rules-cc: Support for external toolchains

6 files changed, 452 insertions, 66 deletions

diff --git a/CC/EXPRESSIONS b/CC/EXPRESSIONS
index 994dbf4..d3cc367 100644
--- a/CC/EXPRESSIONS
+++ b/CC/EXPRESSIONS
@@ -2,54 +2,45 @@
   { "vars": ["defaults-transition"]
   , "imports": {"list_provider": ["./", "..", "field_list_provider"]}
   , "expression":
-    { "type": "join"
-    , "$1":
-      { "type": "let*"
-      , "bindings":
-        [ ["fieldname", "defaults"]
-        , ["provider", "CC"]
-        , [ "transition"
-          , {"type": "var", "name": "defaults-transition", "default": null}
-          ]
+    { "type": "let*"
+    , "bindings":
+      [ ["fieldname", "defaults"]
+      , ["provider", "CC"]
+      , [ "transition"
+        , {"type": "var", "name": "defaults-transition", "default": null}
         ]
-      , "body": {"type": "CALL_EXPRESSION", "name": "list_provider"}
-      }
+      ]
+    , "body": {"type": "CALL_EXPRESSION", "name": "list_provider"}
     }
   }
 , "default-CXX":
   { "vars": ["defaults-transition"]
   , "imports": {"list_provider": ["./", "..", "field_list_provider"]}
   , "expression":
-    { "type": "join"
-    , "$1":
-      { "type": "let*"
-      , "bindings":
-        [ ["fieldname", "defaults"]
-        , ["provider", "CXX"]
-        , [ "transition"
-          , {"type": "var", "name": "defaults-transition", "default": null}
-          ]
+    { "type": "let*"
+    , "bindings":
+      [ ["fieldname", "defaults"]
+      , ["provider", "CXX"]
+      , [ "transition"
+        , {"type": "var", "name": "defaults-transition", "default": null}
         ]
-      , "body": {"type": "CALL_EXPRESSION", "name": "list_provider"}
-      }
+      ]
+    , "body": {"type": "CALL_EXPRESSION", "name": "list_provider"}
     }
   }
 , "default-AR":
   { "vars": ["defaults-transition"]
   , "imports": {"list_provider": ["./", "..", "field_list_provider"]}
   , "expression":
-    { "type": "join"
-    , "$1":
-      { "type": "let*"
-      , "bindings":
-        [ ["fieldname", "defaults"]
-        , ["provider", "AR"]
-        , [ "transition"
-          , {"type": "var", "name": "defaults-transition", "default": null}
-          ]
+    { "type": "let*"
+    , "bindings":
+      [ ["fieldname", "defaults"]
+      , ["provider", "AR"]
+      , [ "transition"
+        , {"type": "var", "name": "defaults-transition", "default": null}
         ]
-      , "body": {"type": "CALL_EXPRESSION", "name": "list_provider"}
-      }
+      ]
+    , "body": {"type": "CALL_EXPRESSION", "name": "list_provider"}
     }
   }
 , "default-CFLAGS":
@@ -113,11 +104,51 @@
     , "body": {"type": "CALL_EXPRESSION", "name": "map_provider"}
     }
   }
+, "default-TOOLCHAIN":
+  { "vars": ["defaults-transition"]
+  , "imports": {"map_provider": ["./", "..", "field_map_provider"]}
+  , "expression":
+    { "type": "let*"
+    , "bindings":
+      [ ["fieldname", "defaults"]
+      , ["provider", "TOOLCHAIN"]
+      , [ "transition"
+        , {"type": "var", "name": "defaults-transition", "default": null}
+        ]
+      , ["default", {"type": "empty_map"}]
+      ]
+    , "body": {"type": "CALL_EXPRESSION", "name": "map_provider"}
+    }
+  }
+, "default-NON_SYSTEM_TOOLS":
+  { "vars": ["defaults-transition"]
+  , "expression":
+    { "type": "map_union"
+    , "$1":
+      { "type": "foreach"
+      , "var": "x"
+      , "range": {"type": "FIELD", "name": "defaults"}
+      , "body":
+        { "type": "DEP_PROVIDES"
+        , "dep": {"type": "var", "name": "x"}
+        , "provider": "NON_SYSTEM_TOOLS"
+        , "transition":
+          { "type": "var"
+          , "name": "defaults-transition"
+          , "default": {"type": "empty_map"}
+          }
+        , "default": {"type": "empty_map"}
+        }
+      }
+    }
+  }
 , "defaults-base-provides":
   { "doc": ["Query list-provider from 'base' targets (last wins)"]
   , "vars": ["provider", "default"]
   , "vars_doc":
-    {"provider": ["The name of the list-provider in the provides map."]}
+    { "provider": ["The name of the list-provider in the provides map."]
+    , "default": ["The default if provider is missing (default: [])."]
+    }
   , "imports": {"provider_list": ["./", "..", "field_provider_list"]}
   , "expression":
     { "type": "let*"
@@ -586,6 +617,7 @@
     [ "COMPILER"
     , "COMPILE_FLAGS"
     , "ENV"
+    , "TOOLCHAIN"
     , "srcs"
     , "hdrs"
     , "private-hdrs"
@@ -648,6 +680,10 @@
                     , "name": "cflags-files"
                     , "default": {"type": "empty_map"}
                     }
+                  , { "type": "var"
+                    , "name": "TOOLCHAIN"
+                    , "default": {"type": "empty_map"}
+                    }
                   ]
                 }
               ]
@@ -706,25 +742,64 @@
     }
   }
 , "compiler-cc":
-  { "vars": ["CC", "defaults-transition"]
+  { "vars": ["CC", "TOOLCHAIN_DIR", "NON_SYSTEM_TOOLS", "defaults-transition"]
   , "imports": {"default-CC": "default-CC"}
   , "expression":
     { "type": "var"
     , "name": "CC"
-    , "default": {"type": "CALL_EXPRESSION", "name": "default-CC"}
+    , "default":
+      { "type": "join"
+      , "$1":
+        { "type": "++"
+        , "$1":
+          [ { "type": "if"
+            , "cond":
+              { "type": "lookup"
+              , "key": "CC"
+              , "map": {"type": "var", "name": "NON_SYSTEM_TOOLS"}
+              }
+            , "then": ["./", {"type": "var", "name": "TOOLCHAIN_DIR"}, "/"]
+            }
+          , {"type": "CALL_EXPRESSION", "name": "default-CC"}
+          ]
+        }
+      }
     }
   }
 , "compiler-cxx":
-  { "vars": ["CXX", "defaults-transition"]
+  { "vars": ["CXX", "TOOLCHAIN_DIR", "NON_SYSTEM_TOOLS", "defaults-transition"]
   , "imports": {"default-CXX": "default-CXX"}
   , "expression":
     { "type": "var"
     , "name": "CXX"
-    , "default": {"type": "CALL_EXPRESSION", "name": "default-CXX"}
+    , "default":
+      { "type": "join"
+      , "$1":
+        { "type": "++"
+        , "$1":
+          [ { "type": "if"
+            , "cond":
+              { "type": "lookup"
+              , "key": "CXX"
+              , "map": {"type": "var", "name": "NON_SYSTEM_TOOLS"}
+              }
+            , "then": ["./", {"type": "var", "name": "TOOLCHAIN_DIR"}, "/"]
+            }
+          , {"type": "CALL_EXPRESSION", "name": "default-CXX"}
+          ]
+        }
+      }
     }
   }
 , "compiler":
-  { "vars": ["CC", "CXX", "pure C", "defaults-transition"]
+  { "vars":
+    [ "CC"
+    , "CXX"
+    , "pure C"
+    , "TOOLCHAIN_DIR"
+    , "NON_SYSTEM_TOOLS"
+    , "defaults-transition"
+    ]
   , "imports": {"compiler-cc": "compiler-cc", "compiler-cxx": "compiler-cxx"}
   , "expression":
     { "type": "if"
@@ -825,11 +900,24 @@
     , "objects": "objects"
     , "default-AR": "default-AR"
     , "default-ENV": "default-ENV"
+    , "default-TOOLCHAIN": "default-TOOLCHAIN"
+    , "default-NON_SYSTEM_TOOLS": "default-NON_SYSTEM_TOOLS"
     }
   , "expression":
     { "type": "let*"
     , "bindings":
-      [ ["COMPILER", {"type": "CALL_EXPRESSION", "name": "compiler"}]
+      [ ["TOOLCHAIN_DIR", "toolchain"]
+      , ["TOOLCHAIN", {"type": "CALL_EXPRESSION", "name": "default-TOOLCHAIN"}]
+      , [ "TOOLCHAIN"
+        , { "type": "to_subdir"
+          , "subdir": {"type": "var", "name": "TOOLCHAIN_DIR"}
+          , "$1": {"type": "var", "name": "TOOLCHAIN"}
+          }
+        ]
+      , [ "NON_SYSTEM_TOOLS"
+        , {"type": "CALL_EXPRESSION", "name": "default-NON_SYSTEM_TOOLS"}
+        ]
+      , ["COMPILER", {"type": "CALL_EXPRESSION", "name": "compiler"}]
       , [ "COMPILE_FLAGS"
         , { "type": "++"
           , "$1":
@@ -841,7 +929,24 @@
       , [ "AR"
         , { "type": "var"
           , "name": "AR"
-          , "default": {"type": "CALL_EXPRESSION", "name": "default-AR"}
+          , "default":
+            { "type": "join"
+            , "$1":
+              { "type": "++"
+              , "$1":
+                [ { "type": "if"
+                  , "cond":
+                    { "type": "lookup"
+                    , "key": "AR"
+                    , "map": {"type": "var", "name": "NON_SYSTEM_TOOLS"}
+                    }
+                  , "then":
+                    ["./", {"type": "var", "name": "TOOLCHAIN_DIR"}, "/"]
+                  }
+                , {"type": "CALL_EXPRESSION", "name": "default-AR"}
+                ]
+              }
+            }
           }
         ]
       , [ "ENV"
@@ -890,7 +995,13 @@
           , "then":
             { "type": "ACTION"
             , "outs": [{"type": "var", "name": "libpath"}]
-            , "inputs": {"type": "var", "name": "objects"}
+            , "inputs":
+              { "type": "map_union"
+              , "$1":
+                [ {"type": "var", "name": "TOOLCHAIN"}
+                , {"type": "var", "name": "objects"}
+                ]
+              }
             , "env":
               {"type": "var", "name": "ENV", "default": {"type": "empty_map"}}
             , "cmd":
@@ -1075,11 +1186,24 @@
     , "objects": "objects"
     , "default-LDFLAGS": "default-LDFLAGS"
     , "default-ENV": "default-ENV"
+    , "default-TOOLCHAIN": "default-TOOLCHAIN"
+    , "default-NON_SYSTEM_TOOLS": "default-NON_SYSTEM_TOOLS"
     }
   , "expression":
     { "type": "let*"
     , "bindings":
       [ ["BUILD_POSITION_INDEPENDENT", true]
+      , ["TOOLCHAIN_DIR", "toolchain"]
+      , ["TOOLCHAIN", {"type": "CALL_EXPRESSION", "name": "default-TOOLCHAIN"}]
+      , [ "TOOLCHAIN"
+        , { "type": "to_subdir"
+          , "subdir": {"type": "var", "name": "TOOLCHAIN_DIR"}
+          , "$1": {"type": "var", "name": "TOOLCHAIN"}
+          }
+        ]
+      , [ "NON_SYSTEM_TOOLS"
+        , {"type": "CALL_EXPRESSION", "name": "default-NON_SYSTEM_TOOLS"}
+        ]
       , ["COMPILER", {"type": "CALL_EXPRESSION", "name": "compiler"}]
       , [ "COMPILE_FLAGS"
         , { "type": "++"
@@ -1148,7 +1272,8 @@
             , "inputs":
               { "type": "map_union"
               , "$1":
-                [ {"type": "var", "name": "objects"}
+                [ {"type": "var", "name": "TOOLCHAIN"}
+                , {"type": "var", "name": "objects"}
                 , {"type": "var", "name": "link-deps"}
                 , {"type": "var", "name": "run-libs"}
                 , { "type": "var"
@@ -1213,6 +1338,7 @@
     , "soversion"
     , "pkg-name"
     , "extra-provides"
+    , "defaults-transition"
     , "deps-transition"
     , "public-fieldnames"
     , "private-fieldnames"
@@ -1392,11 +1518,24 @@
     , "objects": "objects"
     , "default-ENV": "default-ENV"
     , "default-LDFLAGS": "default-LDFLAGS"
+    , "default-TOOLCHAIN": "default-TOOLCHAIN"
+    , "default-NON_SYSTEM_TOOLS": "default-NON_SYSTEM_TOOLS"
     }
   , "expression":
     { "type": "let*"
     , "bindings":
-      [ ["COMPILER", {"type": "CALL_EXPRESSION", "name": "compiler"}]
+      [ ["TOOLCHAIN_DIR", "toolchain"]
+      , ["TOOLCHAIN", {"type": "CALL_EXPRESSION", "name": "default-TOOLCHAIN"}]
+      , [ "TOOLCHAIN"
+        , { "type": "to_subdir"
+          , "subdir": {"type": "var", "name": "TOOLCHAIN_DIR"}
+          , "$1": {"type": "var", "name": "TOOLCHAIN"}
+          }
+        ]
+      , [ "NON_SYSTEM_TOOLS"
+        , {"type": "CALL_EXPRESSION", "name": "default-NON_SYSTEM_TOOLS"}
+        ]
+      , ["COMPILER", {"type": "CALL_EXPRESSION", "name": "compiler"}]
       , [ "COMPILE_FLAGS"
         , { "type": "++"
           , "$1":
@@ -1458,7 +1597,8 @@
           , "inputs":
             { "type": "disjoint_map_union"
             , "$1":
-              [ {"type": "var", "name": "objects"}
+              [ {"type": "var", "name": "TOOLCHAIN"}
+              , {"type": "var", "name": "objects"}
               , {"type": "var", "name": "link-deps"}
               , {"type": "var", "name": "run-libs"}
               , { "type": "var"
diff --git a/CC/RULES b/CC/RULES
index cf4fe19..d2aeece 100644
--- a/CC/RULES
+++ b/CC/RULES
@@ -6,7 +6,7 @@
     , "use of this rule. As targets form a different root, the defaults"
     , "can be provided without changing this directory."
     ]
-  , "target_fields": ["base"]
+  , "target_fields": ["base", "toolchain", "deps"]
   , "string_fields":
     [ "CC"
     , "CXX"
@@ -18,12 +18,28 @@
     , "ADD_LDFLAGS"
     , "AR"
     , "PATH"
+    , "SYSTEM_TOOLS"
     ]
   , "field_doc":
     { "base": ["Other targets (using the same rule) to inherit values from."]
+    , "toolchain":
+      [ "Optional toolchain directory. A collection of artifacts that provide"
+      , "the tools CC, CXX, and AR (if needed). Note that only artifacts of"
+      , "the specified targets are considered (no runfiles etc.). Specifying"
+      , "this field overlays artifacts from \"base\"."
+      ]
+    , "deps":
+      [ "Optional CC libraries any CC library and CC binary implicitly depend"
+      , "on. Those are typically \"libstdc++\" or \"libc++\" for C++ targets."
+      , "Specifying this field extends dependencies from \"base\"."
+      ]
     , "CC": ["The C compiler to use"]
     , "CXX": ["The C++ compiler to use"]
     , "AR": ["The archiver tool to use"]
+    , "SYSTEM_TOOLS":
+      [ "List of tools (\"CC\", \"CXX\", or \"AR\") that should be taken from"
+      , "the system instead of from \"toolchain\" (if specified)."
+      ]
     , "CFLAGS":
       [ "Flags for C compilation. Specifying this field overwrites"
       , "values from \"base\"."
@@ -53,7 +69,22 @@
       , "with \":\"."
       ]
     }
-  , "imports": {"base-provides": "defaults-base-provides"}
+  , "config_vars": ["ARCH", "HOST_ARCH"]
+  , "imports":
+    { "base-provides": "defaults-base-provides"
+    , "artifacts": ["./", "..", "field_artifacts"]
+    , "compile-deps": "compile-deps"
+    , "compile-args-deps": "compile-args-deps"
+    , "link-deps": "link-deps"
+    , "link-args-deps": "link-args-deps"
+    , "run-libs-deps": "run-libs-deps"
+    , "run-libs-args-deps": "run-libs-args-deps"
+    , "cflags-files-deps": "cflags-files-deps"
+    , "ldflags-files-deps": "ldflags-files-deps"
+    , "for host": ["transitions", "for host"]
+    }
+  , "config_transitions":
+    {"toolchain": [{"type": "CALL_EXPRESSION", "name": "for host"}]}
   , "expression":
     { "type": "let*"
     , "bindings":
@@ -129,6 +160,92 @@
           , "else": {"type": "CALL_EXPRESSION", "name": "base-provides"}
           }
         ]
+      , ["provider", "NON_SYSTEM_TOOLS"]
+      , ["default", {"type": "empty_map"}]
+      , [ "NON_SYSTEM_TOOLS"
+        , { "type": "map_union"
+          , "$1":
+            { "type": "++"
+            , "$1":
+              [ [{"type": "CALL_EXPRESSION", "name": "base-provides"}]
+              , { "type": "if"
+                , "cond": {"type": "FIELD", "name": "CC"}
+                , "then":
+                  [ { "type": "singleton_map"
+                    , "key": "CC"
+                    , "value":
+                      { "type": "if"
+                      , "cond": {"type": "FIELD", "name": "toolchain"}
+                      , "then": true
+                      , "else": false
+                      }
+                    }
+                  ]
+                }
+              , { "type": "if"
+                , "cond": {"type": "FIELD", "name": "CXX"}
+                , "then":
+                  [ { "type": "singleton_map"
+                    , "key": "CXX"
+                    , "value":
+                      { "type": "if"
+                      , "cond": {"type": "FIELD", "name": "toolchain"}
+                      , "then": true
+                      , "else": false
+                      }
+                    }
+                  ]
+                }
+              , { "type": "if"
+                , "cond": {"type": "FIELD", "name": "AR"}
+                , "then":
+                  [ { "type": "singleton_map"
+                    , "key": "AR"
+                    , "value":
+                      { "type": "if"
+                      , "cond": {"type": "FIELD", "name": "toolchain"}
+                      , "then": true
+                      , "else": false
+                      }
+                    }
+                  ]
+                }
+              , { "type": "foreach"
+                , "range": {"type": "FIELD", "name": "SYSTEM_TOOLS"}
+                , "var": "tool"
+                , "body":
+                  { "type": "singleton_map"
+                  , "key": {"type": "var", "name": "tool"}
+                  , "value": false
+                  }
+                }
+              ]
+            }
+          }
+        ]
+      , ["provider", "TOOLCHAIN"]
+      , ["default", {"type": "empty_map"}]
+      , [ "TOOLCHAIN"
+        , { "type": "map_union"
+          , "$1":
+            [ {"type": "CALL_EXPRESSION", "name": "base-provides"}
+            , { "type": "if"
+              , "cond": {"type": "FIELD", "name": "toolchain"}
+              , "then":
+                { "type": "let*"
+                , "bindings":
+                  [ ["fieldname", "toolchain"]
+                  , [ "transition"
+                    , {"type": "CALL_EXPRESSION", "name": "for host"}
+                    ]
+                  ]
+                , "body": {"type": "CALL_EXPRESSION", "name": "artifacts"}
+                }
+              , "else": {"type": "empty_map"}
+              }
+            ]
+          }
+        ]
       , [ "CFLAGS"
         , { "type": "++"
           , "$1":
@@ -153,12 +270,47 @@
             ]
           }
         ]
+      , ["deps-fieldnames", ["base", "deps"]]
+      , ["compile-deps", {"type": "CALL_EXPRESSION", "name": "compile-deps"}]
+      , [ "compile-args"
+        , {"type": "CALL_EXPRESSION", "name": "compile-args-deps"}
+        ]
+      , ["link-deps", {"type": "CALL_EXPRESSION", "name": "link-deps"}]
+      , ["link-args", {"type": "CALL_EXPRESSION", "name": "link-args-deps"}]
+      , ["run-libs", {"type": "CALL_EXPRESSION", "name": "run-libs-deps"}]
+      , [ "run-libs-args"
+        , {"type": "CALL_EXPRESSION", "name": "run-libs-args-deps"}
+        ]
+      , [ "cflags-files"
+        , {"type": "CALL_EXPRESSION", "name": "cflags-files-deps"}
+        ]
+      , [ "ldflags-files"
+        , {"type": "CALL_EXPRESSION", "name": "ldflags-files-deps"}
+        ]
+      , ["package", {"type": "env", "vars": ["cflags-files", "ldflags-files"]}]
       ]
     , "body":
       { "type": "RESULT"
       , "provides":
         { "type": "env"
-        , "vars": ["CC", "CXX", "CFLAGS", "CXXFLAGS", "LDFLAGS", "AR", "ENV"]
+        , "vars":
+          [ "CC"
+          , "CXX"
+          , "CFLAGS"
+          , "CXXFLAGS"
+          , "LDFLAGS"
+          , "AR"
+          , "ENV"
+          , "TOOLCHAIN"
+          , "NON_SYSTEM_TOOLS"
+          , "compile-deps"
+          , "compile-args"
+          , "link-deps"
+          , "link-args"
+          , "run-libs"
+          , "run-libs-args"
+          , "package"
+          ]
         }
       }
     }
@@ -370,6 +522,7 @@
     , "proto-deps": [{"type": "CALL_EXPRESSION", "name": "fPIC transition"}]
     , "private-proto-deps":
       [{"type": "CALL_EXPRESSION", "name": "fPIC transition"}]
+    , "defaults": [{"type": "CALL_EXPRESSION", "name": "fPIC transition"}]
     }
   , "expression":
     { "type": "let*"
@@ -449,12 +602,20 @@
           , "else": {"type": "var", "name": "name"}
           }
         ]
+      , [ "defaults-transition"
+        , {"type": "CALL_EXPRESSION", "name": "fPIC transition"}
+        ]
       , [ "deps-transition"
         , {"type": "CALL_EXPRESSION", "name": "fPIC transition"}
         ]
-      , ["public-fieldnames", ["deps", "proto-deps"]]
+      , ["public-fieldnames", ["deps", "proto-deps", "defaults"]]
       , [ "private-fieldnames"
-        , ["deps", "private-deps", "proto-deps", "private-proto-deps"]
+        , [ "deps"
+          , "private-deps"
+          , "proto-deps"
+          , "private-proto-deps"
+          , "defaults"
+          ]
         ]
       ]
     , "body":
@@ -617,7 +778,9 @@
           }
         ]
       , ["private-ldflags", {"type": "FIELD", "name": "private-ldflags"}]
-      , ["private-fieldnames", ["private-deps", "private-proto-deps"]]
+      , [ "private-fieldnames"
+        , ["private-deps", "private-proto-deps", "defaults"]
+        ]
       ]
     , "body": {"type": "CALL_EXPRESSION", "name": "bin result"}
     }
diff --git a/CC/auto/RULES b/CC/auto/RULES
index fb75a64..247ee01 100644
--- a/CC/auto/RULES
+++ b/CC/auto/RULES
@@ -156,6 +156,8 @@
     , "flags-cc": ["./", "..", "flags-cc"]
     , "flags-cxx": ["./", "..", "flags-cxx"]
     , "default-ENV": ["./", "..", "default-ENV"]
+    , "default-TOOLCHAIN": ["./", "..", "default-TOOLCHAIN"]
+    , "default-NON_SYSTEM_TOOLS": ["./", "..", "default-NON_SYSTEM_TOOLS"]
     }
   , "implicit": {"defaults": [["./", "..", "defaults"]]}
   , "expression":
@@ -197,6 +199,17 @@
             }
           }
         ]
+      , ["TOOLCHAIN_DIR", "toolchain"]
+      , ["TOOLCHAIN", {"type": "CALL_EXPRESSION", "name": "default-TOOLCHAIN"}]
+      , [ "TOOLCHAIN"
+        , { "type": "to_subdir"
+          , "subdir": {"type": "var", "name": "TOOLCHAIN_DIR"}
+          , "$1": {"type": "var", "name": "TOOLCHAIN"}
+          }
+        ]
+      , [ "NON_SYSTEM_TOOLS"
+        , {"type": "CALL_EXPRESSION", "name": "default-NON_SYSTEM_TOOLS"}
+        ]
       , ["CC", {"type": "CALL_EXPRESSION", "name": "compiler-cc"}]
       , ["CXX", {"type": "CALL_EXPRESSION", "name": "compiler-cxx"}]
       , ["CFLAGS", {"type": "CALL_EXPRESSION", "name": "flags-cc"}]
@@ -522,7 +535,8 @@
                 , "inputs":
                   { "type": "map_union"
                   , "$1":
-                    [ {"type": "env", "vars": ["file_check.sh", "c.flags"]}
+                    [ {"type": "var", "name": "TOOLCHAIN"}
+                    , {"type": "env", "vars": ["file_check.sh", "c.flags"]}
                     , {"type": "var", "name": "includes"}
                     ]
                   }
@@ -565,7 +579,8 @@
                 , "inputs":
                   { "type": "map_union"
                   , "$1":
-                    [ {"type": "env", "vars": ["file_check.sh", "cxx.flags"]}
+                    [ {"type": "var", "name": "TOOLCHAIN"}
+                    , {"type": "env", "vars": ["file_check.sh", "cxx.flags"]}
                     , {"type": "var", "name": "includes"}
                     ]
                   }
@@ -608,7 +623,8 @@
                 , "inputs":
                   { "type": "map_union"
                   , "$1":
-                    [ {"type": "env", "vars": ["type_check.sh", "c.flags"]}
+                    [ {"type": "var", "name": "TOOLCHAIN"}
+                    , {"type": "env", "vars": ["type_check.sh", "c.flags"]}
                     , {"type": "var", "name": "includes"}
                     ]
                   }
@@ -651,7 +667,8 @@
                 , "inputs":
                   { "type": "map_union"
                   , "$1":
-                    [ {"type": "env", "vars": ["type_check.sh", "cxx.flags"]}
+                    [ {"type": "var", "name": "TOOLCHAIN"}
+                    , {"type": "env", "vars": ["type_check.sh", "cxx.flags"]}
                     , {"type": "var", "name": "includes"}
                     ]
                   }
@@ -696,7 +713,8 @@
                 , "inputs":
                   { "type": "map_union"
                   , "$1":
-                    [ {"type": "env", "vars": ["symbol_check.sh", "c.flags"]}
+                    [ {"type": "var", "name": "TOOLCHAIN"}
+                    , {"type": "env", "vars": ["symbol_check.sh", "c.flags"]}
                     , {"type": "var", "name": "includes"}
                     ]
                   }
@@ -746,7 +764,8 @@
                 , "inputs":
                   { "type": "map_union"
                   , "$1":
-                    [ {"type": "env", "vars": ["symbol_check.sh", "cxx.flags"]}
+                    [ {"type": "var", "name": "TOOLCHAIN"}
+                    , {"type": "env", "vars": ["symbol_check.sh", "cxx.flags"]}
                     , {"type": "var", "name": "includes"}
                     ]
                   }
@@ -796,7 +815,8 @@
                 , "inputs":
                   { "type": "map_union"
                   , "$1":
-                    [ {"type": "env", "vars": ["size_check.sh", "c.flags"]}
+                    [ {"type": "var", "name": "TOOLCHAIN"}
+                    , {"type": "env", "vars": ["size_check.sh", "c.flags"]}
                     , {"type": "var", "name": "includes"}
                     ]
                   }
@@ -853,7 +873,8 @@
                 , "inputs":
                   { "type": "map_union"
                   , "$1":
-                    [ {"type": "env", "vars": ["size_check.sh", "cxx.flags"]}
+                    [ {"type": "var", "name": "TOOLCHAIN"}
+                    , {"type": "env", "vars": ["size_check.sh", "cxx.flags"]}
                     , {"type": "var", "name": "includes"}
                     ]
                   }
diff --git a/CC/foreign/cmake/EXPRESSIONS b/CC/foreign/cmake/EXPRESSIONS
index e1f019b..be345c2 100644
--- a/CC/foreign/cmake/EXPRESSIONS
+++ b/CC/foreign/cmake/EXPRESSIONS
@@ -27,11 +27,24 @@
     , "default-LDFLAGS": ["CC", "default-LDFLAGS"]
     , "default-AR": ["CC", "default-AR"]
     , "default-ENV": ["CC", "default-ENV"]
+    , "default-TOOLCHAIN": ["CC", "default-TOOLCHAIN"]
+    , "default-NON_SYSTEM_TOOLS": ["CC", "default-NON_SYSTEM_TOOLS"]
     }
   , "expression":
     { "type": "let*"
     , "bindings":
-      [ [ "CMAKE_FLAGS"
+      [ ["TOOLCHAIN_DIR", "toolchain"]
+      , ["TOOLCHAIN", {"type": "CALL_EXPRESSION", "name": "default-TOOLCHAIN"}]
+      , [ "TOOLCHAIN"
+        , { "type": "to_subdir"
+          , "subdir": {"type": "var", "name": "TOOLCHAIN_DIR"}
+          , "$1": {"type": "var", "name": "TOOLCHAIN"}
+          }
+        ]
+      , [ "NON_SYSTEM_TOOLS"
+        , {"type": "CALL_EXPRESSION", "name": "default-NON_SYSTEM_TOOLS"}
+        ]
+      , [ "CMAKE_FLAGS"
         , { "type": "++"
           , "$1":
             [ { "type": "foreach"
@@ -95,7 +108,24 @@
       , [ "AR"
         , { "type": "var"
           , "name": "AR"
-          , "default": {"type": "CALL_EXPRESSION", "name": "default-AR"}
+          , "default":
+            { "type": "join"
+            , "$1":
+              { "type": "++"
+              , "$1":
+                [ { "type": "if"
+                  , "cond":
+                    { "type": "lookup"
+                    , "key": "AR"
+                    , "map": {"type": "var", "name": "NON_SYSTEM_TOOLS"}
+                    }
+                  , "then":
+                    ["./", {"type": "var", "name": "TOOLCHAIN_DIR"}, "/"]
+                  }
+                , {"type": "CALL_EXPRESSION", "name": "default-AR"}
+                ]
+              }
+            }
           }
         ]
       , [ "CMAKE_JOBS"
@@ -184,7 +214,8 @@
       , "inputs":
         { "type": "map_union"
         , "$1":
-          [ {"type": "var", "name": "source_dir"}
+          [ {"type": "var", "name": "TOOLCHAIN"}
+          , {"type": "var", "name": "source_dir"}
           , {"type": "var", "name": "script"}
           ]
         }
diff --git a/CC/foreign/make/EXPRESSIONS b/CC/foreign/make/EXPRESSIONS
index 85179a9..3f04bbd 100644
--- a/CC/foreign/make/EXPRESSIONS
+++ b/CC/foreign/make/EXPRESSIONS
@@ -37,11 +37,24 @@
     , "default-LDFLAGS": ["CC", "default-LDFLAGS"]
     , "default-AR": ["CC", "default-AR"]
     , "default-ENV": ["CC", "default-ENV"]
+    , "default-TOOLCHAIN": ["CC", "default-TOOLCHAIN"]
+    , "default-NON_SYSTEM_TOOLS": ["CC", "default-NON_SYSTEM_TOOLS"]
     }
   , "expression":
     { "type": "let*"
     , "bindings":
-      [ ["CC", {"type": "CALL_EXPRESSION", "name": "compiler-cc"}]
+      [ ["TOOLCHAIN_DIR", "toolchain"]
+      , ["TOOLCHAIN", {"type": "CALL_EXPRESSION", "name": "default-TOOLCHAIN"}]
+      , [ "TOOLCHAIN"
+        , { "type": "to_subdir"
+          , "subdir": {"type": "var", "name": "TOOLCHAIN_DIR"}
+          , "$1": {"type": "var", "name": "TOOLCHAIN"}
+          }
+        ]
+      , [ "NON_SYSTEM_TOOLS"
+        , {"type": "CALL_EXPRESSION", "name": "default-NON_SYSTEM_TOOLS"}
+        ]
+      , ["CC", {"type": "CALL_EXPRESSION", "name": "compiler-cc"}]
       , ["CXX", {"type": "CALL_EXPRESSION", "name": "compiler-cxx"}]
       , [ "CFLAGS"
         , { "type": "join"
@@ -74,7 +87,24 @@
       , [ "AR"
         , { "type": "var"
           , "name": "AR"
-          , "default": {"type": "CALL_EXPRESSION", "name": "default-AR"}
+          , "default":
+            { "type": "join"
+            , "$1":
+              { "type": "++"
+              , "$1":
+                [ { "type": "if"
+                  , "cond":
+                    { "type": "lookup"
+                    , "key": "AR"
+                    , "map": {"type": "var", "name": "NON_SYSTEM_TOOLS"}
+                    }
+                  , "then":
+                    ["./", {"type": "var", "name": "TOOLCHAIN_DIR"}, "/"]
+                  }
+                , {"type": "CALL_EXPRESSION", "name": "default-AR"}
+                ]
+              }
+            }
           }
         ]
       , [ "ENV"
@@ -227,7 +257,8 @@
       , "inputs":
         { "type": "map_union"
         , "$1":
-          [ {"type": "var", "name": "source_dir"}
+          [ {"type": "var", "name": "TOOLCHAIN"}
+          , {"type": "var", "name": "source_dir"}
           , {"type": "var", "name": "script"}
           ]
         }
diff --git a/CC/test/RULES b/CC/test/RULES
index f9032b3..8a985be 100644
--- a/CC/test/RULES
+++ b/CC/test/RULES
@@ -165,7 +165,7 @@
       , ["host-trans", {"type": "CALL_EXPRESSION", "name": "host transition"}]
       , ["defaults-transition", {"type": "var", "name": "host-trans"}]
       , ["deps-transition", {"type": "var", "name": "host-trans"}]
-      , ["deps-fieldnames", ["private-deps"]]
+      , ["deps-fieldnames", ["private-deps", "defaults"]]
       , [ "runner"
         , { "type": "map_union"
           , "$1":