From 484152d562f6babaacb3fae08cc5f70ee550e9ee Mon Sep 17 00:00:00 2001
From: Maybe Waffle <waffle.lapkin@gmail.com>
Date: Thu, 15 Feb 2024 19:54:37 +0000
Subject: Support tail calls in mir via `TerminatorKind::TailCall`

---
 compiler/rustc_codegen_ssa/src/mir/analyze.rs | 1 +
 compiler/rustc_codegen_ssa/src/mir/block.rs   | 7 +++++++
 2 files changed, 8 insertions(+)

(limited to 'compiler/rustc_codegen_ssa/src')

diff --git a/compiler/rustc_codegen_ssa/src/mir/analyze.rs b/compiler/rustc_codegen_ssa/src/mir/analyze.rs
index 0577ba32ffd..ac2b6ca4e95 100644
--- a/compiler/rustc_codegen_ssa/src/mir/analyze.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/analyze.rs
@@ -281,6 +281,7 @@ pub fn cleanup_kinds(mir: &mir::Body<'_>) -> IndexVec<mir::BasicBlock, CleanupKi
                 | TerminatorKind::UnwindResume
                 | TerminatorKind::UnwindTerminate(_)
                 | TerminatorKind::Return
+                | TerminatorKind::TailCall { .. }
                 | TerminatorKind::CoroutineDrop
                 | TerminatorKind::Unreachable
                 | TerminatorKind::SwitchInt { .. }
diff --git a/compiler/rustc_codegen_ssa/src/mir/block.rs b/compiler/rustc_codegen_ssa/src/mir/block.rs
index 4adb95f85d6..6a5525dc2b3 100644
--- a/compiler/rustc_codegen_ssa/src/mir/block.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/block.rs
@@ -1389,6 +1389,13 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                 fn_span,
                 mergeable_succ(),
             ),
+            mir::TerminatorKind::TailCall { .. } => {
+                // FIXME(explicit_tail_calls): implement tail calls in ssa backend
+                span_bug!(
+                    terminator.source_info.span,
+                    "`TailCall` terminator is not yet supported by `rustc_codegen_ssa`"
+                )
+            }
             mir::TerminatorKind::CoroutineDrop | mir::TerminatorKind::Yield { .. } => {
                 bug!("coroutine ops in codegen")
             }
-- 
cgit 1.4.1-3-g733a5