On Tue, 2023-08-01 at 09:52 -0400, Eric Feng wrote:
> Hi all,
>
> This patch adds a hook to the end of ana::on_finish_translation_unit
> which calls relevant stashing-related callbacks registered during
> plugin
> initialization. This feature is used to stash named types and global
> variables for a CPython analyzer plugin [PR107646].
>
> Bootstrapped and tested on aarch64-unknown-linux-gnu. Does it look
> okay?
Hi Eric, thanks for the patch.
The patch touches the C frontend, so those parts would need approval
from the C FE maintainers/reviewers; I've CCed them.
Overall, I like the patch, but it's not ready for trunk yet; various
comments inline below...
>
> ---
>
> gcc/analyzer/ChangeLog:
You could add: PR analyzer/107646 to these ChangeLog entries; have a
look at how other ChangeLog entries refer to such bugzilla entries.
>
> * analyzer-language.cc (run_callbacks): New function.
> (on_finish_translation_unit): New function.
> * analyzer-language.h (GCC_ANALYZER_LANGUAGE_H): New include.
> (class translation_unit): New vfuncs.
>
> gcc/c/ChangeLog:
>
> * c-parser.cc: New functions.
I think this ChangeLog entry needs more detail.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.dg/plugin/analyzer_cpython_plugin.c: New test.
>
> Signed-off-by: Eric Feng <ef2...@columbia.edu>
> ---
> gcc/analyzer/analyzer-language.cc | 22 ++
> gcc/analyzer/analyzer-language.h | 9 +
> gcc/c/c-parser.cc | 26 ++
> .../gcc.dg/plugin/analyzer_cpython_plugin.c | 224
> ++++++++++++++++++
> 4 files changed, 281 insertions(+)
> create mode 100644
> gcc/testsuite/gcc.dg/plugin/analyzer_cpython_plugin.c
>
> diff --git a/gcc/analyzer/analyzer-language.cc
> b/gcc/analyzer/analyzer-language.cc
> index 2c8910906ee..fc41b9c17b8 100644
> --- a/gcc/analyzer/analyzer-language.cc
> +++ b/gcc/analyzer/analyzer-language.cc
> @@ -35,6 +35,26 @@ static GTY (()) hash_map <tree, tree>
> *analyzer_stashed_constants;
> #if ENABLE_ANALYZER
>
> namespace ana {
> +static vec<finish_translation_unit_callback>
> + *finish_translation_unit_callbacks;
> +
> +void
> +register_finish_translation_unit_callback (
> + finish_translation_unit_callback callback)
> +{
> + if (!finish_translation_unit_callbacks)
> + vec_alloc (finish_translation_unit_callbacks, 1);
> + finish_translation_unit_callbacks->safe_push (callback);
> +}
> +
> +void
> +run_callbacks (logger *logger, const translation_unit &tu)
This function could be "static" since it's not needed outside of
analyzer-language.cc
> +{
> + for (auto const &cb : finish_translation_unit_callbacks)
> + {
> + cb (logger, tu);
> + }
> +}
>
> /* Call into TU to try to find a value for NAME.
> If found, stash its value within analyzer_stashed_constants. */
> @@ -102,6 +122,8 @@ on_finish_translation_unit (const
> translation_unit &tu)
> the_logger.set_logger (new logger (logfile, 0, 0,
> *global_dc->printer));
> stash_named_constants (the_logger.get_logger (), tu);
> +
> + run_callbacks (the_logger.get_logger (), tu);
> }
>
> /* Lookup NAME in the named constants stashed when the frontend TU
> finished.
> diff --git a/gcc/analyzer/analyzer-language.h
> b/gcc/analyzer/analyzer-language.h
> index 00f85aba041..8deea52d627 100644
> --- a/gcc/analyzer/analyzer-language.h
> +++ b/gcc/analyzer/analyzer-language.h
> @@ -21,6 +21,8 @@ along with GCC; see the file COPYING3. If not see
> #ifndef GCC_ANALYZER_LANGUAGE_H
> #define GCC_ANALYZER_LANGUAGE_H
>
> +#include "analyzer/analyzer-logging.h"
> +
> #if ENABLE_ANALYZER
>
> namespace ana {
> @@ -35,8 +37,15 @@ class translation_unit
> have been seen). If it is defined and an integer (e.g. either
> as a
> macro or enum), return the INTEGER_CST value, otherwise return
> NULL. */
> virtual tree lookup_constant_by_id (tree id) const = 0;
> + virtual tree lookup_type_by_id (tree id) const = 0;
> + virtual tree lookup_global_var_by_id (tree id) const = 0;
> };
>
> +typedef void (*finish_translation_unit_callback)
> + (logger *, const translation_unit &);
> +void register_finish_translation_unit_callback (
> + finish_translation_unit_callback callback);
> +
> /* Analyzer hook for frontends to call at the end of the TU. */
>
> void on_finish_translation_unit (const translation_unit &tu);
> diff --git a/gcc/c/c-parser.cc b/gcc/c/c-parser.cc
> index 80920b31f83..f0ee55e416b 100644
> --- a/gcc/c/c-parser.cc
> +++ b/gcc/c/c-parser.cc
> @@ -1695,6 +1695,32 @@ public:
> return NULL_TREE;
> }
>
> + tree
> + lookup_type_by_id (tree id) const final override
> + {
> + if (tree type_decl = lookup_name (id))
> + {
> + if (TREE_CODE (type_decl) == TYPE_DECL)
> + {
> + tree record_type = TREE_TYPE (type_decl);
> + if (TREE_CODE (record_type) == RECORD_TYPE)
> + return record_type;
> + }
It looks like something's wrong with the indentation here, but the idea
seems OK to me (but needs C FE reviewer approval).
> + }
> +
> + return NULL_TREE;
> + }
> +
> + tree
> + lookup_global_var_by_id (tree id) const final override
> + {
> + if (tree var_decl = lookup_name (id))
> + if (TREE_CODE (var_decl) == VAR_DECL)
> + return var_decl;
Likewise, is this indentation correct?
> +
> + return NULL_TREE;
> + }
> +
> private:
> /* Attempt to get an INTEGER_CST from MACRO.
> Only handle the simplest cases: where MACRO's definition is a
> single
> diff --git a/gcc/testsuite/gcc.dg/plugin/analyzer_cpython_plugin.c
> b/gcc/testsuite/gcc.dg/plugin/analyzer_cpython_plugin.c
> new file mode 100644
> index 00000000000..285da102edb
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/plugin/analyzer_cpython_plugin.c
> @@ -0,0 +1,224 @@
> +/* -fanalyzer plugin for CPython extension modules */
> +/* { dg-options "-g" } */
> +
> +#define INCLUDE_MEMORY
> +#include "gcc-plugin.h"
> +#include "config.h"
> +#include "system.h"
> +#include "coretypes.h"
> +#include "tree.h"
> +#include "function.h"
> +#include "basic-block.h"
> +#include "gimple.h"
> +#include "gimple-iterator.h"
> +#include "diagnostic-core.h"
> +#include "graphviz.h"
> +#include "options.h"
> +#include "cgraph.h"
> +#include "tree-dfa.h"
> +#include "stringpool.h"
> +#include "convert.h"
> +#include "target.h"
> +#include "fold-const.h"
> +#include "tree-pretty-print.h"
> +#include "diagnostic-color.h"
> +#include "diagnostic-metadata.h"
> +#include "tristate.h"
> +#include "bitmap.h"
> +#include "selftest.h"
> +#include "function.h"
> +#include "json.h"
> +#include "analyzer/analyzer.h"
> +#include "analyzer/analyzer-language.h"
> +#include "analyzer/analyzer-logging.h"
> +#include "ordered-hash-map.h"
> +#include "options.h"
> +#include "cgraph.h"
> +#include "cfg.h"
> +#include "digraph.h"
> +#include "analyzer/supergraph.h"
> +#include "sbitmap.h"
> +#include "analyzer/call-string.h"
> +#include "analyzer/program-point.h"
> +#include "analyzer/store.h"
> +#include "analyzer/region-model.h"
> +#include "analyzer/call-details.h"
> +#include "analyzer/call-info.h"
> +#include "make-unique.h"
> +
> +int plugin_is_GPL_compatible;
> +
> +#if ENABLE_ANALYZER
> +static GTY (()) hash_map<tree, tree> *analyzer_stashed_types;
> +static GTY (()) hash_map<tree, tree> *analyzer_stashed_globals;
> +
> +namespace ana
> +{
> +static tree pyobj_record = NULL_TREE;
> +static tree varobj_record = NULL_TREE;
> +static tree pylistobj_record = NULL_TREE;
> +static tree pylongobj_record = NULL_TREE;
> +static tree pylongtype_vardecl = NULL_TREE;
> +static tree pylisttype_vardecl = NULL_TREE;
> +
> +tree
> +get_field_by_name (tree type, const char *name)
> +{
> + for (tree field = TYPE_FIELDS (type); field; field = TREE_CHAIN
> (field))
> + {
> + if (TREE_CODE (field) == FIELD_DECL)
> + {
> + const char *field_name = IDENTIFIER_POINTER (DECL_NAME
> (field));
> + if (strcmp (field_name, name) == 0)
> + return field;
> + }
> + }
> + return NULL_TREE;
> +}
> +
> +static void
> +maybe_stash_named_type (logger *logger, const translation_unit &tu,
> + const char *name)
> +{
> + LOG_FUNC_1 (logger, "name: %qs", name);
> + if (!analyzer_stashed_types)
> + analyzer_stashed_types = hash_map<tree, tree>::create_ggc ();
> +
> + tree id = get_identifier (name);
> + if (tree t = tu.lookup_type_by_id (id))
> + {
> + gcc_assert (TREE_CODE (t) == RECORD_TYPE);
> + analyzer_stashed_types->put (id, t);
> + if (logger)
> + logger->log ("found %qs: %qE", name, t);
> + }
> + else
> + {
> + if (logger)
> + logger->log ("%qs: not found", name);
> + }
> +}
> +
> +static void
> +maybe_stash_global_var (logger *logger, const translation_unit &tu,
> + const char *name)
> +{
> + LOG_FUNC_1 (logger, "name: %qs", name);
> + if (!analyzer_stashed_globals)
> + analyzer_stashed_globals = hash_map<tree, tree>::create_ggc ();
> +
> + tree id = get_identifier (name);
> + if (tree t = tu.lookup_global_var_by_id (id))
> + {
> + gcc_assert (TREE_CODE (t) == VAR_DECL);
> + analyzer_stashed_globals->put (id, t);
> + if (logger)
> + logger->log ("found %qs: %qE", name, t);
> + }
> + else
> + {
> + if (logger)
> + logger->log ("%qs: not found", name);
> + }
> +}
> +
> +static void
> +stash_named_types (logger *logger, const translation_unit &tu)
> +{
> + LOG_SCOPE (logger);
> +
> + maybe_stash_named_type (logger, tu, "PyObject");
> + maybe_stash_named_type (logger, tu, "PyListObject");
> + maybe_stash_named_type (logger, tu, "PyVarObject");
> + maybe_stash_named_type (logger, tu, "PyLongObject");
> +}
> +
> +static void
> +stash_global_vars (logger *logger, const translation_unit &tu)
> +{
> + LOG_SCOPE (logger);
> +
> + maybe_stash_global_var (logger, tu, "PyLong_Type");
> + maybe_stash_global_var (logger, tu, "PyList_Type");
> +}
> +
> +tree
> +get_stashed_type_by_name (const char *name)
> +{
> + if (!analyzer_stashed_types)
> + return NULL_TREE;
> + tree id = get_identifier (name);
> + if (tree *slot = analyzer_stashed_types->get (id))
> + {
> + gcc_assert (TREE_CODE (*slot) == RECORD_TYPE);
> + return *slot;
> + }
> + return NULL_TREE;
> +}
> +
> +tree
> +get_stashed_global_var_by_name (const char *name)
> +{
> + if (!analyzer_stashed_globals)
> + return NULL_TREE;
> + tree id = get_identifier (name);
> + if (tree *slot = analyzer_stashed_globals->get (id))
> + {
> + gcc_assert (TREE_CODE (*slot) == VAR_DECL);
> + return *slot;
> + }
> + return NULL_TREE;
> +}
> +
> +static void
> +init_py_structs ()
> +{
> + if (pyobj_record == NULL_TREE)
> + pyobj_record = get_stashed_type_by_name ("PyObject");
This function is called once as the plugin starts up, so I don't think
we need the various comparisons against NULL_TREE here. Or am I
missing something?
> + if (varobj_record == NULL_TREE)
> + varobj_record = get_stashed_type_by_name ("PyVarObject");
> + if (pylistobj_record == NULL_TREE)
> + pylistobj_record = get_stashed_type_by_name ("PyListObject");
> + if (pylongobj_record == NULL_TREE)
> + pylongobj_record = get_stashed_type_by_name ("PyLongObject");
> + if (pylongtype_vardecl == NULL_TREE)
> + pylongtype_vardecl = get_stashed_global_var_by_name
> ("PyLong_Type");
> + if (pylisttype_vardecl == NULL_TREE)
> + pylisttype_vardecl = get_stashed_global_var_by_name
> ("PyList_Type");
> +}
> +
> +static void
> +cpython_analyzer_init_cb (void *gcc_data, void * /*user_data */)
> +{
> + ana::plugin_analyzer_init_iface *iface
> + = (ana::plugin_analyzer_init_iface *)gcc_data;
> + LOG_SCOPE (iface->get_logger ());
> + if (1)
> + inform (input_location, "got here: cpython_analyzer_init_cb");
We don't want that debugging "inform", or, at least, not on by default.
> +
> + init_py_structs ();
> + if (pyobj_record == NULL_TREE)
> + return;
This conditional doesn't make much sense as-is, but presumably you're
going to use it to eventually conditionalize the rest of the plugin
startup, right?
> +}
> +} // namespace ana
> +
> +#endif /* #if ENABLE_ANALYZER */
> +
> +int
> +plugin_init (struct plugin_name_args *plugin_info,
> + struct plugin_gcc_version *version)
> +{
> +#if ENABLE_ANALYZER
> + const char *plugin_name = plugin_info->base_name;
> + if (1)
> + inform (input_location, "got here; %qs", plugin_name);
Another debugging "inform" that we don't want on by default when
running the tests.
> + ana::register_finish_translation_unit_callback
> (&stash_named_types);
> + ana::register_finish_translation_unit_callback
> (&stash_global_vars);
> + register_callback (plugin_info->base_name, PLUGIN_ANALYZER_INIT,
> + ana::cpython_analyzer_init_cb,
> + NULL); /* void *user_data */
> +#else
> + sorry_no_analyzer ();
> +#endif
> + return 0;
> +}
> \ No newline at end of file
The patch doesn't touch plugin.exp, so this plugin won't actually get
compiled yet as part of the testsuite; I think we need a change to
plugin.exp. You could add a minimal nonempty source file to be
compiled with the plugin (to test the "gracefully handling non-CPython
code" case).
Hope this is constructive; sorry if it comes across as nitpicky in
places (patch review tends to)
Dave
