Our bootstrapping setup compiles multiple versions of the generated code for `descriptor.proto` and `plugin.proto`, one for each stage of the bootstrap. For source files (`.c`), we can always select the correct version of the file in the BUILD rules, but for header files we need to make sure the correct stage's file is always selected via `#include`.
Previously we used `cc_library(includes=[])` to make it appear as though our bootstrapped headers had the same names as the "real" headers. This allowed a lot of the code to be agnostic to whether a bootstrap header was being used, which simplified things because we did not have to change the code performing the `#include`.
Unfortunately, due to build system limitations, this sometimes led to the incorrect header getting included. This should not have been possible, because we had a clean BUILD graph that should have removed all ambiguity about which header should be available. But in non-sandboxed builds, the compiler was able to find headers that were not actually in `deps=[]`, and worse it preferred those headers over the headers that actually were in `deps=[]`. This led to unintended results and errors about layering check violations.
This CL fixes the problem by removing all use of `includes=[]`. We now spell a full pathname to all bootstrap headers, so this class of errors is no longer possible. Unfortunately this adds some complexity, as we have to hard-code these full paths in several places.
A nice improvement in this CL is that `bootstrap_upb_proto_library()` can now only be used for bootstrapping; it only exposes the `descriptor_bootstrap.h` / `plugin_bootstrap.h` files. Anyone wanting to use the normal `net/proto2/proto/descriptor.upb.h` file should depend on `//net/proto2/proto:descriptor_upb_c_proto` target instead.
PiperOrigin-RevId: 664953196
Since maps have a different in-memory representation than repeated messages, it is not safe to tree shake map entry messages.
Specifically, map fields use `kUpb_FieldMode_Map` instead of `kUpb_FieldMode_Array`, and there is no easy way to get the linker to rewrite this when the map entry is dropped.
However it is safe to tree shake message typed map values, since these use `kUpb_FieldMode_Scalar`, which remains valid even after the type is tree shaken.
PiperOrigin-RevId: 646199050
Since statically tree shaken messages can never later become linked, we should not need to use any of the special code in the decoder. By using a distinct "empty" message type, we avoid triggering any of this special behavior. This avoids bugs around hazzers and other presence checks.
Also fixed a bug in the cmake staleness test that was causing test failures.
PiperOrigin-RevId: 643036818
The functionality is enabled when the proto_one_output_per_message option used by C++ Lite is enabled.
This mirrors the behavior of C++ lite protos.
PiperOrigin-RevId: 642327960
The functionality is enabled when the `proto_one_output_per_message` option used by C++ Lite is enabled.
This mirrors the behavior of C++ lite protos.
PiperOrigin-RevId: 640592937
Creates a tracing helper function to associate mini tables with proto full names to use for upcoming upb metrics collectors.
PiperOrigin-RevId: 613290255
This required enabling the feature in the code generator and fixing a few edge cases around label and type.
Also added tests to verify the special cases, and to verify that required fields work as expected.
PiperOrigin-RevId: 580263087
This makes the file layout a bit more consistent with the `protos ->
protos_generator` pattern. I also replaced the `upbc` namespace with
`upb::generator`.
PiperOrigin-RevId: 569264372
This change moves almost everything in the `upb/` directory up one level, so
that for example `upb/upb/generated_code_support.h` becomes just
`upb/generated_code_support.h`. The only exceptions I made to this were that I
left `upb/cmake` and `upb/BUILD` where they are, mostly because that avoids
conflict with other files and the current locations seem reasonable for now.
The `python/` directory is a little bit of a challenge because we had to merge
the existing directory there with `upb/python/`. I made `upb/python/BUILD` into
the BUILD file for the merged directory, and it effectively loads the contents
of the other BUILD file via `python/build_targets.bzl`, but I plan to clean
this up soon.
PiperOrigin-RevId: 568651768
The new rules are:
- `upb_minitable_proto_library()`: contains the MiniTables only
- `upb_c_proto_library()`: Contains the C API. Depends on the MiniTables
This involved splitting upb code generation into two separate aspects, one for MiniTables and one for the C API.
PiperOrigin-RevId: 565518070
Joshua Haberman
Mike Kruskal
Protobuf Team Bot
Eric Salo
Hong Shin
Adam Cozzette