Add numeric SDK version macros to C/C++ (#7127)

### What

* Fixes #6379
* Related to #7104

Allows finally to do `#if` preprocessor checks on Rerun versions.
Uses the same up update version script introduced for Python and does
away with cmake driven duplication of rerun.h

### Checklist
* [x] I have read and agree to [Contributor
Guide](https://github.com/rerun-io/rerun/blob/main/CONTRIBUTING.md) and
the [Code of
Conduct](https://github.com/rerun-io/rerun/blob/main/CODE_OF_CONDUCT.md)
* [x] I've included a screenshot or gif (if applicable)
* [x] I have tested the web demo (if applicable):
* Using examples from latest `main` build:
[rerun.io/viewer](https://rerun.io/viewer/pr/7127?manifest_url=https://app.rerun.io/version/main/examples_manifest.json)
* Using full set of examples from `nightly` build:
[rerun.io/viewer](https://rerun.io/viewer/pr/7127?manifest_url=https://app.rerun.io/version/nightly/examples_manifest.json)
* [x] The PR title and labels are set such as to maximize their
usefulness for the next release's CHANGELOG
* [x] If applicable, add a new check to the [release
checklist](https://github.com/rerun-io/rerun/blob/main/tests/python/release_checklist)!
* [x] If have noted any breaking changes to the log API in
`CHANGELOG.md` and the migration guide

- [PR Build Summary](https://build.rerun.io/pr/7127)
- [Recent benchmark results](https://build.rerun.io/graphs/crates.html)
- [Wasm size tracking](https://build.rerun.io/graphs/sizes.html)

To run all checks from `main`, comment on the PR with `@rerun-bot
full-check`.

Author: Wumpf

.github/workflows/release.yml

@@ -137,9 +137,9 @@ jobs:
           echo "current=$current"   >> "$GITHUB_OUTPUT"
           echo "final=$final"       >> "$GITHUB_OUTPUT"
 
-      - name: Update rerun_py version
+      - name: Update rerun_py & rerun_c version
         run: |
-          pixi run python scripts/ci/update_rerun_py_version.py "${{ steps.versioning.outputs.current }}"
+          pixi run python scripts/ci/update_rerun_py_and_c_version.py "${{ steps.versioning.outputs.current }}"
 
       - name: Update rerun_notebook package version
         run: |
@@ -149,12 +149,6 @@ jobs:
         run: |
           pixi run node rerun_js/scripts/version.mjs "${{ steps.versioning.outputs.current }}"
 
-      - name: Update rerun_c version
-
-        # Configuring CMake is enough to change the version on rerun.h!
-        run: |
-          cmake -B build -S .
-
       - run: pixi run toml-fmt
 
       - name: Commit new version
@@ -428,10 +422,9 @@ jobs:
         run: |
           pixi run node rerun_js/scripts/version.mjs "${{ steps.crates.outputs.version }}"
 
-      - name: Update rerun_c version
-        # Configuring CMake is enough to change the version on rerun.h!
+      - name: Update rerun_py & rerun_c version
         run: |
-          cmake -B build -S .
+          pixi run python scripts/ci/update_rerun_py_and_c_version.py "${{ steps.versioning.outputs.current }}"
 
       - run: pixi run toml-fmt
 

CMakeLists.txt

@@ -137,13 +137,6 @@ endif()
 # Signal to all our build scripts that we're inside the Rerun repository.
 set(RERUN_REPOSITORY YES)
 
-# Set version number.
-# Read it from the Rust toml with a regex so we don't have another place to maintain!
-file(READ "Cargo.toml" CARGO_TOML)
-string(REGEX MATCH "\nversion = \"([a-z0-9\.\+-]+)\"\n" _ ${CARGO_TOML})
-set(RERUN_VERSION ${CMAKE_MATCH_1})
-message(STATUS "Rerun version ${RERUN_VERSION}")
-
 # ------------------------------------------------------------------------------
 # Loguru logging library (https://github.com/emilk/loguru):
 set(CMAKE_DL_LIBS "dl") # Required by Loguru for backtraces

crates/top/rerun_c/CMakeLists.txt

@@ -28,10 +28,3 @@ add_custom_command(
 # In CMake you can't depend on an output file directly. We have to wrap this in a target that rerun_c then depends on.
 add_custom_target(rerun_c_build DEPENDS "${RERUN_C_BUILD_ARTIFACT}")
 add_dependencies(rerun_c rerun_c_build)
-
-# Put `rerun.h` into the same place where it's on a user's machine and apply CMake variables like version number.
-configure_file(
-    "${CMAKE_CURRENT_SOURCE_DIR}/src/rerun.h"
-    "${PROJECT_SOURCE_DIR}/rerun_cpp/src/rerun/c/rerun.h"
-    NEWLINE_STYLE LF # Specify line endings, otherwise CMake wants to change them on Windows.
-)

crates/top/rerun_c/src/lib.rs

@@ -1,6 +1,6 @@
 //! The Rerun C SDK.
 //!
-//! The functions here must match `rerun.h`.
+//! The functions here must match `rerun_cpp/src/rerun/c/rerun.h`.
 
 #![crate_type = "staticlib"]
 #![allow(clippy::missing_safety_doc, clippy::undocumented_unsafe_blocks)] // Too much unsafe
@@ -305,7 +305,15 @@ pub struct CError {
 #[no_mangle]
 pub extern "C" fn rr_version_string() -> *const c_char {
     static VERSION: Lazy<CString> = Lazy::new(|| {
-        CString::new(re_sdk::build_info().version.to_string()).expect("CString::new failed")
+        CString::new(
+            re_sdk::build_info()
+                .version
+                .to_string()
+                // We use `+dev` as a marker for "this version is unreleased".
+                // Ignore it here since we don't update the version macros either on that frequency.
+                .trim_end_matches("+dev"),
+        )
+        .expect("CString::new failed")
     }); // unwrap: there won't be any NUL bytes in the string
 
     VERSION.as_ptr()