Eliminate the "store" global variable

Also, move a few free-standing functions into StoreAPI and Derivation.

Also, introduce a non-nullable smart pointer, ref<T>, which is just a
wrapper around std::shared_ptr ensuring that the pointer is never
null. (For reference-counted values, this is better than passing a
"T&", because the latter doesn't maintain the refcount. Usually, the
caller will have a shared_ptr keeping the value alive, but that's not
always the case, e.g., when passing a reference to a std::thread via
std::bind.)

1 files changed, 4 insertions, 4 deletions

diff --git a/src/libmain/shared.hh b/src/libmain/shared.hh
index 8e756bd5e842..6f826d8f6fd7 100644
--- a/src/libmain/shared.hh
+++ b/src/libmain/shared.hh
@@ -19,8 +19,6 @@ public:
     Exit(int status) : status(status) { }
 };
 
-class StoreAPI;
-
 int handleExceptions(const string & programName, std::function<void()> fun);
 
 void initNix();
@@ -33,9 +31,11 @@ void printVersion(const string & programName);
 /* Ugh.  No better place to put this. */
 void printGCWarning();
 
-void printMissing(StoreAPI & store, const PathSet & paths);
+class StoreAPI;
+
+void printMissing(ref<StoreAPI> store, const PathSet & paths);
 
-void printMissing(StoreAPI & store, const PathSet & willBuild,
+void printMissing(ref<StoreAPI> store, const PathSet & willBuild,
     const PathSet & willSubstitute, const PathSet & unknown,
     unsigned long long downloadSize, unsigned long long narSize);