[libc-commits] [libc] [libc] `__stack_chk_fail` baremetal dependencies (PR #76412)
via libc-commits
libc-commits at lists.llvm.org
Tue Dec 26 14:21:55 PST 2023
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-libc
Author: Petr Hosek (petrhosek)
<details>
<summary>Changes</summary>
`__stack_chk_fail` uses `write_to_stderr` and `abort` but these currently aren't included in baremetal targets resulting in a CMake build error:
```
CMake Error at /llvm-project/libc/cmake/modules/LLVMLibCObjectRules.cmake:693 (target_link_libraries):
Target "libc.src.stdlib.abort" of type UTILITY may not be linked into
another target. One may link only to INTERFACE, OBJECT, STATIC or SHARED
libraries, or to executables with the ENABLE_EXPORTS property set.
Call Stack (most recent call first):
/llvm-project/libc/cmake/modules/LLVMLibCObjectRules.cmake:811 (create_entrypoint_object)
/llvm-project/libc/cmake/modules/LLVMLibCObjectRules.cmake:891 (expand_flags_for_entrypoint_object)
/llvm-project/libc/src/compiler/generic/CMakeLists.txt:1 (add_entrypoint_object)
CMake Error at /llvm-project/libc/cmake/modules/LLVMLibCLibraryRules.cmake:5 (get_target_property):
get_target_property() called with non-existent target
"libc.src.__support.OSUtil.osutil".
Call Stack (most recent call first):
/llvm-project/libc/cmake/modules/LLVMLibCLibraryRules.cmake:36 (collect_object_file_deps)
/llvm-project/libc/cmake/modules/LLVMLibCLibraryRules.cmake:36 (collect_object_file_deps)
/llvm-project/libc/cmake/modules/LLVMLibCLibraryRules.cmake:85 (collect_object_file_deps)
/llvm-project/libc/lib/CMakeLists.txt:26 (add_entrypoint_library)
```
To address these errors, we need to include `abort` in the list of baremetal entrypoints. We also need to provide `write_to_stderr` baremetal implementation, but this is challenging since there is no uniform way to print a message on these platforms (sometimes there may not be any way to print a message). We instead defer to `__libc_log_write` which can be provided by the underlying platform. We use a similar approach for `quick_exit`, defering to `__libc_quick_exit`.
---
Full diff: https://github.com/llvm/llvm-project/pull/76412.diff
7 Files Affected:
- (modified) libc/config/baremetal/arm/entrypoints.txt (+1)
- (modified) libc/config/baremetal/riscv/entrypoints.txt (+1)
- (added) libc/src/__support/OSUtil/baremetal/CMakeLists.txt (+9)
- (added) libc/src/__support/OSUtil/baremetal/io.h (+25)
- (added) libc/src/__support/OSUtil/baremetal/quick_exit.h (+22)
- (modified) libc/src/__support/OSUtil/io.h (+3)
- (modified) libc/src/__support/OSUtil/quick_exit.h (+3)
``````````diff
diff --git a/libc/config/baremetal/arm/entrypoints.txt b/libc/config/baremetal/arm/entrypoints.txt
index a0779c41652aeb..54f74c6a973ce7 100644
--- a/libc/config/baremetal/arm/entrypoints.txt
+++ b/libc/config/baremetal/arm/entrypoints.txt
@@ -74,6 +74,7 @@ set(TARGET_LIBC_ENTRYPOINTS
libc.src.stdio.vsnprintf
# stdlib.h entrypoints
+ libc.src.stdlib.abort
libc.src.stdlib.abs
libc.src.stdlib.atoi
libc.src.stdlib.atof
diff --git a/libc/config/baremetal/riscv/entrypoints.txt b/libc/config/baremetal/riscv/entrypoints.txt
index 3e15cc8901bddf..5da755170fda96 100644
--- a/libc/config/baremetal/riscv/entrypoints.txt
+++ b/libc/config/baremetal/riscv/entrypoints.txt
@@ -74,6 +74,7 @@ set(TARGET_LIBC_ENTRYPOINTS
libc.src.stdio.vsnprintf
# stdlib.h entrypoints
+ libc.src.stdlib.abort
libc.src.stdlib.abs
libc.src.stdlib.atoi
libc.src.stdlib.atol
diff --git a/libc/src/__support/OSUtil/baremetal/CMakeLists.txt b/libc/src/__support/OSUtil/baremetal/CMakeLists.txt
new file mode 100644
index 00000000000000..280ff87cf1470d
--- /dev/null
+++ b/libc/src/__support/OSUtil/baremetal/CMakeLists.txt
@@ -0,0 +1,9 @@
+add_header_library(
+ baremetal_util
+ HDRS
+ io.h
+ quick_exit.h
+ DEPENDS
+ libc.src.__support.common
+ libc.src.__support.CPP.string_view
+)
diff --git a/libc/src/__support/OSUtil/baremetal/io.h b/libc/src/__support/OSUtil/baremetal/io.h
new file mode 100644
index 00000000000000..93de33357c57a4
--- /dev/null
+++ b/libc/src/__support/OSUtil/baremetal/io.h
@@ -0,0 +1,25 @@
+//===---------- Baremetal implementation of IO utils ------------*- C++ -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC___SUPPORT_OSUTIL_BAREMETAL_IO_H
+#define LLVM_LIBC_SRC___SUPPORT_OSUTIL_BAREMETAL_IO_H
+
+#include "src/__support/CPP/string_view.h"
+#include "src/__support/macros/attributes.h" // LIBC_INLINE
+
+namespace LIBC_NAMESPACE {
+
+extern "C" void __libc_log_write(const char* msg, size_t len);
+
+void write_to_stderr(cpp::string_view msg) {
+ __libc_log_write(msg.data(), msg.size());
+}
+
+} // namespace LIBC_NAMESPACE
+
+#endif // LLVM_LIBC_SRC___SUPPORT_OSUTIL_BAREMETAL_IO_H
diff --git a/libc/src/__support/OSUtil/baremetal/quick_exit.h b/libc/src/__support/OSUtil/baremetal/quick_exit.h
new file mode 100644
index 00000000000000..ee0e090b97fd15
--- /dev/null
+++ b/libc/src/__support/OSUtil/baremetal/quick_exit.h
@@ -0,0 +1,22 @@
+//===----- Baremetal implementation of a quick exit function ----*- C++ -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC___SUPPORT_OSUTIL_BAREMETAL_QUICK_EXIT_H
+#define LLVM_LIBC_SRC___SUPPORT_OSUTIL_BAREMETAL_QUICK_EXIT_H
+
+namespace LIBC_NAMESPACE {
+
+extern "C" void __libc_quick_exit(int status);
+
+void quick_exit(int status) {
+ __libc_quick_exit(status);
+}
+
+} // namespace LIBC_NAMESPACE
+
+#endif // LLVM_LIBC_SRC___SUPPORT_OSUTIL_BAREMETAL_QUICK_EXIT_H
diff --git a/libc/src/__support/OSUtil/io.h b/libc/src/__support/OSUtil/io.h
index fc9d7f3ed38a17..cb7e748fc64426 100644
--- a/libc/src/__support/OSUtil/io.h
+++ b/libc/src/__support/OSUtil/io.h
@@ -19,6 +19,9 @@
#include "linux/io.h"
#elif defined(__Fuchsia__)
#include "fuchsia/io.h"
+#elif defined(__ELF__)
+// TODO: Ideally we would have LIBC_TARGET_OS_IS_BAREMETAL.
+#include "baremetal/io.h"
#endif
#endif // LLVM_LIBC_SRC___SUPPORT_OSUTIL_IO_H
diff --git a/libc/src/__support/OSUtil/quick_exit.h b/libc/src/__support/OSUtil/quick_exit.h
index 4329df8ecef05e..6c59c1afcda254 100644
--- a/libc/src/__support/OSUtil/quick_exit.h
+++ b/libc/src/__support/OSUtil/quick_exit.h
@@ -17,6 +17,9 @@
#include "darwin/quick_exit.h"
#elif defined(__linux__)
#include "linux/quick_exit.h"
+#elif defined(__ELF__)
+// TODO: Ideally we would have LIBC_TARGET_OS_IS_BAREMETAL.
+#include "baremetal/quick_exit.h"
#endif
#endif // LLVM_LIBC_SRC___SUPPORT_OSUTIL_QUICK_EXIT_H
``````````
</details>
https://github.com/llvm/llvm-project/pull/76412
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