Series 1: maintenance baseline (README, Python 3 default, GitHub Actions CI)

.github/workflows/ci.yml

@@ -0,0 +1,81 @@
+# Continuous integration for gcc-python-plugin
+#
+# Stage 1 of the CI plan: one reproducible Linux x86_64 job using Python 3
+# and a single GCC release.  Further GCC releases (14, 15, 16 and trunk) and
+# architectures (ppc64le, aarch64) will be added as their compatibility work
+# lands.
+
+name: CI
+
+on:
+  push:
+  pull_request:
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+jobs:
+  build-and-test:
+    name: GCC ${{ matrix.gcc }}, Python 3, ${{ matrix.image }}
+    runs-on: ubuntu-latest
+    container: ${{ matrix.image }}
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          # GCC 11 and later do not build the current sources yet, so use
+          # GCC 10.  Ubuntu 22.04 provides it together with Python 3.10; the
+          # test tooling still relies on distutils and
+          # configparser.SafeConfigParser, which Python 3.12 removed.
+          - image: ubuntu:22.04
+            gcc: 10
+    defaults:
+      run:
+        shell: bash
+    env:
+      DEBIAN_FRONTEND: noninteractive
+    steps:
+      - name: Install build dependencies
+        run: |
+          apt-get update
+          apt-get install -y --no-install-recommends \
+            ca-certificates git make \
+            gcc-${{ matrix.gcc }} g++-${{ matrix.gcc }} \
+            gcc-${{ matrix.gcc }}-plugin-dev \
+            python3 python3-dev python-is-python3 \
+            python3-six python3-pygments python3-lxml graphviz
+          # Make plain "gcc" and "g++" refer to the GCC under test
+          update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-${{ matrix.gcc }} 100
+          update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-${{ matrix.gcc }} 100
+
+      - name: Check out the sources
+        uses: actions/checkout@v7
+
+      - name: Show the toolchain
+        run: |
+          gcc --version | head -n 1
+          python3 --version
+
+      - name: Build the plugin
+        # Serial build: the Makefile is not yet safe for "make -j"
+        run: make CC=gcc plugin
+
+      - name: Check that GCC loads the plugin
+        run: |
+          printf 'int main (void) { return 0; }\n' > ci-smoke.c
+          printf 'import gcc\nprint("gcc-python-plugin loaded")\n' > ci-smoke.py
+          LD_LIBRARY_PATH=gcc-c-api gcc -fplugin="$PWD/python.so" \
+            -fplugin-arg-python-script=ci-smoke.py -c ci-smoke.c -o /dev/null \
+            | tee ci-smoke.out
+          grep -q 'gcc-python-plugin loaded' ci-smoke.out
+
+      - name: Run the Python selftests
+        run: make CC=gcc testcpybuilder testdejagnu
+
+      - name: Run the test suite
+        # Some tests are expected to fail with current Python releases (for
+        # example, SyntaxError reports place the caret differently).  Report
+        # the results without failing the job until those are fixed.
+        continue-on-error: true
+        run: make CC=gcc test-suite

Makefile

@@ -83,19 +83,16 @@ GENERATOR_DEPS=cpybuilder.py wrapperbuilder.py print-gcc-version
 # as we're linking against, and that the cpychecker will be testing that same
 # version of Python
 #
-# By default, build against "python", using "python-config" to query for
+# By default, build against "python3", using "python3-config" to query for
 # compilation options.  You can override this by passing other values for
 # PYTHON and PYTHON_CONFIG when invoking "make" (or by simply hacking up this
 # file): e.g.
-#    make  PYTHON=python3  PYTHON_CONFIG=python3-config  all
+#    make  PYTHON=python3.12  PYTHON_CONFIG=python3.12-config  all
 
 # The python interpreter to use:
-PYTHON=python
+PYTHON=python3
 # The python-config executable to use:
-PYTHON_CONFIG=python-config
-
-#PYTHON=python3
-#PYTHON_CONFIG=python3-config
+PYTHON_CONFIG=python3-config
 
 #PYTHON=python-debug
 #PYTHON_CONFIG=python-debug-config

README.rst

@@ -28,17 +28,38 @@ The documentation can be seen at:
   http://gcc-python-plugin.readthedocs.io/en/latest/index.html
 
 
-Requirements
-------------
+Maintenance status
+------------------
+
+The plugin is being modernized and maintained at
+https://github.com/mmatti-sw/gcc-python-plugin.
+
+It was originally developed against GCC 4.6 through 8 and Python 2.7 and 3.x.
+That support is historical and is no longer maintained.
+
+GCC does not provide a stable plugin API: its internals change from one
+release to the next, so compatibility has to be established, and tested,
+separately for each GCC release.  Compatibility with current GCC releases is
+being re-established, and no GCC release is claimed as supported until the
+plugin has been built and its test suite run against it.  Verified GCC
+releases will be listed here.
 
-* GCC: 4.6 or later (it uses APIs that weren't exposed to plugins in 4.5)
+Python 3 is the maintenance target; Python 2 is no longer supported.
 
-  * tested with 4.8, 4.9, 5, 6, 7, and 8.
+x86_64 and ppc64le are the intended test platforms.
+
+
+Requirements
+------------
 
-* GCC plugin development package: usually available in distribution packages
-  such as ``gcc-N-plugin-dev`` or ``gcc-plugin-devel``.
+* GCC, with the plugin development headers for that exact GCC version: usually
+  available in distribution packages such as ``gcc-N-plugin-dev`` or
+  ``gcc-plugin-devel``.  The plugin is compiled as C++, so the matching C++
+  compiler (e.g. ``g++-N``) is needed as well.  See "Maintenance status" above
+  for which GCC releases have been verified.
 
-* Python: requires 2.7 or 3.2 or later
+* Python 3, with its development headers (e.g. ``python3-dev`` or
+  ``python3-devel``)
 
 * "six": The libcpychecker code uses the "six_" Python compatibility library to
   smooth over Python 2 vs Python 3 differences, both at build-time and
@@ -62,8 +83,8 @@ You can also use::
 
 to demonstrate the new compiler errors.
 
-Development has been on x86_64 and I don't know to what extent it will be
-compatible with other architectures.
+The plugin was originally developed on x86_64.  x86_64 and ppc64le are the
+intended test platforms; other architectures have not been verified.
 
 There isn't an installer yet.  In theory you should be able to add these
 arguments to the gcc invocation::

docs/basics.rst

@@ -23,9 +23,15 @@ Requirements
 
 The plugin has the following requirements:
 
-  * GCC: 4.6 or later (it uses APIs that weren't exposed to plugins in 4.5)
+  * GCC, with the plugin development headers for that exact GCC version
+    (e.g. the ``gcc-N-plugin-dev`` or ``gcc-plugin-devel`` package), and the
+    matching C++ compiler, since the plugin is compiled as C++.
 
-  * Python: requires 2.7 or 3.2 or later
+    GCC's internals change between releases, so compatibility is established
+    and tested separately for each GCC release.  Support for GCC 4.6 through
+    8 is historical; see the README for the GCC releases currently verified.
+
+  * Python 3, with its development headers.  Python 2 is no longer supported.
 
   * "six": The libcpychecker code uses the "six" Python compatibility library to
     smooth over Python 2 vs Python 3 differences, both at build-time and
@@ -79,15 +85,7 @@ On a Fedora box you can install them by running the following as root:
 
 .. code-block:: bash
 
-   yum install gcc-plugin-devel python-devel python-six python-pygments graphviz
-
-for building against Python 2, or:
-
-.. code-block:: bash
-
-   yum install gcc-plugin-devel python3-devel python3-six python3-pygments graphviz
-
-when building for Python 3.
+   dnf install gcc-c++ gcc-plugin-devel python3-devel python3-six python3-pygments graphviz
 
 Building the code
 ------------------
@@ -113,15 +111,14 @@ You can also use::
 
 to demonstrate the new compiler errors.
 
-By default, the `Makefile` builds the plugin using the first ``python-config``
-tool found in `$PATH` (e.g. `/usr/bin/python-config`), which is typically the
-system copy of Python 2.  You can override this (e.g. to build against
-Python 3) by overriding the `PYTHON` and `PYTHON_CONFIG` Makefile variables
-with:
+By default, the `Makefile` builds the plugin with the ``python3`` and
+``python3-config`` tools found in `$PATH`.  You can select a different Python 3
+installation by overriding the `PYTHON` and `PYTHON_CONFIG` Makefile variables,
+e.g.:
 
 .. code-block:: bash
 
-   make PYTHON=python3 PYTHON_CONFIG=python3-config
+   make PYTHON=python3.12 PYTHON_CONFIG=python3.12-config
 
 There isn't a well-defined process yet for installing the plugin (though the
 rpm specfile in the source tree contains some work-in-progress towards this).

gcc-python-callbacks.c

@@ -198,6 +198,24 @@ PyGcc_CallbackFor_tree(void *gcc_data, void *user_data)
 }
 
 
+static void
+PyGcc_CallbackFor_PLUGIN_INCLUDE_FILE(void *gcc_data, void *user_data)
+{
+    PyGILState_STATE gstate;
+    const char *filename = (const char *)gcc_data;
+    PyObject *filename_obj;
+
+    gstate = PyGILState_Ensure();
+
+    filename_obj = filename ? PyGccString_FromString(filename) : Py_None;
+    if (filename == NULL)
+        Py_INCREF(Py_None);
+
+    PyGcc_FinishInvokingCallback(gstate,
+                                        1, filename_obj,
+                                        user_data);
+}
+
 static void
 PyGcc_CallbackFor_PLUGIN_ATTRIBUTES(void *gcc_data, void *user_data)
 {
@@ -386,6 +404,30 @@ PyGcc_RegisterCallback(PyObject *self, PyObject *args, PyObject *kwargs)
 	break;
 #endif /* GCC_PYTHON_PLUGIN_CONFIG_has_PLUGIN_FINISH_DECL */
 
+    /* PLUGIN_START_PARSE_FUNCTION and PLUGIN_FINISH_PARSE_FUNCTION were
+       added in GCC 10; gcc_data is a tree (the function decl). */
+    case PLUGIN_START_PARSE_FUNCTION:
+        register_callback("python", // FIXME
+			  (enum plugin_event)event,
+                          PyGcc_CallbackFor_tree,
+			  closure);
+	break;
+
+    case PLUGIN_FINISH_PARSE_FUNCTION:
+        register_callback("python", // FIXME
+			  (enum plugin_event)event,
+                          PyGcc_CallbackFor_tree,
+			  closure);
+	break;
+
+    /* PLUGIN_INCLUDE_FILE: gcc_data is a const char* filename. */
+    case PLUGIN_INCLUDE_FILE:
+        register_callback("python", // FIXME
+			  (enum plugin_event)event,
+                          PyGcc_CallbackFor_PLUGIN_INCLUDE_FILE,
+			  closure);
+	break;
+
     default:
         PyErr_Format(PyExc_ValueError, "event type %i invalid (or not wired up yet)", event);
 	return NULL;

gcc-python-compat.h

@@ -61,8 +61,11 @@ dump_generic_node (pretty_printer *buffer, tree node, int spc, dump_flags_t flag
 		   bool is_stmt);
 #endif
 
-/* Within gcc/gcc-internal.h, not exposed by plugin API */
+/* Within gcc/gcc-internal.h, not exposed by plugin API.
+   Removed in GCC 12; replaced by ggc_collect(GGC_COLLECT_FORCE). */
+#if (GCC_VERSION < 12000)
 extern bool ggc_force_collect;
+#endif
 
 /* From c-family/c-common.h */
 #if GCC_VERSION < 4008

gcc-python-wrapper.c

@@ -337,11 +337,14 @@ PyGcc_wrapper_init(void)
 static void
 force_gcc_gc(void)
 {
+#if (GCC_VERSION >= 12000)
+    ggc_collect(GGC_COLLECT_FORCE);
+#else
     bool stored = ggc_force_collect;
-
     ggc_force_collect = true;
     ggc_collect();
     ggc_force_collect = stored;
+#endif
 }
 
 PyObject *