[CIR] Upstream support for typedef and type aliases (llvm#136335)

Nothing is actually needed in ClangIR to support typedef and type
aliases, but the Decl kinds need to be explicitly ignored in the
emitDecl handlers to avoid hitting the default NYI errors. This change
does that and adds tests.

Author: andykaylor

clang/lib/CIR/CodeGen/CIRGenDecl.cpp

@@ -276,6 +276,14 @@ void CIRGenFunction::emitDecl(const Decl &d) {
   case Decl::OpenACCRoutine:
     emitOpenACCRoutine(cast<OpenACCRoutineDecl>(d));
     return;
+  case Decl::Typedef:     // typedef int X;
+  case Decl::TypeAlias: { // using X = int; [C++0x]
+    QualType ty = cast<TypedefNameDecl>(d).getUnderlyingType();
+    assert(!cir::MissingFeatures::generateDebugInfo());
+    if (ty->isVariablyModifiedType())
+      cgm.errorNYI(d.getSourceRange(), "emitDecl: variably modified type");
+    return;
+  }
   default:
     cgm.errorNYI(d.getSourceRange(),
                  std::string("emitDecl: unhandled decl type: ") +

clang/lib/CIR/CodeGen/CIRGenModule.cpp

@@ -618,6 +618,8 @@ void CIRGenModule::emitTopLevelDecl(Decl *decl) {
     emitGlobalOpenACCDecl(cast<OpenACCDeclareDecl>(decl));
     break;
 
+  case Decl::Typedef:
+  case Decl::TypeAlias: // using foo = bar; [C++11]
   case Decl::Record:
   case Decl::CXXRecord:
     assert(!cir::MissingFeatures::generateDebugInfo());

clang/test/CIR/CodeGen/basic.c

@@ -232,3 +232,24 @@ int f8(int *p) {
 // OGCG:   store i32 2, ptr %[[P]], align 4
 // OGCG:   %[[P2:.*]] = load ptr, ptr %[[P_PTR]], align 8
 // OGCG:   %[[STAR_P:.*]] = load i32, ptr %[[P2]], align 4
+
+typedef unsigned long size_type;
+typedef unsigned long _Tp;
+
+size_type max_size(void) {
+  return (size_type)~0 / sizeof(_Tp);
+}
+
+// CIR: cir.func @max_size()
+// CIR:   %0 = cir.alloca !u64i, !cir.ptr<!u64i>, ["__retval"] {alignment = 8 : i64}
+// CIR:   %1 = cir.const #cir.int<0> : !s32i
+// CIR:   %2 = cir.unary(not, %1) : !s32i, !s32i
+// CIR:   %3 = cir.cast(integral, %2 : !s32i), !u64i
+// CIR:   %4 = cir.const #cir.int<8> : !u64i
+// CIR:   %5 = cir.binop(div, %3, %4) : !u64i
+
+// LLVM: define i64 @max_size()
+// LLVM:   store i64 2305843009213693951, ptr
+
+// OGCG: define{{.*}} i64 @max_size()
+// OGCG:   ret i64 2305843009213693951

clang/test/CIR/CodeGen/basic.cpp

@@ -87,3 +87,18 @@ int *f5() {
 // CHECK-NEXT:   cir.store %[[P]], %[[RET_ADDR]] : !cir.ptr<!s32i>, !cir.ptr<!cir.ptr<!s32i>>
 // CHECK-NEXT:   %[[RET_VAL:.*]] = cir.load %[[RET_ADDR]] : !cir.ptr<!cir.ptr<!s32i>>, !cir.ptr<!s32i>
 // CHECK-NEXT:   cir.return %[[RET_VAL]] : !cir.ptr<!s32i>
+
+using size_type = unsigned long;
+using _Tp = unsigned long;
+
+size_type max_size() {
+  return size_type(~0) / sizeof(_Tp);
+}
+
+// CHECK: cir.func @max_size()
+// CHECK:   %0 = cir.alloca !u64i, !cir.ptr<!u64i>, ["__retval"] {alignment = 8 : i64}
+// CHECK:   %1 = cir.const #cir.int<0> : !s32i
+// CHECK:   %2 = cir.unary(not, %1) : !s32i, !s32i
+// CHECK:   %3 = cir.cast(integral, %2 : !s32i), !u64i
+// CHECK:   %4 = cir.const #cir.int<8> : !u64i
+// CHECK:   %5 = cir.binop(div, %3, %4) : !u64i

clang/test/CIR/CodeGen/typedef.c

@@ -0,0 +1,27 @@
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -Wno-unused-value -fclangir -emit-cir %s -o %t.cir
+// RUN: FileCheck --input-file=%t.cir %s -check-prefix=CIR
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -Wno-unused-value -fclangir -emit-llvm %s -o %t-cir.ll
+// RUN: FileCheck --input-file=%t-cir.ll %s -check-prefix=LLVM
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -Wno-unused-value -emit-llvm %s -o %t.ll
+// RUN: FileCheck --input-file=%t.ll %s -check-prefix=OGCG
+
+void local_typedef(void) {
+  typedef struct {int a;} Struct;
+  Struct s;
+}
+
+// CIR:      cir.func @local_typedef()
+// CIR:        cir.alloca !cir.record<struct "Struct" {!s32i}>,
+// CIR-SAME:       !cir.ptr<!cir.record<struct "Struct" {!s32i}>>, ["s"]
+// CIR-SAME:       {alignment = 4 : i64}
+// CIR:        cir.return
+
+// LLVM: %struct.Struct = type { i32 }
+// LLVM: define void @local_typedef()
+// LLVM:   alloca %struct.Struct, i64 1, align 4
+// LLVM:   ret void
+
+// OGCG: %struct.Struct = type { i32 }
+// OGCG: define{{.*}} void @local_typedef()
+// OGCG:   alloca %struct.Struct, align 4
+// OGCG:   ret void