/* Mudflap: narrow-pointer bounds-checking by tree rewriting.
- Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.
+ Copyright (C) 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
Contributed by Frank Ch. Eigler <fche@redhat.com>
and Graydon Hoare <graydon@redhat.com>
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING. If not, write to the Free
-Software Foundation, 59 Temple Place - Suite 330, Boston, MA
-02111-1307, USA. */
+Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301, USA. */
#include "config.h"
-#include "errors.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "langhooks.h"
#include "ggc.h"
#include "cgraph.h"
+#include "toplev.h"
/* Internal function decls */
{
const char *declname = NULL;
- if (strcmp ("GNU C++", lang_hooks.name) == 0 &&
- DECL_NAME (decl) != NULL)
+ if (DECL_NAME (decl) != NULL)
{
- /* The gcc/cp decl_printable_name hook doesn't do as good a job as
- the libiberty demangler. */
- declname = cplus_demangle (IDENTIFIER_POINTER (DECL_NAME (decl)),
- DMGL_AUTO | DMGL_VERBOSE);
+ if (strcmp ("GNU C++", lang_hooks.name) == 0)
+ {
+ /* The gcc/cp decl_printable_name hook doesn't do as good a job as
+ the libiberty demangler. */
+ declname = cplus_demangle (IDENTIFIER_POINTER (DECL_NAME (decl)),
+ DMGL_AUTO | DMGL_VERBOSE);
+ }
+ if (declname == NULL)
+ declname = lang_hooks.decl_printable_name (decl, 3);
}
-
- if (declname == NULL)
- declname = lang_hooks.decl_printable_name (decl, 3);
-
if (declname == NULL)
declname = "<unnamed variable>";
unsigned_char_type_node);
mf_cache_mask_decl = mf_make_builtin (VAR_DECL, "__mf_lc_mask",
mf_uintptr_type);
+ /* Don't process these in mudflap_enqueue_decl, should they come by
+ there for some reason. */
+ mf_mark (mf_cache_array_decl);
+ mf_mark (mf_cache_shift_decl);
+ mf_mark (mf_cache_mask_decl);
mf_check_fndecl = mf_make_builtin (FUNCTION_DECL, "__mf_check",
mf_check_register_fntype);
mf_register_fndecl = mf_make_builtin (FUNCTION_DECL, "__mf_register",
! tsi_end_p (tsi);
tsi_next (&tsi))
insert_edge_copies (tsi_stmt (tsi), ENTRY_BLOCK_PTR);
- bsi_commit_edge_inserts (NULL);
+ bsi_commit_edge_inserts ();
}
}
static void
-mf_build_check_statement_for (tree base, tree addr, tree limit,
+mf_build_check_statement_for (tree base, tree limit,
block_stmt_iterator *instr_bsi,
location_t *locus, tree dirflag)
{
tree_stmt_iterator head, tsi;
- tree ptrtype = TREE_TYPE (addr);
block_stmt_iterator bsi;
basic_block cond_bb, then_bb, join_bb;
edge e;
- tree cond, t, u, v, l1, l2;
- tree mf_value;
+ tree cond, t, u, v;
tree mf_base;
tree mf_elem;
tree mf_limit;
/* We first need to split the current basic block, and start altering
the CFG. This allows us to insert the statements we're about to
- construct into the right basic blocks. The label l1 is the label
- of the block for the THEN clause of the conditional jump we're
- about to construct, and l2 is the ELSE clause, which is just the
- continuation of the old statement stream. */
- l1 = create_artificial_label ();
- l2 = create_artificial_label ();
+ construct into the right basic blocks. */
+
cond_bb = bb_for_stmt (bsi_stmt (*instr_bsi));
bsi = *instr_bsi;
bsi_prev (&bsi);
if (! bsi_end_p (bsi))
- {
- /* We're processing a statement in the middle of the block, so
- we need to split the block. This creates a new block and a new
- fallthrough edge. */
- e = split_block (cond_bb, bsi_stmt (bsi));
- cond_bb = e->src;
- join_bb = e->dest;
- }
+ e = split_block (cond_bb, bsi_stmt (bsi));
else
- {
- /* We're processing the first statement in the block, so we need
- to split the incoming edge. This also creates a new block
- and a new fallthrough edge. */
- join_bb = cond_bb;
- cond_bb = split_edge (find_edge (join_bb->prev_bb, join_bb));
- }
-
+ e = split_block_after_labels (cond_bb);
+ cond_bb = e->src;
+ join_bb = e->dest;
+
/* A recap at this point: join_bb is the basic block at whose head
is the gimple statement for which this check expression is being
built. cond_bb is the (possibly new, synthetic) basic block the
make_edge (cond_bb, then_bb, EDGE_TRUE_VALUE);
make_single_succ_edge (then_bb, join_bb, EDGE_FALLTHRU);
- /* We expect that the conditional jump we will construct will not
- be taken very often as it basically is an exception condition. */
- predict_edge_def (EDGE_PRED (then_bb, 0), PRED_MUDFLAP, NOT_TAKEN);
-
/* Mark the pseudo-fallthrough edge from cond_bb to join_bb. */
e = find_edge (cond_bb, join_bb);
e->flags = EDGE_FALSE_VALUE;
- predict_edge_def (e, PRED_MUDFLAP, TAKEN);
+ e->count = cond_bb->count;
+ e->probability = REG_BR_PROB_BASE;
/* Update dominance info. Note that bb_join's data was
updated by split_block. */
- if (dom_computed[CDI_DOMINATORS] >= DOM_CONS_OK)
+ if (dom_info_available_p (CDI_DOMINATORS))
{
set_immediate_dominator (CDI_DOMINATORS, then_bb, cond_bb);
set_immediate_dominator (CDI_DOMINATORS, join_bb, cond_bb);
}
/* Build our local variables. */
- mf_value = create_tmp_var (ptrtype, "__mf_value");
mf_elem = create_tmp_var (mf_cache_structptr_type, "__mf_elem");
mf_base = create_tmp_var (mf_uintptr_type, "__mf_base");
mf_limit = create_tmp_var (mf_uintptr_type, "__mf_limit");
- /* Build: __mf_value = <address expression>. */
- t = build (MODIFY_EXPR, void_type_node, mf_value, unshare_expr (addr));
- SET_EXPR_LOCUS (t, locus);
- gimplify_to_stmt_list (&t);
- head = tsi_start (t);
- tsi = tsi_last (t);
-
/* Build: __mf_base = (uintptr_t) <base address expression>. */
t = build (MODIFY_EXPR, void_type_node, mf_base,
convert (mf_uintptr_type, unshare_expr (base)));
SET_EXPR_LOCUS (t, locus);
gimplify_to_stmt_list (&t);
- tsi_link_after (&tsi, t, TSI_CONTINUE_LINKING);
+ head = tsi_start (t);
+ tsi = tsi_last (t);
/* Build: __mf_limit = (uintptr_t) <limit address expression>. */
t = build (MODIFY_EXPR, void_type_node, mf_limit,
: *locus),
NULL_TREE);
u = tree_cons (NULL_TREE, dirflag, u);
- /* NB: we pass the overall [base..limit] range to mf_check,
- not the [mf_value..mf_value+size-1] range. */
+ /* NB: we pass the overall [base..limit] range to mf_check. */
u = tree_cons (NULL_TREE,
- fold (build (PLUS_EXPR, integer_type_node,
- fold (build (MINUS_EXPR, mf_uintptr_type, mf_limit, mf_base)),
- integer_one_node)),
+ fold_build2 (PLUS_EXPR, integer_type_node,
+ fold_build2 (MINUS_EXPR, mf_uintptr_type, mf_limit, mf_base),
+ integer_one_node),
u);
u = tree_cons (NULL_TREE, mf_base, u);
t = build_function_call_expr (mf_check_fndecl, u);
bsi_next (instr_bsi);
}
+
+/* Check whether the given decl, generally a VAR_DECL or PARM_DECL, is
+ eligible for instrumentation. For the mudflap1 pass, this implies
+ that it should be registered with the libmudflap runtime. For the
+ mudflap2 pass this means instrumenting an indirection operation with
+ respect to the object.
+*/
+static int
+mf_decl_eligible_p (tree decl)
+{
+ return ((TREE_CODE (decl) == VAR_DECL || TREE_CODE (decl) == PARM_DECL)
+ /* The decl must have its address taken. In the case of
+ arrays, this flag is also set if the indexes are not
+ compile-time known valid constants. */
+ && TREE_ADDRESSABLE (decl) /* XXX: not sufficient: return-by-value structs! */
+ /* The type of the variable must be complete. */
+ && COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (decl))
+ /* The decl hasn't been decomposed somehow. */
+ && !DECL_HAS_VALUE_EXPR_P (decl));
+}
+
+
static void
mf_xform_derefs_1 (block_stmt_iterator *iter, tree *tp,
location_t *locus, tree dirflag)
{
- tree type, ptr_type, addr, base, size, limit, t;
+ tree type, base, limit, addr, size, t;
/* Don't instrument read operations. */
if (dirflag == integer_zero_node && flag_mudflap_ignore_reads)
switch (TREE_CODE (t))
{
case ARRAY_REF:
+ case COMPONENT_REF:
{
- /* Omit checking if we can statically determine that the access is
- valid. For non-addressable local arrays this is not optional,
- since we won't have called __mf_register for the object. */
- tree op0, op1;
-
- op0 = TREE_OPERAND (t, 0);
- op1 = TREE_OPERAND (t, 1);
- while (TREE_CODE (op1) == INTEGER_CST)
+ /* This is trickier than it may first appear. The reason is
+ that we are looking at expressions from the "inside out" at
+ this point. We may have a complex nested aggregate/array
+ expression (e.g. "a.b[i].c"), maybe with an indirection as
+ the leftmost operator ("p->a.b.d"), where instrumentation
+ is necessary. Or we may have an innocent "a.b.c"
+ expression that must not be instrumented. We need to
+ recurse all the way down the nesting structure to figure it
+ out: looking just at the outer node is not enough. */
+ tree var;
+ int component_ref_only = (TREE_CODE (t) == COMPONENT_REF);
+ /* If we have a bitfield component reference, we must note the
+ innermost addressable object in ELT, from which we will
+ construct the byte-addressable bounds of the bitfield. */
+ tree elt = NULL_TREE;
+ int bitfield_ref_p = (TREE_CODE (t) == COMPONENT_REF
+ && DECL_BIT_FIELD_TYPE (TREE_OPERAND (t, 1)));
+
+ /* Iterate to the top of the ARRAY_REF/COMPONENT_REF
+ containment hierarchy to find the outermost VAR_DECL. */
+ var = TREE_OPERAND (t, 0);
+ while (1)
{
- tree dom = TYPE_DOMAIN (TREE_TYPE (op0));
-
- /* Test for index in range. Break if not. */
- if (!dom
- || (! TYPE_MIN_VALUE (dom)
- || ! really_constant_p (TYPE_MIN_VALUE (dom)))
- || (! TYPE_MAX_VALUE (dom)
- || ! really_constant_p (TYPE_MAX_VALUE (dom)))
- || (tree_int_cst_lt (op1, TYPE_MIN_VALUE (dom))
- || tree_int_cst_lt (TYPE_MAX_VALUE (dom), op1)))
- break;
+ if (bitfield_ref_p && elt == NULL_TREE
+ && (TREE_CODE (var) == ARRAY_REF || TREE_CODE (var) == COMPONENT_REF))
+ elt = var;
+
+ if (TREE_CODE (var) == ARRAY_REF)
+ {
+ component_ref_only = 0;
+ var = TREE_OPERAND (var, 0);
+ }
+ else if (TREE_CODE (var) == COMPONENT_REF)
+ var = TREE_OPERAND (var, 0);
+ else if (INDIRECT_REF_P (var))
+ {
+ base = TREE_OPERAND (var, 0);
+ break;
+ }
+ else
+ {
+ gcc_assert (TREE_CODE (var) == VAR_DECL
+ || TREE_CODE (var) == PARM_DECL
+ || TREE_CODE (var) == RESULT_DECL
+ || TREE_CODE (var) == STRING_CST);
+ /* Don't instrument this access if the underlying
+ variable is not "eligible". This test matches
+ those arrays that have only known-valid indexes,
+ and thus are not labeled TREE_ADDRESSABLE. */
+ if (! mf_decl_eligible_p (var) || component_ref_only)
+ return;
+ else
+ {
+ base = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (var)), var);
+ break;
+ }
+ }
+ }
- /* If we're looking at a non-external VAR_DECL, then the
- access must be ok. */
- if (TREE_CODE (op0) == VAR_DECL && !DECL_EXTERNAL (op0))
- return;
+ /* Handle the case of ordinary non-indirection structure
+ accesses. These have only nested COMPONENT_REF nodes (no
+ INDIRECT_REF), but pass through the above filter loop.
+ Note that it's possible for such a struct variable to match
+ the eligible_p test because someone else might take its
+ address sometime. */
- /* Only continue if we're still looking at an array. */
- if (TREE_CODE (op0) != ARRAY_REF)
- break;
+ /* We need special processing for bitfield components, because
+ their addresses cannot be taken. */
+ if (bitfield_ref_p)
+ {
+ tree field = TREE_OPERAND (t, 1);
- op1 = TREE_OPERAND (op0, 1);
- op0 = TREE_OPERAND (op0, 0);
+ if (TREE_CODE (DECL_SIZE_UNIT (field)) == INTEGER_CST)
+ size = DECL_SIZE_UNIT (field);
+
+ if (elt)
+ elt = build1 (ADDR_EXPR, build_pointer_type TREE_TYPE (elt), elt);
+ addr = fold_convert (ptr_type_node, elt ? elt : base);
+ addr = fold_build2 (PLUS_EXPR, ptr_type_node,
+ addr, fold_convert (ptr_type_node,
+ byte_position (field)));
}
-
- /* If we got here, we couldn't statically the check. */
- ptr_type = build_pointer_type (type);
- addr = build1 (ADDR_EXPR, ptr_type, t);
- base = build1 (ADDR_EXPR, ptr_type, op0);
- limit = fold (build (MINUS_EXPR, mf_uintptr_type,
- fold (build2 (PLUS_EXPR, mf_uintptr_type, addr, size)),
- integer_one_node));
+ else
+ addr = build1 (ADDR_EXPR, build_pointer_type (type), t);
+
+ limit = fold_build2 (MINUS_EXPR, mf_uintptr_type,
+ fold_build2 (PLUS_EXPR, mf_uintptr_type,
+ convert (mf_uintptr_type, addr),
+ size),
+ integer_one_node);
}
break;
case INDIRECT_REF:
addr = TREE_OPERAND (t, 0);
- ptr_type = TREE_TYPE (addr);
base = addr;
- limit = fold (build (MINUS_EXPR, ptr_type_node,
- fold (build (PLUS_EXPR, ptr_type_node, base, size)),
- integer_one_node));
+ limit = fold_build2 (MINUS_EXPR, ptr_type_node,
+ fold_build2 (PLUS_EXPR, ptr_type_node, base, size),
+ integer_one_node);
+ break;
+
+ case TARGET_MEM_REF:
+ addr = tree_mem_ref_addr (ptr_type_node, t);
+ base = addr;
+ limit = fold_build2 (MINUS_EXPR, ptr_type_node,
+ fold_build2 (PLUS_EXPR, ptr_type_node, base, size),
+ build_int_cst_type (ptr_type_node, 1));
break;
case ARRAY_RANGE_REF:
- warning ("mudflap checking not yet implemented for ARRAY_RANGE_REF");
+ warning (0, "mudflap checking not yet implemented for ARRAY_RANGE_REF");
return;
- case COMPONENT_REF:
- {
- tree field;
-
- /* If we're not dereferencing something, then the access
- must be ok. */
- if (TREE_CODE (TREE_OPERAND (t, 0)) != INDIRECT_REF)
- return;
-
- field = TREE_OPERAND (t, 1);
-
- /* If we're looking at a bit field, then we can't take its address
- with ADDR_EXPR -- lang_hooks.mark_addressable will error. Do
- things the hard way with PLUS. */
- if (DECL_BIT_FIELD_TYPE (field))
- {
- if (TREE_CODE (DECL_SIZE_UNIT (field)) == INTEGER_CST)
- size = DECL_SIZE_UNIT (field);
-
- addr = TREE_OPERAND (TREE_OPERAND (t, 0), 0);
- addr = fold_convert (ptr_type_node, addr);
- addr = fold (build (PLUS_EXPR, ptr_type_node,
- addr, fold_convert (ptr_type_node,
- byte_position (field))));
- }
- else
- {
- ptr_type = build_pointer_type (type);
- addr = build1 (ADDR_EXPR, ptr_type, t);
- }
-
- /* XXXXXX */
- base = addr;
- limit = fold (build (MINUS_EXPR, ptr_type_node,
- fold (build (PLUS_EXPR, ptr_type_node, base, size)),
- integer_one_node));
- }
- break;
-
case BIT_FIELD_REF:
+ /* ??? merge with COMPONENT_REF code above? */
{
tree ofs, rem, bpu;
addr = TREE_OPERAND (TREE_OPERAND (t, 0), 0);
addr = convert (ptr_type_node, addr);
- addr = fold (build (PLUS_EXPR, ptr_type_node, addr, ofs));
+ addr = fold_build2 (PLUS_EXPR, ptr_type_node, addr, ofs);
base = addr;
- limit = fold (build (MINUS_EXPR, ptr_type_node,
- fold (build (PLUS_EXPR, ptr_type_node, base, size)),
- integer_one_node));
+ limit = fold_build2 (MINUS_EXPR, ptr_type_node,
+ fold_build2 (PLUS_EXPR, ptr_type_node, base, size),
+ integer_one_node);
}
break;
return;
}
- mf_build_check_statement_for (base, addr, limit, iter, locus, dirflag);
+ mf_build_check_statement_for (base, limit, iter, locus, dirflag);
}
static void
while (decl != NULL_TREE)
{
- /* Eligible decl? */
- if ((TREE_CODE (decl) == VAR_DECL || TREE_CODE (decl) == PARM_DECL)
- /* It must be a non-external, automatic variable. */
+ if (mf_decl_eligible_p (decl)
+ /* Not already processed. */
+ && ! mf_marked_p (decl)
+ /* Automatic variable. */
&& ! DECL_EXTERNAL (decl)
- && ! TREE_STATIC (decl)
- /* The decl must have its address taken. */
- && TREE_ADDRESSABLE (decl)
- /* The type of the variable must be complete. */
- && COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (decl))
- /* The decl hasn't been decomposed somehow. */
- && DECL_VALUE_EXPR (decl) == NULL
- /* Don't process the same decl twice. */
- && ! mf_marked_p (decl))
+ && ! TREE_STATIC (decl))
{
tree size = NULL_TREE, variable_name;
tree unregister_fncall, unregister_fncall_params;
/* Add the __mf_register call at the current appending point. */
if (tsi_end_p (initially_stmts))
- internal_error ("mudflap ran off end of BIND_EXPR body");
- tsi_link_before (&initially_stmts, register_fncall, TSI_SAME_STMT);
-
- /* Accumulate the FINALLY piece. */
- append_to_statement_list (unregister_fncall, &finally_stmts);
-
+ warning (0, "mudflap cannot track %qs in stub function",
+ IDENTIFIER_POINTER (DECL_NAME (decl)));
+ else
+ {
+ tsi_link_before (&initially_stmts, register_fncall, TSI_SAME_STMT);
+
+ /* Accumulate the FINALLY piece. */
+ append_to_statement_list (unregister_fncall, &finally_stmts);
+ }
mf_mark (decl);
}
break;
}
- return NULL;
+ return NULL_TREE;
}
/* Perform the object lifetime tracking mudflap transform on the given function
delayed until program finish time. If they're still incomplete by
then, warnings are emitted. */
-static GTY (()) varray_type deferred_static_decls;
+static GTY (()) VEC(tree,gc) *deferred_static_decls;
/* A list of statements for calling __mf_register() at startup time. */
static GTY (()) tree enqueued_call_stmt_chain;
if (DECL_P (obj) && DECL_EXTERNAL (obj) && DECL_ARTIFICIAL (obj))
return;
- if (COMPLETE_TYPE_P (TREE_TYPE (obj)))
- {
- tree object_size;
-
- mf_mark (obj);
-
- object_size = size_in_bytes (TREE_TYPE (obj));
-
- if (dump_file)
- {
- fprintf (dump_file, "enqueue_decl obj=`");
- print_generic_expr (dump_file, obj, dump_flags);
- fprintf (dump_file, "' size=");
- print_generic_expr (dump_file, object_size, dump_flags);
- fprintf (dump_file, "\n");
- }
-
- /* NB: the above condition doesn't require TREE_USED or
- TREE_ADDRESSABLE. That's because this object may be a global
- only used from other compilation units. XXX: Maybe static
- objects could require those attributes being set. */
-
- mudflap_register_call (obj, object_size, mf_varname_tree (obj));
- }
- else
- {
- size_t i;
-
- if (! deferred_static_decls)
- VARRAY_TREE_INIT (deferred_static_decls, 10, "deferred static list");
-
- /* Ugh, linear search... */
- for (i = 0; i < VARRAY_ACTIVE_SIZE (deferred_static_decls); i++)
- if (VARRAY_TREE (deferred_static_decls, i) == obj)
- {
- warning ("mudflap cannot track lifetime of %qs",
- IDENTIFIER_POINTER (DECL_NAME (obj)));
- return;
- }
-
- VARRAY_PUSH_TREE (deferred_static_decls, obj);
- }
+ VEC_safe_push (tree, gc, deferred_static_decls, obj);
}
+
void
mudflap_enqueue_constant (tree obj)
{
else
object_size = size_in_bytes (TREE_TYPE (obj));
- if (dump_file)
- {
- fprintf (dump_file, "enqueue_constant obj=`");
- print_generic_expr (dump_file, obj, dump_flags);
- fprintf (dump_file, "' size=");
- print_generic_expr (dump_file, object_size, dump_flags);
- fprintf (dump_file, "\n");
- }
-
if (TREE_CODE (obj) == STRING_CST)
varname = mf_build_string ("string literal");
else
{
tree ctor_statements = NULL_TREE;
- /* Try to give the deferred objects one final try. */
- if (deferred_static_decls)
- {
- size_t i;
-
- for (i = 0; i < VARRAY_ACTIVE_SIZE (deferred_static_decls); i++)
- {
- tree obj = VARRAY_TREE (deferred_static_decls, i);
-
- /* Call enqueue_decl again on the same object it has previously
- put into the table. (It won't modify the table this time, so
- infinite iteration is not a problem.) */
- mudflap_enqueue_decl (obj);
- }
-
- VARRAY_CLEAR (deferred_static_decls);
- }
-
/* Insert a call to __mf_init. */
{
tree call2_stmt = build_function_call_expr (mf_init_fndecl, NULL_TREE);
append_to_statement_list (call_stmt, &ctor_statements);
}
+ /* Process all enqueued object decls. */
+ if (deferred_static_decls)
+ {
+ size_t i;
+ tree obj;
+ for (i = 0; VEC_iterate (tree, deferred_static_decls, i, obj); i++)
+ {
+ gcc_assert (DECL_P (obj));
+
+ if (mf_marked_p (obj))
+ continue;
+
+ /* Omit registration for static unaddressed objects. NB:
+ Perform registration for non-static objects regardless of
+ TREE_USED or TREE_ADDRESSABLE, because they may be used
+ from other compilation units. */
+ if (! TREE_PUBLIC (obj) && ! TREE_ADDRESSABLE (obj))
+ continue;
+
+ if (! COMPLETE_TYPE_P (TREE_TYPE (obj)))
+ {
+ warning (0, "mudflap cannot track unknown size extern %qs",
+ IDENTIFIER_POINTER (DECL_NAME (obj)));
+ continue;
+ }
+
+ mudflap_register_call (obj,
+ size_in_bytes (TREE_TYPE (obj)),
+ mf_varname_tree (obj));
+ }
+
+ VEC_truncate (tree, deferred_static_decls, 0);
+ }
+
/* Append all the enqueued registration calls. */
if (enqueued_call_stmt_chain)
{
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