[clang] [CIR] Upstream coroutine builtin coro_end (PR #176598)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clangir

Author: None (Andres-Salamanca)

<details>
<summary>Changes</summary>

This PR adds support for emitting the `__builtin_coro_end` builtin in CIR.

---
Full diff: https://github.com/llvm/llvm-project/pull/176598.diff


5 Files Affected:

- (modified) clang/include/clang/CIR/MissingFeatures.h (-2) 
- (modified) clang/lib/CIR/CodeGen/CIRGenCoroutine.cpp (+20) 
- (modified) clang/lib/CIR/CodeGen/CIRGenFunction.cpp (+5-3) 
- (modified) clang/lib/CIR/CodeGen/CIRGenModule.h (+1) 
- (modified) clang/test/CIR/CodeGen/coro-task.cpp (+10) 


``````````diff
diff --git a/clang/include/clang/CIR/MissingFeatures.h b/clang/include/clang/CIR/MissingFeatures.h
index 1d066f192d739..e7545626f7ce9 100644
--- a/clang/include/clang/CIR/MissingFeatures.h
+++ b/clang/include/clang/CIR/MissingFeatures.h
@@ -149,8 +149,6 @@ struct MissingFeatures {
   static bool zeroSizeRecordMembers() { return false; }
 
   // Coroutines
-  static bool coroEndBuiltinCall() { return false; }
-  static bool emitBodyAndFallthrough() { return false; }
   static bool coroOutsideFrameMD() { return false; }
   static bool coroutineExceptions() { return false; };
 
diff --git a/clang/lib/CIR/CodeGen/CIRGenCoroutine.cpp b/clang/lib/CIR/CodeGen/CIRGenCoroutine.cpp
index f060568e8db61..f4997b6262c2c 100644
--- a/clang/lib/CIR/CodeGen/CIRGenCoroutine.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenCoroutine.cpp
@@ -215,6 +215,26 @@ CIRGenFunction::emitCoroBeginBuiltinCall(mlir::Location loc,
       mlir::ValueRange{curCoro.data->coroId.getResult(), coroframeAddr});
 }
 
+cir::CallOp CIRGenFunction::emitCoroEndBuiltinCall(mlir::Location loc,
+                                                   mlir::Value nullPtr) {
+  auto boolTy = builder.getBoolTy();
+  mlir::Operation *builtin = cgm.getGlobalValue(cgm.builtinCoroEnd);
+
+  cir::FuncOp fnOp;
+  if (!builtin) {
+    fnOp = cgm.createCIRBuiltinFunction(
+        loc, cgm.builtinCoroEnd,
+        cir::FuncType::get({voidPtrTy, boolTy}, boolTy),
+        /*fd=*/nullptr);
+    assert(fnOp && "should always succeed");
+  } else {
+    fnOp = cast<cir::FuncOp>(builtin);
+  }
+
+  return builder.createCallOp(
+      loc, fnOp, mlir::ValueRange{nullPtr, builder.getBool(false, loc)});
+}
+
 mlir::LogicalResult
 CIRGenFunction::emitCoroutineBody(const CoroutineBodyStmt &s) {
   mlir::Location openCurlyLoc = getLoc(s.getBeginLoc());
diff --git a/clang/lib/CIR/CodeGen/CIRGenFunction.cpp b/clang/lib/CIR/CodeGen/CIRGenFunction.cpp
index ac66d00950f05..f2d73720a9c2b 100644
--- a/clang/lib/CIR/CodeGen/CIRGenFunction.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenFunction.cpp
@@ -355,11 +355,13 @@ void CIRGenFunction::LexicalScope::cleanup() {
 cir::ReturnOp CIRGenFunction::LexicalScope::emitReturn(mlir::Location loc) {
   CIRGenBuilderTy &builder = cgf.getBuilder();
 
-  // If we are on a coroutine, add the coro_end builtin call.
-  assert(!cir::MissingFeatures::coroEndBuiltinCall());
-
   auto fn = dyn_cast<cir::FuncOp>(cgf.curFn);
   assert(fn && "emitReturn from non-function");
+
+  // If we are on a coroutine, add the coro_end builtin call.
+  if (fn.getCoroutine())
+    cgf.emitCoroEndBuiltinCall(loc,
+                               builder.getNullPtr(builder.getVoidPtrTy(), loc));
   if (!fn.getFunctionType().hasVoidReturn()) {
     // Load the value from `__retval` and return it via the `cir.return` op.
     auto value = cir::LoadOp::create(
diff --git a/clang/lib/CIR/CodeGen/CIRGenModule.h b/clang/lib/CIR/CodeGen/CIRGenModule.h
index db63a5d636373..9b01ed338f5f3 100644
--- a/clang/lib/CIR/CodeGen/CIRGenModule.h
+++ b/clang/lib/CIR/CodeGen/CIRGenModule.h
@@ -570,6 +570,7 @@ class CIRGenModule : public CIRGenTypeCache {
   static constexpr const char *builtinCoroId = "__builtin_coro_id";
   static constexpr const char *builtinCoroAlloc = "__builtin_coro_alloc";
   static constexpr const char *builtinCoroBegin = "__builtin_coro_begin";
+  static constexpr const char *builtinCoroEnd = "__builtin_coro_end";
 
   /// Given a builtin id for a function like "__builtin_fabsf", return a
   /// Function* for "fabsf".
diff --git a/clang/test/CIR/CodeGen/coro-task.cpp b/clang/test/CIR/CodeGen/coro-task.cpp
index b98c866de524b..549b156b0fdc0 100644
--- a/clang/test/CIR/CodeGen/coro-task.cpp
+++ b/clang/test/CIR/CodeGen/coro-task.cpp
@@ -250,6 +250,16 @@ VoidTask silly_task() {
 // CIR:   },)
 // CIR: }
 
+// Call builtin coro end and return
+
+// CIR-NEXT: %[[CoroEndArg0:.*]] = cir.const #cir.ptr<null> : !cir.ptr<!void>
+// CIR-NEXT: %[[CoroEndArg1:.*]] = cir.const #false
+// CIR-NEXT: = cir.call @__builtin_coro_end(%[[CoroEndArg0]], %[[CoroEndArg1]])
+
+// CIR: %[[Tmp1:.*]] = cir.load{{.*}} %[[VoidTaskAddr]]
+// CIR-NEXT: cir.return %[[Tmp1]]
+// CIR-NEXT: }
+
 folly::coro::Task<int> byRef(const std::string& s) {
   co_return s.size();
 }

``````````

</details>


https://github.com/llvm/llvm-project/pull/176598