[libc] Include empty remove in baremetal stdio.h

[petrhosek]

This is required to avoid compilation error in libc++.

See #85335 for more details.

[llvmbot]

@llvm/pr-subscribers-libc

Author: Petr Hosek (petrhosek)

Changes

This is required to avoid compilation error in libc++.

See #85335 for more details.

---

Full diff: https://github.com/llvm/llvm-project/pull/85336.diff

4 Files Affected:

• (modified) libc/config/baremetal/arm/entrypoints.txt (+1)
• (modified) libc/config/baremetal/riscv/entrypoints.txt (+1)
• (added) libc/src/stdio/baremetal/CMakeLists.txt (+7)
• (added) libc/src/stdio/baremetal/remove.cpp (+22)

diff --git a/libc/config/baremetal/arm/entrypoints.txt b/libc/config/baremetal/arm/entrypoints.txt
index 589ec5237e98da..d97c8d75fe309a 100644
--- a/libc/config/baremetal/arm/entrypoints.txt
+++ b/libc/config/baremetal/arm/entrypoints.txt
@@ -79,6 +79,7 @@ set(TARGET_LIBC_ENTRYPOINTS
     libc.src.inttypes.strtoumax
 
     # stdio.h entrypoints
+    libc.src.stdio.remove
     libc.src.stdio.sprintf
     libc.src.stdio.snprintf
     libc.src.stdio.vsprintf
diff --git a/libc/config/baremetal/riscv/entrypoints.txt b/libc/config/baremetal/riscv/entrypoints.txt
index 09de1b416e0e94..19c9ac7fbe8515 100644
--- a/libc/config/baremetal/riscv/entrypoints.txt
+++ b/libc/config/baremetal/riscv/entrypoints.txt
@@ -79,6 +79,7 @@ set(TARGET_LIBC_ENTRYPOINTS
     libc.src.inttypes.strtoumax
 
     # stdio.h entrypoints
+    libc.src.stdio.remove
     libc.src.stdio.sprintf
     libc.src.stdio.snprintf
     libc.src.stdio.vsprintf
diff --git a/libc/src/stdio/baremetal/CMakeLists.txt b/libc/src/stdio/baremetal/CMakeLists.txt
new file mode 100644
index 00000000000000..734a66f72ecf6f
--- /dev/null
+++ b/libc/src/stdio/baremetal/CMakeLists.txt
@@ -0,0 +1,7 @@
+add_entrypoint_object(
+  remove
+  SRCS
+    remove.cpp
+  HDRS
+    ../remove.h
+)
diff --git a/libc/src/stdio/baremetal/remove.cpp b/libc/src/stdio/baremetal/remove.cpp
new file mode 100644
index 00000000000000..c1c834d13952bf
--- /dev/null
+++ b/libc/src/stdio/baremetal/remove.cpp
@@ -0,0 +1,22 @@
+//===-- Linux implementation of remove ------------------------------------===//
+//
+// 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 "src/stdio/remove.h"
+
+#include "src/__support/common.h"
+
+namespace LIBC_NAMESPACE {
+
+// TODO: See https://github.com/llvm/llvm-project/issues/85335 for more details
+// on why this is needed.
+
+LLVM_LIBC_FUNCTION(int, remove, (const char *)) {
+  return -1;
+}
+
+} // namespace LIBC_NAMESPACE

[github-actions]

✅ With the latest revision this PR passed the C/C++ code formatter.

[michaelrj-google]

LGTM

[lntue]

nit: Update comment and formatting.

[nickdesaulniers]

I'm curious, does this become a problem for other cases of _LIBCPP_USING_IF_EXISTS in libcxx/include/cstdio such as fopen, freopen, rename, tmpfile, or tmpnam? If so, is baremetal going to need stubs for all of the above?

Or is this specifically because man 3 remove from stdio.h is conflicting with std::remove from <algorithm> (and the functions listed above do not)?

[petrhosek]

I'm curious, does this become a problem for other cases of _LIBCPP_USING_IF_EXISTS in libcxx/include/cstdio such as fopen, freopen, rename, tmpfile, or tmpnam? If so, is baremetal going to need stubs for all of the above?

I expect this to be only a temporary workaround until we address #85335.

Or is this specifically because man 3 remove from stdio.h is conflicting with std::remove from <algorithm> (and the functions listed above do not)?

This is only an issue for remove because of the declaration with the same name provided by <algorithm>.