/* Regions of memory.
- Copyright (C) 2019-2022 Free Software Foundation, Inc.
+ Copyright (C) 2019-2024 Free Software Foundation, Inc.
Contributed by David Malcolm <dmalcolm@redhat.com>.
This file is part of GCC.
#include "fold-const.h"
#include "tree-pretty-print.h"
#include "diagnostic-color.h"
-#include "diagnostic-metadata.h"
#include "bitmap.h"
#include "analyzer/analyzer.h"
#include "analyzer/analyzer-logging.h"
namespace ana {
-/* class region and its various subclasses. */
+region_offset
+region_offset::make_byte_offset (const region *base_region,
+ const svalue *num_bytes_sval)
+{
+ if (tree num_bytes_cst = num_bytes_sval->maybe_get_constant ())
+ {
+ gcc_assert (TREE_CODE (num_bytes_cst) == INTEGER_CST);
+ bit_offset_t num_bits = wi::to_offset (num_bytes_cst) * BITS_PER_UNIT;
+ return make_concrete (base_region, num_bits);
+ }
+ else
+ {
+ return make_symbolic (base_region, num_bytes_sval);
+ }
+}
-/* class region. */
+tree
+region_offset::calc_symbolic_bit_offset (const region_model &model) const
+{
+ if (symbolic_p ())
+ {
+ tree num_bytes_expr = model.get_representative_tree (m_sym_offset);
+ if (!num_bytes_expr)
+ return NULL_TREE;
+ tree bytes_to_bits_scale = build_int_cst (size_type_node, BITS_PER_UNIT);
+ return fold_build2 (MULT_EXPR, size_type_node,
+ num_bytes_expr, bytes_to_bits_scale);
+ }
+ else
+ {
+ tree cst = wide_int_to_tree (size_type_node, m_offset);
+ return cst;
+ }
+}
-region::~region ()
+const svalue *
+region_offset::calc_symbolic_byte_offset (region_model_manager *mgr) const
{
- delete m_cached_offset;
+ if (symbolic_p ())
+ return m_sym_offset;
+ else
+ {
+ byte_offset_t concrete_byte_offset;
+ if (get_concrete_byte_offset (&concrete_byte_offset))
+ return mgr->get_or_create_int_cst (size_type_node,
+ concrete_byte_offset);
+ else
+ /* Can't handle bitfields; return UNKNOWN. */
+ return mgr->get_or_create_unknown_svalue (size_type_node);
+ }
}
-/* Compare REG1 and REG2 by id. */
+void
+region_offset::dump_to_pp (pretty_printer *pp, bool simple) const
+{
+ if (symbolic_p ())
+ {
+ /* We don't bother showing the base region. */
+ pp_string (pp, "byte ");
+ m_sym_offset->dump_to_pp (pp, simple);
+ }
+ else
+ {
+ if (m_offset % BITS_PER_UNIT == 0)
+ {
+ pp_string (pp, "byte ");
+ pp_wide_int (pp, m_offset / BITS_PER_UNIT, SIGNED);
+ }
+ else
+ {
+ pp_string (pp, "bit ");
+ pp_wide_int (pp, m_offset, SIGNED);
+ }
+ }
+}
-int
-region::cmp_ids (const region *reg1, const region *reg2)
+DEBUG_FUNCTION void
+region_offset::dump (bool simple) const
{
- return (long)reg1->get_id () - (long)reg2->get_id ();
+ pretty_printer pp;
+ pp_format_decoder (&pp) = default_tree_printer;
+ pp_show_color (&pp) = pp_show_color (global_dc->printer);
+ pp.buffer->stream = stderr;
+ dump_to_pp (&pp, simple);
+ pp_newline (&pp);
+ pp_flush (&pp);
+}
+
+/* An svalue that matches the pattern (BASE * FACTOR) + OFFSET
+ where FACTOR or OFFSET could be the identity (represented as NULL). */
+
+struct linear_op
+{
+ linear_op (const svalue *base,
+ const svalue *factor,
+ const svalue *offset)
+ : m_base (base), m_factor (factor), m_offset (offset)
+ {
+ }
+
+ bool maybe_get_cst_factor (bit_offset_t *out) const
+ {
+ if (m_factor == nullptr)
+ {
+ *out = 1;
+ return true;
+ }
+ if (tree cst_factor = m_factor->maybe_get_constant ())
+ {
+ *out = wi::to_offset (cst_factor);
+ return true;
+ }
+ return false;
+ }
+
+ bool maybe_get_cst_offset (bit_offset_t *out) const
+ {
+ if (m_offset == nullptr)
+ {
+ *out = 0;
+ return true;
+ }
+ if (tree cst_offset = m_offset->maybe_get_constant ())
+ {
+ *out = wi::to_offset (cst_offset);
+ return true;
+ }
+ return false;
+ }
+
+ static tristate
+ less (const linear_op &a, const linear_op &b)
+ {
+ /* Same base. */
+ if (a.m_base == b.m_base)
+ {
+ bit_offset_t a_wi_factor;
+ bit_offset_t b_wi_factor;
+ if (a.maybe_get_cst_factor (&a_wi_factor)
+ && b.maybe_get_cst_factor (&b_wi_factor))
+ {
+ if (a_wi_factor != b_wi_factor)
+ return tristate (a_wi_factor < b_wi_factor);
+ else
+ {
+ bit_offset_t a_wi_offset;
+ bit_offset_t b_wi_offset;
+ if (a.maybe_get_cst_offset (&a_wi_offset)
+ && b.maybe_get_cst_offset (&b_wi_offset))
+ return tristate (a_wi_offset < b_wi_offset);
+ }
+ }
+ }
+ return tristate::unknown ();
+ }
+
+ static tristate
+ le (const linear_op &a, const linear_op &b)
+ {
+ /* Same base. */
+ if (a.m_base == b.m_base)
+ {
+ bit_offset_t a_wi_factor;
+ bit_offset_t b_wi_factor;
+ if (a.maybe_get_cst_factor (&a_wi_factor)
+ && b.maybe_get_cst_factor (&b_wi_factor))
+ {
+ if (a_wi_factor != b_wi_factor)
+ return tristate (a_wi_factor <= b_wi_factor);
+ else
+ {
+ bit_offset_t a_wi_offset;
+ bit_offset_t b_wi_offset;
+ if (a.maybe_get_cst_offset (&a_wi_offset)
+ && b.maybe_get_cst_offset (&b_wi_offset))
+ return tristate (a_wi_offset <= b_wi_offset);
+ }
+ }
+ }
+ return tristate::unknown ();
+ }
+
+ static bool
+ from_svalue (const svalue &sval, linear_op *out)
+ {
+ switch (sval.get_kind ())
+ {
+ default:
+ break;
+ case SK_BINOP:
+ {
+ const binop_svalue &binop_sval ((const binop_svalue &)sval);
+ if (binop_sval.get_op () == MULT_EXPR)
+ {
+ *out = linear_op (binop_sval.get_arg0 (),
+ binop_sval.get_arg1 (),
+ NULL);
+ return true;
+ }
+ else if (binop_sval.get_op () == PLUS_EXPR)
+ {
+ if (binop_sval.get_arg0 ()->get_kind () == SK_BINOP)
+ {
+ const binop_svalue &inner_binop_sval
+ ((const binop_svalue &)*binop_sval.get_arg0 ());
+ if (inner_binop_sval.get_op () == MULT_EXPR)
+ {
+ *out = linear_op (inner_binop_sval.get_arg0 (),
+ inner_binop_sval.get_arg1 (),
+ binop_sval.get_arg1 ());
+ return true;
+ }
+ }
+
+ *out = linear_op (binop_sval.get_arg0 (),
+ NULL,
+ binop_sval.get_arg1 ());
+ return true;
+ }
+ }
+ break;
+ }
+ return false;
+ }
+
+ const svalue *m_base;
+ const svalue *m_factor;
+ const svalue *m_offset;
+};
+
+bool
+operator< (const region_offset &a, const region_offset &b)
+{
+ if (a.symbolic_p ())
+ {
+ if (b.symbolic_p ())
+ {
+ /* Symbolic vs symbolic. */
+ const svalue &a_sval = *a.get_symbolic_byte_offset ();
+ const svalue &b_sval = *b.get_symbolic_byte_offset ();
+
+ linear_op op_a (NULL, NULL, NULL);
+ linear_op op_b (NULL, NULL, NULL);
+ if (linear_op::from_svalue (a_sval, &op_a)
+ && linear_op::from_svalue (b_sval, &op_b))
+ {
+ tristate ts = linear_op::less (op_a, op_b);
+ if (ts.is_true ())
+ return true;
+ else if (ts.is_false ())
+ return false;
+ }
+ /* Use svalue's deterministic order, for now. */
+ return (svalue::cmp_ptr (a.get_symbolic_byte_offset (),
+ b.get_symbolic_byte_offset ())
+ < 0);
+ }
+ else
+ /* Symbolic vs concrete: put all symbolic after all concrete. */
+ return false;
+ }
+ else
+ {
+ if (b.symbolic_p ())
+ /* Concrete vs symbolic: put all concrete before all symbolic. */
+ return true;
+ else
+ /* Concrete vs concrete. */
+ return a.get_bit_offset () < b.get_bit_offset ();
+ }
+}
+
+bool
+operator<= (const region_offset &a, const region_offset &b)
+{
+ if (a.symbolic_p ())
+ {
+ if (b.symbolic_p ())
+ {
+ /* Symbolic vs symbolic. */
+ const svalue &a_sval = *a.get_symbolic_byte_offset ();
+ const svalue &b_sval = *b.get_symbolic_byte_offset ();
+
+ linear_op op_a (NULL, NULL, NULL);
+ linear_op op_b (NULL, NULL, NULL);
+ if (linear_op::from_svalue (a_sval, &op_a)
+ && linear_op::from_svalue (b_sval, &op_b))
+ {
+ tristate ts = linear_op::le (op_a, op_b);
+ if (ts.is_true ())
+ return true;
+ else if (ts.is_false ())
+ return false;
+ }
+ /* Use svalue's deterministic order, for now. */
+ return (svalue::cmp_ptr (a.get_symbolic_byte_offset (),
+ b.get_symbolic_byte_offset ())
+ <= 0);
+ }
+ else
+ /* Symbolic vs concrete: put all symbolic after all concrete. */
+ return false;
+ }
+ else
+ {
+ if (b.symbolic_p ())
+ /* Concrete vs symbolic: put all concrete before all symbolic. */
+ return true;
+ else
+ /* Concrete vs concrete. */
+ return a.get_bit_offset () <= b.get_bit_offset ();
+ }
+}
+
+bool
+operator> (const region_offset &a, const region_offset &b)
+{
+ return b < a;
+}
+
+bool
+operator>= (const region_offset &a, const region_offset &b)
+{
+ return b <= a;
+}
+
+/* class region and its various subclasses. */
+
+/* class region. */
+
+region::~region ()
+{
+ delete m_cached_offset;
}
/* Determine the base region for this region: when considering bindings
return MEMSPACE_HEAP;
case RK_STRING:
return MEMSPACE_READONLY_DATA;
+ case RK_PRIVATE:
+ return MEMSPACE_PRIVATE;
}
if (iter->get_kind () == RK_CAST)
iter = iter->dyn_cast_cast_region ()->get_original_region ();
case MEMSPACE_CODE:
case MEMSPACE_GLOBALS:
case MEMSPACE_READONLY_DATA:
+ case MEMSPACE_PRIVATE:
/* Such regions have initial_svalues. */
return true;
}
}
+/* For regions within a global decl, get the svalue for the initial
+ value of this region when the program starts, caching the result. */
+
+const svalue *
+region::get_initial_value_at_main (region_model_manager *mgr) const
+{
+ if (!m_cached_init_sval_at_main)
+ m_cached_init_sval_at_main = calc_initial_value_at_main (mgr);
+ return m_cached_init_sval_at_main;
+}
+
+/* Implementation of region::get_initial_value_at_main. */
+
+const svalue *
+region::calc_initial_value_at_main (region_model_manager *mgr) const
+{
+ const decl_region *base_reg = get_base_region ()->dyn_cast_decl_region ();
+ gcc_assert (base_reg);
+
+ /* Attempt to get the initializer value for base_reg. */
+ if (const svalue *base_reg_init
+ = base_reg->get_svalue_for_initializer (mgr))
+ {
+ if (this == base_reg)
+ return base_reg_init;
+ else
+ {
+ /* Get the value for REG within base_reg_init. */
+ binding_cluster c (base_reg);
+ c.bind (mgr->get_store_manager (), base_reg, base_reg_init);
+ const svalue *sval
+ = c.get_any_binding (mgr->get_store_manager (), this);
+ if (sval)
+ {
+ if (get_type ())
+ sval = mgr->get_or_create_cast (get_type (), sval);
+ return sval;
+ }
+ }
+ }
+
+ /* Otherwise, return INIT_VAL(REG). */
+ return mgr->get_or_create_initial_value (this);
+}
+
/* If this region is a decl_region, return the decl.
Otherwise return NULL. */
return *m_cached_offset;
}
+/* Get the region_offset for immediately beyond this region. */
+
+region_offset
+region::get_next_offset (region_model_manager *mgr) const
+{
+ region_offset start = get_offset (mgr);
+
+ bit_size_t bit_size;
+ if (get_bit_size (&bit_size))
+ {
+ if (start.concrete_p ())
+ {
+ bit_offset_t next_bit_offset = start.get_bit_offset () + bit_size;
+ return region_offset::make_concrete (start.get_base_region (),
+ next_bit_offset);
+ }
+ }
+
+ const svalue *start_byte_offset_sval = start.calc_symbolic_byte_offset (mgr);
+ const svalue *byte_size_sval = get_byte_size_sval (mgr);
+ const svalue *sum_sval
+ = mgr->get_or_create_binop (size_type_node,
+ PLUS_EXPR,
+ start_byte_offset_sval,
+ byte_size_sval);
+ return region_offset::make_symbolic (start.get_base_region (),
+ sum_sval);
+}
+
/* Base class implementation of region::get_byte_size vfunc.
If the size of this region (in bytes) is known statically, write it to *OUT
and return true.
}
tree sz = TYPE_SIZE (type);
- if (sz && tree_fits_uhwi_p (sz))
+ if (sz
+ && tree_fits_uhwi_p (sz)
+ /* If the size is zero, then we may have a zero-sized
+ array; handle such cases by returning false. */
+ && !integer_zerop (sz))
{
*out = TREE_INT_CST_LOW (sz);
return true;
return false;
}
+/* Base implementation of region::get_bit_size_sval vfunc. */
+
+const svalue *
+region::get_bit_size_sval (region_model_manager *mgr) const
+{
+ tree type = get_type ();
+
+ /* Bail out e.g. for heap-allocated regions. */
+ if (!type)
+ return mgr->get_or_create_unknown_svalue (size_type_node);
+
+ bit_size_t bits;
+ if (!int_size_in_bits (type, &bits))
+ return mgr->get_or_create_unknown_svalue (size_type_node);
+
+ return mgr->get_or_create_int_cst (size_type_node, bits);
+}
+
/* If the size of this region (in bits) is known statically, write it to *OUT
and return true.
Otherwise return false. */
const svalue *
region::get_relative_symbolic_offset (region_model_manager *mgr) const
{
- return mgr->get_or_create_unknown_svalue (integer_type_node);
+ return mgr->get_or_create_unknown_svalue (ptrdiff_type_node);
}
/* Attempt to get the position and size of this region expressed as a
return get_kind () == RK_SYMBOLIC;
}
+/* Return true if this region is known to be zero bits in size. */
+
+bool
+region::empty_p () const
+{
+ bit_size_t num_bits;
+ if (get_bit_size (&num_bits))
+ if (num_bits == 0)
+ return true;
+ return false;
+}
+
/* Return true if this is a region for a decl with name DECL_NAME.
Intended for use when debugging (for assertions and conditional
breakpoints). */
/* region's ctor. */
-region::region (complexity c, unsigned id, const region *parent, tree type)
-: m_complexity (c), m_id (id), m_parent (parent), m_type (type),
- m_cached_offset (NULL)
+region::region (complexity c, symbol::id_t id, const region *parent, tree type)
+: symbol (c, id),
+ m_parent (parent), m_type (type),
+ m_cached_offset (NULL), m_cached_init_sval_at_main (NULL)
{
gcc_assert (type == NULL_TREE || TYPE_P (type));
}
if (decl_region **slot = mutable_locals.get (expr))
return *slot;
decl_region *reg
- = new decl_region (mgr->alloc_region_id (), this, expr);
+ = new decl_region (mgr->alloc_symbol_id (), this, expr);
mutable_locals.put (expr, reg);
return reg;
}
/* root_region's ctor. */
-root_region::root_region (unsigned id)
+root_region::root_region (symbol::id_t id)
: region (complexity (1, 1), id, NULL, NULL_TREE)
{
}
/* symbolic_region's ctor. */
-symbolic_region::symbolic_region (unsigned id, region *parent,
+symbolic_region::symbolic_region (symbol::id_t id, region *parent,
const svalue *sval_ptr)
: region (complexity::from_pair (parent, sval_ptr), id, parent,
(sval_ptr->get_type ()
const svalue *
decl_region::maybe_get_constant_value (region_model_manager *mgr) const
{
- if (TREE_CODE (m_decl) == VAR_DECL
+ if (VAR_P (m_decl)
&& DECL_IN_CONSTANT_POOL (m_decl)
&& DECL_INITIAL (m_decl)
&& TREE_CODE (DECL_INITIAL (m_decl)) == CONSTRUCTOR)
return NULL;
}
-/* Get an svalue for CTOR, a CONSTRUCTOR for this region's decl. */
+/* Implementation of decl_region::get_svalue_for_constructor
+ for when the cached value hasn't yet been calculated. */
const svalue *
-decl_region::get_svalue_for_constructor (tree ctor,
- region_model_manager *mgr) const
+decl_region::calc_svalue_for_constructor (tree ctor,
+ region_model_manager *mgr) const
{
- gcc_assert (!TREE_CLOBBER_P (ctor));
-
/* Create a binding map, applying ctor to it, using this
decl_region as the base region when building child regions
for offset calculations. */
return mgr->get_or_create_compound_svalue (get_type (), map);
}
+/* Get an svalue for CTOR, a CONSTRUCTOR for this region's decl. */
+
+const svalue *
+decl_region::get_svalue_for_constructor (tree ctor,
+ region_model_manager *mgr) const
+{
+ gcc_assert (!TREE_CLOBBER_P (ctor));
+ gcc_assert (ctor == DECL_INITIAL (m_decl));
+
+ if (!m_ctor_svalue)
+ m_ctor_svalue = calc_svalue_for_constructor (ctor, mgr);
+
+ return m_ctor_svalue;
+}
+
/* For use on decl_regions for global variables.
Get an svalue for the initial value of this region at entry to
if (DECL_EXTERNAL (m_decl))
return NULL;
+ if (empty_p ())
+ return NULL;
+
/* Implicit initialization to zero; use a compound_svalue for it.
Doing so requires that we have a concrete binding for this region,
which can fail if we have a region with unknown size
if (get_relative_concrete_offset (&out))
{
tree cst_tree
- = wide_int_to_tree (integer_type_node, out / BITS_PER_UNIT);
+ = wide_int_to_tree (ptrdiff_type_node, out / BITS_PER_UNIT);
return mgr->get_or_create_constant_svalue (cst_tree);
}
- return mgr->get_or_create_unknown_svalue (integer_type_node);
+ return mgr->get_or_create_unknown_svalue (ptrdiff_type_node);
}
/* class element_region : public region. */
HOST_WIDE_INT hwi_byte_size = int_size_in_bytes (elem_type);
if (hwi_byte_size > 0)
{
- tree byte_size_tree = wide_int_to_tree (integer_type_node,
+ tree byte_size_tree = wide_int_to_tree (ptrdiff_type_node,
hwi_byte_size);
const svalue *byte_size_sval
= mgr->get_or_create_constant_svalue (byte_size_tree);
- return mgr->get_or_create_binop (integer_type_node, MULT_EXPR,
+ return mgr->get_or_create_binop (ptrdiff_type_node, MULT_EXPR,
m_index, byte_size_sval);
}
- return mgr->get_or_create_unknown_svalue (integer_type_node);
+ return mgr->get_or_create_unknown_svalue (ptrdiff_type_node);
}
/* class offset_region : public region. */
}
}
+const svalue *
+offset_region::get_bit_offset (region_model_manager *mgr) const
+{
+ const svalue *bits_per_byte_sval
+ = mgr->get_or_create_int_cst (size_type_node, BITS_PER_UNIT);
+ return mgr->get_or_create_binop (size_type_node, MULT_EXPR,
+ m_byte_offset, bits_per_byte_sval);
+}
+
/* Implementation of region::get_relative_concrete_offset vfunc
for offset_region. */
return region::get_byte_size_sval (mgr);
}
+/* Implementation of region::get_bit_size_sval vfunc for offset_region. */
+
+const svalue *
+offset_region::get_bit_size_sval (region_model_manager *mgr) const
+{
+ tree offset_cst = get_bit_offset (mgr)->maybe_get_constant ();
+ bit_size_t bit_size;
+ /* If the offset points in the middle of the region,
+ return the remaining bits. */
+ if (get_bit_size (&bit_size) && offset_cst)
+ {
+ bit_size_t offset = wi::to_offset (offset_cst);
+ bit_range r (0, bit_size);
+ if (r.contains_p (offset))
+ {
+ tree remaining_bit_size = wide_int_to_tree (size_type_node,
+ bit_size - offset);
+ return mgr->get_or_create_constant_svalue (remaining_bit_size);
+ }
+ }
+
+ return region::get_bit_size_sval (mgr);
+}
+
/* class sized_region : public region. */
/* Implementation of region::accept vfunc for sized_region. */
return true;
}
+/* Implementation of region::get_bit_size_sval vfunc for sized_region. */
+
+const svalue *
+sized_region::get_bit_size_sval (region_model_manager *mgr) const
+{
+ const svalue *bits_per_byte_sval
+ = mgr->get_or_create_int_cst (size_type_node, BITS_PER_UNIT);
+ return mgr->get_or_create_binop (size_type_node, MULT_EXPR,
+ m_byte_size_sval, bits_per_byte_sval);
+}
+
/* class cast_region : public region. */
/* Implementation of region::accept vfunc for cast_region. */
return mgr->get_or_create_int_cst (size_type_node, num_bytes);
}
+/* Implementation of region::get_bit_size_sval vfunc for bit_range_region. */
+
+const svalue *
+bit_range_region::get_bit_size_sval (region_model_manager *mgr) const
+{
+ return mgr->get_or_create_int_cst (size_type_node,
+ m_bits.m_size_in_bits);
+}
+
/* Implementation of region::get_relative_concrete_offset vfunc for
bit_range_region. */
const
{
byte_offset_t start_byte = m_bits.get_start_bit_offset () / BITS_PER_UNIT;
- tree start_bit_tree = wide_int_to_tree (integer_type_node, start_byte);
+ tree start_bit_tree = wide_int_to_tree (ptrdiff_type_node, start_byte);
return mgr->get_or_create_constant_svalue (start_bit_tree);
}
pp_string (pp, "errno_region()");
}
+/* class private_region : public region. */
+
+void
+private_region::dump_to_pp (pretty_printer *pp, bool simple) const
+{
+ if (simple)
+ pp_printf (pp, "PRIVATE_REG(%qs)", m_desc);
+ else
+ pp_printf (pp, "private_region(%qs)", m_desc);
+}
+
/* class unknown_region : public region. */
/* Implementation of region::dump_to_pp vfunc for unknown_region. */
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