[clang] [CIR] Emit CIR builtins: coroAlloc, coroBegin, and coroSize (PR #164180)

[via cfe-commits]

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@@ -73,10 +119,39 @@ CIRGenFunction::emitCoroutineBody(const CoroutineBodyStmt &s) {
   cir::CallOp coroId = emitCoroIDBuiltinCall(openCurlyLoc, nullPtrCst);
   createCoroData(*this, curCoro, coroId);
 
-  assert(!cir::MissingFeatures::coroAllocBuiltinCall());
-
-  assert(!cir::MissingFeatures::coroBeginBuiltinCall());
+  // Backend is allowed to elide memory allocations, to help it, emit
+  // auto mem = coro.alloc() ? 0 : ... allocation code ...;
+  cir::CallOp coroAlloc = emitCoroAllocBuiltinCall(openCurlyLoc);
+
+  // Initialize address of coroutine frame to null
+  CanQualType astVoidPtrTy = cgm.getASTContext().VoidPtrTy;
+  mlir::Type allocaTy = convertTypeForMem(astVoidPtrTy);
+  Address coroFrame =
+      createTempAlloca(allocaTy, getContext().getTypeAlignInChars(astVoidPtrTy),
+                       openCurlyLoc, "__coro_frame_addr",
+                       /*ArraySize=*/nullptr);
+
+  mlir::Value storeAddr = coroFrame.getPointer();
+  builder.CIRBaseBuilderTy::createStore(openCurlyLoc, nullPtrCst, storeAddr);
+  cir::IfOp::create(
+      builder, openCurlyLoc, coroAlloc.getResult(),
+      /*withElseRegion=*/false,
+      /*thenBuilder=*/[&](mlir::OpBuilder &b, mlir::Location loc) {
+        builder.CIRBaseBuilderTy::createStore(
+            loc, emitScalarExpr(s.getAllocate()), storeAddr);
+        builder.create<cir::YieldOp>(loc);
+      });
+  curCoro.data->coroBegin =
+      emitCoroBeginBuiltinCall(
+          openCurlyLoc,
+          builder.create<cir::LoadOp>(openCurlyLoc, allocaTy, storeAddr))
+          .getResult();
+
+  // Handle allocation failure if 'ReturnStmtOnAllocFailure' was provided.
+  if (s.getReturnStmtOnAllocFailure())
+    cgm.errorNYI("NYI");
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Andres-Salamanca wrote:

Done

https://github.com/llvm/llvm-project/pull/164180