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/*
* Copyright (C) 2020 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* @file stdlib_wrapper.cc
*
* This file provides nanoapps with wrapper functions for standard library
* functions in the standard library functions that are not supported alongside
* CHRE, which either redirect the function to an analogous CHRE function, or
* fail silently. The targeted usage of this is expected to be only for third-
* party or generated functions, where changes to either the upstream third-
* party code or the code generators might not be straightforward. It is
* expected that the nanoapp developers are aware of the 'fail silently' clause
* in the wrappers, and handle those cases appropriately.
*/
#include <stdio.h>
#include <stdlib.h>
#include <chre.h>
#include "chre/util/nanoapp/assert.h"
#if defined(stderr) && !defined(_CSTD)
// Provides a definition for stderr when the macro has been defined, but the
// file has been externed. Some platforms might define their own macros for
// stderr (vs the glibc style of matching the macro to the filename), in which
// case we have to guard against those definitions as well (eg: _CSTD check
// above).
FILE *stderr = NULL;
#endif
void *malloc(size_t size) {
// On platforms where size(size_t) might be 8 bytes, we need a cast to
// maintain adherence to CHRE's heap alloc API. The size check to reject
// requests of size > 4Gb could be used for debugging, though any requests
// that even remotely approach this limit is bound to fail anyway.
return size > UINT32_MAX ? nullptr
: chreHeapAlloc(static_cast<uint32_t>(size));
}
void free(void *ptr) {
chreHeapFree(ptr);
}
void *realloc(void * /*ptr*/, size_t /*newSize*/) {
// realloc() is not supported, verify that there's no call to it!
CHRE_ASSERT(false);
return NULL;
}
void exit(int exitCode) {
chreAbort(static_cast<uint32_t>(exitCode));
// Add an explicit forever-loop to bypass compilation warnings on platforms
// that might have defined exit with a noreturn tag. The loop shouldn't ever
// execute, since abort terminates the program.
while (42)
;
}
int fprintf(FILE * /*stream*/, const char * /*fmt*/, ...) {
return 0;
}
size_t fwrite(const void * /*ptr*/, size_t /*size*/, size_t /*count*/,
FILE * /*stream*/) {
return 0;
}
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