Add -frust-cfg=value option for adding config options

This adds the initial support for config expansion on custom config values
it need support for parsing options such as feature=test with apropriate
error handling withing Session::handle_cfg_option(const std::string&).

This also applies the mark_for_strip checks only on AST::Functions and
will need applied to the rest of the crate in #872.

Addresses #889

1 files changed, 19 insertions, 2 deletions

diff --git a/gcc/rust/rust-session-manager.cc b/gcc/rust/rust-session-manager.cc
index 9650086..c930f55 100644
--- a/gcc/rust/rust-session-manager.cc
+++ b/gcc/rust/rust-session-manager.cc
@@ -353,9 +353,11 @@ Session::handle_option (
     case OPT_I:
       // TODO: add search path
       break;
+
     case OPT_L:
       // TODO: add library link path or something
       break;
+
     case OPT_frust_crate_:
       // set the crate name
       if (arg != nullptr)
@@ -363,6 +365,7 @@ Session::handle_option (
       else
 	ret = false;
       break;
+
     case OPT_frust_dump_:
       // enable dump and return whether this was successful
       if (arg != nullptr)
@@ -374,17 +377,31 @@ Session::handle_option (
 	  ret = false;
 	}
       break;
+
     case OPT_frust_mangling_:
       Compile::Mangler::set_mangling (flag_rust_mangling);
-    // no option handling for -o
+      break;
+
+    case OPT_frust_cfg_:
+      ret = handle_cfg_option (std::string (arg));
+      break;
+
     default:
-      // return 1 to indicate option is valid
       break;
     }
 
   return ret;
 }
 
+bool
+Session::handle_cfg_option (const std::string &value)
+{
+  // rustc doesn't seem to error on any duplicate key
+  // TODO handle feature=bla and relevant error handling in parsing
+  options.target_data.insert_key (value);
+  return true;
+}
+
 /* Enables a certain dump depending on the name passed in. Returns true if name
  * is valid, false otherwise. */
 bool