Rework C/C++ standard translation in preparation for experimental/modules

Also fix bug in clang-apple versioning.

1 files changed, 59 insertions, 45 deletions

diff --git a/build2/c/init.cxx b/build2/c/init.cxx
index ada8596..998bc40 100644
--- a/build2/c/init.cxx
+++ b/build2/c/init.cxx
@@ -20,6 +20,7 @@ namespace build2
 {
   namespace c
   {
+    using cc::compiler_id;
     using cc::compiler_info;
 
     class config_module: public cc::config_module
@@ -29,64 +30,77 @@ namespace build2
       config_module (config_data&& d)
           : config_data (move (d)), cc::config_module (move (d)) {}
 
-      string
+      strings
       translate_std (const compiler_info&,
                      scope&,
-                     const string&) const override;
+                     const string*) const override;
     };
 
     using cc::module;
 
-    string config_module::
-    translate_std (const compiler_info& ci, scope& rs, const string& v) const
+    strings config_module::
+    translate_std (const compiler_info& ci, scope& rs, const string* v) const
     {
-      string r;
+      strings r;
 
-      if (ci.id.type == "msvc")
+      switch (ci.id.value ())
       {
-        // Standard-wise, with VC you get what you get. The question is
-        // whether we should verify that the requested standard is provided by
-        // this VC version. And if so, from which version should we say VC
-        // supports 90, 99, and 11? We should probably be as loose as possible
-        // here since the author will always be able to tighten (but not
-        // loosen) this in the buildfile (i.e., detect unsupported versions).
-        //
-        // The state of affairs seem to be (from Herb Sutter's blog):
-        //
-        // 10.0 - most of C95 plus a few C99 features
-        // 11.0 - partial support for the C++11 subset of C11
-        // 12.0 - more C11 features from the C++11 subset, most of C99
-        //
-        // So let's say C99 is supported from 10.0 and C11 from 11.0. And C90
-        // is supported by everything we care to support.
-        //
-        if (v != "90")
+      case compiler_id::msvc:
         {
-          uint64_t cver (ci.version.major);
-
-          if ((v == "99" && cver < 16) || // Since VS2010/10.0.
-              (v == "11" && cver < 17))   // Since VS2012/11.0.
+          // Standard-wise, with VC you get what you get. The question is
+          // whether we should verify that the requested standard is provided
+          // by this VC version. And if so, from which version should we say
+          // VC supports 90, 99, and 11? We should probably be as loose as
+          // possible here since the author will always be able to tighten
+          // (but not loosen) this in the buildfile (i.e., detect unsupported
+          // versions).
+          //
+          // The state of affairs seem to be (from Herb Sutter's blog):
+          //
+          // 10.0 - most of C95 plus a few C99 features
+          // 11.0 - partial support for the C++11 subset of C11
+          // 12.0 - more C11 features from the C++11 subset, most of C99
+          //
+          // So let's say C99 is supported from 10.0 and C11 from 11.0. And
+          // C90 is supported by everything we care to support.
+          //
+          if (v == nullptr)
+            ;
+          else if (*v != "90")
           {
-            fail << "C" << v << " is not supported by " << ci.signature <<
-              info << "required by " << project (rs) << '@' << rs.out_path ();
+            uint64_t cver (ci.version.major);
+
+            if ((*v == "99" && cver < 16) || // Since VS2010/10.0.
+                (*v == "11" && cver < 17))   // Since VS2012/11.0.
+            {
+              fail << "C" << *v << " is not supported by " << ci.signature <<
+                info << "required by " << project (rs) << '@' << rs.out_path ();
+            }
           }
+          break;
+        }
+      case compiler_id::gcc:
+      case compiler_id::clang:
+      case compiler_id::icc:
+        {
+          // 90 and 89 are the same standard. Translate 99 to 9x and 11 to 1x
+          // for compatibility with older versions of the compilers.
+          //
+          if (v == nullptr)
+            ;
+          else
+          {
+            string o ("-std=");
+
+            if      (*v == "90") o += "c90";
+            else if (*v == "99") o += "c9x";
+            else if (*v == "11") o += "c1x";
+            else o += *v; // In case the user specifies e.g., 'gnu11'.
+
+            r.push_back (move (o));
+          }
+          break;
         }
-      }
-      else
-      {
-        // 90 and 89 are the same standard. Translate 99 to 9x and 11 to 1x
-        // for compatibility with older versions of the compilers.
-        //
-        r = "-std=";
-
-        if (v == "90")
-          r += "c90";
-        else if (v == "99")
-          r += "c9x";
-        else if (v == "11")
-          r += "c1x";
-        else
-          r += v; // In case the user specifies something like 'gnu11'.
       }
 
       return r;