rules: Add support for shared libraries

6 files changed, 471 insertions, 7 deletions

diff --git a/CC/EXPRESSIONS b/CC/EXPRESSIONS
index 7db6e9a..2998fa8 100644
--- a/CC/EXPRESSIONS
+++ b/CC/EXPRESSIONS
@@ -270,6 +270,69 @@
       }
     }
   }
+, "run-libs-deps":
+  { "doc": ["Collect runtime libraries from given target_fields"]
+  , "vars": ["deps-fieldnames", "deps-transition"]
+  , "vars_doc":
+    { "deps-fieldnames":
+      ["List of target_field names to collect dependencies from."]
+    , "deps-transition":
+      ["The optional configuration transition for the targets."]
+    }
+  , "imports": {"provider_list": ["./", "..", "field_provider_list"]}
+  , "expression":
+    { "type": "to_subdir"
+    , "flat": true
+    , "$1":
+      { "type": "disjoint_map_union"
+      , "$1":
+        { "type": "++"
+        , "$1":
+          { "type": "foreach"
+          , "var": "fieldname"
+          , "range": {"type": "var", "name": "deps-fieldnames"}
+          , "body":
+            { "type": "let*"
+            , "bindings":
+              [ ["provider", "run-libs"]
+              , ["default", {"type": "empty_map"}]
+              , ["transition", {"type": "var", "name": "deps-transition"}]
+              ]
+            , "body": {"type": "CALL_EXPRESSION", "name": "provider_list"}
+            }
+          }
+        }
+      }
+    }
+  }
+, "run-libs-args-deps":
+  { "doc":
+    ["Collect runtime libraries link arguments from given target_fields"]
+  , "vars": ["deps-fieldnames", "deps-transition"]
+  , "vars_doc":
+    { "deps-fieldnames":
+      ["List of target_field names to collect arguments from."]
+    , "deps-transition":
+      ["The optional configuration transition for the targets."]
+    }
+  , "imports": {"list_provider": ["./", "..", "field_list_provider"]}
+  , "expression":
+    { "type": "++"
+    , "$1":
+      { "type": "foreach"
+      , "var": "fieldname"
+      , "range": {"type": "var", "name": "deps-fieldnames"}
+      , "body":
+        { "type": "let*"
+        , "bindings":
+          [ ["provider", "run-libs-args"]
+          , ["transition", {"type": "var", "name": "deps-transition"}]
+          ]
+        , "body": {"type": "CALL_EXPRESSION", "name": "list_provider"}
+        }
+      }
+    }
+  }
 , "objects":
   { "vars":
     [ "COMPILER"
@@ -418,12 +481,21 @@
     }
   }
 , "flags-cc":
-  { "vars": ["CFLAGS", "ADD_CFLAGS", "defaults-transition"]
+  { "vars":
+    [ "CFLAGS"
+    , "ADD_CFLAGS"
+    , "BUILD_POSITION_INDEPENDENT"
+    , "defaults-transition"
+    ]
   , "imports": {"default-CFLAGS": "default-CFLAGS"}
   , "expression":
     { "type": "++"
     , "$1":
-      [ { "type": "var"
+      [ { "type": "if"
+        , "cond": {"type": "var", "name": "BUILD_POSITION_INDEPENDENT"}
+        , "then": ["-fPIC"]
+        }
+      , { "type": "var"
         , "name": "CFLAGS"
         , "default": {"type": "CALL_EXPRESSION", "name": "default-CFLAGS"}
         }
@@ -432,12 +504,21 @@
     }
   }
 , "flags-cxx":
-  { "vars": ["CXXFLAGS", "ADD_CXXFLAGS", "defaults-transition"]
+  { "vars":
+    [ "CXXFLAGS"
+    , "ADD_CXXFLAGS"
+    , "BUILD_POSITION_INDEPENDENT"
+    , "defaults-transition"
+    ]
   , "imports": {"default-CXXFLAGS": "default-CXXFLAGS"}
   , "expression":
     { "type": "++"
     , "$1":
-      [ { "type": "var"
+      [ { "type": "if"
+        , "cond": {"type": "var", "name": "BUILD_POSITION_INDEPENDENT"}
+        , "then": ["-fPIC"]
+        }
+      , { "type": "var"
         , "name": "CXXFLAGS"
         , "default": {"type": "CALL_EXPRESSION", "name": "default-CXXFLAGS"}
         }
@@ -451,6 +532,7 @@
     , "CXXFLAGS"
     , "ADD_CFLAGS"
     , "ADD_CXXFLAGS"
+    , "BUILD_POSITION_INDEPENDENT"
     , "pure C"
     , "defaults-transition"
     ]
@@ -472,6 +554,7 @@
     , "ADD_CXXFLAGS"
     , "AR"
     , "ENV"
+    , "BUILD_POSITION_INDEPENDENT"
     , "name"
     , "pure C"
     , "srcs"
@@ -590,6 +673,7 @@
     , "ADD_CXXFLAGS"
     , "AR"
     , "ENV"
+    , "BUILD_POSITION_INDEPENDENT"
     , "name"
     , "pure C"
     , "srcs"
@@ -608,6 +692,8 @@
     , "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"
     , "lib artifact": "lib artifact"
     }
   , "expression":
@@ -641,6 +727,12 @@
             }
           }
         ]
+      , ["run-libs", {"type": "CALL_EXPRESSION", "name": "run-libs-deps"}]
+      , [ "run-libs-args"
+        , { "type": "nub_right"
+          , "$1": {"type": "CALL_EXPRESSION", "name": "run-libs-args-deps"}
+          }
+        ]
       , ["deps-fieldnames", {"type": "var", "name": "public-fieldnames"}]
       , ["compile-deps", {"type": "CALL_EXPRESSION", "name": "compile-deps"}]
       , [ "compile-args"
@@ -664,7 +756,277 @@
         , "$1":
           [ { "type": "env"
             , "vars":
-              ["compile-deps", "compile-args", "link-deps", "link-args"]
+              [ "compile-deps"
+              , "compile-args"
+              , "link-deps"
+              , "link-args"
+              , "run-libs"
+              , "run-libs-args"
+              ]
+            }
+          , { "type": "var"
+            , "name": "extra-provides"
+            , "default": {"type": "empty_map"}
+            }
+          ]
+        }
+      }
+    }
+  }
+, "shared artifact":
+  { "vars":
+    [ "CC"
+    , "CXX"
+    , "CFLAGS"
+    , "CXXFLAGS"
+    , "LDFLAGS"
+    , "ADD_CFLAGS"
+    , "ADD_CXXFLAGS"
+    , "ADD_LDFLAGS"
+    , "ENV"
+    , "name"
+    , "pure C"
+    , "srcs"
+    , "hdrs"
+    , "private-hdrs"
+    , "soversion"
+    , "compile-deps"
+    , "compile-args"
+    , "link-deps"
+    , "link-args"
+    , "run-libs"
+    , "run-libs-args"
+    , "defaults-transition"
+    ]
+  , "imports":
+    { "compiler": "compiler"
+    , "flags": "flags"
+    , "objects": "objects"
+    , "default-LDFLAGS": "default-LDFLAGS"
+    , "default-ENV": "default-ENV"
+    }
+  , "expression":
+    { "type": "let*"
+    , "bindings":
+      [ ["BUILD_POSITION_INDEPENDENT", true]
+      , ["COMPILER", {"type": "CALL_EXPRESSION", "name": "compiler"}]
+      , [ "COMPILE_FLAGS"
+        , { "type": "++"
+          , "$1":
+            [ {"type": "CALL_EXPRESSION", "name": "flags"}
+            , {"type": "var", "name": "compile-args"}
+            ]
+          }
+        ]
+      , [ "LDFLAGS"
+        , { "type": "++"
+          , "$1":
+            [ { "type": "var"
+              , "name": "LDFLAGS"
+              , "default":
+                {"type": "CALL_EXPRESSION", "name": "default-LDFLAGS"}
+              }
+            , {"type": "var", "name": "ADD_LDFLAGS", "default": []}
+            ]
+          }
+        ]
+      , [ "ENV"
+        , { "type": "map_union"
+          , "$1":
+            { "type": "++"
+            , "$1":
+              [ {"type": "CALL_EXPRESSION", "name": "default-ENV"}
+              , [ { "type": "var"
+                  , "name": "ENV"
+                  , "default": {"type": "empty_map"}
+                  }
+                ]
+              ]
+            }
+          }
+        ]
+      , ["objects", {"type": "CALL_EXPRESSION", "name": "objects"}]
+      , [ "base name"
+        , { "type": "if"
+          , "cond": {"type": "var", "name": "objects"}
+          , "then":
+            { "type": "assert_non_empty"
+            , "msg": "A name has to be provided for non-header-only libraries"
+            , "$1": {"type": "var", "name": "name"}
+            }
+          , "else": {"type": "var", "name": "name"}
+          }
+        ]
+      , [ "libname"
+        , { "type": "join"
+          , "$1": ["lib", {"type": "var", "name": "base name"}, ".so"]
+          }
+        ]
+      , [ "libname"
+        , { "type": "join"
+          , "separator": "."
+          , "$1":
+            { "type": "++"
+            , "$1":
+              [ [{"type": "var", "name": "libname"}]
+              , {"type": "var", "name": "soversion"}
+              ]
+            }
+          }
+        ]
+      , [ "lib"
+        , { "type": "if"
+          , "cond": {"type": "var", "name": "objects"}
+          , "else": {"type": "empty_map"}
+          , "then":
+            { "type": "ACTION"
+            , "outs": [{"type": "var", "name": "libname"}]
+            , "inputs":
+              { "type": "map_union"
+              , "$1":
+                [ {"type": "var", "name": "objects"}
+                , {"type": "var", "name": "link-deps"}
+                , {"type": "var", "name": "run-libs"}
+                ]
+              }
+            , "env":
+              {"type": "var", "name": "ENV", "default": {"type": "empty_map"}}
+            , "cmd":
+              { "type": "++"
+              , "$1":
+                [ [ {"type": "var", "name": "COMPILER"}
+                  , "-shared"
+                  , "-Wl,-rpath,$ORIGIN"
+                  , "-Wl,-rpath,$ORIGIN/../lib"
+                  , { "type": "join"
+                    , "$1":
+                      ["-Wl,-soname,", {"type": "var", "name": "libname"}]
+                    }
+                  ]
+                , {"type": "var", "name": "COMPILE_FLAGS"}
+                , {"type": "var", "name": "LDFLAGS"}
+                , ["-o", {"type": "var", "name": "libname"}]
+                , {"type": "keys", "$1": {"type": "var", "name": "objects"}}
+                , {"type": "var", "name": "link-args"}
+                , {"type": "var", "name": "run-libs-args"}
+                ]
+              }
+            }
+          }
+        ]
+      ]
+    , "body": {"type": "var", "name": "lib"}
+    }
+  }
+, "shared result":
+  { "vars":
+    [ "CC"
+    , "CXX"
+    , "CFLAGS"
+    , "CXXFLAGS"
+    , "LDFLAGS"
+    , "ADD_CXXFLAGS"
+    , "ADD_CFLAGS"
+    , "ADD_LDFLAGS"
+    , "ENV"
+    , "name"
+    , "pure C"
+    , "srcs"
+    , "hdrs"
+    , "private-hdrs"
+    , "cflags"
+    , "private-cflags"
+    , "private-ldflags"
+    , "soversion"
+    , "extra-provides"
+    , "deps-transition"
+    , "public-fieldnames"
+    , "private-fieldnames"
+    ]
+  , "imports":
+    { "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"
+    , "shared artifact": "shared artifact"
+    }
+  , "expression":
+    { "type": "let*"
+    , "bindings":
+      [ ["deps-fieldnames", {"type": "var", "name": "private-fieldnames"}]
+      , ["compile-deps", {"type": "CALL_EXPRESSION", "name": "compile-deps"}]
+      , [ "compile-args"
+        , { "type": "nub_right"
+          , "$1":
+            { "type": "++"
+            , "$1":
+              [ {"type": "var", "name": "cflags"}
+              , {"type": "var", "name": "private-cflags"}
+              , {"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": "nub_right"
+          , "$1":
+            { "type": "++"
+            , "$1":
+              [ {"type": "var", "name": "private-ldflags", "default": []}
+              , {"type": "CALL_EXPRESSION", "name": "run-libs-args-deps"}
+              ]
+            }
+          }
+        ]
+      , ["lib", {"type": "CALL_EXPRESSION", "name": "shared artifact"}]
+      , ["deps-fieldnames", {"type": "var", "name": "public-fieldnames"}]
+      , ["compile-deps", {"type": "CALL_EXPRESSION", "name": "compile-deps"}]
+      , [ "compile-args"
+        , { "type": "nub_right"
+          , "$1":
+            { "type": "++"
+            , "$1":
+              [ {"type": "var", "name": "cflags"}
+              , {"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": "map_union"
+          , "$1":
+            [ {"type": "var", "name": "lib"}
+            , {"type": "var", "name": "run-libs"}
+            ]
+          }
+        ]
+      , [ "run-libs-args"
+        , {"type": "keys", "$1": {"type": "var", "name": "lib"}}
+        ]
+      ]
+    , "body":
+      { "type": "RESULT"
+      , "artifacts": {"type": "var", "name": "lib"}
+      , "runfiles": {"type": "var", "name": "hdrs"}
+      , "provides":
+        { "type": "map_union"
+        , "$1":
+          [ { "type": "env"
+            , "vars":
+              [ "compile-deps"
+              , "compile-args"
+              , "link-deps"
+              , "link-args"
+              , "run-libs"
+              , "run-libs-args"
+              ]
             }
           , { "type": "var"
             , "name": "extra-provides"
@@ -687,6 +1049,7 @@
     , "ADD_CXXFLAGS"
     , "ADD_LDFLAGS"
     , "ENV"
+    , "BUILD_POSITION_INDEPENDENT"
     , "name"
     , "pure C"
     , "srcs"
@@ -696,6 +1059,8 @@
     , "compile-args"
     , "link-deps"
     , "link-args"
+    , "run-libs"
+    , "run-libs-args"
     , "defaults-transition"
     ]
   , "imports":
@@ -779,18 +1144,22 @@
             , "$1":
               [ {"type": "var", "name": "objects"}
               , {"type": "var", "name": "link-deps"}
+              , {"type": "var", "name": "run-libs"}
               ]
             }
           , "cmd":
             { "type": "++"
             , "$1":
               [ [ {"type": "var", "name": "COMPILER"}
+                , "-Wl,-rpath,$ORIGIN"
+                , "-Wl,-rpath,$ORIGIN/../lib"
                 , "-o"
                 , {"type": "var", "name": "binpath"}
                 ]
               , {"type": "var", "name": "COMPILE_FLAGS"}
               , {"type": "var", "name": "LDFLAGS"}
               , {"type": "var", "name": "link-args"}
+              , {"type": "var", "name": "run-libs-args"}
               ]
             }
           , "env": {"type": "var", "name": "ENV"}
@@ -812,6 +1181,7 @@
     , "ADD_CXXFLAGS"
     , "ADD_LDFLAGS"
     , "ENV"
+    , "BUILD_POSITION_INDEPENDENT"
     , "name"
     , "pure C"
     , "srcs"
@@ -826,6 +1196,8 @@
     , "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"
     , "binary": "bin artifact"
     }
   , "expression":
@@ -853,10 +1225,15 @@
             }
           }
         ]
+      , ["run-libs", {"type": "CALL_EXPRESSION", "name": "run-libs-deps"}]
+      , [ "run-libs-args"
+        , {"type": "CALL_EXPRESSION", "name": "run-libs-args-deps"}
+        ]
       ]
     , "body":
       { "type": "RESULT"
       , "artifacts": {"type": "CALL_EXPRESSION", "name": "binary"}
+      , "provides": {"type": "env", "vars": ["run-libs"]}
       }
     }
   }
diff --git a/CC/RULES b/CC/RULES
index 9577f4d..4d90adc 100644
--- a/CC/RULES
+++ b/CC/RULES
@@ -133,16 +133,21 @@
     , "cflags"
     , "private-cflags"
     , "private-ldflags"
+    , "soversion"
     ]
+  , "config_fields": ["shared"]
   , "config_vars":
     [ "CC"
     , "CXX"
     , "CFLAGS"
     , "CXXFLAGS"
+    , "LDFLAGS"
     , "ADD_CFLAGS"
     , "ADD_CXXFLAGS"
+    , "ADD_LDFLAGS"
     , "AR"
     , "ENV"
+    , "BUILD_POSITION_INDEPENDENT"
     ]
   , "implicit": {"defaults": ["defaults"]}
   , "field_doc":
@@ -192,6 +197,11 @@
       , "duplicate work will be carried out, even if the same proto library"
       , "is used at various places)."
       ]
+    , "shared": ["If non-empty, produce a shared instead of a static library."]
+    , "soversion":
+      [ "The SOVERSION for shared libraries. Individual version components are"
+      , "joined with \".\"."
+      ]
     }
   , "config_doc":
     { "CC":
@@ -214,6 +224,12 @@
       , "adapting the default target [\"CC\", \"defaults\"] is the better"
       , "choice."
       ]
+    , "LDFLAGS":
+      [ "The linker flags to be used instead of the default ones."
+      , "For libraries that should be built in a non-standard way; usually"
+      , "adapting the default target [\"CC\", \"defaults\"] is the better"
+      , "choice."
+      ]
     , "ADD_CFLAGS":
       [ "The flags to add to the default ones for CC."
       , "For libraries that should be built in a non-standard way; usually"
@@ -226,11 +242,18 @@
       , "adapting the default target [\"CC\", \"defaults\"] is the better"
       , "choice."
       ]
+    , "ADD_LDFLAGS":
+      [ "The linker flags to add to the default ones."
+      , "For libraries that should be built in a non-standard way; usually"
+      , "adapting the default target [\"CC\", \"defaults\"] is the better"
+      , "choice."
+      ]
     , "AR":
       [ "The archive tool to used for creating the library"
       , "If None, the respective value from [\"CC\", \"defaults\"] will be taken."
       ]
     , "ENV": ["The environment for any action generated."]
+    , "BUILD_POSITION_INDEPENDENT": ["Build with -fPIC."]
     }
   , "artifacts_doc":
     ["The actual library (libname.a) staged in the specified directory"]
@@ -260,7 +283,16 @@
       }
     }
   , "imports":
-    {"artifacts": ["./", "..", "field_artifacts"], "result": "lib result"}
+    { "artifacts": ["./", "..", "field_artifacts"]
+    , "static result": "lib result"
+    , "shared result": "shared result"
+    , "fPIC transition": ["transitions", "with fPIC"]
+    }
+  , "config_transitions":
+    { "deps": [{"type": "CALL_EXPRESSION", "name": "fPIC transition"}]
+    , "private-deps": [{"type": "CALL_EXPRESSION", "name": "fPIC transition"}]
+    , "proto-deps": [{"type": "CALL_EXPRESSION", "name": "fPIC transition"}]
+    }
   , "expression":
     { "type": "let*"
     , "bindings":
@@ -329,10 +361,19 @@
           }
         ]
       , ["private-ldflags", {"type": "FIELD", "name": "private-ldflags"}]
+      , ["soversion", {"type": "FIELD", "name": "soversion"}]
+      , [ "deps-transition"
+        , {"type": "CALL_EXPRESSION", "name": "fPIC transition"}
+        ]
       , ["public-fieldnames", ["deps", "proto-deps"]]
       , ["private-fieldnames", ["deps", "private-deps", "proto-deps"]]
       ]
-    , "body": {"type": "CALL_EXPRESSION", "name": "result"}
+    , "body":
+      { "type": "if"
+      , "cond": {"type": "FIELD", "name": "shared"}
+      , "then": {"type": "CALL_EXPRESSION", "name": "shared result"}
+      , "else": {"type": "CALL_EXPRESSION", "name": "static result"}
+      }
     }
   }
 , "binary":
@@ -356,6 +397,7 @@
     , "ADD_CXXFLAGS"
     , "ADD_LDFLAGS"
     , "ENV"
+    , "BUILD_POSITION_INDEPENDENT"
     ]
   , "implicit": {"defaults": ["defaults"]}
   , "field_doc":
@@ -420,6 +462,7 @@
       , "taken from the [\"CC\", \"defaults\"] target"
       ]
     , "ENV": ["The environment for any action generated."]
+    , "BUILD_POSITION_INDEPENDENT": ["Build with -fPIC."]
     }
   , "artifacts_doc": ["The final binary, staged to the given directory"]
   , "runfiles_doc": ["None"]
diff --git a/CC/test/RULES b/CC/test/RULES
index 8269b9f..60f33ab 100644
--- a/CC/test/RULES
+++ b/CC/test/RULES
@@ -23,6 +23,7 @@
     , "ADD_CXXFLAGS"
     , "ADD_LDFLAGS"
     , "ENV"
+    , "BUILD_POSITION_INDEPENDENT"
     , "TEST_ENV"
     , "CC_TEST_LAUNCHER"
     ]
@@ -84,6 +85,7 @@
       , "taken from the [\"CC\", \"defaults\"] target"
       ]
     , "ENV": ["The environment for any action generated."]
+    , "BUILD_POSITION_INDEPENDENT": ["Build with -fPIC."]
     , "TEST_ENV": ["The environment for executing the test runner."]
     , "CC_TEST_LAUNCHER":
       [ "List of strings representing the launcher that is prepend to the"
@@ -111,6 +113,8 @@
     , "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"]
     , "binary": ["./", "..", "bin artifact"]
     , "host transition": ["transitions", "for host"]
     }
@@ -183,6 +187,10 @@
             ]
           }
         ]
+      , ["run-libs", {"type": "CALL_EXPRESSION", "name": "run-libs-deps"}]
+      , [ "run-libs-args"
+        , {"type": "CALL_EXPRESSION", "name": "run-libs-args-deps"}
+        ]
       , ["binary", {"type": "CALL_EXPRESSION", "name": "binary"}]
       , [ "staged test binary"
         , { "type": "map_union"
@@ -287,6 +295,7 @@
               , {"type": "var", "name": "test-args"}
               , {"type": "var", "name": "test-launcher"}
               , {"type": "var", "name": "staged test binary"}
+              , {"type": "var", "name": "run-libs"}
               ]
             }
           , "cmd": ["./runner"]
diff --git a/shell/test/EXPRESSIONS b/shell/test/EXPRESSIONS
index d9b1fbc..d1d7e64 100644
--- a/shell/test/EXPRESSIONS
+++ b/shell/test/EXPRESSIONS
@@ -12,6 +12,7 @@
   , "imports":
     { "artifacts_list": ["./", "../..", "field_artifacts_list"]
     , "runfiles_list": ["./", "../..", "field_runfiles_list"]
+    , "map_provider": ["./", "../..", "field_map_provider"]
     }
   , "expression":
     { "type": "let*"
@@ -66,6 +67,19 @@
             }
           }
         ]
+      , [ "run-libs"
+        , { "type": "TREE"
+          , "$1":
+            { "type": "let*"
+            , "bindings":
+              [ ["fieldname", {"type": "var", "name": "deps-fieldname"}]
+              , ["provider", "run-libs"]
+              , ["transition", {"type": "var", "name": "deps-transition"}]
+              ]
+            , "body": {"type": "CALL_EXPRESSION", "name": "map_provider"}
+            }
+          }
+        ]
       , [ "attempt marker"
         , { "type": "if"
           , "cond":
@@ -104,6 +118,10 @@
               , "key": "work"
               , "value": {"type": "var", "name": "deps"}
               }
+            , { "type": "singleton_map"
+              , "key": "libs"
+              , "value": {"type": "var", "name": "run-libs"}
+              }
             , {"type": "var", "name": "runner"}
             , {"type": "var", "name": "test.sh"}
             , {"type": "var", "name": "attempt marker"}
diff --git a/shell/test/test_runner.sh b/shell/test/test_runner.sh
index a99d5b7..97c75ef 100755
--- a/shell/test/test_runner.sh
+++ b/shell/test/test_runner.sh
@@ -25,6 +25,7 @@ echo UNKNOWN > time-stop
 mkdir scratch
 export TEST_TMPDIR=$(realpath scratch)
 export TMPDIR="${TEST_TMPDIR}"
+export LD_LIBRARY_PATH=$(realpath ./libs):$LD_LIBRARY_PATH
 
 # Change to the working directory; note: while unlikely, the test
 # might not have test data, so we have to ensure the presence of
diff --git a/transitions/EXPRESSIONS b/transitions/EXPRESSIONS
index 8ea7550..92be685 100644
--- a/transitions/EXPRESSIONS
+++ b/transitions/EXPRESSIONS
@@ -10,4 +10,20 @@
       }
     }
   }
+, "with fPIC":
+  { "doc":
+    [ "Transition that enables BUILD_POSITION_INDEPENDENT if config_field"
+    , "\"shared\" is not empty."
+    ]
+  , "expression":
+    { "type": "if"
+    , "cond": {"type": "FIELD", "name": "shared"}
+    , "then":
+      { "type": "singleton_map"
+      , "key": "BUILD_POSITION_INDEPENDENT"
+      , "value": true
+      }
+    , "else": {"type": "empty_map"}
+    }
+  }
 }