 +236,6 @@ namespace build2
             cmaj (mj), cmin (mi),
             cpath (path), cmode (mode),
             ctgt (tgt), tsys (ctgt.system), tclass (ctgt.class_),
-            tstd (std),
             modules (fm),
             symexport (fs),
             xlate_hdr (nullptr),
diff --git a/libbuild2/cc/compile-rule.cxx b/libbuild2/cc/compile-rule.cxx
index 29d79d0..29312a8 100644
--- a/libbuild2/cc/compile-rule.cxx
+++ b/libbuild2/cc/compile-rule.cxx
@@ -893,7 +893,6 @@ namespace build2
 
           append_options (cs, t, c_coptions);
           append_options (cs, t, x_coptions);
-          append_options (cs, tstd);
 
           if (ot == otype::s)
           {
@@ -3057,8 +3056,6 @@ namespace build2
 
           append_options (args, t, c_coptions, werror);
           append_options (args, t, x_coptions, werror);
-          append_options (args, tstd,
-                          tstd.size () - (modules && clang ? 1 : 0));
 
           switch (cclass)
           {
@@ -3127,7 +3124,8 @@ namespace build2
                 }
               }
 
-              append_options (args, cmode);
+              append_options (args, cmode,
+                              cmode.size () - (modules && clang ? 1 : 0));
               append_sys_inc_options (args); // Extra system header dirs (last).
 
               // Setup the dynamic module mapper if needed.
@@ -4312,8 +4310,6 @@ namespace build2
 
           append_options (args, t, c_coptions, werror);
           append_options (args, t, x_coptions, werror);
-          append_options (args, tstd,
-                          tstd.size () - (modules && clang ? 1 : 0));
 
           append_header_options (env, args, header_args, a, t, md, dd);
 
@@ -4359,7 +4355,8 @@ namespace build2
                 }
               }
 
-              append_options (args, cmode);
+              append_options (args, cmode,
+                              cmode.size () - (modules && clang ? 1 : 0));
               append_sys_inc_options (args);
 
               args.push_back ("-E");
@@ -5916,7 +5913,6 @@ namespace build2
 
       append_options (args, t, c_coptions);
       append_options (args, t, x_coptions);
-      append_options (args, tstd);
 
       string out, out1;                    // Output options storage.
       small_vector<string, 2> header_args; // Header unit options storage.
diff --git a/libbuild2/cc/gcc.cxx b/libbuild2/cc/gcc.cxx
index 29bf824..30f2092 100644
--- a/libbuild2/cc/gcc.cxx
+++ b/libbuild2/cc/gcc.cxx
@@ -77,7 +77,6 @@ namespace build2
       // line are factored into the output.
       //
       cstrings args {xc.recall_string ()};
-      append_options (args, tstd);
       append_options (args, rs, x_mode);
 
       // Compile as.
@@ -253,7 +252,6 @@ namespace build2
       size_t rn (r.size ());
 
       cstrings args {xc.recall_string ()};
-      append_options (args, tstd);
       append_options (args, rs, x_mode);
       args.push_back ("-print-search-dirs");
       args.push_back (nullptr);
diff --git a/libbuild2/cc/link-rule.cxx b/libbuild2/cc/link-rule.cxx
index 9b526ee..e94f538 100644
--- a/libbuild2/cc/link-rule.cxx
+++ b/libbuild2/cc/link-rule.cxx
@@ -2346,7 +2346,6 @@ namespace build2
         {
           append_options (args, t, c_coptions);
           append_options (args, t, x_coptions);
-          append_options (args, tstd);
         }
 
         // Note that these come in the reverse order of coptions since the
diff --git a/libbuild2/cc/module.cxx b/libbuild2/cc/module.cxx
index a80d770..eed2510 100644
--- a/libbuild2/cc/module.cxx
+++ b/libbuild2/cc/module.cxx
@@ -389,6 +389,7 @@ namespace build2
 
       // config.x.std overrides x.std
       //
+      strings& mode (cast<strings> (rs.assign (x_mode))); // Set by guess.
       {
         lookup l (lookup_config (rs, config_x_std));
 
@@ -401,9 +402,10 @@ namespace build2
         else
           v = cast_null<string> (rs[x_std]);
 
-        // Translate x_std value (if any) to the compiler option(s) (if any).
+        // Translate x_std value (if any) to the compiler option(s) (if any)
+        // and fold them into the compiler mode.
         //
-        tstd = translate_std (xi, tt, rs, v);
+        translate_std (xi, tt, rs, mode, v);
       }
 
       // config.x.translatable_header
@@ -546,8 +548,6 @@ namespace build2
       //
       if (verb >= (new_config ? 2 : 3))
       {
-        const strings& mode (cast<strings> (rs[x_mode]));
-
         diag_record dr (text);
 
         {
@@ -609,12 +609,6 @@ namespace build2
             dr << "\n  c stdlib   " << xi.c_stdlib;
         }
 
-        if (!tstd.empty ())
-        {
-          dr << "\n  std       "; // One less space.
-          for (const string& o: tstd) dr << ' ' << o;
-        }
-
         if (!xi.pattern.empty ()) // Note: bin_pattern printed by bin
         {
           dr << "\n  pattern    " << xi.pattern;
diff --git a/libbuild2/cc/module.hxx b/libbuild2/cc/module.hxx
index 28e8d51..81456b3 100644
--- a/libbuild2/cc/module.hxx
+++ b/libbuild2/cc/module.hxx
@@ -44,17 +44,17 @@ namespace build2
       init (scope&, const location&, const variable_map&);
 
       // Translate the x.std value (if any) to the standard-selecting
-      // option(s) (if any). May also check/set x.features.* variables on the
-      // root scope.
+      // option(s) (if any) and fold them (normally by pre-pending) into the
+      // compiler mode options. This function may also check/set x.features.*
+      // variables on the root scope.
       //
-      virtual strings
+      virtual void
       translate_std (const compiler_info&,
                      const target_triplet&,
                      scope&,
+                     strings&,
                      const string*) const = 0;
 
-      strings tstd;
-
       const compiler_info* x_info;
 
       // Temporary storage for data::sys_*_dirs_*.
diff --git a/libbuild2/cxx/init.cxx b/libbuild2/cxx/init.cxx
index bb6653d..a43dcb2 100644
--- a/libbuild2/cxx/init.cxx
+++ b/libbuild2/cxx/init.cxx
@@ -37,23 +37,23 @@ namespace build2
       explicit
       config_module (config_data&& d): cc::config_module (move (d)) {}
 
-      virtual strings
+      virtual void
       translate_std (const compiler_info&,
                      const target_triplet&,
                      scope&,
+                     strings&,
                      const string*) const override;
     };
 
     using cc::module;
 
-    strings config_module::
+    void config_module::
     translate_std (const compiler_info& ci,
                    const target_triplet& tt,
                    scope& rs,
+                   strings& mode,
                    const string* v) const
     {
-      strings r;
-
       compiler_type ct (ci.id.type);
       compiler_class cl (ci.class_);
       uint64_t mj (ci.version.major);
@@ -104,6 +104,11 @@ namespace build2
 
       string o;
 
+      auto prepend = [&mode, i = mode.begin ()] (string o) mutable
+      {
+        i = mode.insert (i, move (o)) + 1;
+      };
+
       switch (cl)
       {
       case compiler_class::msvc:
@@ -182,7 +187,7 @@ namespace build2
           }
 
           if (!o.empty ())
-            r.push_back (move (o));
+            prepend (move (o));
 
           break;
         }
@@ -257,7 +262,7 @@ namespace build2
           }
 
           if (!o.empty ())
-            r.push_back (move (o));
+            prepend (move (o));
 
           break;
         }
@@ -275,7 +280,7 @@ namespace build2
             // the experimenters to enjoy.
             //
             if (mj > 19 || (mj == 19 && mi >= 12))
-              r.push_back ("/permissive-");
+              prepend ("/permissive-");
 
             break;
           }
@@ -301,14 +306,14 @@ namespace build2
               //
               if (mj > 19 || (mj == 19 && mi >= (l ? 10 : 12)))
               {
-                r.push_back (
+                prepend (
                   mj > 19  || mi >= 24     ?
                   "/D__cpp_modules=201810" : // p1103 (merged modules)
                   mj == 19 || mi >= 12     ?
                   "/D__cpp_modules=201704" : // p0629r0 (export module M;)
                   "/D__cpp_modules=201703"); // n4647   (       module M;)
 
-                r.push_back ("/experimental:module");
+                prepend ("/experimental:module");
                 modules = true;
               }
               break;
@@ -328,7 +333,7 @@ namespace build2
                 // Currently defines __cpp_modules=201810 which is said to
                 // correspond to p1103 (merged modules).
                 //
-                r.push_back ("-fmodules-ts");
+                prepend ("-fmodules-ts");
                 modules = true;
               }
               break;
@@ -350,8 +355,8 @@ namespace build2
               //
               if (l)
               {
-                r.push_back ("-D__cpp_modules=201704"); // p0629r0
-                r.push_back ("-fmodules-ts");
+                prepend ("-D__cpp_modules=201704"); // p0629r0
+                mode.push_back ("-fmodules-ts"); // For the hack to work.
                 modules = true;
               }
               break;
@@ -364,8 +369,6 @@ namespace build2
 
       rs.assign (v_m) = modules;
       //rs.assign (v_c) = concepts;
-
-      return r;
     }
 
     static const char* const hinters[] = {"c", nullptr};
@@ -627,8 +630,6 @@ namespace build2
         cast<strings>        (rs[cm.x_mode]),
         cast<target_triplet> (rs[cm.x_target]),
 
-        cm.tstd,
-
         modules,
         symexport,