analyzer: remove add_any_constraints_from_ssa_def_stmt

I'm working on reimplementing -Wanalyzer-use-of-uninitialized-value, but
I ran into issues with
region_model::add_any_constraints_from_ssa_def_stmt.
This function is from the initial commit of the analyzer and walks the
SSA names finding conditions that were missed due to the GCC 10 era
region_model not retaining useful information on how values were
created; as of GCC 11 the symbolic values contain this information,
and so the conditions can be reconstructed from them instead.

region_model::add_any_constraints_from_ssa_def_stmt is a liability
when tracking uninitialized values as it requires looking up SSA
values when those values may have been purged, thus greatly complicating
detection of uses of uninitialized values.

It's simplest to eliminate it and reimplement the condition-finding
via the makeup of the svalues, which this patch does.  Doing so requires
supporting add_condition on svalues rather than just on trees, which
requires some changes to ana::state_machine and its subclasses.

gcc/analyzer/ChangeLog:
	* diagnostic-manager.cc (null_assignment_sm_context::get_state):
	New overload.
	(null_assignment_sm_context::set_next_state): New overload.
	(null_assignment_sm_context::get_diagnostic_tree): New.
	* engine.cc (impl_sm_context::get_state): New overload.
	(impl_sm_context::set_next_state): New overload.
	(impl_sm_context::get_diagnostic_tree): New overload.
	(impl_region_model_context::on_condition): Convert params from
	tree to const svalue *.
	* exploded-graph.h (impl_region_model_context::on_condition):
	Likewise.
	* region-model.cc (region_model::on_call_pre): Move handling of
	internal calls to before checking for get_fndecl_for_call.
	(region_model::add_constraints_from_binop): New.
	(region_model::add_constraint): Split out into a new overload
	working on const svalue * rather than tree.  Call
	add_constraints_from_binop.  Drop call to
	add_any_constraints_from_ssa_def_stmt.
	(region_model::add_any_constraints_from_ssa_def_stmt): Delete.
	(region_model::add_any_constraints_from_gassign): Delete.
	(region_model::add_any_constraints_from_gcall): Delete.
	* region-model.h
	(region_model::add_any_constraints_from_ssa_def_stmt): Delete.
	(region_model::add_any_constraints_from_gassign): Delete.
	(region_model::add_any_constraints_from_gcall): Delete.
	(region_model::add_constraint): Add overload decl.
	(region_model::add_constraints_from_binop): New decl.
	(region_model_context::on_condition): Convert params from tree to
	const svalue *.
	(noop_region_model_context::on_condition): Likewise.
	* sm-file.cc (fileptr_state_machine::condition): Likewise.
	* sm-malloc.cc (malloc_state_machine::on_condition): Likewise.
	* sm-pattern-test.cc: Include tristate.h, selftest.h,
	analyzer/call-string.h, analyzer/program-point.h,
	analyzer/store.h, and analyzer/region-model.h.
	(pattern_test_state_machine::on_condition): Convert params from tree to
	const svalue *.
	* sm-sensitive.cc (sensitive_state_machine::on_condition): Delete.
	* sm-signal.cc (signal_state_machine::on_condition): Delete.
	* sm-taint.cc (taint_state_machine::on_condition): Convert params
	from tree to const svalue *.
	* sm.cc: Include tristate.h, selftest.h, analyzer/call-string.h,
	analyzer/program-point.h, analyzer/store.h, and
	analyzer/region-model.h.
	(any_pointer_p): Add overload taking const svalue *sval.
	* sm.h (any_pointer_p): Add overload taking const svalue *sval.
	(state_machine::on_condition): Convert params from tree to
	const svalue *.  Provide no-op default implementation.
	(sm_context::get_state): Add overload taking const svalue *sval.
	(sm_context::set_next_state): Likewise.
	(sm_context::on_transition): Likewise.
	(sm_context::get_diagnostic_tree): Likewise.
	* svalue.cc (svalue::all_zeroes_p): New.
	(constant_svalue::all_zeroes_p): New.
	(repeated_svalue::all_zeroes_p): Convert to vfunc.
	* svalue.h (svalue::all_zeroes_p): New decl.
	(constant_svalue::all_zeroes_p): New decl.
	(repeated_svalue::all_zeroes_p): Convert decl to vfunc.

gcc/testsuite/ChangeLog:
	* gcc.dg/analyzer/pattern-test-2.c: Update expected results.
	* gcc.dg/plugin/analyzer_gil_plugin.c
	(gil_state_machine::on_condition): Remove.

Signed-off-by: David Malcolm <dmalcolm@redhat.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/gcc/analyzer/svalue.h b/gcc/analyzer/svalue.h
index 3965a5f..5552fcf 100644
--- a/gcc/analyzer/svalue.h
+++ b/gcc/analyzer/svalue.h
@@ -157,6 +157,8 @@ public:
 			  const bit_range &subrange,
 			  region_model_manager *mgr) const;
 
+  virtual bool all_zeroes_p () const;
+
  protected:
   svalue (complexity c, tree type)
   : m_complexity (c), m_type (type)
@@ -277,6 +279,8 @@ public:
 			  const bit_range &subrange,
 			  region_model_manager *mgr) const FINAL OVERRIDE;
 
+  bool all_zeroes_p () const FINAL OVERRIDE;
+
  private:
   tree m_cst_expr;
 };
@@ -858,7 +862,7 @@ public:
   const svalue *get_outer_size () const { return m_outer_size; }
   const svalue *get_inner_svalue () const { return m_inner_svalue; }
 
-  bool all_zeroes_p () const;
+  bool all_zeroes_p () const FINAL OVERRIDE;
 
   const svalue *
   maybe_fold_bits_within (tree type,