meson2hermetic: the world's premiere build system converter

.github/workflows/os_comp.yml

@@ -162,3 +162,25 @@ jobs:
           update-alternatives --set i686-w64-mingw32-g++   /usr/bin/i686-w64-mingw32-g++-posix
 
           ./run_tests.py $RUN_TESTS_ARGS -- $MESON_ARGS
+
+  check-toolchain-and-convert:
+    name: 'Check toolchain and build system conversion'
+    runs-on: ubuntu-latest
+    container:
+      image: mesonbuild/ubuntu-rolling
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Run check-toolchain unit tests
+        shell: bash
+        run: |
+          source /ci/env_vars.sh
+          python3 run_unittests.py CheckToolchainTests
+
+    - name: Run convert unit tests
+        shell: bash
+        run: |
+          source /ci/env_vars.sh
+          python3 run_unittests.py ConvertTests

docs/markdown/Commands.md

@@ -17,6 +17,71 @@ Optional arguments. The most common workflow is to run
 For the full list of all available options for a specific command use
 the following syntax: `meson COMMAND --help`
 
+### check-toolchain
+
+{{ check-toolchain_usage.inc }}
+
+Check the properties of the specified toolchain and sysroot.
+The output is displayed as a TOML file.
+
+The checked properties are an amalgamation of checks performed
+by popular Meson-based projects. Users are encouraged to
+upstream properties of interest.
+
+{{ check-toolchain_arguments.inc }}
+
+#### Examples:
+
+Check the properties of the default system toolchain.
+
+```
+meson check-toolchain
+```
+
+Check the properties with a cross-file specified toolchain.
+
+```
+meson check-toolchain --cross-file CROSS_FILE
+```
+
+Check the properties of Android NDK toolchains.
+
+```
+meson check-toolchain --android-ndk-path PATH_TO_ANDROID_NDK
+```
+
+### convert
+
+{{ convert_usage.inc }}
+
+Converts the meson project to an another build system. The input
+are a series of TOML files, and the output are files in the target
+build system. Soong and Bazel are supported to varying degrees.
+
+Meson maintains reference TOML files for certain hermetic trees
+and projects, and users are encouraged to upstream their use
+cases.
+
+{{ convert_arguments.inc }}
+
+#### Examples:
+
+Convert Mesa3D to Soong using reference TOML files.
+
+```
+meson convert android aosp_mesa3d
+```
+
+Power user maintains own TOML for their hermetic project.
+
+```
+meson convert --config=/path/to/myproject.toml \
+--project-dir=/path/to/my/target_repo
+--toolchain=/path/to/mytoolchain.toml \
+--dependencies=/path/to/mydeps.toml
+--output_dir=/path/to/output-dir
+```
+
 ### configure
 
 {{ configure_usage.inc }}

mesonbuild/backend/nonebackend.py

@@ -20,8 +20,10 @@ def generate(self, capture: bool = False, vslite_ctx: T.Optional[T.Dict] = None)
         if vslite_ctx:
             raise MesonBugException('We do not expect the none backend to be given a valid \'vslite_ctx\'')
 
-        if self.build.get_targets():
-            raise MesonBugException('None backend cannot generate target rules, but should have failed earlier.')
-        mlog.log('Generating simple install-only backend')
-        self.serialize_tests()
-        self.create_install_data_files()
+        # The `meson convert` tool generates build targets, but uses the none backend
+        # The below clause covers the non-convert use cases of the none backend, when
+        # build targets are not generated.
+        if not self.build.get_targets():
+            mlog.log('Generating simple install-only backend')
+            self.serialize_tests()
+            self.create_install_data_files()

mesonbuild/check_toolchain/__init__.py

@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: Apache-2.0
+# Copyright 2026 The Meson Authors