`mkstemps` generates a unique temporary file name from a pattern like
`prefixXXXXXXsuffix` where `prefix` and `suffix` can be any string with
only characters that are valid in a filename. The second parameter is
the length of the suffix.
`mkstemp` is `mkstemps` with suffix length 0, so to avoid code
duplication it calls `mkstemps`. It is unlikely this has any
significant performance impact on SerenityOS.
`generate_unique_filename` now takes the suffix length as a `size_t`.
The original behavior of this function is preserved when specifying a
suffix length of 0. All original uses of this function have been
adapted.
`mkstemps()` was added because it is required by version 4.6.3 of the
ccache port.
We now have a proper aligned allocation implementation, and the
toolchain patch to make Clang use the intermediary implementation
has already been removed in an earlier iteration.
Some ports linked against posix_memalign, but didn't use it, and others
used it if it was Available. So I decided to implement posix_memalign.
My implementation adds almost no overhead to regular mallocs. However,
if an alignment is specified, it will use the smallest ChunkedBlock, for
which aligned chunks exist, and simply use one of the chunks that is
aligned. If it cannot use a ChunkedBlock, for size or alignment reasons,
it will use a BigAllocationBlock, and return a pointer to the first
aligned address past the start of the block. This implementation
supports alignments up to 32768, due to the limitations of the
BigAllocationBlock technique.
I also added a common interface with StringView compatible parameters:
int serenity_setenv(const char*, ssize_t, const char*, ssize_t, int)
This function is called by both C and C++ API for setenv().
We don't mutate the pointed-to memory, so let's be const correct.
Fixes building the `mimalloc` library that's optionally used by the mold
linker (note that it isn't enabled yet as I haven't tested it).
In C++, a function declaration with an empty parameter list means that
the function takes no arguments. In C, however, it means that the
function takes an unspecified number of parameters.
What we did previously was therefore non-conforming. This caused a
config check to fail in the curl port, as it was able to redeclare
`rand` as taking an int parameter.
C++17 introduced aligned versions of `new` and `delete`, which are
automatically called by the compiler when allocating over-aligned
objects. As with the regular allocator functions, these are generally
thin wrappers around LibC.
We did not have support for aligned allocations in LibC, so this was not
possible. While libstdc++ has a fallback implementation, libc++ does
not, so the aligned allocation function was disabled internally. This
made building the LLVM port with Clang impossible.
Note that while the Microsoft docs say that aligned_malloc and
_aligned_free are declared in `malloc.h`, libc++ doesn't #include that
file, but instead relies on the definition coming from `stdlib.h`.
Therefore, I chose to declare it in that file instead of creating a new
LibC header.
I chose not to implement the more Unix-y `memalign`, `posix_memalign`,
or the C11 `aligned_alloc`, because that would require us to
significantly alter the memory allocator's internals. See the comment in
malloc.cpp.
We always use UTF-8, meaning that a single `wchar_t` might be converted
into up to 4 `char`s. This would cause a buffer overflow if something
actually relied on this being the right value.
This implements the macOS API malloc_good_size() which returns the
true allocation size for a given requested allocation size. This
allows us to make use of all the available memory in a malloc chunk.
For example, for a malloc request of 35 bytes our malloc would
internally use a chunk of size 64, however the remaining 29 bytes
would be unused.
Knowing the true allocation size allows us to request more usable
memory that would otherwise be wasted and make that available for
Vector, HashTable and potentially other callers in the future.
SPDX License Identifiers are a more compact / standardized
way of representing file license information.
See: https://spdx.dev/resources/use/#identifiers
This was done with the `ambr` search and replace tool.
ambr --no-parent-ignore --key-from-file --rep-from-file key.txt rep.txt *
Just ignore all these environment flags if the AT_SECURE flag is set in
the program's auxiliary vector.
This prevents a user from tricking set-uid programs into dumping debug
information via environment flags.
