[clang] [CIR] Upstream support for calling constructors (PR #143579)

[Erich Keane via cfe-commits]

================
@@ -63,3 +66,74 @@ Address CIRGenFunction::getAddressOfBaseClass(
 
   return value;
 }
+
+void CIRGenFunction::emitCXXConstructorCall(const clang::CXXConstructorDecl *d,
+                                            clang::CXXCtorType type,
+                                            bool forVirtualBase,
+                                            bool delegating,
+                                            AggValueSlot thisAVS,
+                                            const clang::CXXConstructExpr *e) {
+  CallArgList args;
+  Address thisAddr = thisAVS.getAddress();
+  QualType thisType = d->getThisType();
+  mlir::Value thisPtr = thisAddr.getPointer();
+
+  assert(!cir::MissingFeatures::addressSpace());
+
+  args.add(RValue::get(thisPtr), thisType);
+
+  // In LLVM Codegen: If this is a trivial constructor, just emit what's needed.
+  // If this is a union copy constructor, we must emit a memcpy, because the AST
+  // does not model that copy.
+  assert(!cir::MissingFeatures::isMemcpyEquivalentSpecialMember());
+
+  const FunctionProtoType *fpt = d->getType()->castAs<FunctionProtoType>();
+
+  assert(!cir::MissingFeatures::opCallArgEvaluationOrder());
+
+  emitCallArgs(args, fpt, e->arguments(), e->getConstructor(),
+               /*ParamsToSkip=*/0);
+
+  assert(!cir::MissingFeatures::sanitizers());
+  emitCXXConstructorCall(d, type, forVirtualBase, delegating, thisAddr, args,
+                         e->getExprLoc());
+}
+
+void CIRGenFunction::emitCXXConstructorCall(
+    const CXXConstructorDecl *d, CXXCtorType type, bool forVirtualBase,
+    bool delegating, Address thisAddr, CallArgList &args, SourceLocation loc) {
+
+  const auto *cd = d->getParent();
+
+  // If this is a call to a trivial default constructor:
+  // In LLVM: do nothing.
+  // In CIR: emit as a regular call, other later passes should lower the
+  // ctor call into trivial initialization.
+  assert(!cir::MissingFeatures::isTrivialCtorOrDtor());
+
+  assert(!cir::MissingFeatures::isMemcpyEquivalentSpecialMember());
+
+  bool passPrototypeArgs = true;
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erichkeane wrote:

Read, but never set?

https://github.com/llvm/llvm-project/pull/143579