#include "tree-vector-builder.h"
#include "tree-ssa-strlen.h"
-static bool get_range_strlen (tree, tree[2], bitmap *, int,
- int, bool *, unsigned, tree *);
+enum strlen_range_kind {
+ /* Compute the exact constant string length. */
+ SRK_STRLEN,
+ /* Compute the maximum constant string length. */
+ SRK_STRLENMAX,
+ /* Compute a range of string lengths bounded by object sizes. When
+ the length of a string cannot be determined, consider as the upper
+ bound the size of the enclosing object the string may be a member
+ or element of. Also determine the size of the largest character
+ array the string may refer to. */
+ SRK_LENRANGE,
+ /* Temporary until the rest of Martin's strlen range work is integrated. */
+ SRK_LENRANGE_2,
+ /* Determine the integer value of the argument (not string length). */
+ SRK_INT_VALUE
+};
+
+static bool get_range_strlen (tree, tree[2], bitmap *, strlen_range_kind,
+ bool *, unsigned, tree *);
/* Return true when DECL can be referenced from current unit.
FROM_DECL (if non-null) specify constructor of variable DECL was taken from.
/* Helper of get_range_strlen for ARG that is not an SSA_NAME. */
static bool
-get_range_strlen_tree (tree arg, tree length[2], bitmap *visited, int type,
- int fuzzy, bool *flexp, unsigned eltsize, tree *nonstr)
+get_range_strlen_tree (tree arg, tree length[2], bitmap *visited,
+ strlen_range_kind rkind,
+ bool *flexp, unsigned eltsize, tree *nonstr)
{
gcc_assert (TREE_CODE (arg) != SSA_NAME);
if (TREE_CODE (aop0) == INDIRECT_REF
&& TREE_CODE (TREE_OPERAND (aop0, 0)) == SSA_NAME)
return get_range_strlen (TREE_OPERAND (aop0, 0), length,
- visited, type, fuzzy, flexp,
+ visited, rkind, flexp,
eltsize, nonstr);
}
- else if (TREE_CODE (TREE_OPERAND (op, 0)) == COMPONENT_REF && fuzzy)
+ else if (TREE_CODE (TREE_OPERAND (op, 0)) == COMPONENT_REF
+ && (rkind == SRK_LENRANGE || rkind == SRK_LENRANGE_2))
{
/* Fail if an array is the last member of a struct object
since it could be treated as a (fake) flexible array
}
}
- if (type == 2)
+ if (rkind == SRK_INT_VALUE)
{
/* We are computing the maximum value (not string length). */
val = arg;
*nonstr = lendata.decl;
*minlen = lendata.minlen;
*maxlen = lendata.minlen;
- return type == 0 ? false : true;
+ return rkind == SRK_STRLEN ? false : true;
}
}
- if (!val && fuzzy)
+ if (!val && (rkind == SRK_LENRANGE || rkind == SRK_LENRANGE_2))
{
if (TREE_CODE (arg) == ADDR_EXPR)
return get_range_strlen (TREE_OPERAND (arg, 0), length,
- visited, type, fuzzy, flexp,
+ visited, rkind, flexp,
eltsize, nonstr);
if (TREE_CODE (arg) == ARRAY_REF)
/* Adjust the lower bound on the string length as necessary. */
if (!*minlen
- || (type > 0
+ || (rkind != SRK_STRLEN
&& TREE_CODE (*minlen) == INTEGER_CST
&& TREE_CODE (val) == INTEGER_CST
&& tree_int_cst_lt (val, *minlen)))
{
/* Adjust the more conservative bound if possible/necessary
and fail otherwise. */
- if (type > 0)
+ if (rkind != SRK_STRLEN)
{
if (TREE_CODE (*maxlen) != INTEGER_CST
|| TREE_CODE (val) != INTEGER_CST)
TYPE == 0, if LENGTH[1] is not equal to the length we determine or
if we are unable to determine the length or value, return false.
VISITED is a bitmap of visited variables.
- TYPE is 0 if string length should be obtained, 1 for maximum string
- length and 2 for maximum value ARG can have.
- When FUZZY is non-zero and the length of a string cannot be determined,
- the function instead considers as the maximum possible length the
- size of a character array it may refer to. If FUZZY is 2, it will handle
- PHIs and COND_EXPRs optimistically, if we can determine string length
- minimum and maximum, it will use the minimum from the ones where it
- can be determined.
- Set *FLEXP to true if the range of the string lengths has been
- obtained from the upper bound of an array at the end of a struct.
- Such an array may hold a string that's longer than its upper bound
- due to it being used as a poor-man's flexible array member.
- Pass NONSTR through to children.
- ELTSIZE is 1 for normal single byte character strings, and 2 or
- 4 for wide characer strings. ELTSIZE is by default 1. */
+ RKIND determines the kind of value or range to obtain (see
+ strlen_range_kind).
+ Set PDATA->DECL if ARG refers to an unterminated constant array.
+ On input, set ELTSIZE to 1 for normal single byte character strings,
+ and either 2 or 4 for wide characer strings (the size of wchar_t).
+ Return true if *PDATA was successfully populated and false otherwise. */
static bool
-get_range_strlen (tree arg, tree length[2], bitmap *visited, int type,
- int fuzzy, bool *flexp, unsigned eltsize, tree *nonstr)
+get_range_strlen (tree arg, tree length[2], bitmap *visited,
+ strlen_range_kind rkind,
+ bool *flexp, unsigned eltsize, tree *nonstr)
{
if (TREE_CODE (arg) != SSA_NAME)
- return get_range_strlen_tree (arg, length, visited, type, fuzzy, flexp,
+ return get_range_strlen_tree (arg, length, visited, rkind, flexp,
eltsize, nonstr);
/* If ARG is registered for SSA update we cannot look at its defining
switch (gimple_code (def_stmt))
{
case GIMPLE_ASSIGN:
- /* The RHS of the statement defining VAR must either have a
- constant length or come from another SSA_NAME with a constant
- length. */
+ /* The RHS of the statement defining VAR must either have a
+ constant length or come from another SSA_NAME with a constant
+ length. */
if (gimple_assign_single_p (def_stmt)
|| gimple_assign_unary_nop_p (def_stmt))
{
- tree rhs = gimple_assign_rhs1 (def_stmt);
- return get_range_strlen (rhs, length, visited, type, fuzzy, flexp,
+ tree rhs = gimple_assign_rhs1 (def_stmt);
+ return get_range_strlen (rhs, length, visited, rkind, flexp,
eltsize, nonstr);
}
else if (gimple_assign_rhs_code (def_stmt) == COND_EXPR)
gimple_assign_rhs3 (def_stmt) };
for (unsigned int i = 0; i < 2; i++)
- if (!get_range_strlen (ops[i], length, visited, type, fuzzy,
+ if (!get_range_strlen (ops[i], length, visited, rkind,
flexp, eltsize, nonstr))
{
- if (fuzzy == 2)
+ if (rkind == SRK_LENRANGE_2)
*maxlen = build_all_ones_cst (size_type_node);
else
return false;
return false;
case GIMPLE_PHI:
- /* All the arguments of the PHI node must have the same constant
- length. */
+ /* Unless RKIND == SRK_LENRANGE, all arguments of the PHI node
+ must have a constant length. */
for (unsigned i = 0; i < gimple_phi_num_args (def_stmt); i++)
{
tree arg = gimple_phi_arg (def_stmt, i)->def;
if (arg == gimple_phi_result (def_stmt))
continue;
- if (!get_range_strlen (arg, length, visited, type, fuzzy, flexp,
+ if (!get_range_strlen (arg, length, visited, rkind, flexp,
eltsize, nonstr))
{
- if (fuzzy == 2)
+ if (rkind == SRK_LENRANGE_2)
*maxlen = build_all_ones_cst (size_type_node);
else
return false;
*nonstr = NULL_TREE;
bool flexarray = false;
- if (!get_range_strlen (arg, minmaxlen, &visited, 1, strict ? 1 : 2,
+ if (!get_range_strlen (arg, minmaxlen, &visited,
+ strict ? SRK_LENRANGE : SRK_LENRANGE_2,
&flexarray, eltsize, nonstr))
{
minmaxlen[0] = NULL_TREE;
unterminated strings, then bubble up the offending DECL and
return the maximum size. Otherwise return NULL. */
-tree
-get_maxval_strlen (tree arg, int type, tree *nonstr /* = NULL */)
+static tree
+get_maxval_strlen (tree arg, strlen_range_kind rkind, tree *nonstr = NULL)
{
+ /* A non-null NONSTR is meaningless when determining the maximum
+ value of an integer ARG. */
+ gcc_assert (rkind != SRK_INT_VALUE || nonstr == NULL);
+ /* ARG must have an integral type when RKIND says so. */
+ gcc_assert (rkind != SRK_INT_VALUE || INTEGRAL_TYPE_P (TREE_TYPE (arg)));
+
bitmap visited = NULL;
tree len[2] = { NULL_TREE, NULL_TREE };
bool dummy;
/* Set to non-null if ARG refers to an untermianted array. */
tree mynonstr = NULL_TREE;
- if (!get_range_strlen (arg, len, &visited, type, 0, &dummy, 1, &mynonstr))
+ if (!get_range_strlen (arg, len, &visited, rkind, &dummy, 1, &mynonstr))
len[1] = NULL_TREE;
if (visited)
BITMAP_FREE (visited);
/* Set to non-null if ARG refers to an unterminated array. */
tree nonstr = NULL;
- tree len = get_maxval_strlen (src, 0, &nonstr);
+ tree len = get_maxval_strlen (src, SRK_STRLEN, &nonstr);
if (nonstr)
{
/* Warn about the lack of nul termination: the result is not
a (nul-terminated) string. */
- tree slen = get_maxval_strlen (src, 0);
+ tree slen = get_maxval_strlen (src, SRK_STRLEN);
if (slen && !integer_zerop (slen))
warning_at (loc, OPT_Wstringop_truncation,
"%G%qD destination unchanged after copying no bytes "
return false;
/* Now, we must be passed a constant src ptr parameter. */
- tree slen = get_maxval_strlen (src, 0);
+ tree slen = get_maxval_strlen (src, SRK_STRLEN);
if (!slen || TREE_CODE (slen) != INTEGER_CST)
return false;
/* If the length of the source string isn't computable don't
split strcat into strlen and memcpy. */
- tree len = get_maxval_strlen (src, 0);
+ tree len = get_maxval_strlen (src, SRK_STRLEN);
if (! len)
return false;
/* Get the length of the string passed to fputs. If the length
can't be determined, punt. */
- tree len = get_maxval_strlen (arg0, 0);
+ tree len = get_maxval_strlen (arg0, SRK_STRLEN);
if (!len
|| TREE_CODE (len) != INTEGER_CST)
return false;
if (! tree_fits_uhwi_p (size))
return false;
- tree maxlen = get_maxval_strlen (len, 2);
+ tree maxlen = get_maxval_strlen (len, SRK_INT_VALUE);
if (! integer_all_onesp (size))
{
if (! tree_fits_uhwi_p (len))
if (! tree_fits_uhwi_p (size))
return false;
- tree maxlen = get_maxval_strlen (src, 1);
+ tree maxlen = get_maxval_strlen (src, SRK_STRLENMAX);
if (! integer_all_onesp (size))
{
len = c_strlen (src, 1);
if (! tree_fits_uhwi_p (size))
return false;
- tree maxlen = get_maxval_strlen (len, 2);
+ tree maxlen = get_maxval_strlen (len, SRK_INT_VALUE);
if (! integer_all_onesp (size))
{
if (! tree_fits_uhwi_p (len))
if (! integer_all_onesp (size))
{
- tree maxlen = get_maxval_strlen (len, 2);
+ tree maxlen = get_maxval_strlen (len, SRK_INT_VALUE);
if (! tree_fits_uhwi_p (len))
{
/* If LEN is not constant, try MAXLEN too.
tree orig_len = NULL_TREE;
if (gimple_call_lhs (stmt))
{
- orig_len = get_maxval_strlen (orig, 0);
+ orig_len = get_maxval_strlen (orig, SRK_STRLEN);
if (!orig_len)
return false;
}
if (!orig)
return false;
- tree orig_len = get_maxval_strlen (orig, 0);
+ tree orig_len = get_maxval_strlen (orig, SRK_STRLEN);
if (!orig_len || TREE_CODE (orig_len) != INTEGER_CST)
return false;
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