[CIR] Handle character literal values

[andykaylor]

This change adds a handler for emitting a cir.constant op when a character literal is encountered outside an initializer expression.

[llvmbot]

@llvm/pr-subscribers-clangir

@llvm/pr-subscribers-clang

Author: Andy Kaylor (andykaylor)

Changes

This change adds a handler for emitting a cir.constant op when a character literal is encountered outside an initializer expression.

---

Full diff: https://github.com/llvm/llvm-project/pull/144141.diff

2 Files Affected:

• (modified) clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp (+6)
• (modified) clang/test/CIR/CodeGen/basic.c (+14)

diff --git a/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp b/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp
index 30d231e2c61de..998bb29da8b08 100644
--- a/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp
@@ -162,6 +162,12 @@ class ScalarExprEmitter : public StmtVisitor<ScalarExprEmitter, mlir::Value> {
         builder.getAttr<cir::FPAttr>(type, e->getValue()));
   }
 
+  mlir::Value VisitCharacterLiteral(const CharacterLiteral *e) {
+    mlir::Type ty = cgf.convertType(e->getType());
+    auto init = cir::IntAttr::get(ty, e->getValue());
+    return builder.create<cir::ConstantOp>(cgf.getLoc(e->getExprLoc()), init);
+  }
+
   mlir::Value VisitCXXBoolLiteralExpr(const CXXBoolLiteralExpr *e) {
     return builder.getBool(e->getValue(), cgf.getLoc(e->getExprLoc()));
   }
diff --git a/clang/test/CIR/CodeGen/basic.c b/clang/test/CIR/CodeGen/basic.c
index abc1a45fd433f..7ff73ee95f799 100644
--- a/clang/test/CIR/CodeGen/basic.c
+++ b/clang/test/CIR/CodeGen/basic.c
@@ -309,3 +309,17 @@ size_type max_size(void) {
 // CHECK:   %6 = cir.load{{.*}} %0 : !cir.ptr<!u64i>, !u64i
 // CHECK:   cir.return %6 : !u64i
 // CHECK:   }
+
+void test_char_literal() {
+  char c;
+  c = 'X';
+}
+
+// CIR: cir.func @test_char_literal
+// CIR:   cir.const #cir.int<88>
+
+// LLVM: define void @test_char_literal()
+// LLVM:   store i8 88, ptr %{{.*}}, align 1
+
+// OGCG: define{{.*}} void @test_char_literal()
+// OGCG:   store i8 88, ptr %{{.*}}, align 1

[AmrDeveloper]

LGTM!