1a92cc5a0a
Summary: This patch implements 'getenv'. I was torn on how to implement this, since realistically we only have access to this environment pointer in the "loader" interface. An alternative would be to use an RPC call every time, but I think that's overkill for what this will be used for. A better solution is just to emit a common `DataEnvironment` that contains all of the host visible resources to initialize. Right now this is the `env_ptr`, `clock_freq`, and `rpc_client`. I did this by making the `app.h` interface that Linux uses more general, could possibly move that into a separate patch, but I figured it's easier to see with the usage.
76 lines
2.9 KiB
C++
76 lines
2.9 KiB
C++
//===-- Implementation of crt for nvptx -----------------------------------===//
|
|
//
|
|
// 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 "config/gpu/app.h"
|
|
#include "src/__support/GPU/utils.h"
|
|
#include "src/__support/RPC/rpc_client.h"
|
|
#include "src/__support/macros/config.h"
|
|
#include "src/stdlib/atexit.h"
|
|
#include "src/stdlib/exit.h"
|
|
|
|
extern "C" int main(int argc, char **argv, char **envp);
|
|
|
|
namespace LIBC_NAMESPACE_DECL {
|
|
|
|
DataEnvironment app;
|
|
|
|
extern "C" {
|
|
// Nvidia's 'nvlink' linker does not provide these symbols. We instead need
|
|
// to manually create them and update the globals in the loader implememtation.
|
|
uintptr_t *__init_array_start [[gnu::visibility("protected")]];
|
|
uintptr_t *__init_array_end [[gnu::visibility("protected")]];
|
|
uintptr_t *__fini_array_start [[gnu::visibility("protected")]];
|
|
uintptr_t *__fini_array_end [[gnu::visibility("protected")]];
|
|
}
|
|
|
|
// Nvidia requires that the signature of the function pointers match. This means
|
|
// we cannot support the extended constructor arguments.
|
|
using InitCallback = void(void);
|
|
using FiniCallback = void(void);
|
|
|
|
static void call_init_array_callbacks(int, char **, char **) {
|
|
size_t init_array_size = __init_array_end - __init_array_start;
|
|
for (size_t i = 0; i < init_array_size; ++i)
|
|
reinterpret_cast<InitCallback *>(__init_array_start[i])();
|
|
}
|
|
|
|
static void call_fini_array_callbacks() {
|
|
size_t fini_array_size = __fini_array_end - __fini_array_start;
|
|
for (size_t i = fini_array_size; i > 0; --i)
|
|
reinterpret_cast<FiniCallback *>(__fini_array_start[i - 1])();
|
|
}
|
|
|
|
} // namespace LIBC_NAMESPACE_DECL
|
|
|
|
extern "C" [[gnu::visibility("protected"), clang::nvptx_kernel]] void
|
|
_begin(int argc, char **argv, char **env) {
|
|
__atomic_store_n(&LIBC_NAMESPACE::app.env_ptr,
|
|
reinterpret_cast<uintptr_t *>(env), __ATOMIC_RELAXED);
|
|
|
|
// We want the fini array callbacks to be run after other atexit
|
|
// callbacks are run. So, we register them before running the init
|
|
// array callbacks as they can potentially register their own atexit
|
|
// callbacks.
|
|
LIBC_NAMESPACE::atexit(&LIBC_NAMESPACE::call_fini_array_callbacks);
|
|
LIBC_NAMESPACE::call_init_array_callbacks(argc, argv, env);
|
|
}
|
|
|
|
extern "C" [[gnu::visibility("protected"), clang::nvptx_kernel]] void
|
|
_start(int argc, char **argv, char **envp, int *ret) {
|
|
// Invoke the 'main' function with every active thread that the user launched
|
|
// the _start kernel with.
|
|
__atomic_fetch_or(ret, main(argc, argv, envp), __ATOMIC_RELAXED);
|
|
}
|
|
|
|
extern "C" [[gnu::visibility("protected"), clang::nvptx_kernel]] void
|
|
_end(int retval) {
|
|
// To finis the execution we invoke all the callbacks registered via 'atexit'
|
|
// and then exit with the appropriate return value.
|
|
LIBC_NAMESPACE::exit(retval);
|
|
}
|