/* Type based alias analysis.
- Copyright (C) 2004, 2005 Free Software Foundation, Inc.
+ Copyright (C) 2004, 2005, 2006, 2007, 2008 Free Software Foundation,
+ Inc.
Contributed by Kenneth Zadeck <zadeck@naturalbridge.com>
This file is part of GCC.
GCC 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 2, or (at your option) any later
+Software Foundation; either version 3, or (at your option) any later
version.
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
for more details.
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, 51 Franklin Street, Fifth Floor, Boston, MA
-02110-1301, USA. */
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
/* This pass determines which types in the program contain only
instances that are completely encapsulated by the compilation unit.
#include "tree-pass.h"
#include "langhooks.h"
#include "pointer-set.h"
+#include "splay-tree.h"
#include "ggc.h"
#include "ipa-utils.h"
#include "ipa-type-escape.h"
-#include "c-common.h"
-#include "tree-gimple.h"
+#include "gimple.h"
#include "cgraph.h"
#include "output.h"
#include "flags.h"
this phase has been run. */
static bool initialized = false;
-/* This bitmap contains the set of local vars that are the lhs of
- calls to mallocs. These variables, when seen on the rhs as part of
- a cast, the cast are not marked as doing bad things to the type
- even though they are generally of the form
- "foo = (type_of_foo)void_temp". */
-static bitmap results_of_malloc;
-
/* Scratch bitmap for avoiding work. */
static bitmap been_there_done_that;
static bitmap bitmap_tmp;
scan_for_refs. */
static struct pointer_set_t *visited_nodes;
+/* Visited stmts by walk_use_def_chains function because it's called
+ recursively. */
+static struct pointer_set_t *visited_stmts;
+
static bitmap_obstack ipa_obstack;
+/* Static functions from this file that are used
+ before being defined. */
+static unsigned int look_for_casts (tree);
+static bool is_cast_from_non_pointer (tree, gimple, void *);
+
/* Get the name of TYPE or return the string "<UNNAMED>". */
-static char*
+static const char*
get_name_of_type (tree type)
{
tree name = TYPE_NAME (type);
if (!name)
/* Unnamed type, do what you like here. */
- return (char*)"<UNNAMED>";
+ return "<UNNAMED>";
/* It will be a TYPE_DECL in the case of a typedef, otherwise, an
identifier_node */
IDENTIFIER_NODE. (Some decls, most often labels, may have
zero as the DECL_NAME). */
if (DECL_NAME (name))
- return (char*)IDENTIFIER_POINTER (DECL_NAME (name));
+ return IDENTIFIER_POINTER (DECL_NAME (name));
else
/* Unnamed type, do what you like here. */
- return (char*)"<UNNAMED>";
+ return "<UNNAMED>";
}
else if (TREE_CODE (name) == IDENTIFIER_NODE)
- return (char*)IDENTIFIER_POINTER (name);
+ return IDENTIFIER_POINTER (name);
else
- return (char*)"<UNNAMED>";
+ return "<UNNAMED>";
}
struct type_brand_s
{
- char* name;
+ const char* name;
int seq;
};
/* This is a trivial algorithm for removing duplicate types. This
would not work for any language that used structural equivalence as
the basis of its type system. */
-/* Return either TYPE if this is first time TYPE has been seen an
- compatible TYPE that has already been processed. */
+/* Return TYPE if no type compatible with TYPE has been seen so far,
+ otherwise return a type compatible with TYPE that has already been
+ processed. */
static tree
discover_unique_type (tree type)
/* Create an alias since this is just the same as
other_type. */
tree other_type = (tree) result->value;
- if (lang_hooks.types_compatible_p (type, other_type) == 1)
+ if (types_compatible_p (type, other_type))
{
free (brand);
/* Insert this new type as an alias for other_type. */
switch (TREE_CODE (type))
{
case BOOLEAN_TYPE:
- case CHAR_TYPE:
case COMPLEX_TYPE:
case ENUMERAL_TYPE:
case INTEGER_TYPE:
case QUAL_UNION_TYPE:
case REAL_TYPE:
+ case FIXED_POINT_TYPE:
case RECORD_TYPE:
case UNION_TYPE:
case VECTOR_TYPE:
while (POINTER_TYPE_P (type))
type = TYPE_MAIN_VARIANT (TREE_TYPE (type));
- result = splay_tree_lookup(type_to_canon_type, (splay_tree_key) type);
+ result = splay_tree_lookup (type_to_canon_type, (splay_tree_key) type);
if (result == NULL)
return discover_unique_type (type);
get_canon_type_uid (type, true, false));
}
-/* Return true a modification to a field of type FIELD_TYPE cannot
+/* Return true if a modification to a field of type FIELD_TYPE cannot
clobber a record of RECORD_TYPE. */
bool
}
enum cast_type {
- CT_UP,
- CT_DOWN,
- CT_SIDEWAYS,
- CT_USELESS
+ CT_UP = 0x1,
+ CT_DOWN = 0x2,
+ CT_SIDEWAYS = 0x4,
+ CT_USELESS = 0x8,
+ CT_FROM_P_BAD = 0x10,
+ CT_FROM_NON_P = 0x20,
+ CT_TO_NON_INTER = 0x40,
+ CT_FROM_MALLOC = 0x80,
+ CT_NO_CAST = 0x100
};
/* Check the cast FROM_TYPE to TO_TYPE. This function requires that
return CT_SIDEWAYS;
}
+/* This function returns nonzero if VAR is result of call
+ to malloc function. */
+
+static bool
+is_malloc_result (tree var)
+{
+ gimple def_stmt;
+
+ if (!var)
+ return false;
+
+ if (SSA_NAME_IS_DEFAULT_DEF (var))
+ return false;
+
+ def_stmt = SSA_NAME_DEF_STMT (var);
+
+ if (!is_gimple_call (def_stmt))
+ return false;
+
+ if (var != gimple_call_lhs (def_stmt))
+ return false;
+
+ return ((gimple_call_flags (def_stmt) & ECF_MALLOC) != 0);
+
+}
+
/* Check a cast FROM this variable, TO_TYPE. Mark the escaping types
- if appropriate. */
-static void
+ if appropriate. Returns cast_type as detected. */
+
+static enum cast_type
check_cast (tree to_type, tree from)
{
tree from_type = get_canon_type (TREE_TYPE (from), false, false);
bool to_interesting_type, from_interesting_type;
+ enum cast_type cast = CT_NO_CAST;
to_type = get_canon_type (to_type, false, false);
if (!from_type || !to_type || from_type == to_type)
- return;
+ return cast;
to_interesting_type =
ipa_type_escape_star_count_of_interesting_type (to_type) >= 0;
both sides get marked as escaping. Downcasts are not
interesting here because if type is marked as escaping, all
of its subtypes escape. */
- switch (check_cast_type (to_type, from_type))
+ cast = check_cast_type (to_type, from_type);
+ switch (cast)
{
case CT_UP:
case CT_USELESS:
mark_type (to_type, FULL_ESCAPE);
mark_type (from_type, FULL_ESCAPE);
break;
+
+ default:
+ break;
}
}
else
{
- /* If this is a cast from the local that is a result from a
- call to malloc, do not mark the cast as bad. */
- if (DECL_P (from) && !bitmap_bit_p (results_of_malloc, DECL_UID (from)))
- mark_type (to_type, FULL_ESCAPE);
+ /* This code excludes two cases from marking as escaped:
+
+ 1. if this is a cast of index of array of structures/unions
+ that happens before accessing array element, we should not
+ mark it as escaped.
+ 2. if this is a cast from the local that is a result from a
+ call to malloc, do not mark the cast as bad.
+
+ */
+
+ if (POINTER_TYPE_P (to_type) && !POINTER_TYPE_P (from_type))
+ cast = CT_FROM_NON_P;
+ else if (TREE_CODE (from) == SSA_NAME
+ && is_malloc_result (from))
+ cast = CT_FROM_MALLOC;
+ else
+ {
+ cast = CT_FROM_P_BAD;
+ mark_type (to_type, FULL_ESCAPE);
+ }
}
else if (from_interesting_type)
- mark_type (from_type, FULL_ESCAPE);
+ {
+ mark_type (from_type, FULL_ESCAPE);
+ cast = CT_TO_NON_INTER;
+ }
+
+ return cast;
+}
+
+
+/* Scan assignment statement S to see if there are any casts within it. */
+
+static unsigned int
+look_for_casts_stmt (gimple s)
+{
+ unsigned int cast = 0;
+
+ gcc_assert (is_gimple_assign (s));
+
+ if (gimple_assign_cast_p (s))
+ {
+ tree castfromvar = gimple_assign_rhs1 (s);
+ cast |= check_cast (TREE_TYPE (gimple_assign_lhs (s)), castfromvar);
+ }
+ else
+ {
+ size_t i;
+ for (i = 0; i < gimple_num_ops (s); i++)
+ cast |= look_for_casts (gimple_op (s, i));
+ }
+
+ if (!cast)
+ cast = CT_NO_CAST;
+
+ return cast;
+}
+
+
+typedef struct cast
+{
+ int type;
+ gimple stmt;
+} cast_t;
+
+/* This function is a callback for walk_use_def_chains function called
+ from is_array_access_through_pointer_and_index. */
+
+static bool
+is_cast_from_non_pointer (tree var, gimple def_stmt, void *data)
+{
+ if (!def_stmt || !var)
+ return false;
+
+ if (gimple_code (def_stmt) == GIMPLE_PHI)
+ return false;
+
+ if (SSA_NAME_IS_DEFAULT_DEF (var))
+ return false;
+
+ if (is_gimple_assign (def_stmt))
+ {
+ use_operand_p use_p;
+ ssa_op_iter iter;
+ unsigned int cast = look_for_casts_stmt (def_stmt);
+
+ /* Check that only one cast happened, and it's of non-pointer
+ type. */
+ if ((cast & CT_FROM_NON_P) == (CT_FROM_NON_P)
+ && (cast & ~(CT_FROM_NON_P)) == 0)
+ {
+ ((cast_t *)data)->stmt = def_stmt;
+ ((cast_t *)data)->type++;
+
+ FOR_EACH_SSA_USE_OPERAND (use_p, def_stmt, iter, SSA_OP_ALL_USES)
+ {
+ walk_use_def_chains (USE_FROM_PTR (use_p),
+ is_cast_from_non_pointer, data, false);
+ if (((cast_t*)data)->type == -1)
+ break;
+ }
+ }
+ /* Check that there is no cast, or cast is not harmful. */
+ else if ((cast & CT_NO_CAST) == (CT_NO_CAST)
+ || (cast & CT_DOWN) == (CT_DOWN)
+ || (cast & CT_UP) == (CT_UP)
+ || (cast & CT_USELESS) == (CT_USELESS)
+ || (cast & CT_FROM_MALLOC) == (CT_FROM_MALLOC))
+ {
+ FOR_EACH_SSA_USE_OPERAND (use_p, def_stmt, iter, SSA_OP_ALL_USES)
+ {
+ walk_use_def_chains (USE_FROM_PTR (use_p),
+ is_cast_from_non_pointer, data, false);
+ if (((cast_t*)data)->type == -1)
+ break;
+ }
+ }
+ /* The cast is harmful. */
+ else
+ ((cast_t *)data)->type = -1;
+ }
+
+ if (((cast_t*)data)->type == -1)
+ return true;
+
+ return false;
+}
+
+/* When array element a_p[i] is accessed through the pointer a_p
+ and index i, it's translated into the following sequence
+ in gimple:
+
+ i.1_5 = (unsigned int) i_1;
+ D.1605_6 = i.1_5 * 16;
+ D.1606_7 = (struct str_t *) D.1605_6;
+ a_p.2_8 = a_p;
+ D.1608_9 = D.1606_7 + a_p.2_8;
+
+ OP0 and OP1 are of the same pointer types and stand for
+ D.1606_7 and a_p.2_8 or vise versa.
+
+ This function checks that:
+
+ 1. one of OP0 and OP1 (D.1606_7) has passed only one cast from
+ non-pointer type (D.1606_7 = (struct str_t *) D.1605_6;).
+
+ 2. one of OP0 and OP1 which has passed the cast from
+ non-pointer type (D.1606_7), is actually generated by multiplication of
+ index by size of type to which both OP0 and OP1 point to
+ (in this case D.1605_6 = i.1_5 * 16; ).
+
+ 3. an address of def of the var to which was made cast (D.1605_6)
+ was not taken.(How can it happen?)
+
+ The following items are checked implicitly by the end of algorithm:
+
+ 4. one of OP0 and OP1 (a_p.2_8) have never been cast
+ (because if it was cast to pointer type, its type, that is also
+ the type of OP0 and OP1, will be marked as escaped during
+ analysis of casting stmt (when check_cast() is called
+ from scan_for_refs for this stmt)).
+
+ 5. defs of OP0 and OP1 are not passed into externally visible function
+ (because if they are passed then their type, that is also the type of OP0
+ and OP1, will be marked and escaped during check_call function called from
+ scan_for_refs with call stmt).
+
+ In total, 1-5 guaranty that it's an access to array by pointer and index.
+
+*/
+
+bool
+is_array_access_through_pointer_and_index (enum tree_code code, tree op0,
+ tree op1, tree *base, tree *offset,
+ gimple *offset_cast_stmt)
+{
+ tree before_cast;
+ gimple before_cast_def_stmt;
+ cast_t op0_cast, op1_cast;
+
+ *base = NULL;
+ *offset = NULL;
+ *offset_cast_stmt = NULL;
+
+ /* Check 1. */
+ if (code == POINTER_PLUS_EXPR)
+ {
+ tree op0type = TYPE_MAIN_VARIANT (TREE_TYPE (op0));
+ tree op1type = TYPE_MAIN_VARIANT (TREE_TYPE (op1));
+
+ /* One of op0 and op1 is of pointer type and the other is numerical. */
+ if (POINTER_TYPE_P (op0type) && NUMERICAL_TYPE_CHECK (op1type))
+ {
+ *base = op0;
+ *offset = op1;
+ }
+ else if (POINTER_TYPE_P (op1type) && NUMERICAL_TYPE_CHECK (op0type))
+ {
+ *base = op1;
+ *offset = op0;
+ }
+ else
+ return false;
+ }
+ else
+ {
+ /* Init data for walk_use_def_chains function. */
+ op0_cast.type = op1_cast.type = 0;
+ op0_cast.stmt = op1_cast.stmt = NULL;
+
+ visited_stmts = pointer_set_create ();
+ walk_use_def_chains (op0, is_cast_from_non_pointer,(void *)(&op0_cast),
+ false);
+ pointer_set_destroy (visited_stmts);
+
+ visited_stmts = pointer_set_create ();
+ walk_use_def_chains (op1, is_cast_from_non_pointer,(void *)(&op1_cast),
+ false);
+ pointer_set_destroy (visited_stmts);
+
+ if (op0_cast.type == 1 && op1_cast.type == 0)
+ {
+ *base = op1;
+ *offset = op0;
+ *offset_cast_stmt = op0_cast.stmt;
+ }
+ else if (op0_cast.type == 0 && op1_cast.type == 1)
+ {
+ *base = op0;
+ *offset = op1;
+ *offset_cast_stmt = op1_cast.stmt;
+ }
+ else
+ return false;
+ }
+
+ /* Check 2.
+ offset_cast_stmt is of the form:
+ D.1606_7 = (struct str_t *) D.1605_6; */
+
+ if (*offset_cast_stmt)
+ {
+ before_cast = SINGLE_SSA_TREE_OPERAND (*offset_cast_stmt, SSA_OP_USE);
+ if (!before_cast)
+ return false;
+
+ if (SSA_NAME_IS_DEFAULT_DEF (before_cast))
+ return false;
+
+ before_cast_def_stmt = SSA_NAME_DEF_STMT (before_cast);
+ if (!before_cast_def_stmt)
+ return false;
+ }
+ else
+ before_cast_def_stmt = SSA_NAME_DEF_STMT (*offset);
+
+ /* before_cast_def_stmt should be of the form:
+ D.1605_6 = i.1_5 * 16; */
+
+ if (is_gimple_assign (before_cast_def_stmt))
+ {
+ /* We expect temporary here. */
+ if (!is_gimple_reg (gimple_assign_lhs (before_cast_def_stmt)))
+ return false;
+
+ if (gimple_assign_rhs_code (before_cast_def_stmt) == MULT_EXPR)
+ {
+ tree arg0 = gimple_assign_rhs1 (before_cast_def_stmt);
+ tree arg1 = gimple_assign_rhs2 (before_cast_def_stmt);
+ tree unit_size =
+ TYPE_SIZE_UNIT (TREE_TYPE (TYPE_MAIN_VARIANT (TREE_TYPE (op0))));
+
+ if (!(CONSTANT_CLASS_P (arg0)
+ && simple_cst_equal (arg0, unit_size))
+ && !(CONSTANT_CLASS_P (arg1)
+ && simple_cst_equal (arg1, unit_size)))
+ return false;
+ }
+ else
+ return false;
+ }
+ else
+ return false;
+
+ /* Check 3.
+ check that address of D.1605_6 was not taken.
+ FIXME: if D.1605_6 is gimple reg than it cannot be addressable. */
+
+ return true;
}
/* Register the parameter and return types of function FN. The type
static void
check_tree (tree t)
{
- if ((TREE_CODE (t) == EXC_PTR_EXPR) || (TREE_CODE (t) == FILTER_EXPR))
- return;
-
- while (TREE_CODE (t) == REALPART_EXPR
- || TREE_CODE (t) == IMAGPART_EXPR
- || handled_component_p (t))
+ /* We want to catch here also REALPART_EXPR and IMAGEPART_EXPR,
+ but they already included in handled_component_p. */
+ while (handled_component_p (t))
{
if (TREE_CODE (t) == ARRAY_REF)
check_operand (TREE_OPERAND (t, 1));
check_tree (TREE_OPERAND (t, 0));
if (SSA_VAR_P (t) || (TREE_CODE (t) == FUNCTION_DECL))
- check_operand (t);
+ {
+ check_operand (t);
+ if (DECL_P (t) && DECL_INITIAL (t))
+ check_tree (DECL_INITIAL (t));
+ }
}
/* Create an address_of edge FROM_TYPE.TO_TYPE. */
to_uid,
(splay_tree_value)type_map);
}
- bitmap_set_bit (type_map, TYPE_UID (to_type));
+ bitmap_set_bit (type_map, TYPE_UID (from_type));
}
/* Scan tree T to see if there are any addresses taken in within T. */
}
-/* Scan tree T to see if there are any casts within it.
- LHS Is the LHS of the expression involving the cast. */
+/* Scan tree T to see if there are any casts within it. */
-static void
-look_for_casts (tree lhs __attribute__((unused)), tree t)
+static unsigned int
+look_for_casts (tree t)
{
+ unsigned int cast = 0;
+
if (is_gimple_cast (t) || TREE_CODE (t) == VIEW_CONVERT_EXPR)
{
tree castfromvar = TREE_OPERAND (t, 0);
- check_cast (TREE_TYPE (t), castfromvar);
+ cast = cast | check_cast (TREE_TYPE (t), castfromvar);
}
- else if (TREE_CODE (t) == COMPONENT_REF
- || TREE_CODE (t) == INDIRECT_REF
- || TREE_CODE (t) == BIT_FIELD_REF)
- {
- tree base = get_base_address (t);
- while (t != base)
- {
- t = TREE_OPERAND (t, 0);
- if (TREE_CODE (t) == VIEW_CONVERT_EXPR)
- {
- /* This may be some part of a component ref.
- IE it may be a.b.VIEW_CONVERT_EXPR<weird_type>(c).d, AFAIK.
- castfromref will give you a.b.c, not a. */
- tree castfromref = TREE_OPERAND (t, 0);
- check_cast (TREE_TYPE (t), castfromref);
- }
- else if (TREE_CODE (t) == COMPONENT_REF)
- get_canon_type (TREE_TYPE (TREE_OPERAND (t, 1)), false, false);
- }
- }
+ else
+ while (handled_component_p (t))
+ {
+ t = TREE_OPERAND (t, 0);
+ if (TREE_CODE (t) == VIEW_CONVERT_EXPR)
+ {
+ /* This may be some part of a component ref.
+ IE it may be a.b.VIEW_CONVERT_EXPR<weird_type>(c).d, AFAIK.
+ castfromref will give you a.b.c, not a. */
+ tree castfromref = TREE_OPERAND (t, 0);
+ cast = cast | check_cast (TREE_TYPE (t), castfromref);
+ }
+ else if (TREE_CODE (t) == COMPONENT_REF)
+ get_canon_type (TREE_TYPE (TREE_OPERAND (t, 1)), false, false);
+ }
+
+ if (!cast)
+ cast = CT_NO_CAST;
+ return cast;
}
/* Check to see if T is a read or address of operation on a static var
check_rhs_var (tree t)
{
look_for_address_of (t);
- check_tree(t);
+ check_tree (t);
}
/* Check to see if T is an assignment to a static var we are
static void
check_lhs_var (tree t)
{
- check_tree(t);
+ check_tree (t);
}
/* This is a scaled down version of get_asm_expr_operands from
analyzed and STMT is the actual asm statement. */
static void
-get_asm_expr_operands (tree stmt)
+check_asm (gimple stmt)
{
- int noutputs = list_length (ASM_OUTPUTS (stmt));
- const char **oconstraints
- = (const char **) alloca ((noutputs) * sizeof (const char *));
- int i;
- tree link;
- const char *constraint;
- bool allows_mem, allows_reg, is_inout;
-
- for (i=0, link = ASM_OUTPUTS (stmt); link; ++i, link = TREE_CHAIN (link))
- {
- oconstraints[i] = constraint
- = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
- parse_output_constraint (&constraint, i, 0, 0,
- &allows_mem, &allows_reg, &is_inout);
-
- check_lhs_var (TREE_VALUE (link));
- }
+ size_t i;
- for (link = ASM_INPUTS (stmt); link; link = TREE_CHAIN (link))
- {
- constraint
- = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
- parse_input_constraint (&constraint, 0, 0, noutputs, 0,
- oconstraints, &allows_mem, &allows_reg);
-
- check_rhs_var (TREE_VALUE (link));
- }
+ for (i = 0; i < gimple_asm_noutputs (stmt); i++)
+ check_lhs_var (gimple_asm_output_op (stmt, i));
+
+ for (i = 0; i < gimple_asm_ninputs (stmt); i++)
+ check_rhs_var (gimple_asm_input_op (stmt, i));
/* There is no code here to check for asm memory clobbers. The
casual maintainer might think that such code would be necessary,
assumed to already escape. So, we are protected here. */
}
-/* Check the parameters of a function call to CALL_EXPR to mark the
+
+/* Check the parameters of function call to CALL to mark the
types that pass across the function boundary. Also check to see if
this is either an indirect call, a call outside the compilation
unit. */
-static bool
-check_call (tree call_expr)
+static void
+check_call (gimple call)
{
- int flags = call_expr_flags(call_expr);
- tree operand_list = TREE_OPERAND (call_expr, 1);
- tree operand;
- tree callee_t = get_callee_fndecl (call_expr);
- tree argument;
+ tree callee_t = gimple_call_fndecl (call);
struct cgraph_node* callee;
enum availability avail = AVAIL_NOT_AVAILABLE;
+ size_t i;
- for (operand = operand_list;
- operand != NULL_TREE;
- operand = TREE_CHAIN (operand))
- {
- tree argument = TREE_VALUE (operand);
- check_rhs_var (argument);
- }
+ for (i = 0; i < gimple_call_num_args (call); i++)
+ check_rhs_var (gimple_call_arg (call, i));
if (callee_t)
{
parameters. */
if (TYPE_ARG_TYPES (TREE_TYPE (callee_t)))
{
- operand = operand_list;
- for (arg_type = TYPE_ARG_TYPES (TREE_TYPE (callee_t));
+ for (arg_type = TYPE_ARG_TYPES (TREE_TYPE (callee_t)), i = 0;
arg_type && TREE_VALUE (arg_type) != void_type_node;
- arg_type = TREE_CHAIN (arg_type))
+ arg_type = TREE_CHAIN (arg_type), i++)
{
+ tree operand = gimple_call_arg (call, i);
if (operand)
{
- argument = TREE_VALUE (operand);
last_arg_type = TREE_VALUE(arg_type);
- check_cast (last_arg_type, argument);
- operand = TREE_CHAIN (operand);
+ check_cast (last_arg_type, operand);
}
else
/* The code reaches here for some unfortunate
/* FIXME - According to Geoff Keating, we should never
have to do this; the front ends should always process
the arg list from the TYPE_ARG_LIST. */
- operand = operand_list;
- for (arg_type = DECL_ARGUMENTS (callee_t);
+ for (arg_type = DECL_ARGUMENTS (callee_t), i = 0;
arg_type;
- arg_type = TREE_CHAIN (arg_type))
+ arg_type = TREE_CHAIN (arg_type), i++)
{
+ tree operand = gimple_call_arg (call, i);
if (operand)
{
- argument = TREE_VALUE (operand);
- last_arg_type = TREE_TYPE(arg_type);
- check_cast (last_arg_type, argument);
- operand = TREE_CHAIN (operand);
+ last_arg_type = TREE_TYPE (arg_type);
+ check_cast (last_arg_type, operand);
}
else
/* The code reaches here for some unfortunate
/* In the case where we have a var_args function, we need to
check the remaining parameters against the last argument. */
arg_type = last_arg_type;
- for (;
- operand != NULL_TREE;
- operand = TREE_CHAIN (operand))
+ for ( ; i < gimple_call_num_args (call); i++)
{
- argument = TREE_VALUE (operand);
+ tree operand = gimple_call_arg (call, i);
if (arg_type)
- check_cast (arg_type, argument);
+ check_cast (arg_type, operand);
else
{
/* The code reaches here for some unfortunate
argument types. Most of these functions have
been marked as having their parameters not
escape, but for the rest, the type is doomed. */
- tree type = get_canon_type (TREE_TYPE (argument), false, false);
+ tree type = get_canon_type (TREE_TYPE (operand), false, false);
mark_interesting_type (type, FULL_ESCAPE);
}
}
are any bits available for the callee (such as by declaration or
because it is builtin) and process solely on the basis of those
bits. */
-
if (avail == AVAIL_NOT_AVAILABLE || avail == AVAIL_OVERWRITABLE)
{
/* If this is a direct call to an external function, mark all of
the parameter and return types. */
- for (operand = operand_list;
- operand != NULL_TREE;
- operand = TREE_CHAIN (operand))
+ for (i = 0; i < gimple_call_num_args (call); i++)
{
- tree type =
- get_canon_type (TREE_TYPE (TREE_VALUE (operand)), false, false);
+ tree operand = gimple_call_arg (call, i);
+ tree type = get_canon_type (TREE_TYPE (operand), false, false);
mark_interesting_type (type, EXPOSED_PARAMETER);
- }
+ }
if (callee_t)
{
mark_interesting_type (type, EXPOSED_PARAMETER);
}
}
- return (flags & ECF_MALLOC);
}
/* CODE is the operation on OP0 and OP1. OP0 is the operand that we
okay_pointer_operation (enum tree_code code, tree op0, tree op1)
{
tree op0type = TYPE_MAIN_VARIANT (TREE_TYPE (op0));
- tree op1type = TYPE_MAIN_VARIANT (TREE_TYPE (op1));
- if (POINTER_TYPE_P (op1type))
- return false;
+
switch (code)
{
case MULT_EXPR:
- case PLUS_EXPR:
+ /* Multiplication does not change alignment. */
+ return true;
+ break;
case MINUS_EXPR:
- /* TODO: Handle multiples of op0 size as well */
- if (operand_equal_p (size_in_bytes (op0type), op1, 0))
- return true;
- /* fallthrough */
+ case PLUS_EXPR:
+ case POINTER_PLUS_EXPR:
+ {
+ tree base, offset;
+ gimple offset_cast_stmt;
+
+ if (POINTER_TYPE_P (op0type)
+ && TREE_CODE (op0) == SSA_NAME
+ && TREE_CODE (op1) == SSA_NAME
+ && is_array_access_through_pointer_and_index (code, op0, op1,
+ &base,
+ &offset,
+ &offset_cast_stmt))
+ return true;
+ else
+ {
+ tree size_of_op0_points_to = TYPE_SIZE_UNIT (TREE_TYPE (op0type));
+
+ if (CONSTANT_CLASS_P (op1)
+ && size_of_op0_points_to
+ && multiple_of_p (TREE_TYPE (size_of_op0_points_to),
+ op1, size_of_op0_points_to))
+ return true;
+ if (CONSTANT_CLASS_P (op0)
+ && size_of_op0_points_to
+ && multiple_of_p (TREE_TYPE (size_of_op0_points_to),
+ op0, size_of_op0_points_to))
+ return true;
+ }
+ }
+ break;
default:
return false;
}
return false;
}
-/* TP is the part of the tree currently under the microscope.
- WALK_SUBTREES is part of the walk_tree api but is unused here.
- DATA is cgraph_node of the function being walked. */
-/* FIXME: When this is converted to run over SSA form, this code
- should be converted to use the operand scanner. */
-static tree
-scan_for_refs (tree *tp, int *walk_subtrees, void *data)
+/* Helper for scan_for_refs. Check the operands of an assignment to
+ mark types that may escape. */
+
+static void
+check_assign (gimple t)
{
- struct cgraph_node *fn = data;
- tree t = *tp;
+ /* First look on the lhs and see what variable is stored to */
+ check_lhs_var (gimple_assign_lhs (t));
- switch (TREE_CODE (t))
+ /* For the purposes of figuring out what the cast affects */
+
+ /* Next check the operands on the rhs to see if they are ok. */
+ switch (TREE_CODE_CLASS (gimple_assign_rhs_code (t)))
{
- case VAR_DECL:
- if (DECL_INITIAL (t))
- walk_tree (&DECL_INITIAL (t), scan_for_refs, fn, visited_nodes);
- *walk_subtrees = 0;
+ case tcc_binary:
+ {
+ tree op0 = gimple_assign_rhs1 (t);
+ tree type0 = get_canon_type (TREE_TYPE (op0), false, false);
+ tree op1 = gimple_assign_rhs2 (t);
+ tree type1 = get_canon_type (TREE_TYPE (op1), false, false);
+
+ /* If this is pointer arithmetic of any bad sort, then
+ we need to mark the types as bad. For binary
+ operations, no binary operator we currently support
+ is always "safe" in regard to what it would do to
+ pointers for purposes of determining which types
+ escape, except operations of the size of the type.
+ It is possible that min and max under the right set
+ of circumstances and if the moon is in the correct
+ place could be safe, but it is hard to see how this
+ is worth the effort. */
+ if (type0 && POINTER_TYPE_P (type0)
+ && !okay_pointer_operation (gimple_assign_rhs_code (t), op0, op1))
+ mark_interesting_type (type0, FULL_ESCAPE);
+
+ if (type1 && POINTER_TYPE_P (type1)
+ && !okay_pointer_operation (gimple_assign_rhs_code (t), op1, op0))
+ mark_interesting_type (type1, FULL_ESCAPE);
+
+ look_for_casts (op0);
+ look_for_casts (op1);
+ check_rhs_var (op0);
+ check_rhs_var (op1);
+ }
break;
- case MODIFY_EXPR:
+ case tcc_unary:
{
- /* First look on the lhs and see what variable is stored to */
- tree lhs = TREE_OPERAND (t, 0);
- tree rhs = TREE_OPERAND (t, 1);
+ tree op0 = gimple_assign_rhs1 (t);
+ tree type0 = get_canon_type (TREE_TYPE (op0), false, false);
+
+ /* For unary operations, if the operation is NEGATE or ABS on
+ a pointer, this is also considered pointer arithmetic and
+ thus, bad for business. */
+ if (type0
+ && POINTER_TYPE_P (type0)
+ && (TREE_CODE (op0) == NEGATE_EXPR
+ || TREE_CODE (op0) == ABS_EXPR))
+ mark_interesting_type (type0, FULL_ESCAPE);
+
+ check_rhs_var (op0);
+ look_for_casts (op0);
+ }
+ break;
- check_lhs_var (lhs);
- check_cast (TREE_TYPE (lhs), rhs);
+ case tcc_reference:
+ look_for_casts (gimple_assign_rhs1 (t));
+ check_rhs_var (gimple_assign_rhs1 (t));
+ break;
- /* For the purposes of figuring out what the cast affects */
+ case tcc_declaration:
+ check_rhs_var (gimple_assign_rhs1 (t));
+ break;
- /* Next check the operands on the rhs to see if they are ok. */
- switch (TREE_CODE_CLASS (TREE_CODE (rhs)))
- {
- case tcc_binary:
- {
- tree op0 = TREE_OPERAND (rhs, 0);
- tree type0 = get_canon_type (TREE_TYPE (op0), false, false);
- tree op1 = TREE_OPERAND (rhs, 1);
- tree type1 = get_canon_type (TREE_TYPE (op1), false, false);
-
- /* If this is pointer arithmetic of any bad sort, then
- we need to mark the types as bad. For binary
- operations, no binary operator we currently support
- is always "safe" in regard to what it would do to
- pointers for purposes of determining which types
- escape, except operations of the size of the type.
- It is possible that min and max under the right set
- of circumstances and if the moon is in the correct
- place could be safe, but it is hard to see how this
- is worth the effort. */
-
- if (type0 && POINTER_TYPE_P (type0)
- && !okay_pointer_operation (TREE_CODE (rhs), op0, op1))
- mark_interesting_type (type0, FULL_ESCAPE);
- if (type1 && POINTER_TYPE_P (type1)
- && !okay_pointer_operation (TREE_CODE (rhs), op1, op0))
- mark_interesting_type (type1, FULL_ESCAPE);
-
- look_for_casts (lhs, op0);
- look_for_casts (lhs, op1);
- check_rhs_var (op0);
- check_rhs_var (op1);
- }
- break;
- case tcc_unary:
- {
- tree op0 = TREE_OPERAND (rhs, 0);
- tree type0 = get_canon_type (TREE_TYPE (op0), false, false);
- /* For unary operations, if the operation is NEGATE or
- ABS on a pointer, this is also considered pointer
- arithmetic and thus, bad for business. */
- if (type0 && (TREE_CODE (op0) == NEGATE_EXPR
- || TREE_CODE (op0) == ABS_EXPR)
- && POINTER_TYPE_P (type0))
- {
- mark_interesting_type (type0, FULL_ESCAPE);
- }
- check_rhs_var (op0);
- look_for_casts (lhs, op0);
- look_for_casts (lhs, rhs);
- }
+ case tcc_expression:
+ if (gimple_assign_rhs_code (t) == ADDR_EXPR)
+ {
+ tree rhs = gimple_assign_rhs1 (t);
+ look_for_casts (TREE_OPERAND (rhs, 0));
+ check_rhs_var (rhs);
+ }
+ break;
- break;
- case tcc_reference:
- look_for_casts (lhs, rhs);
- check_rhs_var (rhs);
- break;
- case tcc_declaration:
- check_rhs_var (rhs);
- break;
- case tcc_expression:
- switch (TREE_CODE (rhs))
- {
- case ADDR_EXPR:
- look_for_casts (lhs, TREE_OPERAND (rhs, 0));
- check_rhs_var (rhs);
- break;
- case CALL_EXPR:
- /* If this is a call to malloc, squirrel away the
- result so we do mark the resulting cast as being
- bad. */
- if (check_call (rhs))
- bitmap_set_bit (results_of_malloc, DECL_UID (lhs));
- break;
- default:
- break;
- }
- break;
- default:
- break;
- }
- *walk_subtrees = 0;
- }
+ default:
break;
+ }
+}
+
+
+/* Scan statement T for references to types and mark anything
+ interesting. */
- case ADDR_EXPR:
- /* This case is here to find addresses on rhs of constructors in
- decl_initial of static variables. */
- check_rhs_var (t);
- *walk_subtrees = 0;
+static void
+scan_for_refs (gimple t)
+{
+ switch (gimple_code (t))
+ {
+ case GIMPLE_ASSIGN:
+ check_assign (t);
break;
- case CALL_EXPR:
+ case GIMPLE_CALL:
+ /* If this is a call to malloc, squirrel away the result so we
+ do mark the resulting cast as being bad. */
check_call (t);
- *walk_subtrees = 0;
break;
- case ASM_EXPR:
- get_asm_expr_operands (t);
- *walk_subtrees = 0;
+ case GIMPLE_ASM:
+ check_asm (t);
break;
default:
break;
}
- return NULL;
+
+ return;
}
global_types_exposed_parameter = BITMAP_ALLOC (&ipa_obstack);
global_types_full_escape = BITMAP_ALLOC (&ipa_obstack);
global_types_seen = BITMAP_ALLOC (&ipa_obstack);
- results_of_malloc = BITMAP_ALLOC (&ipa_obstack);
uid_to_canon_type = splay_tree_new (splay_tree_compare_ints, 0, 0);
all_canon_types = splay_tree_new (compare_type_brand, 0, 0);
/* Check out the rhs of a static or global initialization VNODE to see
if any of them contain addressof operations. Note that some of
- these variables may not even be referenced in the code in this
+ these variables may not even be referenced in the code in this
compilation unit but their right hand sides may contain references
to variables defined within this unit. */
static void
-analyze_variable (struct cgraph_varpool_node *vnode)
+analyze_variable (struct varpool_node *vnode)
{
tree global = vnode->decl;
tree type = get_canon_type (TREE_TYPE (global), false, false);
gcc_assert (TREE_CODE (global) == VAR_DECL);
if (DECL_INITIAL (global))
- walk_tree (&DECL_INITIAL (global), scan_for_refs, NULL, visited_nodes);
+ check_tree (DECL_INITIAL (global));
}
/* This is the main routine for finding the reference patterns for
FOR_EACH_BB_FN (this_block, this_cfun)
{
- block_stmt_iterator bsi;
- for (bsi = bsi_start (this_block); !bsi_end_p (bsi); bsi_next (&bsi))
- walk_tree (bsi_stmt_ptr (bsi), scan_for_refs,
- fn, visited_nodes);
+ gimple_stmt_iterator gsi;
+ for (gsi = gsi_start_bb (this_block); !gsi_end_p (gsi); gsi_next (&gsi))
+ scan_for_refs (gsi_stmt (gsi));
}
}
if (DECL_STRUCT_FUNCTION (decl))
{
tree step;
- for (step = DECL_STRUCT_FUNCTION (decl)->unexpanded_var_list;
+ for (step = DECL_STRUCT_FUNCTION (decl)->local_decls;
step;
step = TREE_CHAIN (step))
{
if (TREE_CODE (var) == VAR_DECL
&& DECL_INITIAL (var)
&& !TREE_STATIC (var))
- walk_tree (&DECL_INITIAL (var), scan_for_refs,
- fn, visited_nodes);
+ check_tree (DECL_INITIAL (var));
get_canon_type (TREE_TYPE (var), false, false);
}
}
else return NULL;
}
-/* Return the a bitmap with the subtypes of the type for UID. If it
+/* Return a bitmap with the subtypes of the type for UID. If it
does not exist, return either NULL or a new bitmap depending on the
value of CREATE. */
\f
/* The main entry point for type escape analysis. */
-static void
+static unsigned int
type_escape_execute (void)
{
struct cgraph_node *node;
- struct cgraph_varpool_node *vnode;
+ struct varpool_node *vnode;
unsigned int i;
bitmap_iterator bi;
splay_tree_node result;
ipa_init ();
/* Process all of the variables first. */
- for (vnode = cgraph_varpool_nodes_queue; vnode; vnode = vnode->next_needed)
+ FOR_EACH_STATIC_VARIABLE (vnode)
analyze_variable (vnode);
- /* Process all of the functions. next
+ /* Process all of the functions next.
We do not want to process any of the clones so we check that this
is a master clone. However, we do need to process any
they may cause a type variable to escape.
*/
for (node = cgraph_nodes; node; node = node->next)
- if (node->analyzed
- && (cgraph_is_master_clone (node)
- || (cgraph_function_body_availability (node) == AVAIL_OVERWRITABLE)))
+ if (node->analyzed)
analyze_function (node);
BITMAP_FREE (global_types_exposed_parameter);
BITMAP_FREE (been_there_done_that);
BITMAP_FREE (bitmap_tmp);
- BITMAP_FREE (results_of_malloc);
+ return 0;
}
static bool
gate_type_escape_vars (void)
{
- return (flag_unit_at_a_time != 0 && flag_ipa_type_escape
+ return (flag_ipa_type_escape
/* Don't bother doing anything if the program has errors. */
&& !(errorcount || sorrycount));
}
-struct tree_opt_pass pass_ipa_type_escape =
+struct simple_ipa_opt_pass pass_ipa_type_escape =
{
+ {
+ SIMPLE_IPA_PASS,
"type-escape-var", /* name */
gate_type_escape_vars, /* gate */
type_escape_execute, /* execute */
0, /* properties_provided */
0, /* properties_destroyed */
0, /* todo_flags_start */
- 0, /* todo_flags_finish */
- 0 /* letter */
+ 0 /* todo_flags_finish */
+ }
};
-
OSDN Git Service
