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PR tree-optimization/87490 - ICE in expand_builtin_strnlen with a constant argument and non-constant bound

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gcc/ChangeLog:

	PR tree-optimization/87490
	* builtins.c (expand_builtin_strnlen): Handle a null data.decl
	consistently.

gcc/testsuite/ChangeLog:

	PR tree-optimization/87490
	* gcc.dg/pr87490.c: New test.
	* gcc.dg/warn-strnlen-no-nul-2.c: Same.

From-SVN: r264876
This commit is contained in:
Martin Sebor 2018-10-05 16:43:11 +00:00 • committed by Martin Sebor
parent e0b9bc230a
commit f343165275
5 changed files with 120 additions and 11 deletions
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6
gcc/ChangeLog
View file

@ -1,3 +1,9 @@
2018-10-05 Martin Sebor <msebor@redhat.com>
PR tree-optimization/87490
* builtins.c (expand_builtin_strnlen): Handle a null data.decl
consistently.
2018-10-05 Richard Biener <rguenther@suse.de>
PR tree-optimization/63155

40
gcc/builtins.c
View file

@ -3151,21 +3151,39 @@ expand_builtin_strnlen (tree exp, rtx target, machine_mode target_mode)
exp, func, min.to_uhwi (), max.to_uhwi (), maxobjsize))
TREE_NO_WARNING (exp) = true;
bool exact = true;
if (!len || TREE_CODE (len) != INTEGER_CST)
return NULL_RTX;
if (!TREE_NO_WARNING (exp)
&& wi::ltu_p (wi::to_wide (len), min)
&& warning_at (loc, OPT_Wstringop_overflow_,
"%K%qD specified bound [%wu, %wu] "
"exceeds the size %E of unterminated array",
exp, func, min.to_uhwi (), max.to_uhwi (), len))
{
inform (DECL_SOURCE_LOCATION (data.decl),
"referenced argument declared here");
TREE_NO_WARNING (exp) = true;
data.decl = unterminated_array (src, &len, &exact);
if (!data.decl)
return NULL_RTX;
}
if (data.decl
&& !TREE_NO_WARNING (exp)
&& (wi::ltu_p (wi::to_wide (len), min)
|| !exact))
{
location_t warnloc
= expansion_point_location_if_in_system_header (loc);
if (warning_at (warnloc, OPT_Wstringop_overflow_,
exact
? G_("%K%qD specified bound [%wu, %wu] exceeds "
"the size %E of unterminated array")
: G_("%K%qD specified bound [%wu, %wu] may exceed "
"the size of at most %E of unterminated array"),
exp, func, min.to_uhwi (), max.to_uhwi (), len))
{
inform (DECL_SOURCE_LOCATION (data.decl),
"referenced argument declared here");
TREE_NO_WARNING (exp) = true;
}
}
if (data.decl)
return NULL_RTX;
if (wi::gtu_p (min, wi::to_wide (len)))
return expand_expr (len, target, target_mode, EXPAND_NORMAL);

6
gcc/testsuite/ChangeLog
View file

@ -1,3 +1,9 @@
2018-10-05 Martin Sebor <msebor@redhat.com>
PR tree-optimization/87490
* gcc.dg/pr87490.c: New test.
* gcc.dg/warn-strnlen-no-nul-2.c: Same.
2018-10-05 Steve Ellcey <sellcey@cavium.com>
PR tree-optimization/71625

13
gcc/testsuite/gcc.dg/pr87490.c Normal file
View file

@ -0,0 +1,13 @@
/* PR tree-optimization/87490 - ICE in expand_builtin_strnlen with a constant
argument and non-constant bound
{ dg-do compile }
{ dg-options "-O1 -Wall -fno-optimize-strlen" } */
void test_O1 (int i)
{
int n = (i & 3) | 1;
/* The ICE here triggers at -O1, with tree-ssa-strlen disabled. */
if (__builtin_strnlen ("", n) != 0)
__builtin_abort ();
}

66
gcc/testsuite/gcc.dg/warn-strnlen-no-nul-2.c Normal file
View file

@ -0,0 +1,66 @@
/* Verify that calls to strnlen with an unterminated array and
an excessive non-constant bound are diagnosed.
{ dg-do compile }
{ dg-options "-O2 -Wall -ftrack-macro-expansion=0" } */
#include "range.h"
extern size_t strnlen (const char*, size_t);
const char a[5] = "12345"; /* { dg-message "declared here" } */
enum { asz = sizeof a };
int v0 = 0;
int v1 = 1;
void sink (int, ...);
#define CONCAT(a, b) a ## b
#define CAT(a, b) CONCAT(a, b)
#define T(str, n) \
__attribute__ ((noipa)) \
void CAT (test_, __LINE__) (void) { \
int i0 = 0, i1 = i0 + 1, i2 = i1 + 1, i3 = i2 + 1; \
sink (strnlen (str, n), i0, i1, i2, i3); \
} typedef void dummy_type
T (a, UR (asz, -1));
T (a, UR (asz - 1, -1));
T (a, UR (asz - 2, -1));
T (a, UR (asz - 5, -1));
T (&a[0], UR (asz, -1));
T (&a[0] + 1, UR (asz, asz + 1)); /* { dg-warning "specified bound \\\[5, 6] exceeds the size 4 of unterminated array" } */
T (&a[1], UR (asz, 6)); /* { dg-warning "specified bound \\\[5, 6] exceeds the size 4 of unterminated array" } */
T (&a[1], UR (asz - 1, 7));
T (&a[v0], UR (asz, 8)); /* { dg-warning "specified bound \\\[5, 8] may exceed the size of at most 5 of unterminated array" } */
T (&a[v0] + 1, UR (asz, 9)); /* { dg-warning "specified bound \\\[5, 9] may exceed the size of at most 5 of unterminated array" } */
T (a, UR (asz + 1, asz + 2)); /* { dg-warning "specified bound \\\[6, 7] exceeds the size 5 " } */
T (&a[0], UR (asz + 1, 10)); /* { dg-warning "unterminated" } */
T (&a[0] + 1, UR (asz - 1, 11));
T (&a[0] + 1, UR (asz + 1, 12)); /* { dg-warning "unterminated" } */
T (&a[1], UR (asz + 1, 13)); /* { dg-warning "unterminated" } */
T (&a[v0], UR (asz + 1, 14)); /* { dg-warning "unterminated" } */
T (&a[v0] + 1, UR (asz + 1, 15)); /* { dg-warning "unterminated" } */
T (&a[v0] + 1, UR (DIFF_MAX, SIZE_MAX)); /* { dg-warning "unterminated" } */
T (&a[v0] + 1, UR (DIFF_MAX + (size_t)1, SIZE_MAX)); /* { dg-warning "specified bound \\\[\[0-9\]+, \[0-9\]+] exceeds maximum object size " } */
const char c[4] = "1234";
void test (int n0)
{
char a[] = "123";
if (n0 < 4)
n0 = 4;
int n1 = __builtin_strlen (a);
int n = n0 < n1 ? n1 : n0;
sink (strnlen (c + n, n + 1)); /* { dg-warning "specified bound \\\[5, \[0-9\]+] may exceed the size of at most 4 of unterminated array" } */
}