Refactor interaction between Pass and PassRunner (#5093)

Previously only WalkerPasses had access to the `getPassRunner` and
`getPassOptions` methods. Move those methods to `Pass` so all passes can use
them. As a result, the `PassRunner` passed to `Pass::run` and
`Pass::runOnFunction` is no longer necessary, so remove it.

Also update `Pass::create` to return a unique_ptr, which is more efficient than
having it return a raw pointer only to have the `PassRunner` wrap that raw
pointer in a `unique_ptr`.

Delete the unused template `PassRunner::getLast()`, which looks like it was
intended to enable retrieving previous analyses and has been in the code base
since 2015 but is not implemented anywhere.

1 files changed, 3 insertions, 1 deletions

diff --git a/src/passes/SpillPointers.cpp b/src/passes/SpillPointers.cpp
index 04193c2d2..991a7b8c1 100644
--- a/src/passes/SpillPointers.cpp
+++ b/src/passes/SpillPointers.cpp
@@ -37,7 +37,9 @@ struct SpillPointers
   : public WalkerPass<LivenessWalker<SpillPointers, Visitor<SpillPointers>>> {
   bool isFunctionParallel() override { return true; }
 
-  Pass* create() override { return new SpillPointers; }
+  std::unique_ptr<Pass> create() override {
+    return std::make_unique<SpillPointers>();
+  }
 
   // a mapping of the pointers to all the spillable things. We need to know
   // how to replace them, and as we spill we may modify them. This map