From bf5eaa45506bbaa5fe9322c4e114d89fd87ad5f4 Mon Sep 17 00:00:00 2001
From: Maybe Waffle <waffle.lapkin@gmail.com>
Date: Tue, 9 May 2023 10:02:59 +0000
Subject: [PATCH] llvm ffi: Expose `CallInst->setTailCallKind`

---
 compiler/rustc_codegen_llvm/src/llvm/ffi.rs   | 11 ++++++++
 .../rustc_llvm/llvm-wrapper/RustWrapper.cpp   | 26 +++++++++++++++++++
 2 files changed, 37 insertions(+)

diff --git a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
index 6ef3418cc5f..1883a8aa0a3 100644
--- a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
+++ b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
@@ -585,6 +585,16 @@ pub enum ThreadLocalMode {
     LocalExec,
 }
 
+/// LLVMRustTailCallKind
+#[derive(Copy, Clone)]
+#[repr(C)]
+pub enum TailCallKind {
+    None,
+    Tail,
+    MustTail,
+    NoTail,
+}
+
 /// LLVMRustChecksumKind
 #[derive(Copy, Clone)]
 #[repr(C)]
@@ -1195,6 +1205,7 @@ extern "C" {
         NameLen: size_t,
     ) -> Option<&Value>;
     pub fn LLVMSetTailCall(CallInst: &Value, IsTailCall: Bool);
+    pub fn LLVMRustSetTailCallKind(CallInst: &Value, TKC: TailCallKind);
 
     // Operations on attributes
     pub fn LLVMRustCreateAttrNoValue(C: &Context, attr: AttributeKind) -> &Attribute;
diff --git a/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp b/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp
index ea04899ab68..3a43fa415bb 100644
--- a/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp
+++ b/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp
@@ -116,6 +116,32 @@ extern "C" LLVMValueRef LLVMRustGetNamedValue(LLVMModuleRef M, const char *Name,
   return wrap(unwrap(M)->getNamedValue(StringRef(Name, NameLen)));
 }
 
+enum class LLVMRustTailCallKind {
+  None,
+  Tail,
+  MustTail,
+  NoTail,
+};
+
+static CallInst::TailCallKind fromRust(LLVMRustTailCallKind Kind) {
+  switch (Kind) {
+  case LLVMRustTailCallKind::None:
+    return CallInst::TailCallKind::TCK_None;
+  case LLVMRustTailCallKind::Tail:
+    return CallInst::TailCallKind::TCK_Tail;
+  case LLVMRustTailCallKind::MustTail:
+    return CallInst::TailCallKind::TCK_MustTail;
+  case LLVMRustTailCallKind::NoTail:
+    return CallInst::TailCallKind::TCK_NoTail;
+  default:
+    report_fatal_error("bad CallInst::TailCallKind.");
+  }
+}
+
+extern "C" void LLVMRustSetTailCallKind(LLVMValueRef Call, LLVMRustTailCallKind TCK) {
+  unwrap<CallInst>(Call)->setTailCallKind(fromRust(TCK));
+}
+
 extern "C" LLVMValueRef LLVMRustGetOrInsertFunction(LLVMModuleRef M,
                                                     const char *Name,
                                                     size_t NameLen,