[clang] [CIR] Support aggregate co_await / co_yield in AggExprEmitter (PR #225412)
Aman Maurya via cfe-commits
cfe-commits at lists.llvm.org
Wed Sep 23 03:22:42 PDT 2026
https://github.com/amanmaurya92 updated https://github.com/llvm/llvm-project/pull/225412
>From 1089bc4d9f013586a97f5f357974c9ed86b2a04a Mon Sep 17 00:00:00 2001
From: amanmaurya92 <amanmaurya9209 at gmail.com>
Date: Tue, 22 Sep 2026 20:04:50 +0530
Subject: [PATCH 1/2] [CIR] Support aggregate co_await / co_yield in
AggExprEmitter
Implement support for evaluating co_await and co_yield expressions whose result is an aggregate type in AggExprEmitter.
Assisted by Antigravity.
Reviewed by amanmaurya92.
Fixes #225317
---
clang/lib/CIR/CodeGen/CIRGenCoroutine.cpp | 37 +++++-----
clang/lib/CIR/CodeGen/CIRGenExprAggregate.cpp | 8 +--
clang/test/CIR/CodeGenCoroutines/coro-agg.cpp | 72 +++++++++++++++++++
3 files changed, 93 insertions(+), 24 deletions(-)
create mode 100644 clang/test/CIR/CodeGenCoroutines/coro-agg.cpp
diff --git a/clang/lib/CIR/CodeGen/CIRGenCoroutine.cpp b/clang/lib/CIR/CodeGen/CIRGenCoroutine.cpp
index 6f2c0e33ce1d96..2fa9bd19a62f3c 100644
--- a/clang/lib/CIR/CodeGen/CIRGenCoroutine.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenCoroutine.cpp
@@ -707,25 +707,20 @@ emitSuspendExpression(CIRGenFunction &cgf, CGCoroData &coro,
awaitRes.rv =
cgf.emitAnyExpr(s.getResumeExpr(), aggSlot, ignoreResult);
if (!awaitRes.rv.isIgnored()) {
- // Create the alloca in the block before the scope wrapping
- // cir.await.
- mlir::Value value;
RValue rv = awaitRes.rv;
- if (rv.isScalar()) {
- value = rv.getValue();
- } else if (rv.isComplex()) {
- value = rv.getComplexValue();
+ if (rv.isScalar() || rv.isComplex()) {
+ mlir::Value value =
+ rv.isScalar() ? rv.getValue() : rv.getComplexValue();
+ tmpResumeRValAddr = cgf.emitAlloca(
+ "__coawait_resume_rval", value.getType(), loc,
+ CharUnits::One(),
+ builder.getBestAllocaInsertPoint(scopeParentBlock));
+ // Store the rvalue so we can reload it before the promise call.
+ builder.CIRBaseBuilderTy::createStore(loc, value,
+ tmpResumeRValAddr);
} else {
- cgf.cgm.errorNYI("emitSuspendExpression: Aggregate value");
- return;
+ assert(rv.isAggregate() && "unexpected rvalue kind");
}
-
- tmpResumeRValAddr = cgf.emitAlloca(
- "__coawait_resume_rval", value.getType(), loc, CharUnits::One(),
- builder.getBestAllocaInsertPoint(scopeParentBlock));
- // Store the rvalue so we can reload it before the promise call.
- builder.CIRBaseBuilderTy::createStore(loc, value,
- tmpResumeRValAddr);
}
}
@@ -744,6 +739,12 @@ static RValue emitSuspendExpr(CIRGenFunction &cgf,
RValue rval;
mlir::Location scopeLoc = cgf.getLoc(e.getSourceRange());
+ if (!ignoreResult && aggSlot.isIgnored() &&
+ cgf.getEvaluationKind(e.getType()) == cir::TEK_Aggregate) {
+ aggSlot = cgf.createAggTemp(e.getType(), scopeLoc,
+ cgf.getCounterAggTmpAsString());
+ }
+
// Since we model suspend / resume as an inner region, we must store
// resume scalar results in a tmp alloca, and load it after we build the
// suspend expression. An alternative way to do this would be to make
@@ -768,9 +769,7 @@ static RValue emitSuspendExpr(CIRGenFunction &cgf,
rval.getValue().getType(),
tmpResumeRValAddr));
} else if (rval.isAggregate()) {
- // This is probably already handled via AggSlot, remove this assertion
- // once we have a testcase and prove all pieces work.
- cgf.cgm.errorNYI("emitSuspendExpr Aggregate");
+ return rval;
} else { // complex
rval = RValue::getComplex(cir::LoadOp::create(
cgf.getBuilder(), scopeLoc, rval.getComplexValue().getType(),
diff --git a/clang/lib/CIR/CodeGen/CIRGenExprAggregate.cpp b/clang/lib/CIR/CodeGen/CIRGenExprAggregate.cpp
index 2fb66232d806cd..e6ce32390d2c63 100644
--- a/clang/lib/CIR/CodeGen/CIRGenExprAggregate.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenExprAggregate.cpp
@@ -392,14 +392,12 @@ class AggExprEmitter : public StmtVisitor<AggExprEmitter> {
Visit(ge->getResultExpr());
}
void VisitCoawaitExpr(CoawaitExpr *e) {
- cgf.cgm.errorNYI(e->getSourceRange(), "AggExprEmitter: VisitCoawaitExpr");
+ cgf.emitCoawaitExpr(*e, dest, dest.isIgnored());
}
void VisitCoyieldExpr(CoyieldExpr *e) {
- cgf.cgm.errorNYI(e->getSourceRange(), "AggExprEmitter: VisitCoyieldExpr");
- }
- void VisitUnaryCoawait(UnaryOperator *e) {
- cgf.cgm.errorNYI(e->getSourceRange(), "AggExprEmitter: VisitUnaryCoawait");
+ cgf.emitCoyieldExpr(*e, dest, dest.isIgnored());
}
+ void VisitUnaryCoawait(UnaryOperator *e) { Visit(e->getSubExpr()); }
void VisitUnaryExtension(UnaryOperator *e) { Visit(e->getSubExpr()); }
void VisitSubstNonTypeTemplateParmExpr(SubstNonTypeTemplateParmExpr *e) {
Visit(e->getReplacement());
diff --git a/clang/test/CIR/CodeGenCoroutines/coro-agg.cpp b/clang/test/CIR/CodeGenCoroutines/coro-agg.cpp
new file mode 100644
index 00000000000000..5b31f07b0aea3f
--- /dev/null
+++ b/clang/test/CIR/CodeGenCoroutines/coro-agg.cpp
@@ -0,0 +1,72 @@
+// RUN: %clang_cc1 -std=c++20 -triple x86_64-unknown-linux-gnu -fclangir -Wno-coroutine-missing-unhandled-exception -emit-cir %s -o %t.cir
+// RUN: FileCheck --input-file=%t.cir %s -check-prefix=CIR
+
+#include "Inputs/coroutine.h"
+
+struct B {
+ int x;
+ int y;
+ bool await_ready() { return true; }
+ B await_resume() { return {}; }
+ template <typename F> void await_suspend(F) {}
+};
+
+struct coro_t {
+ struct promise_type {
+ coro_t get_return_object() { return {}; }
+ std::suspend_never initial_suspend() { return {}; }
+ std::suspend_never final_suspend() noexcept { return {}; }
+ void return_void() {}
+ static void unhandled_exception() {}
+ B yield_value(int) { return {}; }
+ };
+};
+
+// CIR-LABEL: cir.func coroutine {{.*}} @_Z22aggregate_coawait_exprv
+coro_t aggregate_coawait_expr() {
+ // CIR: %[[VAL:.*]] = cir.alloca "val" align(4) init : !cir.ptr<!rec_B>
+ // CIR: cir.await(user, ready : {
+ // CIR: }, suspend : {
+ // CIR: }, resume : {
+ // CIR: cir.call @_ZN1B12await_resumeEv(%{{.*}})
+ // CIR: cir.store align(4) %{{.*}}, %[[VAL]] : !rec_B, !cir.ptr<!rec_B>
+ // CIR: cir.yield
+ // CIR: },)
+ B val = co_await B{};
+}
+
+// CIR-LABEL: cir.func coroutine {{.*}} @_Z29aggregate_coawait_expr_unusedv
+coro_t aggregate_coawait_expr_unused() {
+ // CIR: cir.await(user, ready : {
+ // CIR: }, suspend : {
+ // CIR: }, resume : {
+ // CIR: cir.call @_ZN1B12await_resumeEv(%{{.*}})
+ // CIR: cir.yield
+ // CIR: },)
+ co_await B{};
+}
+
+// CIR-LABEL: cir.func coroutine {{.*}} @_Z22aggregate_coyield_exprv
+coro_t aggregate_coyield_expr() {
+ // CIR: %[[VAL:.*]] = cir.alloca "val" align(4) init : !cir.ptr<!rec_B>
+ // CIR: cir.await(yield, ready : {
+ // CIR: }, suspend : {
+ // CIR: }, resume : {
+ // CIR: cir.call @_ZN1B12await_resumeEv(%{{.*}})
+ // CIR: cir.store align(4) %{{.*}}, %[[VAL]] : !rec_B, !cir.ptr<!rec_B>
+ // CIR: cir.yield
+ // CIR: },)
+ B val = co_yield 42;
+}
+
+// CIR-LABEL: cir.func coroutine {{.*}} @_Z29aggregate_coyield_expr_unusedv
+coro_t aggregate_coyield_expr_unused() {
+ // CIR: cir.await(yield, ready : {
+ // CIR: }, suspend : {
+ // CIR: }, resume : {
+ // CIR: cir.call @_ZN1B12await_resumeEv(%{{.*}})
+ // CIR: cir.yield
+ // CIR: },)
+ co_yield 42;
+}
+
>From 6e4df09f8fe0dea4a3a10be8dadd398ad9ffb0eb Mon Sep 17 00:00:00 2001
From: amanmaurya92 <amanmaurya9209 at gmail.com>
Date: Wed, 23 Sep 2026 12:54:24 +0530
Subject: [PATCH 2/2] [CIR] Address review comments on aggregate co_await /
co_yield
- Remove redundant aggregate temporary allocation in emitSuspendExpr, as emitAnyExpr already provisions one when dest is ignored and AggExprEmitter passes dest.isIgnored() as ignoreResult.
- Add OGCG test coverage comparing classic Clang CodeGen side-by-side with CIR in coro-agg.cpp.
---
clang/lib/CIR/CodeGen/CIRGenCoroutine.cpp | 6 ------
clang/test/CIR/CodeGenCoroutines/coro-agg.cpp | 21 ++++++++++++++++++-
2 files changed, 20 insertions(+), 7 deletions(-)
diff --git a/clang/lib/CIR/CodeGen/CIRGenCoroutine.cpp b/clang/lib/CIR/CodeGen/CIRGenCoroutine.cpp
index 2fa9bd19a62f3c..b0e03ce10d5a61 100644
--- a/clang/lib/CIR/CodeGen/CIRGenCoroutine.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenCoroutine.cpp
@@ -739,12 +739,6 @@ static RValue emitSuspendExpr(CIRGenFunction &cgf,
RValue rval;
mlir::Location scopeLoc = cgf.getLoc(e.getSourceRange());
- if (!ignoreResult && aggSlot.isIgnored() &&
- cgf.getEvaluationKind(e.getType()) == cir::TEK_Aggregate) {
- aggSlot = cgf.createAggTemp(e.getType(), scopeLoc,
- cgf.getCounterAggTmpAsString());
- }
-
// Since we model suspend / resume as an inner region, we must store
// resume scalar results in a tmp alloca, and load it after we build the
// suspend expression. An alternative way to do this would be to make
diff --git a/clang/test/CIR/CodeGenCoroutines/coro-agg.cpp b/clang/test/CIR/CodeGenCoroutines/coro-agg.cpp
index 5b31f07b0aea3f..7f3d7775729044 100644
--- a/clang/test/CIR/CodeGenCoroutines/coro-agg.cpp
+++ b/clang/test/CIR/CodeGenCoroutines/coro-agg.cpp
@@ -1,5 +1,7 @@
// RUN: %clang_cc1 -std=c++20 -triple x86_64-unknown-linux-gnu -fclangir -Wno-coroutine-missing-unhandled-exception -emit-cir %s -o %t.cir
// RUN: FileCheck --input-file=%t.cir %s -check-prefix=CIR
+// RUN: %clang_cc1 -std=c++20 -triple x86_64-unknown-linux-gnu -emit-llvm -disable-llvm-passes -Wno-coroutine-missing-unhandled-exception %s -o %t.ll
+// RUN: FileCheck --input-file=%t.ll %s -check-prefix=OGCG
#include "Inputs/coroutine.h"
@@ -23,6 +25,7 @@ struct coro_t {
};
// CIR-LABEL: cir.func coroutine {{.*}} @_Z22aggregate_coawait_exprv
+// OGCG-LABEL: define dso_local void @_Z22aggregate_coawait_exprv
coro_t aggregate_coawait_expr() {
// CIR: %[[VAL:.*]] = cir.alloca "val" align(4) init : !cir.ptr<!rec_B>
// CIR: cir.await(user, ready : {
@@ -32,10 +35,15 @@ coro_t aggregate_coawait_expr() {
// CIR: cir.store align(4) %{{.*}}, %[[VAL]] : !rec_B, !cir.ptr<!rec_B>
// CIR: cir.yield
// CIR: },)
+ // OGCG: %[[VAL:.*]] = alloca %struct.B, align 4
+ // OGCG: await.ready:
+ // OGCG: %[[RES:.*]] = call i64 @_ZN1B12await_resumeEv(ptr {{.*}})
+ // OGCG: store i64 %[[RES]], ptr %[[VAL]], align 4
B val = co_await B{};
}
// CIR-LABEL: cir.func coroutine {{.*}} @_Z29aggregate_coawait_expr_unusedv
+// OGCG-LABEL: define dso_local void @_Z29aggregate_coawait_expr_unusedv
coro_t aggregate_coawait_expr_unused() {
// CIR: cir.await(user, ready : {
// CIR: }, suspend : {
@@ -43,10 +51,14 @@ coro_t aggregate_coawait_expr_unused() {
// CIR: cir.call @_ZN1B12await_resumeEv(%{{.*}})
// CIR: cir.yield
// CIR: },)
+ // OGCG: await.ready:
+ // OGCG: %[[RES:.*]] = call i64 @_ZN1B12await_resumeEv(ptr {{.*}})
+ // OGCG: store i64 %[[RES]], ptr %{{.*}}, align 4
co_await B{};
}
// CIR-LABEL: cir.func coroutine {{.*}} @_Z22aggregate_coyield_exprv
+// OGCG-LABEL: define dso_local void @_Z22aggregate_coyield_exprv
coro_t aggregate_coyield_expr() {
// CIR: %[[VAL:.*]] = cir.alloca "val" align(4) init : !cir.ptr<!rec_B>
// CIR: cir.await(yield, ready : {
@@ -56,10 +68,15 @@ coro_t aggregate_coyield_expr() {
// CIR: cir.store align(4) %{{.*}}, %[[VAL]] : !rec_B, !cir.ptr<!rec_B>
// CIR: cir.yield
// CIR: },)
+ // OGCG: %[[VAL:.*]] = alloca %struct.B, align 4
+ // OGCG: yield.ready:
+ // OGCG: %[[RES:.*]] = call i64 @_ZN1B12await_resumeEv(ptr {{.*}})
+ // OGCG: store i64 %[[RES]], ptr %[[VAL]], align 4
B val = co_yield 42;
}
// CIR-LABEL: cir.func coroutine {{.*}} @_Z29aggregate_coyield_expr_unusedv
+// OGCG-LABEL: define dso_local void @_Z29aggregate_coyield_expr_unusedv
coro_t aggregate_coyield_expr_unused() {
// CIR: cir.await(yield, ready : {
// CIR: }, suspend : {
@@ -67,6 +84,8 @@ coro_t aggregate_coyield_expr_unused() {
// CIR: cir.call @_ZN1B12await_resumeEv(%{{.*}})
// CIR: cir.yield
// CIR: },)
+ // OGCG: yield.ready:
+ // OGCG: %[[RES:.*]] = call i64 @_ZN1B12await_resumeEv(ptr {{.*}})
+ // OGCG: store i64 %[[RES]], ptr %{{.*}}, align 4
co_yield 42;
}
-
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