cpychecker: get the checker working on C++ code

Attempting to run the checker on C++ code would fail: it could not locate any global declarations. The logic to locate them in gccutils (searching for blocks in the translation units) worked for C, but not for C++. For C++, we add a new function: gcc.get_global_namespace() to locate the gcc.NamespaceDecl for the "::" namespace, and add a lookup method to gcc.NamespaceDecl. We then use this for C++ to locate global declarations, enabling the checker to run. Also, introduce raise_cplusplus_only()
eevee · Mar 7, 2012 · 194c353 · 194c353
1 parent 02a0d59
commit 194c353
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Showing 12 changed files with 239 additions and 7 deletions.
diff --git a/docs/basics.rst b/docs/basics.rst
@@ -459,6 +459,11 @@ Global data access
 	       The source language of this translation unit, as a string
 	       (e.g. "GNU C")
 
+.. py:function:: gcc.get_global_namespace(name)
+
+      C++ only: locate the :py:class:`gcc.NamespaceDecl` for the global
+      namespace (a.k.a. "::")
+
 .. py:function:: gccutils.get_global_typedef(name)
 
       Given a string `name`, look for a C/C++ `typedef` in global scope with

diff --git a/docs/tree.rst b/docs/tree.rst
@@ -320,6 +320,15 @@ Declarations
 
       (boolean) Is this variable to be allocated with static storage?
 
+.. py:class:: gcc.NamespaceDecl
+
+   A subclass of :py:class:`gcc.Declaration` representing a C++ namespace
+
+   .. py:method:: locate(name)
+
+      Locate the given name within the namespace, returning a
+      :py:class:`gcc.Tree` or `None`
+
 
   ..        Declaration
   ..            ClassMethodDecl

diff --git a/gcc-python-tree.c b/gcc-python-tree.c
@@ -40,6 +40,16 @@
 
 __typeof__ (decl_as_string) decl_as_string __attribute__ ((weak));
 
+/* Similar for namespace_binding: */
+__typeof__ (namespace_binding) namespace_binding __attribute__ ((weak));
+
+static PyObject *
+raise_cplusplus_only(const char *what)
+{
+    return PyErr_Format(PyExc_RuntimeError,
+                        "%s is only available when compiling C++ code",
+                        what);
+}
 
 //#include "rtl.h"
 /*
@@ -191,8 +201,7 @@ gcc_FunctionDecl_get_fullname(struct PyGccTree *self, void *closure)
     const char *str;
 
     if (NULL == decl_as_string) {
-        return PyErr_Format(PyExc_RuntimeError,
-                            "attribute 'fullname' is only available when compiling C++ code");
+        return raise_cplusplus_only("attribute 'fullname'");
     }
 
     str = decl_as_string(self->t,
@@ -568,6 +577,34 @@ gcc_TreeList_repr(struct PyGccTree * self)
     return result;
 }
 
+
+PyObject *
+gcc_NamespaceDecl_lookup(struct PyGccTree * self, PyObject *args, PyObject *kwargs)
+{
+    tree t_result;
+    tree t_name;
+
+    const char *name;
+    char *keywords[] = {"name",
+                        NULL};
+
+
+    if (!PyArg_ParseTupleAndKeywords(args, kwargs,
+                                     "s:lookup", keywords,
+                                     &name)) {
+        return NULL;
+    }
+
+    if (NULL == namespace_binding) {
+        return raise_cplusplus_only("gcc.NamespaceDecl.lookup");
+    }
+
+    t_name = get_identifier(name);
+
+    t_result = namespace_binding(t_name, self->t);
+    return gcc_python_make_wrapper_tree(t_result);
+}
+
 /* 
    GCC's debug_tree is implemented in:
      gcc/print-tree.c

diff --git a/gcc-python-wrappers.h b/gcc-python-wrappers.h
@@ -182,6 +182,9 @@ gcc_TypeDecl_get_pointer(struct PyGccTree *self, void *closure);
 PyObject *
 gcc_TreeList_repr(struct PyGccTree * self);
 
+PyObject *
+gcc_NamespaceDecl_lookup(struct PyGccTree * self, PyObject *args, PyObject *kwargs);
+
 /* gcc-python-gimple.c: */
 PyObject *
 gcc_Gimple_repr(struct PyGccGimple * self);

diff --git a/gcc-python.c b/gcc-python.c
@@ -27,6 +27,7 @@ int plugin_is_GPL_compatible;
 
 #include "plugin-version.h"
 
+#include "cp/name-lookup.h" /* for global_namespace */
 #include "tree.h"
 #include "function.h"
 #include "diagnostic.h"
@@ -271,6 +272,17 @@ gcc_python_get_translation_units(PyObject *self, PyObject *args)
     return VEC_tree_as_PyList(all_translation_units);
 }
 
+/* Weakly import global_namespace; it will be non-NULL for the C++ frontend: */
+__typeof__ (global_namespace) global_namespace __attribute__ ((weak));
+
+static PyObject *
+gcc_python_get_global_namespace(PyObject *self, PyObject *args)
+{
+    /* (global_namespace will be NULL outside the C++ frontend, giving a
+       result of None) */
+    return gcc_python_make_wrapper_tree(global_namespace);
+}
+
 /* Dump files */
 
 static PyObject *
@@ -395,6 +407,9 @@ static PyMethodDef GccMethods[] = {
     {"get_translation_units", gcc_python_get_translation_units, METH_VARARGS,
      "Get a list of all gcc.TranslationUnitDecl"},
 
+    {"get_global_namespace", gcc_python_get_global_namespace, METH_VARARGS,
+     "C++: get the global namespace (aka '::') as a gcc.NamespaceDecl"},
+
     /* Version handling: */
     {"get_plugin_gcc_version", gcc_python_get_plugin_gcc_version, METH_VARARGS,
      "Get the gcc.Version that this plugin was compiled with"},

diff --git a/gccutils.py b/gccutils.py
@@ -35,10 +35,14 @@ def get_global_typedef(name):
     # Look up a typedef in global scope by name, returning a gcc.TypeDecl,
     # or None if not found
     for u in gcc.get_translation_units():
-        for v in u.block.vars:
-            if isinstance(v, gcc.TypeDecl):
-                if v.name == name:
-                    return v
+        if u.language == 'GNU C++':
+            gns = gcc.get_global_namespace()
+            return gns.lookup(name)
+        if u.block:
+            for v in u.block.vars:
+                if isinstance(v, gcc.TypeDecl):
+                    if v.name == name:
+                        return v
 
 def get_variables_as_dict():
     result = {}
@@ -50,6 +54,9 @@ def get_global_vardecl_by_name(name):
     # Look up a variable in global scope by name, returning a gcc.VarDecl,
     # or None if not found
     for u in gcc.get_translation_units():
+        if u.language == 'GNU C++':
+            gns = gcc.get_global_namespace()
+            return gns.lookup(name)
         for v in u.block.vars:
             if isinstance(v, gcc.VarDecl):
                 if v.name == name:

diff --git a/generate-tree-c.py b/generate-tree-c.py
@@ -314,6 +314,8 @@ def generate_tree_code_classes():
         tp_repr = None
         tp_str = None
 
+        methods = PyMethodTable('gcc_%s_methods' % cc, [])
+
         def get_getter_identifier(name):
             return 'gcc_%s_get_%s' % (cc, name)
 
@@ -472,6 +474,12 @@ def add_complex_getter(name, doc):
                               'gcc_tree_list_from_chain(BLOCK_VARS(self->t))',
                                "The list of gcc.Tree for the declarations and labels in this block")
 
+        if tree_type.SYM == 'NAMESPACE_DECL':
+            methods.add_method('lookup',
+                               '(PyCFunction)gcc_NamespaceDecl_lookup',
+                               'METH_VARARGS|METH_KEYWORDS',
+                               "Look up the given string within this namespace")
+
         if tree_type.SYM == 'TYPE_DECL':
             getsettable.add_gsdef('pointer',
                                   'gcc_TypeDecl_get_pointer',
@@ -542,7 +550,7 @@ def add_complex_getter(name, doc):
                               "The target of the case label, as a gcc.LabelDecl")
 
         cu.add_defn(getsettable.c_defn())
-
+        cu.add_defn(methods.c_defn())
         pytype = PyGccWrapperTypeObject(identifier = 'gcc_%sType' % cc,
                               localname = cc,
                               tp_name = 'gcc.%s' % cc,
@@ -552,6 +560,7 @@ def add_complex_getter(name, doc):
                               tp_getset = getsettable.identifier,
                               tp_str = tp_str,
                               tp_repr = tp_repr,
+                              tp_methods = methods.identifier,
                               )
         if tp_as_number:
             pytype.tp_as_number = '&%s' % tp_as_number

diff --git a/tests/cpychecker/refcounts/cplusplus/input.cc b/tests/cpychecker/refcounts/cplusplus/input.cc
@@ -0,0 +1,46 @@
+/*
+   Copyright 2012 David Malcolm <dmalcolm@redhat.com>
+   Copyright 2012 Red Hat, Inc.
+
+   This is free software: you can redistribute it and/or modify it
+   under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see
+   <http://www.gnu.org/licenses/>.
+*/
+
+#include <Python.h>
+
+/* Verify that the checker will run on C++ code */
+
+PyObject *
+test(int i)
+{
+    if (i) {
+        /* 
+           Verify that C++ frontend can locate globals
+           for types ("PyDict_Type") and exceptions (PyExc_MemoryError)
+        */
+        return PyDict_New();
+    } else {
+        /* Verify that bugs are reported: 
+           this code is missing a Py_INCREF on Py_None */
+        return Py_None;
+    }
+}
+
+/*
+  PEP-7
+Local variables:
+c-basic-offset: 4
+indent-tabs-mode: nil
+End:
+*/
diff --git a/tests/cpychecker/refcounts/cplusplus/metadata.ini b/tests/cpychecker/refcounts/cplusplus/metadata.ini
@@ -0,0 +1,3 @@
+[ExpectedBehavior]
+# We expect only compilation *warnings*, so we expect a 0 exit code
+exitcode = 0
diff --git a/tests/cpychecker/refcounts/cplusplus/script.py b/tests/cpychecker/refcounts/cplusplus/script.py
@@ -0,0 +1,22 @@
+# -*- coding: utf-8 -*-
+#   Copyright 2011 David Malcolm <dmalcolm@redhat.com>
+#   Copyright 2011 Red Hat, Inc.
+#
+#   This is free software: you can redistribute it and/or modify it
+#   under the terms of the GNU General Public License as published by
+#   the Free Software Foundation, either version 3 of the License, or
+#   (at your option) any later version.
+#
+#   This program is distributed in the hope that it will be useful, but
+#   WITHOUT ANY WARRANTY; without even the implied warranty of
+#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+#   General Public License for more details.
+#
+#   You should have received a copy of the GNU General Public License
+#   along with this program.  If not, see
+#   <http://www.gnu.org/licenses/>.
+
+from libcpychecker import main
+main(verify_refcounting=True,
+     dump_traces=True,
+     show_traces=False)
diff --git a/tests/cpychecker/refcounts/cplusplus/stderr.txt b/tests/cpychecker/refcounts/cplusplus/stderr.txt
@@ -0,0 +1,12 @@
+tests/cpychecker/refcounts/cplusplus/input.cc: In function 'PyObject* test(int)':
+tests/cpychecker/refcounts/cplusplus/input.cc:38:1: warning: ob_refcnt of return value is 1 too low [enabled by default]
+tests/cpychecker/refcounts/cplusplus/input.cc:38:1: note: was expecting final ob_refcnt to be N + 1 (for some unknown N)
+tests/cpychecker/refcounts/cplusplus/input.cc:38:1: note: due to object being referenced by: return value
+tests/cpychecker/refcounts/cplusplus/input.cc:38:1: note: but final ob_refcnt is N + 0
+tests/cpychecker/refcounts/cplusplus/input.cc:27:5: note: when considering value == (int)0 from tests/cpychecker/refcounts/cplusplus/input.cc:25 at:     if (i) {
+tests/cpychecker/refcounts/cplusplus/input.cc:27:5: note: taking False path at:     if (i) {
+tests/cpychecker/refcounts/cplusplus/input.cc:36:16: note: reaching:         return Py_None;
+tests/cpychecker/refcounts/cplusplus/input.cc:27:5: note: ob_refcnt is now refs: 0 + N where N >= 1
+tests/cpychecker/refcounts/cplusplus/input.cc:38:1: note: returning
+tests/cpychecker/refcounts/cplusplus/input.cc:38:1: note: consider using "Py_RETURN_NONE;"
+tests/cpychecker/refcounts/cplusplus/input.cc:26:1: note: graphical error report for function 'test' written out to 'tests/cpychecker/refcounts/cplusplus/input.cc.test-refcount-errors.html'
diff --git a/tests/cpychecker/refcounts/cplusplus/stdout.txt b/tests/cpychecker/refcounts/cplusplus/stdout.txt
@@ -0,0 +1,64 @@
+Trace 0:
+  Transitions:
+    'when considering range: -0x80000000 <= value <= -1'
+    'taking True path'
+    'when PyDict_New() succeeds'
+    'returning'
+  Return value:
+    repr(): PointerToRegion(gcctype='struct PyObject *', loc=gcc.Location(file='tests/cpychecker/refcounts/cplusplus/input.cc', line=32), region=RegionOnHeap('PyDictObject', gcc.Location(file='tests/cpychecker/refcounts/cplusplus/input.cc', line=32)))
+    str(): (struct PyObject *)&RegionOnHeap('PyDictObject', gcc.Location(file='tests/cpychecker/refcounts/cplusplus/input.cc', line=32)) from tests/cpychecker/refcounts/cplusplus/input.cc:32
+    r->ob_refcnt: refs: 1 + N where N >= 0
+    r->ob_type: PointerToRegion(gcctype='struct PyTypeObject *', loc=gcc.Location(file='tests/cpychecker/refcounts/cplusplus/input.cc', line=32), region=RegionForGlobal(gcc.VarDecl('PyDict_Type')))
+  Exception:
+    (struct PyObject *)0 from tests/cpychecker/refcounts/cplusplus/input.cc:26
+
+Trace 1:
+  Transitions:
+    'when considering range: -0x80000000 <= value <= -1'
+    'taking True path'
+    'when PyDict_New() fails'
+    'returning'
+  Return value:
+    repr(): ConcreteValue(gcctype='struct PyObject *', loc=gcc.Location(file='tests/cpychecker/refcounts/cplusplus/input.cc', line=32), value=0)
+    str(): (struct PyObject *)0 from tests/cpychecker/refcounts/cplusplus/input.cc:32
+  Exception:
+    (struct PyObject *)&RegionForGlobal(gcc.VarDecl('PyExc_MemoryError')) from tests/cpychecker/refcounts/cplusplus/input.cc:32
+
+Trace 2:
+  Transitions:
+    'when considering value == (int)0 from tests/cpychecker/refcounts/cplusplus/input.cc:25'
+    'taking False path'
+    'returning'
+  Return value:
+    repr(): PointerToRegion(gcctype='struct PyObject *', loc=gcc.Location(file='tests/cpychecker/refcounts/cplusplus/input.cc', line=36), region=RegionForGlobal(gcc.VarDecl('_Py_NoneStruct')))
+    str(): (struct PyObject *)&RegionForGlobal(gcc.VarDecl('_Py_NoneStruct')) from tests/cpychecker/refcounts/cplusplus/input.cc:36
+    r->ob_refcnt: refs: 0 + N where N >= 1
+    r->ob_type: None
+  Exception:
+    (struct PyObject *)0 from tests/cpychecker/refcounts/cplusplus/input.cc:26
+
+Trace 3:
+  Transitions:
+    'when considering range: 1 <= value <= 0x7fffffff'
+    'taking True path'
+    'when PyDict_New() succeeds'
+    'returning'
+  Return value:
+    repr(): PointerToRegion(gcctype='struct PyObject *', loc=gcc.Location(file='tests/cpychecker/refcounts/cplusplus/input.cc', line=32), region=RegionOnHeap('PyDictObject', gcc.Location(file='tests/cpychecker/refcounts/cplusplus/input.cc', line=32)))
+    str(): (struct PyObject *)&RegionOnHeap('PyDictObject', gcc.Location(file='tests/cpychecker/refcounts/cplusplus/input.cc', line=32)) from tests/cpychecker/refcounts/cplusplus/input.cc:32
+    r->ob_refcnt: refs: 1 + N where N >= 0
+    r->ob_type: PointerToRegion(gcctype='struct PyTypeObject *', loc=gcc.Location(file='tests/cpychecker/refcounts/cplusplus/input.cc', line=32), region=RegionForGlobal(gcc.VarDecl('PyDict_Type')))
+  Exception:
+    (struct PyObject *)0 from tests/cpychecker/refcounts/cplusplus/input.cc:26
+
+Trace 4:
+  Transitions:
+    'when considering range: 1 <= value <= 0x7fffffff'
+    'taking True path'
+    'when PyDict_New() fails'
+    'returning'
+  Return value:
+    repr(): ConcreteValue(gcctype='struct PyObject *', loc=gcc.Location(file='tests/cpychecker/refcounts/cplusplus/input.cc', line=32), value=0)
+    str(): (struct PyObject *)0 from tests/cpychecker/refcounts/cplusplus/input.cc:32
+  Exception:
+    (struct PyObject *)&RegionForGlobal(gcc.VarDecl('PyExc_MemoryError')) from tests/cpychecker/refcounts/cplusplus/input.cc:32