Originally, I thought that the dSYM bundle has to reside side-by-side
with the binary it carries the debugging information for. However, it
turns out macOS is clever enough that it auto-searches for matching
dSYM bundle based on the embedded UUID of the binary.
To verify this, run this on your macOS:
```
mdfind "com_apple_xcode_dsym_uuids == <UUID from LC_UUID>"
```
See [here] for more info.
[here]: https://developer.apple.com/documentation/xcode/adding-identifiable-symbol-names-to-a-crash-report
* `-lc++` now implies `-lc`.
* `-lunwind` is now pulled out into a separate `link_libunwind` flag in
the frontend driver code. This allows a project to request zig to
provide libunwind even if the default situation that causes it to be
implicitly added, is not active.
* build.zig: ask for -lunwind when building the self-hosted compiler on
Linux. Otherwise we get linker errors with unresolved symbols to
libunwind.
* for cross testing stage2 tests, we use `darling shell` command
since the path to the tested binary is relative to cwd
* for the `zig test` command, we simply use `darling` since the
path to the binary is absolute
5ac91794cce8bd53916a378815be01e4365d53d9 made Zig link against the
system libc when targeting the native C ABI. However this made it stop
putting libunwind.a on the linker line when it needed to sometimes,
causing undefined symbols when linking against C++ code.
The CPU detection code is nearly at feature parity, we do support
detecting the native CPU on Sparc systems and macos, our ARM/AArch64
model list is quite comprehensive and so is our PPC one.
The only missing pieces are:
- ARM32 detection on Darwin hosts (I don't think anybody is planning on
running the compiler on a old-ass iPhone)
- s390x detection on Linux hosts, this can be easily added at a later
stage.
Currently zig will always try to build its own libc and compile against
that. This of course makes sense for cross-compilation, but can cause
problems when targeting the native OS/ABI.
For example, if the system uses a newer glibc version than zig ships
zig will fall back to using the newest version it does ship. However
this causes linking system libraries to fail as they are built against a
different glibc version than the zig code is built against.
To remedy this, simply default to linking the system libc when targeting
the native OS/ABI.
Previously, I mistakenly assumed that offset of the relocation
is enough when calculating relative offset of the target from the
source target section base address in case of section-based relocs
on x86_64. While this is true for `__TEXT,__text` section which
always starts at 0x0 in object files, this is absolutely not true
for `__TEXT,__StaticInit` section which will have nonzero base
address hence resulting in incorrect displacement calculations for
SIGNED relocs.
Coming from other languages it might be tempting for programmers to
accidentally leave out the return type instead of returning 'void'.
The error for this used to be
error: invalid token: '{'
pub fn main() {
^
which is misleading. The '{' is expected but only after a return type.
The new message is
error: expected return type (use 'void' to return nothing), found: '{'
pub fn main() {
^
which not only points out the real error but also hints at a (probably)
very common case where someone coming from e.g. Go is used to not
specifying a return type if a function returns nothing and thus forgets
to put 'void' there.
It might seem overkill to hint at the 'void' option but then the
compiler error messages are our user interface to the programmer. We
can be better than other languages in our error messages and leaving
out the return type seems to be a rather clear indication of the above
mentioned issue. Adding this will help more than distract.
PR #7827 added some new `std.Target.Os.Tag` before `other`.
The corresponding enum in stage1.h was not updated, which caused a
mismatch in the underlying integer values. While attempting to target
`other`, I encountered crashes.
This PR updates the stage1.h enum to include the added OS tags.
The new tags also had to be added to various switch cases to fix
compiler warnings, but have not been tested in any way.
* UTF16 gets its own section, `__TEXT,__ustring`
* TLV data and bss sections have to aligned to the same max alignment
according to Apple rdar comment in the latest ld64
