cmake: parse project version

This properly sets the project version in projects meson generates from
cmake projects. This allows dependency fallbacks to properly check the
version constraints in dependency calls when falling back to a cmake
subproject. Before this would fail, because the project version was
undefined.

5 files changed, 26 insertions, 4 deletions

diff --git a/docs/markdown/snippets/cmake-project-version.md b/docs/markdown/snippets/cmake-project-version.md
new file mode 100644
index 0000000..0bc120b
--- /dev/null
+++ b/docs/markdown/snippets/cmake-project-version.md
@@ -0,0 +1,6 @@
+## Meson now reads the project version of cmake subprojects
+
+CMake subprojects configured by meson will now have their project
+version set to the project version in their CMakeLists.txt. This
+allows version constraints to be properly checked when falling back to
+a cmake subproject.
diff --git a/mesonbuild/cmake/fileapi.py b/mesonbuild/cmake/fileapi.py
index baf499f..c82c51f 100644
--- a/mesonbuild/cmake/fileapi.py
+++ b/mesonbuild/cmake/fileapi.py
@@ -30,8 +30,10 @@ class CMakeFileAPI:
         self.reply_dir = self.api_base_dir / 'reply'
         self.cmake_sources: T.List[CMakeBuildFile] = []
         self.cmake_configurations: T.List[CMakeConfiguration] = []
+        self.project_version = ''
         self.kind_resolver_map = {
             'codemodel': self._parse_codemodel,
+            'cache': self._parse_cache,
             'cmakeFiles': self._parse_cmakeFiles,
         }
 
@@ -41,12 +43,16 @@ class CMakeFileAPI:
     def get_cmake_configurations(self) -> T.List[CMakeConfiguration]:
         return self.cmake_configurations
 
+    def get_project_version(self) -> str:
+        return self.project_version
+
     def setup_request(self) -> None:
         self.request_dir.mkdir(parents=True, exist_ok=True)
 
         query = {
             'requests': [
                 {'kind': 'codemodel', 'version': {'major': 2, 'minor': 0}},
+                {'kind': 'cache', 'version': {'major': 2, 'minor': 0}},
                 {'kind': 'cmakeFiles', 'version': {'major': 1, 'minor': 0}},
             ]
         }
@@ -279,6 +285,13 @@ class CMakeFileAPI:
             path = path if path.is_absolute() else src_dir / path
             self.cmake_sources += [CMakeBuildFile(path, i.get('isCMake', False), i.get('isGenerated', False))]
 
+    def _parse_cache(self, data: T.Dict[str, T.Any]) -> None:
+        assert 'entries' in data
+
+        for e in data['entries']:
+            if e['name'] == 'CMAKE_PROJECT_VERSION':
+                self.project_version = e['value']
+
     def _strip_data(self, data: T.Any) -> T.Any:
         if isinstance(data, list):
             for idx, i in enumerate(data):
diff --git a/mesonbuild/cmake/interpreter.py b/mesonbuild/cmake/interpreter.py
index 8e9ea18..20348b5 100644
--- a/mesonbuild/cmake/interpreter.py
+++ b/mesonbuild/cmake/interpreter.py
@@ -784,6 +784,7 @@ class CMakeInterpreter:
 
         # Analysed data
         self.project_name = ''
+        self.project_version = ''
         self.languages: T.List[str] = []
         self.targets: T.List[ConverterTarget] = []
         self.custom_targets: T.List[ConverterCustomTarget] = []
@@ -875,6 +876,8 @@ class CMakeInterpreter:
         # Load the codemodel configurations
         self.codemodel_configs = self.fileapi.get_cmake_configurations()
 
+        self.project_version = self.fileapi.get_project_version()
+
     def analyse(self) -> None:
         if self.codemodel_configs is None:
             raise CMakeException('CMakeInterpreter was not initialized')
@@ -949,7 +952,7 @@ class CMakeInterpreter:
         for tgt in self.targets:
             tgt.cleanup_dependencies()
 
-        mlog.log('CMake project', mlog.bold(self.project_name), 'has', mlog.bold(str(len(self.targets) + len(self.custom_targets))), 'build targets.')
+        mlog.log('CMake project', mlog.bold(self.project_name), mlog.bold(self.project_version), 'has', mlog.bold(str(len(self.targets) + len(self.custom_targets))), 'build targets.')
 
     def pretend_to_be_meson(self, options: TargetOptions) -> CodeBlockNode:
         if not self.project_name:
@@ -1023,7 +1026,7 @@ class CMakeInterpreter:
 
         # Generate the root code block and the project function call
         root_cb = CodeBlockNode(token())
-        root_cb.lines += [function('project', [self.project_name] + self.languages)]
+        root_cb.lines += [function('project', [self.project_name] + self.languages, {'version': self.project_version} if self.project_version else None)]
 
         # Add the run script for custom commands
 
diff --git a/test cases/cmake/27 dependency fallback/meson.build b/test cases/cmake/27 dependency fallback/meson.build
index 871d70c..76230bb 100644
--- a/test cases/cmake/27 dependency fallback/meson.build
+++ b/test cases/cmake/27 dependency fallback/meson.build
@@ -1,7 +1,7 @@
 project('cmakeSubTest', ['c', 'cpp'])
 
 # Fallback to a CMake subproject
-sub_dep = dependency('cmModLib++')
+sub_dep = dependency('cmModLib++', version: '>=1.2.3')
 exe1 = executable('main', ['main.cpp'], dependencies: [sub_dep])
 test('test1', exe1)
 
diff --git a/test cases/cmake/27 dependency fallback/subprojects/cmMod/CMakeLists.txt b/test cases/cmake/27 dependency fallback/subprojects/cmMod/CMakeLists.txt
index d08e55c..f920576 100644
--- a/test cases/cmake/27 dependency fallback/subprojects/cmMod/CMakeLists.txt
+++ b/test cases/cmake/27 dependency fallback/subprojects/cmMod/CMakeLists.txt
@@ -1,6 +1,6 @@
 cmake_minimum_required(VERSION 3.5)
 
-project(cmMod)
+project(cmMod VERSION 1.2.3)
 set(CMAKE_CXX_STANDARD 14)
 
 include_directories(${CMAKE_CURRENT_BINARY_DIR})