Rollup merge of rust-lang#99027 - tmiasko:basic-blocks, r=oli-obk

Replace `Body::basic_blocks()` with field access

Since the refactoring in rust-lang#98930, it is possible to borrow the basic blocks
independently from other parts of MIR by accessing the `basic_blocks` field
directly.

Replace unnecessary `Body::basic_blocks()` method with a direct field access,
which has an additional benefit of borrowing the basic blocks only.

compiler/rustc_borrowck/src/constraint_generation.rs

@@ -31,7 +31,7 @@ pub(super) fn generate_constraints<'cx, 'tcx>(
         body,
     };
 
-    for (bb, data) in body.basic_blocks().iter_enumerated() {
+    for (bb, data) in body.basic_blocks.iter_enumerated() {
         cg.visit_basic_block_data(bb, data);
     }
 }

compiler/rustc_borrowck/src/dataflow.rs

@@ -143,7 +143,7 @@ struct OutOfScopePrecomputer<'a, 'tcx> {
 impl<'a, 'tcx> OutOfScopePrecomputer<'a, 'tcx> {
     fn new(body: &'a Body<'tcx>, regioncx: &'a RegionInferenceContext<'tcx>) -> Self {
         OutOfScopePrecomputer {
-            visited: BitSet::new_empty(body.basic_blocks().len()),
+            visited: BitSet::new_empty(body.basic_blocks.len()),
             visit_stack: vec![],
             body,
             regioncx,

compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs

@@ -459,7 +459,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                 return outmost_back_edge;
             }
 
-            let block = &self.body.basic_blocks()[location.block];
+            let block = &self.body.basic_blocks[location.block];
 
             if location.statement_index < block.statements.len() {
                 let successor = location.successor_within_block();
@@ -518,7 +518,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
         }
 
         if loop_head.dominates(from, &self.dominators) {
-            let block = &self.body.basic_blocks()[from.block];
+            let block = &self.body.basic_blocks[from.block];
 
             if from.statement_index < block.statements.len() {
                 let successor = from.successor_within_block();
@@ -568,7 +568,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
             UseSpans::PatUse(span)
             | UseSpans::OtherUse(span)
             | UseSpans::FnSelfUse { var_span: span, .. } => {
-                let block = &self.body.basic_blocks()[location.block];
+                let block = &self.body.basic_blocks[location.block];
 
                 let kind = if let Some(&Statement {
                     kind: StatementKind::FakeRead(box (FakeReadCause::ForLet(_), _)),

compiler/rustc_borrowck/src/diagnostics/move_errors.rs

@@ -88,7 +88,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
                 if let Some(StatementKind::Assign(box (
                     place,
                     Rvalue::Use(Operand::Move(move_from)),
-                ))) = self.body.basic_blocks()[location.block]
+                ))) = self.body.basic_blocks[location.block]
                     .statements
                     .get(location.statement_index)
                     .map(|stmt| &stmt.kind)

compiler/rustc_borrowck/src/location.rs

@@ -33,7 +33,7 @@ impl LocationTable {
     pub(crate) fn new(body: &Body<'_>) -> Self {
         let mut num_points = 0;
         let statements_before_block = body
-            .basic_blocks()
+            .basic_blocks
             .iter()
             .map(|block_data| {
                 let v = num_points;

compiler/rustc_borrowck/src/region_infer/values.rs

@@ -25,7 +25,7 @@ impl RegionValueElements {
     pub(crate) fn new(body: &Body<'_>) -> Self {
         let mut num_points = 0;
         let statements_before_block: IndexVec<BasicBlock, usize> = body
-            .basic_blocks()
+            .basic_blocks
             .iter()
             .map(|block_data| {
                 let v = num_points;
@@ -37,7 +37,7 @@ impl RegionValueElements {
         debug!("RegionValueElements: num_points={:#?}", num_points);
 
         let mut basic_blocks = IndexVec::with_capacity(num_points);
-        for (bb, bb_data) in body.basic_blocks().iter_enumerated() {
+        for (bb, bb_data) in body.basic_blocks.iter_enumerated() {
             basic_blocks.extend((0..=bb_data.statements.len()).map(|_| bb));
         }
 

compiler/rustc_borrowck/src/type_check/mod.rs

@@ -2633,7 +2633,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
             self.check_local(&body, local, local_decl);
         }
 
-        for (block, block_data) in body.basic_blocks().iter_enumerated() {
+        for (block, block_data) in body.basic_blocks.iter_enumerated() {
             let mut location = Location { block, statement_index: 0 };
             for stmt in &block_data.statements {
                 if !stmt.source_info.span.is_dummy() {

compiler/rustc_codegen_cranelift/src/analyze.rs

@@ -26,7 +26,7 @@ pub(crate) fn analyze(fx: &FunctionCx<'_, '_, '_>) -> IndexVec<Local, SsaKind> {
         })
         .collect::<IndexVec<Local, SsaKind>>();
 
-    for bb in fx.mir.basic_blocks().iter() {
+    for bb in fx.mir.basic_blocks.iter() {
         for stmt in bb.statements.iter() {
             match &stmt.kind {
                 Assign(place_and_rval) => match &place_and_rval.1 {

compiler/rustc_codegen_cranelift/src/base.rs

@@ -73,7 +73,7 @@ pub(crate) fn codegen_fn<'tcx>(
     // Predefine blocks
     let start_block = bcx.create_block();
     let block_map: IndexVec<BasicBlock, Block> =
-        (0..mir.basic_blocks().len()).map(|_| bcx.create_block()).collect();
+        (0..mir.basic_blocks.len()).map(|_| bcx.create_block()).collect();
 
     // Make FunctionCx
     let target_config = module.target_config();
@@ -271,7 +271,7 @@ fn codegen_fn_body(fx: &mut FunctionCx<'_, '_, '_>, start_block: Block) {
     }
     fx.tcx.sess.time("codegen prelude", || crate::abi::codegen_fn_prelude(fx, start_block));
 
-    for (bb, bb_data) in fx.mir.basic_blocks().iter_enumerated() {
+    for (bb, bb_data) in fx.mir.basic_blocks.iter_enumerated() {
         let block = fx.get_block(bb);
         fx.bcx.switch_to_block(block);
 

compiler/rustc_codegen_cranelift/src/constant.rs

@@ -505,7 +505,7 @@ pub(crate) fn mir_operand_get_const_val<'tcx>(
                 return None;
             }
             let mut computed_const_val = None;
-            for bb_data in fx.mir.basic_blocks() {
+            for bb_data in fx.mir.basic_blocks.iter() {
                 for stmt in &bb_data.statements {
                     match &stmt.kind {
                         StatementKind::Assign(local_and_rvalue) if &local_and_rvalue.0 == place => {

compiler/rustc_codegen_ssa/src/mir/analyze.rs

@@ -266,7 +266,7 @@ pub fn cleanup_kinds(mir: &mir::Body<'_>) -> IndexVec<mir::BasicBlock, CleanupKi
         result: &mut IndexVec<mir::BasicBlock, CleanupKind>,
         mir: &mir::Body<'tcx>,
     ) {
-        for (bb, data) in mir.basic_blocks().iter_enumerated() {
+        for (bb, data) in mir.basic_blocks.iter_enumerated() {
             match data.terminator().kind {
                 TerminatorKind::Goto { .. }
                 | TerminatorKind::Resume
@@ -296,7 +296,7 @@ pub fn cleanup_kinds(mir: &mir::Body<'_>) -> IndexVec<mir::BasicBlock, CleanupKi
     }
 
     fn propagate<'tcx>(result: &mut IndexVec<mir::BasicBlock, CleanupKind>, mir: &mir::Body<'tcx>) {
-        let mut funclet_succs = IndexVec::from_elem(None, mir.basic_blocks());
+        let mut funclet_succs = IndexVec::from_elem(None, &mir.basic_blocks);
 
         let mut set_successor = |funclet: mir::BasicBlock, succ| match funclet_succs[funclet] {
             ref mut s @ None => {
@@ -359,7 +359,7 @@ pub fn cleanup_kinds(mir: &mir::Body<'_>) -> IndexVec<mir::BasicBlock, CleanupKi
         }
     }
 
-    let mut result = IndexVec::from_elem(CleanupKind::NotCleanup, mir.basic_blocks());
+    let mut result = IndexVec::from_elem(CleanupKind::NotCleanup, &mir.basic_blocks);
 
     discover_masters(&mut result, mir);
     propagate(&mut result, mir);

compiler/rustc_codegen_ssa/src/mir/mod.rs

@@ -150,13 +150,13 @@ pub fn codegen_mir<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
     let start_llbb = Bx::append_block(cx, llfn, "start");
     let mut bx = Bx::build(cx, start_llbb);
 
-    if mir.basic_blocks().iter().any(|bb| bb.is_cleanup) {
+    if mir.basic_blocks.iter().any(|bb| bb.is_cleanup) {
         bx.set_personality_fn(cx.eh_personality());
     }
 
     let cleanup_kinds = analyze::cleanup_kinds(&mir);
     let cached_llbbs: IndexVec<mir::BasicBlock, Option<Bx::BasicBlock>> = mir
-        .basic_blocks()
+        .basic_blocks
         .indices()
         .map(|bb| if bb == mir::START_BLOCK { Some(start_llbb) } else { None })
         .collect();
@@ -172,8 +172,8 @@ pub fn codegen_mir<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
         unreachable_block: None,
         double_unwind_guard: None,
         cleanup_kinds,
-        landing_pads: IndexVec::from_elem(None, mir.basic_blocks()),
-        funclets: IndexVec::from_fn_n(|_| None, mir.basic_blocks().len()),
+        landing_pads: IndexVec::from_elem(None, &mir.basic_blocks),
+        funclets: IndexVec::from_fn_n(|_| None, mir.basic_blocks.len()),
         locals: IndexVec::new(),
         debug_context,
         per_local_var_debug_info: None,

compiler/rustc_const_eval/src/interpret/eval_context.rs

@@ -782,7 +782,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
         assert_eq!(
             unwinding,
             match self.frame().loc {
-                Ok(loc) => self.body().basic_blocks()[loc.block].is_cleanup,
+                Ok(loc) => self.body().basic_blocks[loc.block].is_cleanup,
                 Err(_) => true,
             }
         );

compiler/rustc_const_eval/src/interpret/intrinsics/caller_location.rs

@@ -28,7 +28,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
             let mut source_info = *frame.body.source_info(loc);
 
             // If this is a `Call` terminator, use the `fn_span` instead.
-            let block = &frame.body.basic_blocks()[loc.block];
+            let block = &frame.body.basic_blocks[loc.block];
             if loc.statement_index == block.statements.len() {
                 debug!(
                     "find_closest_untracked_caller_location: got terminator {:?} ({:?})",

compiler/rustc_const_eval/src/interpret/step.rs

@@ -53,7 +53,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
             self.pop_stack_frame(/* unwinding */ true)?;
             return Ok(true);
         };
-        let basic_block = &self.body().basic_blocks()[loc.block];
+        let basic_block = &self.body().basic_blocks[loc.block];
 
         if let Some(stmt) = basic_block.statements.get(loc.statement_index) {
             let old_frames = self.frame_idx();

compiler/rustc_const_eval/src/transform/check_consts/check.rs

@@ -135,7 +135,7 @@ impl<'mir, 'tcx> Qualifs<'mir, 'tcx> {
         // qualifs for the return type.
         let return_block = ccx
             .body
-            .basic_blocks()
+            .basic_blocks
             .iter_enumerated()
             .find(|(_, block)| matches!(block.terminator().kind, TerminatorKind::Return))
             .map(|(bb, _)| bb);

compiler/rustc_const_eval/src/transform/promote_consts.rs

@@ -710,7 +710,7 @@ impl<'a, 'tcx> Promoter<'a, 'tcx> {
     }
 
     fn assign(&mut self, dest: Local, rvalue: Rvalue<'tcx>, span: Span) {
-        let last = self.promoted.basic_blocks().last().unwrap();
+        let last = self.promoted.basic_blocks.last().unwrap();
         let data = &mut self.promoted[last];
         data.statements.push(Statement {
             source_info: SourceInfo::outermost(span),
@@ -803,7 +803,7 @@ impl<'a, 'tcx> Promoter<'a, 'tcx> {
                         self.visit_operand(arg, loc);
                     }
 
-                    let last = self.promoted.basic_blocks().last().unwrap();
+                    let last = self.promoted.basic_blocks.last().unwrap();
                     let new_target = self.new_block();
 
                     *self.promoted[last].terminator_mut() = Terminator {
@@ -1041,7 +1041,7 @@ pub fn is_const_fn_in_array_repeat_expression<'tcx>(
         _ => {}
     }
 
-    for block in body.basic_blocks() {
+    for block in body.basic_blocks.iter() {
         if let Some(Terminator { kind: TerminatorKind::Call { func, destination, .. }, .. }) =
             &block.terminator
         {

compiler/rustc_const_eval/src/transform/validate.rs

@@ -140,8 +140,8 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
         if bb == START_BLOCK {
             self.fail(location, "start block must not have predecessors")
         }
-        if let Some(bb) = self.body.basic_blocks().get(bb) {
-            let src = self.body.basic_blocks().get(location.block).unwrap();
+        if let Some(bb) = self.body.basic_blocks.get(bb) {
+            let src = self.body.basic_blocks.get(location.block).unwrap();
             match (src.is_cleanup, bb.is_cleanup, edge_kind) {
                 // Non-cleanup blocks can jump to non-cleanup blocks along non-unwind edges
                 (false, false, EdgeKind::Normal)
@@ -881,13 +881,13 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
             }
             TerminatorKind::Resume | TerminatorKind::Abort => {
                 let bb = location.block;
-                if !self.body.basic_blocks()[bb].is_cleanup {
+                if !self.body.basic_blocks[bb].is_cleanup {
                     self.fail(location, "Cannot `Resume` or `Abort` from non-cleanup basic block")
                 }
             }
             TerminatorKind::Return => {
                 let bb = location.block;
-                if self.body.basic_blocks()[bb].is_cleanup {
+                if self.body.basic_blocks[bb].is_cleanup {
                     self.fail(location, "Cannot `Return` from cleanup basic block")
                 }
             }

compiler/rustc_middle/src/mir/generic_graph.rs

@@ -12,14 +12,14 @@ pub fn mir_fn_to_generic_graph<'tcx>(tcx: TyCtxt<'tcx>, body: &Body<'_>) -> Grap
 
     // Nodes
     let nodes: Vec<Node> = body
-        .basic_blocks()
+        .basic_blocks
         .iter_enumerated()
         .map(|(block, _)| bb_to_graph_node(block, body, dark_mode))
         .collect();
 
     // Edges
     let mut edges = Vec::new();
-    for (source, _) in body.basic_blocks().iter_enumerated() {
+    for (source, _) in body.basic_blocks.iter_enumerated() {
         let def_id = body.source.def_id();
         let terminator = body[source].terminator();
         let labels = terminator.kind.fmt_successor_labels();

compiler/rustc_middle/src/mir/mod.rs

@@ -331,11 +331,6 @@ impl<'tcx> Body<'tcx> {
         body
     }
 
-    #[inline]
-    pub fn basic_blocks(&self) -> &IndexVec<BasicBlock, BasicBlockData<'tcx>> {
-        &self.basic_blocks
-    }
-
     #[inline]
     pub fn basic_blocks_mut(&mut self) -> &mut IndexVec<BasicBlock, BasicBlockData<'tcx>> {
         self.basic_blocks.as_mut()
@@ -490,7 +485,7 @@ impl<'tcx> Index<BasicBlock> for Body<'tcx> {
 
     #[inline]
     fn index(&self, index: BasicBlock) -> &BasicBlockData<'tcx> {
-        &self.basic_blocks()[index]
+        &self.basic_blocks[index]
     }
 }
 

compiler/rustc_middle/src/mir/patch.rs

@@ -19,7 +19,7 @@ pub struct MirPatch<'tcx> {
 impl<'tcx> MirPatch<'tcx> {
     pub fn new(body: &Body<'tcx>) -> Self {
         let mut result = MirPatch {
-            patch_map: IndexVec::from_elem(None, body.basic_blocks()),
+            patch_map: IndexVec::from_elem(None, &body.basic_blocks),
             new_blocks: vec![],
             new_statements: vec![],
             new_locals: vec![],
@@ -29,7 +29,7 @@ impl<'tcx> MirPatch<'tcx> {
         };
 
         // Check if we already have a resume block
-        for (bb, block) in body.basic_blocks().iter_enumerated() {
+        for (bb, block) in body.basic_blocks.iter_enumerated() {
             if let TerminatorKind::Resume = block.terminator().kind && block.statements.is_empty() {
                 result.resume_block = Some(bb);
                 break;
@@ -61,7 +61,7 @@ impl<'tcx> MirPatch<'tcx> {
     }
 
     pub fn terminator_loc(&self, body: &Body<'tcx>, bb: BasicBlock) -> Location {
-        let offset = match bb.index().checked_sub(body.basic_blocks().len()) {
+        let offset = match bb.index().checked_sub(body.basic_blocks.len()) {
             Some(index) => self.new_blocks[index].statements.len(),
             None => body[bb].statements.len(),
         };
@@ -129,7 +129,7 @@ impl<'tcx> MirPatch<'tcx> {
         debug!(
             "MirPatch: {} new blocks, starting from index {}",
             self.new_blocks.len(),
-            body.basic_blocks().len()
+            body.basic_blocks.len()
         );
         let bbs = if self.patch_map.is_empty() && self.new_blocks.is_empty() {
             body.basic_blocks.as_mut_preserves_cfg()
@@ -173,7 +173,7 @@ impl<'tcx> MirPatch<'tcx> {
     }
 
     pub fn source_info_for_location(&self, body: &Body<'tcx>, loc: Location) -> SourceInfo {
-        let data = match loc.block.index().checked_sub(body.basic_blocks().len()) {
+        let data = match loc.block.index().checked_sub(body.basic_blocks.len()) {
             Some(new) => &self.new_blocks[new],
             None => &body[loc.block],
         };

compiler/rustc_middle/src/mir/pretty.rs

@@ -318,10 +318,10 @@ where
     F: FnMut(PassWhere, &mut dyn Write) -> io::Result<()>,
 {
     write_mir_intro(tcx, body, w)?;
-    for block in body.basic_blocks().indices() {
+    for block in body.basic_blocks.indices() {
         extra_data(PassWhere::BeforeBlock(block), w)?;
         write_basic_block(tcx, block, body, extra_data, w)?;
-        if block.index() + 1 != body.basic_blocks().len() {
+        if block.index() + 1 != body.basic_blocks.len() {
             writeln!(w)?;
         }
     }

compiler/rustc_middle/src/mir/spanview.rs

@@ -105,7 +105,7 @@ where
     }
     let body_span = hir_body.unwrap().value.span;
     let mut span_viewables = Vec::new();
-    for (bb, data) in body.basic_blocks().iter_enumerated() {
+    for (bb, data) in body.basic_blocks.iter_enumerated() {
         match spanview {
             MirSpanview::Statement => {
                 for (i, statement) in data.statements.iter().enumerate() {

compiler/rustc_middle/src/mir/traversal.rs

@@ -37,7 +37,7 @@ impl<'a, 'tcx> Preorder<'a, 'tcx> {
 
         Preorder {
             body,
-            visited: BitSet::new_empty(body.basic_blocks().len()),
+            visited: BitSet::new_empty(body.basic_blocks.len()),
             worklist,
             root_is_start_block: root == START_BLOCK,
         }
@@ -71,7 +71,7 @@ impl<'a, 'tcx> Iterator for Preorder<'a, 'tcx> {
 
     fn size_hint(&self) -> (usize, Option<usize>) {
         // All the blocks, minus the number of blocks we've visited.
-        let upper = self.body.basic_blocks().len() - self.visited.count();
+        let upper = self.body.basic_blocks.len() - self.visited.count();
 
         let lower = if self.root_is_start_block {
             // We will visit all remaining blocks exactly once.