[CIR] Add builtin operator new/delete (#168578)

This PR adds `__builtin_operator_new` and `__builtin_operator_delete`.

The implementation is taken from clang code gen.

Author: HendrikHuebner

clang/include/clang/CIR/MissingFeatures.h

@@ -200,6 +200,7 @@ struct MissingFeatures {
   static bool aggValueSlotMayOverlap() { return false; }
   static bool aggValueSlotVolatile() { return false; }
   static bool alignCXXRecordDecl() { return false; }
+  static bool allocToken() { return false; }
   static bool appleKext() { return false; }
   static bool armComputeVolatileBitfields() { return false; }
   static bool asmGoto() { return false; }

clang/lib/CIR/CodeGen/CIRGenBuiltin.cpp

@@ -18,9 +18,11 @@
 #include "mlir/IR/BuiltinAttributes.h"
 #include "mlir/IR/Value.h"
 #include "mlir/Support/LLVM.h"
+#include "clang/AST/DeclBase.h"
 #include "clang/AST/Expr.h"
 #include "clang/AST/GlobalDecl.h"
 #include "clang/Basic/Builtins.h"
+#include "clang/Basic/OperatorKinds.h"
 #include "clang/CIR/Dialect/IR/CIRTypes.h"
 #include "clang/CIR/MissingFeatures.h"
 #include "llvm/Support/ErrorHandling.h"
@@ -1093,8 +1095,14 @@ RValue CIRGenFunction::emitBuiltinExpr(const GlobalDecl &gd, unsigned builtinID,
   case Builtin::BI__addressof:
   case Builtin::BI__builtin_addressof:
   case Builtin::BI__builtin_function_start:
+    return errorBuiltinNYI(*this, e, builtinID);
   case Builtin::BI__builtin_operator_new:
+    return emitNewOrDeleteBuiltinCall(
+        e->getCallee()->getType()->castAs<FunctionProtoType>(), e, OO_New);
   case Builtin::BI__builtin_operator_delete:
+    emitNewOrDeleteBuiltinCall(
+        e->getCallee()->getType()->castAs<FunctionProtoType>(), e, OO_Delete);
+    return RValue::get(nullptr);
   case Builtin::BI__builtin_is_aligned:
   case Builtin::BI__builtin_align_up:
   case Builtin::BI__builtin_align_down:

clang/lib/CIR/CodeGen/CIRGenExprCXX.cpp

@@ -16,6 +16,7 @@
 
 #include "clang/AST/DeclCXX.h"
 #include "clang/AST/ExprCXX.h"
+#include "clang/Basic/OperatorKinds.h"
 #include "clang/CIR/MissingFeatures.h"
 
 using namespace clang;
@@ -648,6 +649,36 @@ static RValue emitNewDeleteCall(CIRGenFunction &cgf,
   return rv;
 }
 
+RValue CIRGenFunction::emitNewOrDeleteBuiltinCall(const FunctionProtoType *type,
+                                                  const CallExpr *callExpr,
+                                                  OverloadedOperatorKind op) {
+  CallArgList args;
+  emitCallArgs(args, type, callExpr->arguments());
+  // Find the allocation or deallocation function that we're calling.
+  ASTContext &astContext = getContext();
+  assert(op == OO_New || op == OO_Delete);
+  DeclarationName name = astContext.DeclarationNames.getCXXOperatorName(op);
+
+  clang::DeclContextLookupResult lookupResult =
+      astContext.getTranslationUnitDecl()->lookup(name);
+  for (const auto *decl : lookupResult) {
+    if (const auto *funcDecl = dyn_cast<FunctionDecl>(decl)) {
+      if (astContext.hasSameType(funcDecl->getType(), QualType(type, 0))) {
+        if (sanOpts.has(SanitizerKind::AllocToken)) {
+          // TODO: Set !alloc_token metadata.
+          assert(!cir::MissingFeatures::allocToken());
+          cgm.errorNYI("Alloc token sanitizer not yet supported!");
+        }
+
+        // Emit the call to operator new/delete.
+        return emitNewDeleteCall(*this, funcDecl, type, args);
+      }
+    }
+  }
+
+  llvm_unreachable("predeclared global operator new/delete is missing");
+}
+
 namespace {
 /// Calls the given 'operator delete' on a single object.
 struct CallObjectDelete final : EHScopeStack::Cleanup {

clang/lib/CIR/CodeGen/CIRGenFunction.h

@@ -30,6 +30,7 @@
 #include "clang/AST/ExprCXX.h"
 #include "clang/AST/Stmt.h"
 #include "clang/AST/Type.h"
+#include "clang/Basic/OperatorKinds.h"
 #include "clang/CIR/Dialect/IR/CIRDialect.h"
 #include "clang/CIR/MissingFeatures.h"
 #include "clang/CIR/TypeEvaluationKind.h"
@@ -1487,6 +1488,10 @@ class CIRGenFunction : public CIRGenTypeCache {
 
   RValue emitCXXPseudoDestructorExpr(const CXXPseudoDestructorExpr *expr);
 
+  RValue emitNewOrDeleteBuiltinCall(const FunctionProtoType *type,
+                                    const CallExpr *callExpr,
+                                    OverloadedOperatorKind op);
+
   void emitCXXTemporary(const CXXTemporary *temporary, QualType tempType,
                         Address ptr);
 

clang/test/CIR/CodeGen/builtin_new_delete.cpp

@@ -0,0 +1,44 @@
+// RUN: %clang_cc1 -std=c++20 -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 -std=c++20 -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 -std=c++20 -triple x86_64-unknown-linux-gnu -emit-llvm %s -o %t.ll
+// RUN: FileCheck --check-prefix=OGCG --input-file=%t.ll %s
+
+
+void test_builtins_basic() {
+  __builtin_operator_delete(__builtin_operator_new(4));
+  // CIR-LABEL: test_builtins_basic
+  // CIR: [[P:%.*]] = cir.call @_Znwm({{%.*}}) : (!u64i) -> !cir.ptr<!void>
+  // CIR: cir.call @_ZdlPv([[P]]) {{.*}}: (!cir.ptr<!void>) -> ()
+  // CIR: cir.return
+
+  // LLVM-LABEL: test_builtins_basic
+  // LLVM: [[P:%.*]] = call ptr @_Znwm(i64 4)
+  // LLVM: call void @_ZdlPv(ptr [[P]])
+  // LLVM: ret void
+
+  // OGCG-LABEL: test_builtins_basic
+  // OGCG: [[P:%.*]] = call {{.*}} ptr @_Znwm(i64 {{.*}} 4)
+  // OGCG: call void @_ZdlPv(ptr {{.*}} [[P]])
+  // OGCG: ret void
+}
+
+void test_sized_delete() {
+  __builtin_operator_delete(__builtin_operator_new(4), 4);
+
+  // CIR-LABEL: test_sized_delete
+  // CIR: [[P:%.*]] = cir.call @_Znwm({{%.*}}) : (!u64i) -> !cir.ptr<!void>
+  // CIR: cir.call @_ZdlPvm([[P]], {{%.*}}) {{.*}}: (!cir.ptr<!void>, !u64i) -> ()
+  // CIR: cir.return
+
+  // LLVM-LABEL: test_sized_delete
+  // LLVM: [[P:%.*]] = call ptr @_Znwm(i64 4)
+  // LLVM: call void @_ZdlPvm(ptr [[P]], i64 4)
+  // LLVM: ret void
+
+  // OGCG-LABEL: test_sized_delete
+  // OGCG: [[P:%.*]] = call {{.*}} ptr @_Znwm(i64 {{.*}} 4)
+  // OGCG: call void @_ZdlPvm(ptr {{.*}} [[P]], i64 {{.*}} 4)
+  // OGCG: ret void
+}