commit 52887e1cc726bff24b8b0dd6f2b1babf7632db8a
author Grégoire Geis <opensource@gregoirege.is> Thu Nov 07 11:19:39 2024 -0800
committer Copybara-Service <copybara-worker@google.com> Thu Nov 07 11:27:03 2024 -0800
tree 37a50ab28b0e8294b14e2ac702aaf8eb8504d927
parent b591280b1233d564ba6c7e638e39fa26c797cd4b

Fix DEPENDENCIES in protobuf_generate() to accept multiple values instead of silently dropping

cmake: make DEPENDENCIES in protobuf_generate() a multi-value keyword (#19175)

It was previously a one-value keyword, so given

```cmake
protobuf_generate(
  ...
  DEPENDENCIES
    a
    b
)
```

`a` would be a dependency, and `b` would be discarded (or, more precisely, added to `protobuf_generate_UNPARSED_ARGUMENTS`).

This can be confirmed with the following changes:

```diff
diff --git a/cmake/protobuf-generate.cmake b/cmake/protobuf-generate.cmake
index 244407ee2..6dfbcef6d 100644
--- a/cmake/protobuf-generate.cmake
+++ b/cmake/protobuf-generate.cmake
@@ -10,6 +10,9 @@ function(protobuf_generate)

   cmake_parse_arguments(protobuf_generate "${_options}" "${_singleargs}" "${_multiargs}" "${ARGN}")

+  message("Deps: ${protobuf_generate_DEPENDENCIES}")
+  message("Unparsed args: ${protobuf_generate_UNPARSED_ARGUMENTS}")
+
   if(NOT protobuf_generate_PROTOS AND NOT protobuf_generate_TARGET)
     message(SEND_ERROR "Error: protobuf_generate called without any targets or source files")
     return()
diff --git a/cmake/tests.cmake b/cmake/tests.cmake
index 7976546fe..1cadf1e5a 100644
--- a/cmake/tests.cmake
+++ b/cmake/tests.cmake
@@ -27,6 +27,7 @@ foreach(proto_file ${lite_test_protos})
     LANGUAGE cpp
     OUT_VAR pb_generated_files
     IMPORT_DIRS ${protobuf_SOURCE_DIR}/src
+    DEPENDENCIES a b
   )
   set(lite_test_proto_files ${lite_test_proto_files} ${pb_generated_files})
 endforeach(proto_file)
```

Which printed "Deps: a" and "Unparsed args: b" for lite test files. With this change, it now prints "Deps: a;b" and "Unparsed args: ".

AFAIK, making `DEPENDENCIES` a multi-value keyword is mostly backwards-compatible; however, users who specified dependencies that were being ignored may be surprised to see that they are no longer ignored (which could cause build errors).

To prevent this kind of problem in the future, validating that `protobuf_generate_UNPARSED_ARGUMENTS` is empty could be useful, but to avoid potentially breaking more builds I did not do this in this PR.

Closes #19175

COPYBARA_INTEGRATE_REVIEW=https://github.com/protocolbuffers/protobuf/pull/19175 from 71:protobuf-generate-dependencies c998afa11a99e85560f612c92e09e69d29bc8c1a
PiperOrigin-RevId: 694186507