It is now possible to force linking with system linker `ld` instead
of the LLVM `lld` linker when building natively on the target. This
can be done at each stage by specifying `--system-linker-hack` flag,
and can be useful on platforms where `lld` fails to operate properly
such as macOS 11 Big Sur on ARM64 where every binary/dylib is expected
to be codesigned.
Some example invocations for each stage of compilation of Zig
toolchain:
```
cmake .. -DCMAKE_PREFIX_PATH=/path/to/llvm -DSYSTEM_LINKER_HACK=1
```
```
build/zig build test --system-linker-hack
```
```
build/zig build --prefix $(pwd)/stage2 -Denable-llvm
--system-linker-hack
```
```
build/zig build-exe hello.zig --system-linker-hack
```
This commit fixes linking issue on macOS 11 BigSur by appending
a prefix path to all lib and framework search paths known as
`-syslibroot`.
The reason this is needed is that in macOS 11, the system libraries
and frameworks are no longer readily available in the filesystem.
Instead, the new macOS ships with a built-in dynamic linker cache
of all system-provided libraries, and hence, when linking with either
`lld.ld64` or `ld64`, it is required to pass in `-syslibroot [dir]`.
The latter can usually be obtained by invoking `xcrun --show-sdk-path`.
With this commit, Zig will do this automatically when compiling natively
on macOS. However, it also provides a flag `-syslibroot` which can be
used to overwrite the automtically populated value.
To summarise, with this change, the user of Zig is not required to
generate and append their own syslibroot path. Standard invocations
such as `zig build-exe hello.zig` or `zig build` for projects will
work out of the box. The only missing bit is `zig cc` and `zig c++`
since the addition of the `-syslibroot` option would be a mismatch
between the values provided by `clang` itself and Zig's wrapper.
The code was using the length of the local symbols, which also
includes the null symbol. Fix this by using the offset table instead,
which only keeps track of the symbols that end up in the got.
Unlike glibc and musl, MinGW provides no libssp symbols leading to
countless compile errors if FORTIFY_SOURCE is defined.
Add a (incomplete) implementation of libssp written in Zig so that
linking succeeds.
Closes#6492
* remove GetModuleHandleA from kernel32.zig. use of A functions
considered harmful.
* make it a compile error to expose WinMain instead of wWinMain. same
thing.
* start code declares wWinMainCRTStartup instead of WinMainCRTStartup
when it has the choice.
* std.fs.Dir.readFile: add doc comments to explain what it means when
the returned slice has the same length as the supplied buffer.
* introduce readSmallFile / writeSmallFile to abstract over the
decision to use symlink or file contents to store data.
* std.fs.File.copyRange and copyRangeAll return u64 instead of usize -
the returned value is how much of the `len` is transferred, so the
types should match. This removes the need for an `@intCast`.
* fix typo that removed a subtraction
* Fix the size of codegen.AnyMCValue which gave me a compile error when
I tried to build self-hosted for i386-linux.
* restore the coercion to u64 of syms_sect.sh_info. We want to make
sure the multiplication happens with 64 bits and not the smaller type
used by the ELF format.
* fix another offset parameter in link/Elf.zig to be u64 instead of usize
* add a nice little TODO note to help out Jakub
* FmtError already has FileTooBig in it; we just need to return it.
It was regressed in 2 ways from the merge of #6250:
* it was not being enabled by default when the target OS is native.
* we were testing the libfoo.so file path existence with bogus format
string ('{}' instead of '{s}') and so it ended up being something
like "libstd.HashMap(K,V,...).Entry.so" instead of "libfoo.so". Using
{} rather than {s} is a footgun, be careful!
Previous functionality is now restored.
closes#6523
This commit refactors free space analysis (and VM analysis) somewhat.
This is still far from perfect, but at least it's not using any
hardcoded values.
This commit also reorganizes different flushing bits here and there,
so that bit common to Exe and Obj are put in the common path, while
Exe-specific are behind an appropriate switch/if statement.
* Convert draft to generate all relevant segments and sections in right places
* Do not prealloc space in text blocks until we can NOP
* Write out LC_LOAD_DYLINKER command
* Add LC_LOAD_DYLIB command in order to specify to load libSystem
* Redo update decl exports (similar to Elf globals, globals need to be contiguous in
memory)
Jakub Konka