Add support for versioning in git archives

While releasing UMF we should update VERSION file with the current version.
It will be used only if git is not available or tags were not fetched.

To underline it is not a "detailed version" we will add "-dev" in CMake version
parsing, so it will stand out (comparing to e.g. versions like "1.0.3-dev1-...").

Author: lukaszstolarczuk

.github/copilot-instructions.md

@@ -35,7 +35,7 @@ cmake -B build -DCMAKE_BUILD_TYPE=Debug \
   2. `VERSION` file fallback
   3. "0.0.0" default
 - `set_version_variables()` in `cmake/helpers.cmake` handles version detection
-- For releases: create `VERSION` file with semver format (e.g., "1.0.3-dev")
+- For releases: create `VERSION` file with semver format (e.g., "1.0.3")
 
 ### Code Formatting
 - **Always format code before committing**: `make format-apply`

CMakeLists.txt

@@ -32,7 +32,8 @@ if(UMF_CMAKE_VERSION VERSION_EQUAL "0.0.0")
     message(
         WARNING
             "UMF version is set to 0.0.0, which most likely is not expected! "
-            "Please checkout the git tags to get a proper version.")
+            "Please install git and checkout the git tags to get a proper version."
+    )
 endif()
 
 if(PROJECT_VERSION_PATCH GREATER 0)

RELEASE_STEPS.md

@@ -50,7 +50,11 @@ Prepare changes for the release:
 - Once all changes are done, build locally (and/or verify changes on CI), including:
   - Verify if scanners/linters/checkers passed
   - Verify if version is set properly, especially in `.dll` and `.so` files
+- Create/update a VERSION file for GitHub ZIP downloads (users without git):
+  - `echo "$VERSION" > VERSION`
+  - It will always contain "the last released version". In logs/CMake build it will introduce itself as `$VERSION-dev`, only if git is not available
 - Commit these changes and tag the release:
+  - `git add VERSION`
   - `git commit -a -S -m "$VERSION release"`
   - `git tag -a -s -m "Version $VERSION" v$VERSION`
 - Verify if commit and tag are properly signed:

cmake/helpers.cmake

@@ -11,10 +11,12 @@ include(CheckCCompilerFlag)
 include(CheckCXXCompilerFlag)
 
 # This function establishes version variables based on the git describe output.
-# If there's no git available in the system, the version will be set to "0.0.0".
-# If git reports only a hash, the version will be set to "0.0.0.git.<hash>".
-# Otherwise we'll use 3-component version: major.minor.patch, just for CMake's
-# sake. A few extra variables will be set for Win dll metadata.
+# If there's no git available in the system, it falls back to reading a VERSION
+# file from the project root. If neither git nor VERSION file is available, the
+# version will be set to "0.0.0". If git reports only a hash, the version will
+# be set to "0.0.0.git.<hash>". Otherwise we'll use 3-component version:
+# major.minor.patch, just for CMake's sake. A few extra variables will be set
+# for Win dll metadata.
 #
 # Important note: CMake does not support rc or git information. According to
 # semver rules, 1.5.1-rc1 should be less than 1.5.1, but it seems hard to
@@ -78,8 +80,24 @@ function(set_version_variables)
         OUTPUT_STRIP_TRAILING_WHITESPACE ERROR_QUIET)
 
     if(NOT GIT_VERSION)
-        # no git or it reported no version. Use default ver: "0.0.0"
-        return()
+        # no git or it reported no version. Try fallback to VERSION file
+        if(EXISTS "${UMF_CMAKE_SOURCE_DIR}/VERSION")
+            file(READ "${UMF_CMAKE_SOURCE_DIR}/VERSION" FILE_VERSION)
+            string(STRIP ${FILE_VERSION} FILE_VERSION)
+            if(FILE_VERSION)
+                set(GIT_VERSION "v${FILE_VERSION}-dev")
+                message(
+                    STATUS
+                        "Using version from VERSION file: ${FILE_VERSION}. To get detailed version, use git and fetch tags."
+                )
+            else()
+                # VERSION file exists but is empty, use default ver: "0.0.0"
+                return()
+            endif()
+        else()
+            # no git and no VERSION file. Use default ver: "0.0.0"
+            return()
+        endif()
     endif()
 
     # v1.5.0 - we're exactly on a tag -> UMF ver: "1.5.0"