When any of the object files reference the __heap_end symbol, we will
create it as a synthetic symbol. The symbol only exists within the
linker and will not be emit within the binary as it's solely used for
relocations. The symbol represents where the heap ends, so allocators
can determine whether to allocate a new page or not.
When any object files provides an undefined reference to the __heap_base
symbol, we create a new defined symbol for it. During setupMemory we
set the virtual address of this symbol so it can be used for relocations.
This symbol represents where the heap starts and allocators can use
this value for its allocations when it needs to determine where the heap
lives.
This implements the `__wasm_call_ctors` symbol. This symbol is
automatically referenced by libc to initialize its constructors.
We first retrieve all constructors from each object file, and then
create a function body that calls each constructor based on its
priority. Constructors are not allowed to have any parameters, but are
allowed to have a return type. When a return type does exist, we simply
drop its value from the stack after calling the constructor to ensure
we pass the stack validator.
When emitting errors for undefined symbols, rather than
unconditionally always using the name from an import, we must verify
it's a symbol type that could have such an import. e.g. undefined
data symbols do not have a corresponding import. For this reason we
must use the regular name.
During symbol resolution when both symbols are undefined, we must
discard the new symbol with a reference to the existing symbol. This
ensures the original symbol remains undefined. This fixes symbol
resolution when linking with WASI-libC.
* Changed the interface to align with the new allocator interface.
* Fixed bug where not enough memory was allocated for the header or to
align the pointer.
Some notable changes:
- `ENOENT` is returned instead of `ENOTCAPABLE` when a path has not
be pre-opened (https://github.com/WebAssembly/wasi-libc/pull/370)
- `fd_readdir()`: some implementations may not set the inode number,
so an additional call to `fstatat()` is now done in order to get it
when that happens.
This API converts a config.h.in file into config.h. This is useful when
introducing a build.zig file to an existing C/C++ project that is
configured with autotools or cmake.
The cmake syntax is not implemented yet.
Currently llvm-linkage mode (static vs dynamic) decides linkage mode
for system libstdc++/libc++ .
A previous commit only tested static mode for *BSD and netbsd was
reported to not work in dynamic mode.
We now special-case freebsd, openbsd, netbsd and dragonfly for dynamic
linking too.
