14e20eebd1
Summary: The configs all need default values which targets then override. This one was an empty string which made the logic report an error. The only reason it wasn't a build failure was because of a stray `:`.
97 lines
3.3 KiB
C++
97 lines
3.3 KiB
C++
//===-- Implementation of libc_errno --------------------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#include "libc_errno.h"
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#include "src/__support/macros/config.h"
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// libc uses a fallback default value, either system or thread local.
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#define LIBC_ERRNO_MODE_DEFAULT 0
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// libc never stores a value; `errno` macro uses get link-time failure.
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#define LIBC_ERRNO_MODE_UNDEFINED 1
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// libc maintains per-thread state (requires C++ `thread_local` support).
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#define LIBC_ERRNO_MODE_THREAD_LOCAL 2
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// libc maintains shared state used by all threads, contrary to standard C
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// semantics unless always single-threaded; nothing prevents data races.
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#define LIBC_ERRNO_MODE_SHARED 3
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// libc doesn't maintain any internal state, instead the embedder must define
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// `int *__llvm_libc_errno(void);` C function.
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#define LIBC_ERRNO_MODE_EXTERNAL 4
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// libc uses system `<errno.h>` `errno` macro directly in the overlay mode; in
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// fullbuild mode, effectively the same as `LIBC_ERRNO_MODE_EXTERNAL`.
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#define LIBC_ERRNO_MODE_SYSTEM 5
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#if !defined(LIBC_ERRNO_MODE) || LIBC_ERRNO_MODE == LIBC_ERRNO_MODE_DEFAULT
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#undef LIBC_ERRNO_MODE
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#if defined(LIBC_FULL_BUILD) || !defined(LIBC_COPT_PUBLIC_PACKAGING)
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#define LIBC_ERRNO_MODE LIBC_ERRNO_MODE_THREAD_LOCAL
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#else
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#define LIBC_ERRNO_MODE LIBC_ERRNO_MODE_SYSTEM
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#endif
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#endif // LIBC_ERRNO_MODE
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#if LIBC_ERRNO_MODE != LIBC_ERRNO_MODE_DEFAULT && \
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LIBC_ERRNO_MODE != LIBC_ERRNO_MODE_UNDEFINED && \
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LIBC_ERRNO_MODE != LIBC_ERRNO_MODE_THREAD_LOCAL && \
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LIBC_ERRNO_MODE != LIBC_ERRNO_MODE_SHARED && \
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LIBC_ERRNO_MODE != LIBC_ERRNO_MODE_EXTERNAL && \
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LIBC_ERRNO_MODE != LIBC_ERRNO_MODE_SYSTEM
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#error LIBC_ERRNO_MODE must be one of the following values: \
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LIBC_ERRNO_MODE_DEFAULT, \
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LIBC_ERRNO_MODE_UNDEFINED, \
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LIBC_ERRNO_MODE_THREAD_LOCAL, \
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LIBC_ERRNO_MODE_SHARED, \
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LIBC_ERRNO_MODE_EXTERNAL, \
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LIBC_ERRNO_MODE_SYSTEM
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#endif
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namespace LIBC_NAMESPACE_DECL {
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#if LIBC_ERRNO_MODE == LIBC_ERRNO_MODE_UNDEFINED
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void Errno::operator=(int) {}
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Errno::operator int() { return 0; }
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#elif LIBC_ERRNO_MODE == LIBC_ERRNO_MODE_THREAD_LOCAL
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namespace {
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LIBC_THREAD_LOCAL int thread_errno;
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}
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extern "C" int *__llvm_libc_errno() noexcept { return &thread_errno; }
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void Errno::operator=(int a) { thread_errno = a; }
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Errno::operator int() { return thread_errno; }
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#elif LIBC_ERRNO_MODE == LIBC_ERRNO_MODE_SHARED
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namespace {
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int shared_errno;
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}
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extern "C" int *__llvm_libc_errno() noexcept { return &shared_errno; }
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void Errno::operator=(int a) { shared_errno = a; }
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Errno::operator int() { return shared_errno; }
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#elif LIBC_ERRNO_MODE == LIBC_ERRNO_MODE_EXTERNAL
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void Errno::operator=(int a) { *__llvm_libc_errno() = a; }
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Errno::operator int() { return *__llvm_libc_errno(); }
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#elif LIBC_ERRNO_MODE == LIBC_ERRNO_MODE_SYSTEM
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void Errno::operator=(int a) { errno = a; }
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Errno::operator int() { return errno; }
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#endif
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// Define the global `libc_errno` instance.
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Errno libc_errno;
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} // namespace LIBC_NAMESPACE_DECL
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