[CIR] Add Aggregate Expression LValue Visitors

[mmha]

This patch implements visitors for MemberExpr, UnaryDeref, StringLiteral, CompoundLiteralExpr and PredefinedExpr inside aggregate expressions.

[llvmbot]

@llvm/pr-subscribers-clang

@llvm/pr-subscribers-clangir

Author: Morris Hafner (mmha)

Changes

This patch implements visitors for MemberExpr, UnaryDeref, StringLiteral, CompoundLiteralExpr and PredefinedExpr inside aggregate expressions.

---

Full diff: https://github.com/llvm/llvm-project/pull/163410.diff

4 Files Affected:

• (modified) clang/lib/CIR/CodeGen/CIRGenExprAggregate.cpp (+30-17)
• (modified) clang/lib/CIR/CodeGen/CIRGenValue.h (+2)
• (added) clang/test/CIR/CodeGen/agg-expr-lvalue.c (+111)
• (modified) clang/test/CIR/CodeGen/compound_literal.cpp (+27)

diff --git a/clang/lib/CIR/CodeGen/CIRGenExprAggregate.cpp b/clang/lib/CIR/CodeGen/CIRGenExprAggregate.cpp
index 901b937e4e3e7..e59bec4106bc5 100644
--- a/clang/lib/CIR/CodeGen/CIRGenExprAggregate.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenExprAggregate.cpp
@@ -170,23 +170,11 @@ class AggExprEmitter : public StmtVisitor<AggExprEmitter> {
   void VisitConstantExpr(ConstantExpr *e) {
     cgf.cgm.errorNYI(e->getSourceRange(), "AggExprEmitter: VisitConstantExpr");
   }
-  void VisitMemberExpr(MemberExpr *e) {
-    cgf.cgm.errorNYI(e->getSourceRange(), "AggExprEmitter: VisitMemberExpr");
-  }
-  void VisitUnaryDeref(UnaryOperator *e) {
-    cgf.cgm.errorNYI(e->getSourceRange(), "AggExprEmitter: VisitUnaryDeref");
-  }
-  void VisitStringLiteral(StringLiteral *e) {
-    cgf.cgm.errorNYI(e->getSourceRange(), "AggExprEmitter: VisitStringLiteral");
-  }
-  void VisitCompoundLiteralExpr(CompoundLiteralExpr *e) {
-    cgf.cgm.errorNYI(e->getSourceRange(),
-                     "AggExprEmitter: VisitCompoundLiteralExpr");
-  }
-  void VisitPredefinedExpr(const PredefinedExpr *e) {
-    cgf.cgm.errorNYI(e->getSourceRange(),
-                     "AggExprEmitter: VisitPredefinedExpr");
-  }
+  void VisitMemberExpr(MemberExpr *e) { emitAggLoadOfLValue(e); }
+  void VisitUnaryDeref(UnaryOperator *e) { emitAggLoadOfLValue(e); }
+  void VisitStringLiteral(StringLiteral *e) { emitAggLoadOfLValue(e); }
+  void VisitCompoundLiteralExpr(CompoundLiteralExpr *e);
+  void VisitPredefinedExpr(const PredefinedExpr *e) { emitAggLoadOfLValue(e); }
   void VisitBinaryOperator(const BinaryOperator *e) {
     cgf.cgm.errorNYI(e->getSourceRange(),
                      "AggExprEmitter: VisitBinaryOperator");
@@ -325,6 +313,31 @@ void AggExprEmitter::emitAggLoadOfLValue(const Expr *e) {
   emitFinalDestCopy(e->getType(), lv);
 }
 
+void AggExprEmitter::VisitCompoundLiteralExpr(CompoundLiteralExpr *e) {
+  if (dest.isPotentiallyAliased() && e->getType().isPODType(cgf.getContext())) {
+    // For a POD type, just emit a load of the lvalue + a copy, because our
+    // compound literal might alias the destination.
+    emitAggLoadOfLValue(e);
+    return;
+  }
+
+  AggValueSlot slot = ensureSlot(cgf.getLoc(e->getSourceRange()), e->getType());
+
+  // Block-scope compound literals are destroyed at the end of the enclosing
+  // scope in C.
+  bool destruct =
+      !cgf.getLangOpts().CPlusPlus && !slot.isExternallyDestructed();
+  if (destruct)
+    slot.setExternallyDestructed();
+
+  cgf.emitAggExpr(e->getInitializer(), slot);
+
+  if (destruct)
+    if ([[maybe_unused]] QualType::DestructionKind dtorKind =
+            e->getType().isDestructedType())
+      cgf.cgm.errorNYI(e->getSourceRange(), "compound literal with destructor");
+}
+
 void AggExprEmitter::emitArrayInit(Address destPtr, cir::ArrayType arrayTy,
                                    QualType arrayQTy, Expr *e,
                                    ArrayRef<Expr *> args, Expr *arrayFiller) {
diff --git a/clang/lib/CIR/CodeGen/CIRGenValue.h b/clang/lib/CIR/CodeGen/CIRGenValue.h
index 25b6ecb503a6e..c4ff351afa871 100644
--- a/clang/lib/CIR/CodeGen/CIRGenValue.h
+++ b/clang/lib/CIR/CodeGen/CIRGenValue.h
@@ -390,6 +390,8 @@ class AggValueSlot {
 
   IsZeroed_t isZeroed() const { return IsZeroed_t(zeroedFlag); }
 
+  IsAliased_t isPotentiallyAliased() const { return IsAliased_t(aliasedFlag); }
+
   RValue asRValue() const {
     if (isIgnored())
       return RValue::getIgnored();
diff --git a/clang/test/CIR/CodeGen/agg-expr-lvalue.c b/clang/test/CIR/CodeGen/agg-expr-lvalue.c
new file mode 100644
index 0000000000000..c826f8fa829d0
--- /dev/null
+++ b/clang/test/CIR/CodeGen/agg-expr-lvalue.c
@@ -0,0 +1,111 @@
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fclangir -emit-cir %s -o %t.cir
+// RUN: FileCheck --check-prefix=CIR --input-file=%t.cir %s
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fclangir -emit-llvm %s -o %t-cir.ll
+// RUN: FileCheck --check-prefix=LLVM --input-file=%t-cir.ll %s
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -emit-llvm %s -o %t.ll
+// RUN: FileCheck --check-prefix=OGCG --input-file=%t.ll %s
+
+struct Point {
+  int x, y;
+};
+
+struct Line {
+  struct Point start;
+  struct Point end;
+};
+
+// AggExprEmitter::VisitMemberExpr
+void test_member_in_array(void) {
+  struct Line line = {{1, 2}, {3, 4}};
+  struct Point arr[1] = {line.start};
+}
+
+// CIR-LABEL: cir.func{{.*}} @test_member_in_array
+// CIR:   %[[LINE:.*]] = cir.alloca !rec_Line{{.*}}, ["line", init]
+// CIR:   %[[ARR:.*]] = cir.alloca !cir.array<!rec_Point x 1>{{.*}}, ["arr", init]
+// CIR:   %[[MEMBER:.*]] = cir.get_member %[[LINE]][0] {name = "start"}
+// CIR:   cir.copy
+
+// LLVM-LABEL: define{{.*}} @test_member_in_array
+// LLVM:   %[[LINE:.*]] = alloca %struct.Line
+// LLVM:   %[[ARR:.*]] = alloca [1 x %struct.Point]
+// LLVM:   %[[MEMBER:.*]] = getelementptr{{.*}}%struct.Line{{.*}}%[[LINE]]{{.*}}i32 0, i32 0
+// LLVM:   call void @llvm.memcpy
+
+// OGCG-LABEL: define{{.*}} @test_member_in_array
+// OGCG:   %[[LINE:.*]] = alloca %struct.Line
+// OGCG:   %[[ARR:.*]] = alloca [1 x %struct.Point]
+// OGCG:   %[[MEMBER:.*]] = getelementptr{{.*}}%struct.Line{{.*}}%[[LINE]]{{.*}}i32 0, i32 0
+// OGCG:   call void @llvm.memcpy
+
+// AggExprEmitter::VisitMemberExpr
+void test_member_arrow_in_array(void) {
+  struct Line *line_ptr;
+  struct Point arr[1] = {line_ptr->start};
+}
+
+// CIR-LABEL: cir.func{{.*}} @test_member_arrow_in_array
+// CIR:   %[[PTR:.*]] = cir.alloca !cir.ptr<!rec_Line>{{.*}}, ["line_ptr"]
+// CIR:   %[[ARR:.*]] = cir.alloca !cir.array<!rec_Point x 1>{{.*}}, ["arr", init]
+// CIR:   %[[LOADED:.*]] = cir.load{{.*}}%[[PTR]]
+// CIR:   %[[MEMBER:.*]] = cir.get_member %[[LOADED]][0] {name = "start"}
+// CIR:   cir.copy
+
+// LLVM-LABEL: define{{.*}} @test_member_arrow_in_array
+// LLVM:   %[[PTR:.*]] = alloca ptr
+// LLVM:   %[[ARR:.*]] = alloca [1 x %struct.Point]
+// LLVM:   %[[LOADED:.*]] = load ptr{{.*}}%[[PTR]]
+// LLVM:   %[[MEMBER:.*]] = getelementptr{{.*}}%struct.Line{{.*}}%[[LOADED]]{{.*}}i32 0, i32 0
+// LLVM:   call void @llvm.memcpy
+
+// OGCG-LABEL: define{{.*}} @test_member_arrow_in_array
+// OGCG:   %[[PTR:.*]] = alloca ptr
+// OGCG:   %[[ARR:.*]] = alloca [1 x %struct.Point]
+// OGCG:   %[[LOADED:.*]] = load ptr{{.*}}%[[PTR]]
+// OGCG:   %[[MEMBER:.*]] = getelementptr{{.*}}%struct.Line{{.*}}%[[LOADED]]{{.*}}i32 0, i32 0
+// OGCG:   call void @llvm.memcpy
+
+// AggExprEmitter::VisitUnaryDeref
+void test_deref_in_array(void) {
+  struct Point *ptr;
+  struct Point arr[1] = {*ptr};
+}
+
+// CIR-LABEL: cir.func{{.*}} @test_deref_in_array
+// CIR:   %[[PTR:.*]] = cir.alloca !cir.ptr<!rec_Point>{{.*}}, ["ptr"]
+// CIR:   %[[ARR:.*]] = cir.alloca !cir.array<!rec_Point x 1>{{.*}}, ["arr", init]
+// CIR:   %[[LOADED:.*]] = cir.load{{.*}}%[[PTR]]
+// CIR:   cir.copy
+
+// LLVM-LABEL: define{{.*}} @test_deref_in_array
+// LLVM:   %[[PTR:.*]] = alloca ptr
+// LLVM:   %[[ARR:.*]] = alloca [1 x %struct.Point]
+// LLVM:   %[[LOADED:.*]] = load ptr{{.*}}%[[PTR]]
+// LLVM:   call void @llvm.memcpy
+
+// OGCG-LABEL: define{{.*}} @test_deref_in_array
+// OGCG:   %[[PTR:.*]] = alloca ptr
+// OGCG:   %[[ARR:.*]] = alloca [1 x %struct.Point]
+// OGCG:   %[[LOADED:.*]] = load ptr{{.*}}%[[PTR]]
+// OGCG:   call void @llvm.memcpy
+
+// AggExprEmitter::VisitStringLiteral
+void test_string_array_in_array(void) {
+    char matrix[2][6] = {"hello", "world"};
+}
+  
+// CIR-LABEL: cir.func{{.*}} @test_string_array_in_array
+// CIR:   cir.alloca !cir.array<!cir.array<!s8i x 6> x 2>, {{.*}}, ["matrix", init]
+// CIR:   cir.get_global
+// CIR:   cir.copy
+// CIR:   cir.get_global
+// CIR:   cir.copy
+
+// LLVM-LABEL: define{{.*}} @test_string_array_in_array
+// LLVM:   alloca [2 x [6 x i8]]
+// LLVM:   call void @llvm.memcpy
+// LLVM:   call void @llvm.memcpy
+
+// OGCG-LABEL: define{{.*}} @test_string_array_in_array
+// OGCG:   alloca [2 x [6 x i8]]
+// OGCG:   call void @llvm.memcpy{{.*}}@__const.test_string_array_in_array
diff --git a/clang/test/CIR/CodeGen/compound_literal.cpp b/clang/test/CIR/CodeGen/compound_literal.cpp
index a92af95c62a1b..30a1dc03c449b 100644
--- a/clang/test/CIR/CodeGen/compound_literal.cpp
+++ b/clang/test/CIR/CodeGen/compound_literal.cpp
@@ -97,3 +97,30 @@ void foo3() {
 // OGCG: %[[TMP:.*]] = load <4 x i32>, ptr %[[CL_ADDR]], align 16
 // OGCG: store <4 x i32> %[[TMP]], ptr %[[A_ADDR]], align 16
 
+struct Point {
+  int x, y;
+};
+
+void foo4() {
+  Point p = (Point){5, 10};
+}
+
+// CIR-LABEL: @_Z4foo4v
+// CIR:   %[[P:.*]] = cir.alloca !rec_Point, !cir.ptr<!rec_Point>, ["p", init]
+// CIR:   %[[P_X:.*]] = cir.get_member %[[P]][0] {name = "x"}
+// CIR:   %[[FIVE:.*]] = cir.const #cir.int<5> : !s32i
+// CIR:   cir.store{{.*}} %[[FIVE]], %[[P_X]]
+// CIR:   %[[P_Y:.*]] = cir.get_member %[[P]][1] {name = "y"}
+// CIR:   %[[TEN:.*]] = cir.const #cir.int<10> : !s32i
+// CIR:   cir.store{{.*}} %[[TEN]], %[[P_Y]]
+
+// LLVM-LABEL: @_Z4foo4v
+// LLVM:   %[[P:.*]] = alloca %struct.Point
+// LLVM:   %[[P_X:.*]] = getelementptr %struct.Point, ptr %[[P]], i32 0, i32 0
+// LLVM:   store i32 5, ptr %[[P_X]]
+// LLVM:   %[[P_Y:.*]] = getelementptr %struct.Point, ptr %[[P]], i32 0, i32 1
+// LLVM:   store i32 10, ptr %[[P_Y]]
+
+// OGCG-LABEL: @_Z4foo4v
+// OGCG:   %[[P:.*]] = alloca %struct.Point
+// OGCG:   call void @llvm.memcpy{{.*}}(ptr{{.*}} %[[P]], ptr{{.*}} @__const._Z4foo4v.p

[andykaylor]

Looks good, except a possibly missing test case

[bcardosolopes]

LGTM once visitors all get tested (or continue NYI)