Conan: simplify Conan recipe

The qt-conan-common package contains shared functionality
for recipes that should be used:
 - environment wrap during the build()
 - package_info() is generic for all recipes

Move the _build() out from the class so that it is usable for
the callback from qt-conan-common package.

Simplify how the Qt module version and prerelease tag is
read from .cmake.conf and how the file is being referenced.
As the .cmake.conf is included in the "exports" it will
be always present next to the recipe:
  - in .git source tree
  - in Conan cache

Pick-to: 6.2
Change-Id: I4bbd683f7b49151620397e0b7f4272929a93c060
Reviewed-by: Toni Saario <[email protected]>

conanfile.py

@@ -32,6 +32,7 @@
 import re
 import json
 import subprocess
+from functools import lru_cache
 from pathlib import Path
 from typing import Dict, List, Any, Optional
 
@@ -124,28 +125,14 @@ def __init__(self) -> None:
         self.extra_options: Dict[str, Any] = {"extra_cmake_args": "ANY"}
         self.extra_options_default_values = {"extra_cmake_args": None}
 
-    def get_recipe_path_from_current_context(self) -> Path:
-        def _recipe_exists(recipe_path: Path) -> bool:
-            return Path(recipe_path / "conanfile.py").exists()
-
-        current_path = Path(__file__).parent.resolve()
-        if _recipe_exists(current_path):
-            return current_path
-
-        root_path = Path(current_path / ".." / "export").resolve()
-        if _recipe_exists(root_path):
-            return root_path
-
-        raise QtConanError(f"Unable to locate recipe path from current context: {current_path}")
-
     def load_configure_options(self) -> None:
         """Read the configure options and features dynamically via configure(.bat).
         There are two contexts where the ConanFile is initialized:
           - 'conan export' i.e. when the conan package is being created from sources (.git)
           - inside conan's cache when invoking: 'conan install, conan info, conan inspect, ..'
         """
         print("QtOptionParser: load configure options ..")
-        recipe_folder = self.get_recipe_path_from_current_context()
+        recipe_folder = Path(__file__).parent.resolve()
         configure_options = Path(recipe_folder) / "configure_options.json"
         configure_features = Path(recipe_folder) / "configure_features.txt"
         if not configure_options.exists() or not configure_features.exists():
@@ -316,6 +303,26 @@ def get_extra_cmake_args_for_configure(self, conan_options: Options) -> List[Opt
         return ret
 
 
+def _build_qtbase(conan_file: ConanFile):
+    # we call the Qt's configure(.bat) directly
+    script = Path("configure.bat") if tools.os_info.is_windows else Path("configure")
+    configure = Path(Path(conan_file.build_folder).resolve() / script).resolve(strict=True)
+
+    # convert the Conan options to Qt configure(.bat) arguments
+    qt_configure_options = conan_file._qt_option_parser.convert_conan_options_to_qt_options(conan_file.options)
+    cmd = " ".join([str(configure), " ".join(qt_configure_options), "-prefix", conan_file.package_folder])
+    cmake_args = conan_file._qt_option_parser.get_extra_cmake_args_for_configure(conan_file.options)
+    if cmake_args:
+        cmd += f" -- {' '.join(cmake_args)}"
+    conan_file.output.info(f"Calling: {cmd}")
+    conan_file.run(cmd)
+
+    cmd = " ".join(["cmake", "--build", ".", "--parallel"])
+    conan_file.output.info(f"Calling: {cmd}")
+    conan_file.run(cmd)
+
+
+@lru_cache(maxsize=8)
 def _parse_qt_version_by_key(key: str) -> str:
     with open(Path(Path(__file__).parent.resolve() / ".cmake.conf")) as f:
         ret = [m.group(1) for m in [re.search(r"{0} .*\"(.*)\"".format(key), f.read())] if m]
@@ -337,6 +344,7 @@ class QtBase(ConanFile):
     exports_sources = "*", "!conan*.*"
     # use commit ID as the RREV (recipe revision) if this is exported from .git repository
     revision_mode = "scm" if Path(Path(__file__).parent.resolve() / ".git").exists() else "hash"
+    python_requires = f"qt-conan-common/{_parse_qt_version_by_key('QT_REPO_MODULE_VERSION')[0:3]}@qt/everywhere"
 
     def set_version(self):
         # Executed during "conan export" i.e. in source tree
@@ -387,27 +395,7 @@ def _set_default_if_not_set(option_name: str, option_value: str) -> None:
             self.options.force_debug_info = "yes"
 
     def build(self):
-        # This context manager tool has no effect if used in a platform different from Windows
-        with tools.vcvars(self):
-            self._build()
-
-    def _build(self):
-        # we call the Qt's configure(.bat) directly
-        script = Path("configure.bat") if tools.os_info.is_windows else Path("configure")
-        configure = Path(Path(self.build_folder).resolve() / script).resolve(strict=True)
-
-        # convert the Conan options to Qt configure(.bat) arguments
-        qt_configure_options = self._qt_option_parser.convert_conan_options_to_qt_options(self.options)
-        cmd = " ".join([str(configure), " ".join(qt_configure_options), "-prefix", self.package_folder])
-        cmake_args = self._qt_option_parser.get_extra_cmake_args_for_configure(self.options)
-        if cmake_args:
-            cmd += f" -- {' '.join(cmake_args)}"
-        self.output.info(f"Calling: {cmd}")
-        self.run(cmd)
-
-        cmd = " ".join(["cmake", "--build", ".", "--parallel"])
-        self.output.info(f"Calling: {cmd}")
-        self.run(cmd)
+        self.python_requires["qt-conan-common"].module.build_env_wrap(self, _build_qtbase)
 
     def package(self):
         cmd = ["cmake", "--install", "."]
@@ -417,18 +405,7 @@ def package(self):
             f.write("[Paths]\nPrefix = ..\n")
 
     def package_info(self):
-        self.cpp_info.libs = tools.collect_libs(self)
-
-        # For virtualenv generator: build and run environment for qmake, CMake
-        self.env_info.CMAKE_PREFIX_PATH.append(self.package_folder)
-        if tools.os_info.is_windows:
-            self.env_info.PATH.append(os.path.join(self.package_folder, "bin"))
-        self.env_info.QMAKEPATH.append(self.package_folder)
-        self.env_info.QT_ADDITIONAL_PACKAGES_PREFIX_PATH.append(self.package_folder)
-
-        for item in Path(Path(self.package_folder) / "lib" / "cmake").resolve().glob("Qt6*"):
-            if item.is_dir():
-                setattr(self.env_info, str(item.name) + "_DIR", str(item))
+        self.python_requires["qt-conan-common"].module.package_info(self)
 
     def package_id(self):
         # https://docs.conan.io/en/latest/creating_packages/define_abi_compatibility.html