[clang] [CIR] Upstream basic alloca and load support (PR #128792)

[Bruno Cardoso Lopes via cfe-commits]

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@@ -0,0 +1,82 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This contains code to emit Decl nodes as CIR code.
+//
+//===----------------------------------------------------------------------===//
+
+#include "CIRGenFunction.h"
+#include "clang/AST/Expr.h"
+#include "clang/CIR/MissingFeatures.h"
+
+using namespace clang;
+using namespace clang::CIRGen;
+
+/// Emit code and set up symbol table for a variable declaration with auto,
+/// register, or no storage class specifier. These turn into simple stack
+/// objects, globals depending on target.
+void CIRGenFunction::emitAutoVarDecl(const VarDecl &d) {
+  QualType ty = d.getType();
+  assert(ty.getAddressSpace() == LangAS::Default);
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bcardosolopes wrote:

> upstreaming seems to be a mix of errorNYI and silently ignoring things

If upstream is silently ignoring things this is pretty bad, because it leads to subtle miscompilations that are super hard to debug/find. My understanding is that `errorNYI` should be covering all cases where we use unrecheable in the incubator, but if that isn't enough, unrecheable is 1000x better than silently ignoring

https://github.com/llvm/llvm-project/pull/128792