Stuffing all the files together and compiling the resulting blob with
the main program is a terrible idea.
Some files, namely the .S ones, must be run trough the C preprocessor
before assembling them (#2437).
Beside that the aggregate may be mis-compiled due to the presence of
some flags that affect the following code.
For example let's consider two files, a.s and b.s
a.s
```
fn1:
ret
.data
data1:
.word 0
```
b.s
```
fn2:
ret
```
Now, fn1 and fn2 will be both placed in the .text section as intended if
the two files are compiled separately. But if we merge them the `.data`
flag ends up placing fn2 in the wrong section!
This fixes a nasty crash where musl's memset ended up in the
non-executable data segment, leading to too many hours of
head-scratching.
Sadly due to a workaround for LLD linker limitations on macOS
we cannot put libuserland into an .a file; instead we have to use object
files. Again due to linker limitations, bundling compiler_rt.o into
another relocatable object also doesn't work. So we're left with
disabling stack probing on macOS for the stage1 self-hosted code.
These workarounds could all be removed if the macos support in the LLD
linker improved, or if Zig project had its own linker that did not have
these issues.
and use it when building libuserland.a
The self-hosted part of stage1 relies on zig's compiler-rt, and so we
include it in libuserland.a.
This should potentially be the default, but for now it's behind a linker
option.
self-hosted translate-c: small progress on translating functions.
zig --help -> ok
zig --help --c-source -> ok
zig --c-source --help -> crash [fixed]
'i' was being incremented without regard for the 'argc' limit, so
we were running off the end of 'argv'.
Previously, `zig fmt` on the stage1 compiler (which is what we currently
ship) would perform what equates to `zig run std/special/fmt_runner.zig`
Now, `zig fmt` is implemented with the hybrid zig/C++ strategy outlined
by #1964.
This means Zig no longer has to ship some of the stage2 .zig files, and
there is no longer a delay when running `zig fmt` for the first time.
This modifies the build process of Zig to put all of the source files
into libcompiler.a, except main.cpp and userland.cpp.
Next, the build process links main.cpp, userland.cpp, and libcompiler.a
into zig1. userland.cpp is a shim for functions that will later be
replaced with self-hosted implementations.
Next, the build process uses zig1 to build src-self-hosted/stage1.zig
into libuserland.a, which does not depend on any of the things that
are shimmed in userland.cpp, such as translate-c.
Finally, the build process re-links main.cpp and libcompiler.a, except
with libuserland.a instead of userland.cpp. Now the shims are replaced
with .zig code. This provides all of the Zig standard library to the
stage1 C++ compiler, and enables us to move certain things to userland,
such as translate-c.
As a proof of concept I have made the `zig zen` command use text defined
in userland. I added `zig translate-c-2` which is a work-in-progress
reimplementation of translate-c in userland, which currently calls
`std.debug.panic("unimplemented")` and you can see the stack trace makes
it all the way back into the C++ main() function (Thanks LemonBoy for
improving that!).
This could potentially let us move other things into userland, such as
hashing algorithms, the entire cache system, .d file parsing, pretty
much anything that libuserland.a itself doesn't need to depend on.
This can also let us have `zig fmt` in stage1 without the overhead
of child process execution, and without the initial compilation delay
before it gets cached.
See #1964
This fixes comes thanks to Rich Felker from the musl libc project,
who gave me this crucial information:
"to satisfy the abi, your init code has to write the same value
to that memory location as the value passed to the [arch_prctl]
syscall"
This commit also changes the rules for when to build statically
by default. When building objects and static libraries, position
independent code is disabled if no libraries will be dynamically
linked and the target does not require position independent code.
closes#2063
The `--` double-hyphen is now used to end further `zig` processing
of command line options. All arguments after `--` will be passed
on to the executable. eg. `--help` will be passed on.
`zig run foo.zig -- --help`
closes#2148
`--static` is no longer an option. Instead, Zig makes things as static
as possible by default. `-dynamic` can be used to choose a dynamic
library rather than a static one.
`--enable-pic` is a new option. Usually it will be enabled
automatically, but in the case of build-exe with no dynamic libraries
on Linux or freestanding, Zig chooses off by default.
closes#1703closes#1828
* in Zig build scripts, getOutputPath() is no longer a valid function
to call, unless setOutputDir() was used, or within a custom make()
function. Instead there is more convenient API to use which takes
advantage of the caching system. Search this commit diff for
`exe.run()` for an example.
* Zig build by default enables caching. All build artifacts will go
into zig-cache. If you want to access build artifacts in a convenient
location, it is recommended to add an `install` step. Otherwise
you can use the `run()` API mentioned above to execute programs
directly from their location in the cache. Closes#330.
`addSystemCommand` is available for programs not built with Zig
build.
* Please note that Zig does no cache evicting yet. You may have to
manually delete zig-cache directories periodically to keep disk
usage down. It's planned for this to be a simple Least Recently
Used eviction system eventually.
* `--output`, `--output-lib`, and `--output-h` are removed. Instead,
use `--output-dir` which defaults to the current working directory.
Or take advantage of `--cache on`, which will print the main output
path to stdout, and the other artifacts will be in the same directory
with predictable file names. `--disable-gen-h` is available when
one wants to prevent .h file generation.
* `@cImport` is always independently cached now. Closes#2015.
It always writes the generated Zig code to disk which makes debug
info and compile errors better. No more "TODO: remember C source
location to display here"
* Fix .d file parsing. (Fixes the MacOS CI failure)
* Zig no longer creates "temporary files" other than inside a
zig-cache directory.
This breaks the CLI API that Godbolt uses. The suggested new invocation
can be found in this commit diff, in the changes to `test/cli.zig`.
closes#2024
there's a new cli option `--main-pkg-path` which you can use to choose
a different root package directory besides the one inferred from the
root source file
and a corresponding build.zig API:
foo.setMainPkgPath(path)
* CLI: `-target [name]` instead of `--target-*` args.
This matches clang's API.
* `builtin.Environ` renamed to `builtin.Abi`
- likewise `builtin.environ` renamed to `builtin.abi`
* stop hiding the concept of sub-arch. closes#1526
* `zig targets` only shows available targets. closes#438
* include all targets in readme, even those that don't
print with `zig targets` but note they are Tier 4
* refactor target.cpp and make the naming conventions
more consistent
* introduce the concept of a "default C ABI" for a given
OS/Arch combo. As a rule of thumb, if the system compiler
is clang or gcc then the default C ABI is the gnu ABI.
New CLI parameter: --c-source [options] [file]
It even works with `--cache on` when there are transitive dependencies.
Instead of `builder.addCExecutable`, use `builder.addExecutable` and pass
`null` for the root source file. Then use `builder.addCSourceFile`,
which takes the path to the C code, and a list of C compiler args.
Be sure to linkSystemLibrary("c") if you want libc headers to be
available.
Merge TestStep into LibExeObjStep. That was long overdue.
