rules: Propagate PATH list from defaults

... instead of creating an ENV from it and propagating this.
The idea is to keep PATH entries separate and only join them
with ":" when we need it. In this way, we can accumulate
PATHs from multiple defaults later, and perform a
deduplication ("nub_left") to shorten the final string
length.

1 files changed, 31 insertions, 0 deletions

diff --git a/CC/prebuilt/EXPRESSIONS b/CC/prebuilt/EXPRESSIONS
index c404bec..7b35c21 100644
--- a/CC/prebuilt/EXPRESSIONS
+++ b/CC/prebuilt/EXPRESSIONS
@@ -111,6 +111,7 @@
     , "cflags-files-deps": ["./", "..", "cflags-files-deps"]
     , "ldflags-files-deps": ["./", "..", "ldflags-files-deps"]
     , "default-ENV": ["./", "..", "default-ENV"]
+    , "default-PATH": ["./", "..", "default-PATH"]
     }
   , "expression":
     { "type": "let*"
@@ -239,6 +240,36 @@
             ]
           }
         ]
+      , [ "ENV_PATH"
+        , { "type": "lookup"
+          , "map": {"type": "var", "name": "ENV"}
+          , "key": "PATH"
+          }
+        ]
+      , [ "ENV"
+        , { "type": "map_union"
+          , "$1":
+            [ {"type": "var", "name": "ENV"}
+            , { "type": "singleton_map"
+              , "key": "PATH"
+              , "value":
+                { "type": "join"
+                , "separator": ":"
+                , "$1":
+                  { "type": "++"
+                  , "$1":
+                    [ {"type": "CALL_EXPRESSION", "name": "default-PATH"}
+                    , { "type": "if"
+                      , "cond": {"type": "var", "name": "ENV_PATH"}
+                      , "then": [{"type": "var", "name": "ENV_PATH"}]
+                      }
+                    ]
+                  }
+                }
+              }
+            ]
+          }
+        ]
       , [ "main-pkg-config"
         , { "type": "foldl"
           , "range":