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.
The `zig build` command now makes `@import("@dependencies")` available
to the build runner package. It contains all the dependencies in a
generated file that looks something like this:
```zig
pub const imports = struct {
pub const foo = @import("foo");
pub const @"bar.baz" = @import("bar.baz");
};
pub const build_root = struct {
pub const foo = "<path>";
pub const @"bar.baz" = "<path>";
};
```
The build runner exports this import so that `std.build.Builder` can
access it. `std.build.Builder` uses it to implement the new `dependency`
function which can be used like so:
```zig
const libz_dep = b.dependency("libz", .{});
const libmp3lame_dep = b.dependency("libmp3lame", .{});
// ...
lib.linkLibrary(libz_dep.artifact("z"));
lib.linkLibrary(libmp3lame_dep.artifact("mp3lame"));
```
The `dependency` function calls the build.zig file of the dependency as
a child Builder, and then can be ransacked for its build steps via the
`artifact` function.
This commit also renames `dependency.id` to `dependency.name` in the
`build.zig.ini` file.
This allows setting a custom buffer size. In this case I wanted it
because using a buffer size large enough to fit a TLS ciphertext record
elides a memcpy().
This commit also adds `readAtLeast` to the Reader interface.
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.
