Rollup of 10 pull requests

tests/mir-opt/remove_unneeded_drops.cannot_opt_generic.RemoveUnneededDrops.diff

@@ -0,0 +1,15 @@
+- // MIR for `cannot_opt_generic` before RemoveUnneededDrops
++ // MIR for `cannot_opt_generic` after RemoveUnneededDrops
+
+  fn cannot_opt_generic(_1: T) -> () {
+      let mut _0: ();
+
+      bb0: {
+          drop(_1) -> [return: bb1, unwind unreachable];
+      }
+
+      bb1: {
+          return;
+      }
+  }
+

tests/mir-opt/remove_unneeded_drops.dont_opt.RemoveUnneededDrops.diff

@@ -0,0 +1,15 @@
+- // MIR for `dont_opt` before RemoveUnneededDrops
++ // MIR for `dont_opt` after RemoveUnneededDrops
+
+  fn dont_opt(_1: Vec<bool>) -> () {
+      let mut _0: ();
+
+      bb0: {
+          drop(_1) -> [return: bb1, unwind unreachable];
+      }
+
+      bb1: {
+          return;
+      }
+  }
+

tests/mir-opt/remove_unneeded_drops.opt.RemoveUnneededDrops.diff

@@ -0,0 +1,15 @@
+- // MIR for `opt` before RemoveUnneededDrops
++ // MIR for `opt` after RemoveUnneededDrops
+
+  fn opt(_1: bool) -> () {
+      let mut _0: ();
+
+      bb0: {
+-         drop(_1) -> [return: bb1, unwind unreachable];
+-     }
+- 
+-     bb1: {
+          return;
+      }
+  }
+

tests/mir-opt/remove_unneeded_drops.opt_generic_copy.RemoveUnneededDrops.diff

@@ -0,0 +1,15 @@
+- // MIR for `opt_generic_copy` before RemoveUnneededDrops
++ // MIR for `opt_generic_copy` after RemoveUnneededDrops
+
+  fn opt_generic_copy(_1: T) -> () {
+      let mut _0: ();
+
+      bb0: {
+-         drop(_1) -> [return: bb1, unwind unreachable];
+-     }
+- 
+-     bb1: {
+          return;
+      }
+  }
+

tests/mir-opt/remove_unneeded_drops.rs

@@ -1,28 +1,56 @@
-// skip-filecheck
-// EMIT_MIR_FOR_EACH_PANIC_STRATEGY
+//@ test-mir-pass: RemoveUnneededDrops
+
+#![feature(custom_mir, core_intrinsics)]
+use std::intrinsics::mir::*;
+
 // EMIT_MIR remove_unneeded_drops.opt.RemoveUnneededDrops.diff
+#[custom_mir(dialect = "runtime")]
 fn opt(x: bool) {
-    drop(x);
+    // CHECK-LABEL: fn opt(
+    // CHECK-NOT: drop(
+    mir! {
+        { Drop(x, ReturnTo(bb1), UnwindUnreachable()) }
+        bb1 = { Return() }
+    }
 }
 
 // EMIT_MIR remove_unneeded_drops.dont_opt.RemoveUnneededDrops.diff
+#[custom_mir(dialect = "runtime")]
 fn dont_opt(x: Vec<bool>) {
-    drop(x);
+    // CHECK-LABEL: fn dont_opt(
+    // CHECK: drop(
+    mir! {
+        { Drop(x, ReturnTo(bb1), UnwindUnreachable()) }
+        bb1 = { Return() }
+    }
 }
 
 // EMIT_MIR remove_unneeded_drops.opt_generic_copy.RemoveUnneededDrops.diff
+#[custom_mir(dialect = "runtime")]
 fn opt_generic_copy<T: Copy>(x: T) {
-    drop(x);
+    // CHECK-LABEL: fn opt_generic_copy(
+    // CHECK-NOT: drop(
+    mir! {
+        { Drop(x, ReturnTo(bb1), UnwindUnreachable()) }
+        bb1 = { Return() }
+    }
 }
 
 // EMIT_MIR remove_unneeded_drops.cannot_opt_generic.RemoveUnneededDrops.diff
 // since the pass is not running on monomorphisized code,
 // we can't (but probably should) optimize this
+#[custom_mir(dialect = "runtime")]
 fn cannot_opt_generic<T>(x: T) {
-    drop(x);
+    // CHECK-LABEL: fn cannot_opt_generic(
+    // CHECK: drop(
+    mir! {
+        { Drop(x, ReturnTo(bb1), UnwindUnreachable()) }
+        bb1 = { Return() }
+    }
 }
 
 fn main() {
+    // CHECK-LABEL: fn main(
     opt(true);
     opt_generic_copy(42);
     cannot_opt_generic(42);