[libc-commits] [libc] [libc][uefi] add crt1 (PR #132150)

[Petr Hosek via libc-commits]

================
@@ -0,0 +1,29 @@
+//===-- Implementation of crt for UEFI ----------------------------------===//
+//
+// 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
+//
+//===--------------------------------------------------------------------===//
+
+#include "include/llvm-libc-macros/stdlib-macros.h"
+#include "include/llvm-libc-types/EFI_HANDLE.h"
+#include "include/llvm-libc-types/EFI_STATUS.h"
+#include "include/llvm-libc-types/EFI_SYSTEM_TABLE.h"
+#include "src/__support/macros/config.h"
+
+EFI_HANDLE efi_image_handle;
+EFI_SYSTEM_TABLE *efi_system_table;
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petrhosek wrote:

We shouldn't be placing new symbols into the global namespace, that's problematic from C standard perspective, so these symbols need to prefixed with `__llvm_libc_`.

```suggestion
EFI_HANDLE __llvm_libc_efi_image_handle;
EFI_SYSTEM_TABLE *__llvm_libc_efi_system_table;
```

Do you know if there's a common convention for accessing these symbols? I looked at EDK2 and there it seems like these symbols are usually passed through explicitly as input arguments to functions that need them, but I don't know if there are other examples other than EDK2.

https://github.com/llvm/llvm-project/pull/132150