mainly this addresses the following use case:
1. Someone creates a template with build.zig.zon, id field included
(note that zig init does not create this problem since it generates
fresh id every time it runs).
2. User A uses the template, changing package name to "example" but not
id field.
3. User B uses the same template, changing package name also to
"example", also not changing the id field.
Here, both packages have unintentional conflicting logical ids.
By making the field a combination of name checksum + random id, this
accident is avoided. "nonce" is an OK name for this.
Also relaxes errors on remote packages when using `zig fetch`.
Introduces the `id` field to `build.zig.zon`.
Together with name, this represents a globally unique package
identifier. This field should be initialized with a 16-bit random number
when the package is first created, and then *never change*. This allows
Zig to unambiguously detect when one package is an updated version of
another.
When forking a Zig project, this id should be regenerated with a new
random number if the upstream project is still maintained. Otherwise,
the fork is *hostile*, attempting to take control over the original
project's identity.
`0x0000` is invalid because it obviously means a random number wasn't
used.
`0xffff` is reserved to represent "naked" packages.
Tracking issue #14288
Additionally:
* Fix bad path in error messages regarding build.zig.zon file.
* Manifest validates that `name` and `version` field of build.zig.zon
are maximum 32 bytes.
* Introduce error for root package to not switch to enum literal for
name.
* Introduce error for root package to omit `id`.
* Update init template to generate `id`
* Update init template to populate `minimum_zig_version`.
* New package hash format changes:
- name and version limited to 32 bytes via error rather than truncation
- truncate sha256 to 192 bits rather than 40 bits
- include the package id
This means that, given only the package hashes for a complete dependency
tree, it is possible to perform version selection and know the final
size on disk, without doing any fetching whatsoever. This prevents
wasted bandwidth since package versions not selected do not need to be
fetched.
Instead of hardcoding a call to defaultRandomSeed() use the customizable
std.options.cryptoRandomSeed() like in the rest of the function.
Closes#19943.
In #22522 I said:
> RC="zig rc" will now work in combination with zig cc and CMake. Here's an example of cross-compiling a simple Windows GUI CMake project
>
> $ RC="zig rc" CC="zig cc --target=x86_64-windows-gnu" cmake .. -DCMAKE_SYSTEM_NAME=Windows -G Ninja
However, I didn't realize that the time that this only works because of the `-G Ninja` part. When not using Ninja as the build tool, CMake adds a workaround for 'very long lists of object files' where it takes all object files and runs them through `ar` to combine them into one archive:
4a11fd8dde/Modules/Platform/Windows-GNU.cmake (L141-L158)
This is a problem for the Windows resource use-case, because `ar` doesn't know how to deal with `.res` files and so this object combining step fails with:
unknown file type: foo.rc.res
Only the linker knows what to do with .res files (since it has its own `.res` -> `.obj` ('cvtres') conversion mechanism). So, when using Ninja, this object file combining step is skipped and the .res file gets passed to the linker and everyone is happy.
Note: When CMake thinks that its using `windres` as the Windows resource compiler, it will pass `-O coff` to windres which causes it to output a COFF object file instead of a `.res` file, which means that the `ar` step can succeed because it's only working on actual object files.
---
This commit gives `zig rc` the ability to output COFF object files directly when `/:output-format coff` is provided as an argument. This effectively matches what happens when CMake uses `windres` for resource compilation, but requires the argument to be provided explicitly.
So, after this change, the following CMake cross-compilation use case will work, even when not using Ninja as the generator:
RC="zig rc /:output-format coff" CC="zig cc --target=x86_64-windows-gnu" cmake .. -DCMAKE_SYSTEM_NAME=Windows
