[CIR] Add support for DumpRecordLayouts (#1667)

This PR adds support for the `-fdump-record-layouts` flag. It enables
printing both the `CIRGenRecordLayout` and the `ASTRecordLayout`,
similar to what is done in CodeGen.

Author: Andres-Salamanca

clang/lib/CIR/CodeGen/CIRGenRecordLayout.h

@@ -107,7 +107,7 @@ struct CIRGenBitFieldInfo {
         StorageSize(StorageSize), StorageOffset(StorageOffset) {}
 
   void print(llvm::raw_ostream &OS) const;
-  void dump() const;
+  LLVM_DUMP_METHOD void dump() const;
 
   /// Given a bit-field decl, build an appropriate helper object for
   /// accessing that field (which is expected to have the given offset and
@@ -201,6 +201,8 @@ class CIRGenRecordLayout {
     assert(it != BitFields.end() && "Unable to find bitfield info");
     return it->second;
   }
+  void print(raw_ostream &os) const;
+  LLVM_DUMP_METHOD void dump() const;
 };
 
 } // namespace clang::CIRGen

clang/lib/CIR/CodeGen/CIRRecordLayoutBuilder.cpp

@@ -760,13 +760,55 @@ CIRGenTypes::computeRecordLayout(const RecordDecl *D, cir::RecordType *Ty) {
 
   // Dump the layout, if requested.
   if (getContext().getLangOpts().DumpRecordLayouts) {
-    llvm_unreachable("NYI");
+    llvm::outs() << "\n*** Dumping CIRgen Record Layout\n";
+    llvm::outs() << "Record: ";
+    D->dump(llvm::outs());
+    llvm::outs() << "\nLayout: ";
+    RL->print(llvm::outs());
   }
 
   // TODO: implement verification
   return RL;
 }
 
+void CIRGenRecordLayout::print(raw_ostream &os) const {
+  os << "<CIRecordLayout\n";
+  os << "   CIR Type:" << CompleteObjectType << "\n";
+  if (BaseSubobjectType)
+    os << "   NonVirtualBaseCIRType:" << BaseSubobjectType << "\n";
+  os << "   IsZeroInitializable:" << IsZeroInitializable << "\n";
+  os << "   BitFields:[\n";
+  std::vector<std::pair<unsigned, const CIRGenBitFieldInfo *>> bitInfo;
+  for (auto &[decl, info] : BitFields) {
+    const RecordDecl *rd = decl->getParent();
+    unsigned index = 0;
+    for (RecordDecl::field_iterator it = rd->field_begin(); *it != decl; ++it)
+      ++index;
+    bitInfo.push_back(std::make_pair(index, &info));
+  }
+  llvm::array_pod_sort(bitInfo.begin(), bitInfo.end());
+  for (auto &info : bitInfo) {
+    os.indent(4);
+    info.second->print(os);
+    os << "\n";
+  }
+  os << "   ]>\n";
+}
+
+void CIRGenRecordLayout::dump() const { print(llvm::errs()); }
+
+void CIRGenBitFieldInfo::print(raw_ostream &os) const {
+  os << "<CIRBitFieldInfo" << " name:" << Name << " offset:" << Offset
+     << " size:" << Size << " isSigned:" << IsSigned
+     << " storageSize:" << StorageSize
+     << " storageOffset:" << StorageOffset.getQuantity()
+     << " volatileOffset:" << VolatileOffset
+     << " volatileStorageSize:" << VolatileStorageSize
+     << " volatileStorageOffset:" << VolatileStorageOffset.getQuantity() << ">";
+}
+
+void CIRGenBitFieldInfo::dump() const { print(llvm::errs()); }
+
 CIRGenBitFieldInfo CIRGenBitFieldInfo::MakeInfo(CIRGenTypes &Types,
                                                 const FieldDecl *FD,
                                                 uint64_t Offset, uint64_t Size,

clang/test/CIR/CodeGen/dumb-record.cpp

@@ -0,0 +1,64 @@
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fclangir -emit-cir -fdump-record-layouts %s -o - | FileCheck %s
+
+struct SimpleStruct {
+  int a;
+  float b;
+} simple;
+// CHECK: Layout: <CIRecordLayout
+// CHECK: CIR Type:!cir.record<struct "SimpleStruct" {!cir.int<s, 32>, !cir.float} #cir.record.decl.ast>
+// CHECK: NonVirtualBaseCIRType:!cir.record<struct "SimpleStruct" {!cir.int<s, 32>, !cir.float} #cir.record.decl.ast>
+// CHECK: IsZeroInitializable:1
+// CHECK:   BitFields:[
+// CHECK: ]>
+
+struct Empty {
+} empty;
+
+// CHECK: Layout: <CIRecordLayout
+// CHECK:  CIR Type:!cir.record<struct "Empty" padded {!cir.int<u, 8>} #cir.record.decl.ast>
+// CHECK:  NonVirtualBaseCIRType:!cir.record<struct "Empty" padded {!cir.int<u, 8>} #cir.record.decl.ast>
+// CHECK:  IsZeroInitializable:1
+// CHECK:  BitFields:[
+// CHECK:  ]>
+
+struct BitfieldsInOrder {
+  char a;
+  unsigned bit: 8;
+  unsigned should : 20;
+  unsigned have: 3;
+  unsigned order: 1;
+} bitfield_order;
+
+// CHECK: Layout: <CIRecordLayout
+// CHECK:  CIR Type:!cir.record<struct "BitfieldsInOrder" padded {!cir.int<s, 8>, !cir.int<u, 8>, !cir.array<!cir.int<u, 8> x 2>, !cir.array<!cir.int<u, 8> x 3>, !cir.int<u, 8>} #cir.record.decl.ast>
+// CHECK:  NonVirtualBaseCIRType:!cir.record<struct "BitfieldsInOrder" padded {!cir.int<s, 8>, !cir.int<u, 8>, !cir.array<!cir.int<u, 8> x 2>, !cir.array<!cir.int<u, 8> x 3>, !cir.int<u, 8>} #cir.record.decl.ast>
+// CHECK:  IsZeroInitializable:1
+// CHECK:  BitFields:[
+// CHECK-NEXT:  <CIRBitFieldInfo name:bit offset:0 size:8 isSigned:0 storageSize:8 storageOffset:1 volatileOffset:0 volatileStorageSize:0 volatileStorageOffset:0>
+// CHECK-NEXT:   <CIRBitFieldInfo name:should offset:0 size:20 isSigned:0 storageSize:24 storageOffset:4 volatileOffset:0 volatileStorageSize:0 volatileStorageOffset:0>
+// CHECK-NEXT:   <CIRBitFieldInfo name:have offset:20 size:3 isSigned:0 storageSize:24 storageOffset:4 volatileOffset:0 volatileStorageSize:0 volatileStorageOffset:0>
+// CHECK-NEXT:   <CIRBitFieldInfo name:order offset:23 size:1 isSigned:0 storageSize:24 storageOffset:4 volatileOffset:0 volatileStorageSize:0 volatileStorageOffset:0>
+// CHECK:]>
+
+struct Inner {
+  int x;
+} in;
+
+//CHECK: Layout: <CIRecordLayout
+//CHECK:  CIR Type:!cir.record<struct "Inner" {!cir.int<s, 32>} #cir.record.decl.ast>
+//CHECK:  NonVirtualBaseCIRType:!cir.record<struct "Inner" {!cir.int<s, 32>} #cir.record.decl.ast>
+//CHECK:  IsZeroInitializable:1
+//CHECK:  BitFields:[
+//CHECK:  ]>
+
+struct Outer {
+  Inner i;
+  int y = 6;
+} ou;
+
+//CHECK: Layout: <CIRecordLayout
+//CHECK:  CIR Type:!cir.record<struct "Outer" {!cir.record<struct "Inner" {!cir.int<s, 32>} #cir.record.decl.ast>, !cir.int<s, 32>} #cir.record.decl.ast>
+//CHECK:  NonVirtualBaseCIRType:!cir.record<struct "Outer" {!cir.record<struct "Inner" {!cir.int<s, 32>} #cir.record.decl.ast>, !cir.int<s, 32>} #cir.record.decl.ast>
+//CHECK:  IsZeroInitializable:1
+//CHECK:  BitFields:[
+//CHECK:  ]>