Rename Abort terminator to Terminate

Unify terminology used in unwind action and terminator, and reflect
the fact that a nounwind panic is triggered instead of an immediate
abort is triggered for this terminator.

compiler/rustc_middle/src/mir/patch.rs

@@ -37,7 +37,19 @@ impl<'tcx> MirPatch<'tcx> {
             // Check if we already have a resume block
             if let TerminatorKind::Resume = block.terminator().kind && block.statements.is_empty() {
                 result.resume_block = Some(bb);
-                break;
+                continue;
+            }
+
+            // Check if we already have an unreachable block
+            if let TerminatorKind::Unreachable = block.terminator().kind && block.statements.is_empty() {
+                result.unreachable_block = Some(bb);
+                continue;
+            }
+
+            // Check if we already have a terminate block
+            if let TerminatorKind::Terminate = block.terminator().kind && block.statements.is_empty() {
+                result.terminate_block = Some(bb);
+                continue;
             }
         }
 
@@ -61,6 +73,40 @@ impl<'tcx> MirPatch<'tcx> {
         bb
     }
 
+    pub fn unreachable_block(&mut self) -> BasicBlock {
+        if let Some(bb) = self.unreachable_block {
+            return bb;
+        }
+
+        let bb = self.new_block(BasicBlockData {
+            statements: vec![],
+            terminator: Some(Terminator {
+                source_info: SourceInfo::outermost(self.body_span),
+                kind: TerminatorKind::Unreachable,
+            }),
+            is_cleanup: true,
+        });
+        self.unreachable_block = Some(bb);
+        bb
+    }
+
+    pub fn terminate_block(&mut self) -> BasicBlock {
+        if let Some(bb) = self.terminate_block {
+            return bb;
+        }
+
+        let bb = self.new_block(BasicBlockData {
+            statements: vec![],
+            terminator: Some(Terminator {
+                source_info: SourceInfo::outermost(self.body_span),
+                kind: TerminatorKind::Terminate,
+            }),
+            is_cleanup: true,
+        });
+        self.terminate_block = Some(bb);
+        bb
+    }
+
     pub fn is_patched(&self, bb: BasicBlock) -> bool {
         self.patch_map[bb].is_some()
     }

compiler/rustc_middle/src/mir/spanview.rs

@@ -262,7 +262,7 @@ pub fn terminator_kind_name(term: &Terminator<'_>) -> &'static str {
         Goto { .. } => "Goto",
         SwitchInt { .. } => "SwitchInt",
         Resume => "Resume",
-        Abort => "Abort",
+        Terminate => "Terminate",
         Return => "Return",
         Unreachable => "Unreachable",
         Drop { .. } => "Drop",

compiler/rustc_middle/src/mir/syntax.rs

@@ -522,8 +522,8 @@ pub struct CopyNonOverlapping<'tcx> {
 ///
 /// The basic block pointed to by a `Cleanup` unwind action must have its `cleanup` flag set.
 /// `cleanup` basic blocks have a couple restrictions:
-///  1. All `unwind` fields in them must be `UnwindAction::Continue`.
-///  2. `Return` terminators are not allowed in them. `Abort` and `Unwind` terminators are.
+///  1. All `unwind` fields in them must be `UnwindAction::Terminate` or `UnwindAction::Unreachable`.
+///  2. `Return` terminators are not allowed in them. `Terminate` and `Unwind` terminators are.
 ///  3. All other basic blocks (in the current body) that are reachable from `cleanup` basic blocks
 ///     must also be `cleanup`. This is a part of the type system and checked statically, so it is
 ///     still an error to have such an edge in the CFG even if it's known that it won't be taken at
@@ -565,11 +565,11 @@ pub enum TerminatorKind<'tcx> {
     /// deaggregation runs.
     Resume,
 
-    /// Indicates that the landing pad is finished and that the process should abort.
+    /// Indicates that the landing pad is finished and that the process should terminate.
     ///
     /// Used to prevent unwinding for foreign items or with `-C unwind=abort`. Only permitted in
     /// cleanup blocks.
-    Abort,
+    Terminate,
 
     /// Returns from the function.
     ///

compiler/rustc_middle/src/mir/terminator.rs

@@ -155,7 +155,7 @@ impl<'tcx> TerminatorKind<'tcx> {
                 Some(t).into_iter().chain((&[]).into_iter().copied())
             }
             Resume
-            | Abort
+            | Terminate
             | GeneratorDrop
             | Return
             | Unreachable
@@ -197,7 +197,7 @@ impl<'tcx> TerminatorKind<'tcx> {
                 Some(t).into_iter().chain(&mut [])
             }
             Resume
-            | Abort
+            | Terminate
             | GeneratorDrop
             | Return
             | Unreachable
@@ -214,7 +214,7 @@ impl<'tcx> TerminatorKind<'tcx> {
         match *self {
             TerminatorKind::Goto { .. }
             | TerminatorKind::Resume
-            | TerminatorKind::Abort
+            | TerminatorKind::Terminate
             | TerminatorKind::Return
             | TerminatorKind::Unreachable
             | TerminatorKind::GeneratorDrop
@@ -233,7 +233,7 @@ impl<'tcx> TerminatorKind<'tcx> {
         match *self {
             TerminatorKind::Goto { .. }
             | TerminatorKind::Resume
-            | TerminatorKind::Abort
+            | TerminatorKind::Terminate
             | TerminatorKind::Return
             | TerminatorKind::Unreachable
             | TerminatorKind::GeneratorDrop
@@ -310,7 +310,7 @@ impl<'tcx> TerminatorKind<'tcx> {
             Return => write!(fmt, "return"),
             GeneratorDrop => write!(fmt, "generator_drop"),
             Resume => write!(fmt, "resume"),
-            Abort => write!(fmt, "abort"),
+            Terminate => write!(fmt, "abort"),
             Yield { value, resume_arg, .. } => write!(fmt, "{:?} = yield({:?})", resume_arg, value),
             Unreachable => write!(fmt, "unreachable"),
             Drop { place, .. } => write!(fmt, "drop({:?})", place),
@@ -389,7 +389,7 @@ impl<'tcx> TerminatorKind<'tcx> {
     pub fn fmt_successor_labels(&self) -> Vec<Cow<'static, str>> {
         use self::TerminatorKind::*;
         match *self {
-            Return | Resume | Abort | Unreachable | GeneratorDrop => vec![],
+            Return | Resume | Terminate | Unreachable | GeneratorDrop => vec![],
             Goto { .. } => vec!["".into()],
             SwitchInt { ref targets, .. } => targets
                 .values

compiler/rustc_middle/src/mir/visit.rs

@@ -462,7 +462,7 @@ macro_rules! make_mir_visitor {
                 match kind {
                     TerminatorKind::Goto { .. } |
                     TerminatorKind::Resume |
-                    TerminatorKind::Abort |
+                    TerminatorKind::Terminate |
                     TerminatorKind::GeneratorDrop |
                     TerminatorKind::Unreachable |
                     TerminatorKind::FalseEdge { .. } |