* [PATCH 2/2] analyzer: use ultimate alias target at calls (PR 93288)
2020-02-06 20:27 [PATCH 1/2] analyzer: g++ testsuite support David Malcolm
@ 2020-02-06 20:27 ` David Malcolm
2020-02-12 1:41 ` [PATCH 1/2] analyzer: g++ testsuite support Mike Stump
2020-02-13 7:11 ` testsuite: Fix g++.dg/analyzer/pr93212.C with check-c++-all Jakub Jelinek
2 siblings, 0 replies; 5+ messages in thread
From: David Malcolm @ 2020-02-06 20:27 UTC (permalink / raw)
To: gcc-patches; +Cc: David Malcolm
PR analyzer/93288 reports an ICE in a C++ testcase when calling a
constructor.
The issue is that when building the supergraph, we encounter the
cgraph edge to "__ct_comp ", the DECL_COMPLETE_CONSTRUCTOR_P, and
this node's DECL_STRUCT_FUNCTION has a NULL CFG, which the analyzer
reads through, leading to the ICE.
This patch reworks function and fndecl lookup at calls throughout the
analyzer so that it looks for the ultimate_alias_target of the callee.
In the case above, this means using the "__ct_base " for the ctor,
which has a CFG, fixing the ICE.
Getting this right allows for some simple C++ cases involving ctors to
work, so the patch also adds some test coverage for that.
Successfully bootstrapped & regrtested on x86_64-pc-linux-gnu.
gcc/analyzer/ChangeLog:
PR analyzer/93288
* analysis-plan.cc (analysis_plan::use_summary_p): Look through
the ultimate_alias_target when getting the called function.
* engine.cc (exploded_node::on_stmt): Rename second "ctxt" to
"sm_ctxt". Use the region_model's get_fndecl_for_call rather than
gimple_call_fndecl.
* region-model.cc (region_model::get_fndecl_for_call): Use
ultimate_alias_target on fndecl.
* supergraph.cc (get_ultimate_function_for_cgraph_edge): New
function.
(supergraph_call_edge): Use it when rejecting edges without
functions.
(supergraph::supergraph): Use it to get the function for the
cgraph_edge when building interprocedural superedges.
(callgraph_superedge::get_callee_function): Use it.
* supergraph.h (supergraph::get_num_snodes): Make param const.
(supergraph::function_to_num_snodes_t): Make first type param
const.
gcc/testsuite/ChangeLog:
PR analyzer/93288
* g++.dg/analyzer/malloc.C: Add test coverage for a double-free
called in a constructor.
* g++.dg/analyzer/pr93288.C: New test.
---
gcc/analyzer/analysis-plan.cc | 6 +++++-
gcc/analyzer/engine.cc | 12 +++++------
gcc/analyzer/region-model.cc | 5 ++++-
gcc/analyzer/supergraph.cc | 28 +++++++++++++++++++------
gcc/analyzer/supergraph.h | 4 ++--
gcc/testsuite/g++.dg/analyzer/malloc.C | 16 ++++++++++++++
gcc/testsuite/g++.dg/analyzer/pr93288.C | 8 +++++++
7 files changed, 63 insertions(+), 16 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/analyzer/pr93288.C
diff --git a/gcc/analyzer/analysis-plan.cc b/gcc/analyzer/analysis-plan.cc
index 8ad2fa2ebb4..3c8b10b3314 100644
--- a/gcc/analyzer/analysis-plan.cc
+++ b/gcc/analyzer/analysis-plan.cc
@@ -120,7 +120,11 @@ analysis_plan::use_summary_p (const cgraph_edge *edge) const
/* Require the callee to be sufficiently complex to be worth
summarizing. */
- if ((int)m_sg.get_num_snodes (callee->get_fun ())
+ const function *fun
+ = const_cast <cgraph_node *> (callee)->ultimate_alias_target ()->get_fun ();
+ /* TODO(stage1): can ultimate_alias_target be made const? */
+
+ if ((int)m_sg.get_num_snodes (fun)
< param_analyzer_min_snodes_for_call_summary)
return false;
diff --git a/gcc/analyzer/engine.cc b/gcc/analyzer/engine.cc
index 63579da953a..c4d7088d3e9 100644
--- a/gcc/analyzer/engine.cc
+++ b/gcc/analyzer/engine.cc
@@ -1044,19 +1044,19 @@ exploded_node::on_stmt (exploded_graph &eg,
const sm_state_map *old_smap
= old_state.m_checker_states[sm_idx];
sm_state_map *new_smap = state->m_checker_states[sm_idx];
- impl_sm_context ctxt (eg, sm_idx, sm, this, &old_state, state,
- change,
- old_smap, new_smap);
+ impl_sm_context sm_ctxt (eg, sm_idx, sm, this, &old_state, state,
+ change,
+ old_smap, new_smap);
/* Allow the state_machine to handle the stmt. */
- if (sm.on_stmt (&ctxt, snode, stmt))
+ if (sm.on_stmt (&sm_ctxt, snode, stmt))
unknown_side_effects = false;
else
{
/* For those stmts that were not handled by the state machine. */
if (const gcall *call = dyn_cast <const gcall *> (stmt))
{
- tree callee_fndecl = gimple_call_fndecl (call);
- // TODO: maybe we can be smarter about handling function pointers?
+ tree callee_fndecl
+ = state->m_region_model->get_fndecl_for_call (call, &ctxt);
if (!fndecl_has_gimple_body_p (callee_fndecl))
new_smap->purge_for_unknown_fncall (eg, sm, call, callee_fndecl,
diff --git a/gcc/analyzer/region-model.cc b/gcc/analyzer/region-model.cc
index 61390aa4cd1..0ae7536a032 100644
--- a/gcc/analyzer/region-model.cc
+++ b/gcc/analyzer/region-model.cc
@@ -6665,7 +6665,10 @@ region_model::get_fndecl_for_call (const gcall *call,
if (code)
{
tree fn_decl = code->get_tree_for_child_region (fn_rid);
- return fn_decl;
+ const cgraph_node *ultimate_node
+ = cgraph_node::get (fn_decl)->ultimate_alias_target ();
+ if (ultimate_node)
+ return ultimate_node->decl;
}
}
diff --git a/gcc/analyzer/supergraph.cc b/gcc/analyzer/supergraph.cc
index b20daa081d2..fb4dbdfd8b9 100644
--- a/gcc/analyzer/supergraph.cc
+++ b/gcc/analyzer/supergraph.cc
@@ -56,6 +56,18 @@ along with GCC; see the file COPYING3. If not see
namespace ana {
+/* Get the function of the ultimate alias target being called at EDGE,
+ if any. */
+
+static function *
+get_ultimate_function_for_cgraph_edge (cgraph_edge *edge)
+{
+ cgraph_node *ultimate_node = edge->callee->ultimate_alias_target ();
+ if (!ultimate_node)
+ return NULL;
+ return ultimate_node->get_fun ();
+}
+
/* Get the cgraph_edge, but only if there's an underlying function body. */
cgraph_edge *
@@ -69,7 +81,7 @@ supergraph_call_edge (function *fun, gimple *stmt)
return NULL;
if (!edge->callee)
return NULL; /* e.g. for a function pointer. */
- if (!edge->callee->get_fun ())
+ if (!get_ultimate_function_for_cgraph_edge (edge))
return NULL;
return edge;
}
@@ -178,8 +190,10 @@ supergraph::supergraph (logger *logger)
{
cgraph_edge *edge = (*iter).first;
supernode *caller_prev_supernode = (*iter).second;
- basic_block callee_cfg_block
- = ENTRY_BLOCK_PTR_FOR_FN (edge->callee->get_fun ());
+ function* callee_fn = get_ultimate_function_for_cgraph_edge (edge);
+ if (!callee_fn || !callee_fn->cfg)
+ continue;
+ basic_block callee_cfg_block = ENTRY_BLOCK_PTR_FOR_FN (callee_fn);
supernode *callee_supernode
= *m_bb_to_initial_node.get (callee_cfg_block);
call_superedge *sedge
@@ -199,8 +213,10 @@ supergraph::supergraph (logger *logger)
{
cgraph_edge *edge = (*iter).first;
supernode *caller_next_supernode = (*iter).second;
- basic_block callee_cfg_block
- = EXIT_BLOCK_PTR_FOR_FN (edge->callee->get_fun ());
+ function* callee_fn = get_ultimate_function_for_cgraph_edge (edge);
+ if (!callee_fn || !callee_fn->cfg)
+ continue;
+ basic_block callee_cfg_block = EXIT_BLOCK_PTR_FOR_FN (callee_fn);
supernode *callee_supernode
= *m_bb_to_initial_node.get (callee_cfg_block);
return_superedge *sedge
@@ -840,7 +856,7 @@ callgraph_superedge::dump_label_to_pp (pretty_printer *pp,
function *
callgraph_superedge::get_callee_function () const
{
- return m_cedge->callee->get_fun ();
+ return get_ultimate_function_for_cgraph_edge (m_cedge);
}
/* Get the calling function at this interprocedural call/return edge. */
diff --git a/gcc/analyzer/supergraph.h b/gcc/analyzer/supergraph.h
index 0eac0b8bfc9..2c94f0544ce 100644
--- a/gcc/analyzer/supergraph.h
+++ b/gcc/analyzer/supergraph.h
@@ -156,7 +156,7 @@ public:
return m_nodes[idx];
}
- unsigned get_num_snodes (function *fun) const
+ unsigned get_num_snodes (const function *fun) const
{
function_to_num_snodes_t &map
= const_cast <function_to_num_snodes_t &>(m_function_to_num_snodes);
@@ -201,7 +201,7 @@ private:
typedef ordered_hash_map<gimple *, supernode *> stmt_to_node_t;
stmt_to_node_t m_stmt_to_node_t;
- typedef hash_map<function *, unsigned> function_to_num_snodes_t;
+ typedef hash_map<const function *, unsigned> function_to_num_snodes_t;
function_to_num_snodes_t m_function_to_num_snodes;
};
diff --git a/gcc/testsuite/g++.dg/analyzer/malloc.C b/gcc/testsuite/g++.dg/analyzer/malloc.C
index 0637295e1f2..76baab98222 100644
--- a/gcc/testsuite/g++.dg/analyzer/malloc.C
+++ b/gcc/testsuite/g++.dg/analyzer/malloc.C
@@ -7,3 +7,19 @@ void test_1 (void *ptr)
free (ptr);
free (ptr); /* { dg-warning "double-'free' of 'ptr'" } */
}
+
+/* Test of double-free in ctor. */
+
+struct s2
+{
+ s2 (void *v)
+ {
+ free (v); // { dg-warning "double-'free' of 'v'" }
+ }
+};
+
+void test_2 (void *ptr)
+{
+ free (ptr); // { dg-message "first 'free' here" }
+ s2 a (ptr); // { dg-message "passing freed pointer 'ptr' in call to 's2::s2' from 'test_2'" }
+}
diff --git a/gcc/testsuite/g++.dg/analyzer/pr93288.C b/gcc/testsuite/g++.dg/analyzer/pr93288.C
new file mode 100644
index 00000000000..1798fed805f
--- /dev/null
+++ b/gcc/testsuite/g++.dg/analyzer/pr93288.C
@@ -0,0 +1,8 @@
+// { dg-do compile }
+
+struct a {
+ a();
+};
+class foo {
+ a b;
+} c;
--
2.21.0
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