Rollup merge of #98930 - tmiasko:pub-basic-blocks, r=oli-obk

Make MIR basic blocks field public

This makes it possible to mutably borrow different fields of the MIR
body without resorting to methods like `basic_blocks_local_decls_mut_and_var_debug_info`.

To preserve validity of control flow graph caches in the presence of
modifications, a new struct `BasicBlocks` wraps together basic blocks
and control flow graph caches.

The `BasicBlocks` dereferences to `IndexVec<BasicBlock, BasicBlockData>`.
On the other hand a mutable access requires explicit `as_mut()` call.

2 files changed, 3 insertions, 3 deletions

diff --git a/compiler/rustc_mir_dataflow/src/framework/direction.rs b/compiler/rustc_mir_dataflow/src/framework/direction.rs
index 05a4d7bbf3e..5c77f3ea395 100644
--- a/compiler/rustc_mir_dataflow/src/framework/direction.rs
+++ b/compiler/rustc_mir_dataflow/src/framework/direction.rs
@@ -228,7 +228,7 @@ impl Direction for Backward {
     ) where
         A: Analysis<'tcx>,
     {
-        for pred in body.predecessors()[bb].iter().copied() {
+        for pred in body.basic_blocks.predecessors()[bb].iter().copied() {
             match body[pred].terminator().kind {
                 // Apply terminator-specific edge effects.
                 //
@@ -316,7 +316,7 @@ where
     fn apply(&mut self, mut apply_edge_effect: impl FnMut(&mut D, SwitchIntTarget)) {
         assert!(!self.effects_applied);
 
-        let values = &self.body.switch_sources()[&(self.bb, self.pred)];
+        let values = &self.body.basic_blocks.switch_sources()[&(self.bb, self.pred)];
         let targets = values.iter().map(|&value| SwitchIntTarget { value, target: self.bb });
 
         let mut tmp = None;
diff --git a/compiler/rustc_mir_dataflow/src/framework/engine.rs b/compiler/rustc_mir_dataflow/src/framework/engine.rs
index 20e14a77c1e..180376d648a 100644
--- a/compiler/rustc_mir_dataflow/src/framework/engine.rs
+++ b/compiler/rustc_mir_dataflow/src/framework/engine.rs
@@ -101,7 +101,7 @@ where
         // transfer function for each block exactly once (assuming that we process blocks in RPO).
         //
         // In this case, there's no need to compute the block transfer functions ahead of time.
-        if !body.is_cfg_cyclic() {
+        if !body.basic_blocks.is_cfg_cyclic() {
             return Self::new(tcx, body, analysis, None);
         }