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PR middle-end/97391 - bogus -Warray-bounds accessing a multidimensional array parameter

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gcc/ChangeLog:

	PR middle-end/97391
	* builtins.c (gimple_parm_array_size): Peel off one less layer
	of array types.

gcc/testsuite/ChangeLog:

	PR middle-end/97391
	* gcc.dg/Warray-bounds-68.c: New test.
This commit is contained in:
Martin Sebor 2020-10-14 15:19:39 -06:00
parent 34efa5c2a8
commit 14d83c6f58
2 changed files with 120 additions and 5 deletions
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7
gcc/builtins.c
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@ -4493,12 +4493,9 @@ gimple_parm_array_size (tree ptr, wide_int rng[2],
rng[0] = wi::zero (prec);
rng[1] = wi::uhwi (access->minsize, prec);
/* If the PTR argument points to an array multiply MINSIZE by the size
of array element type. Otherwise, multiply it by the size of what
the pointer points to. */
/* Multiply the array bound encoded in the attribute by the size
of what the pointer argument to which it decays points to. */
tree eltype = TREE_TYPE (TREE_TYPE (ptr));
if (TREE_CODE (eltype) == ARRAY_TYPE)
eltype = TREE_TYPE (eltype);
tree size = TYPE_SIZE_UNIT (eltype);
if (!size || TREE_CODE (size) != INTEGER_CST)
return NULL_TREE;

118
gcc/testsuite/gcc.dg/Warray-bounds-68.c Normal file
View file

@ -0,0 +1,118 @@
/* PR middle-end/97391 - bogus -Warray-bounds accessing a multidimensional
array parameter
{ dg-do compile }
{ dg-options "-O2 -Wall" } */
void nowarn_access_loop_idx (char a[3][5])
{
for (int i = 0; i < 3; i++)
for (int j = 0; j < 5; j++)
a[i][j] = 0;
}
void warn_access_loop_idx (char a[3][5])
{
for (int i = 0; i < 3; i++)
for (int j = 0; j < 5; j++)
a[j][i] = 0; // { dg-warning "\\\[-Warray-bounds" }
}
void nowarn_access_cst_idx (int a[5][7][9])
{
a[0][0][0] = __LINE__;
a[0][0][8] = __LINE__;
a[0][6][0] = __LINE__;
a[0][6][8] = __LINE__;
a[4][0][0] = __LINE__;
a[4][0][8] = __LINE__;
a[4][6][8] = __LINE__;
}
void test_ptr_access_cst_idx (int a[5][7][9])
{
int *p = &a[0][0][0];
p[0] = __LINE__;
p[8] = __LINE__;
/* The following access should trigger a warning but it's represented
the same as the valid access in
p = a[0][1][0];
p[1] = __LINE__;
both as
MEM[(int *)a_1(D) + 36B] = __LINE__; */
p[9] = __LINE__; // { dg-warning "\\\[-Warray-bounds" "pr?????" { xfail *-*-* } }
p[315] = __LINE__;
// { dg-warning "subscript 315 is outside array bounds of 'int\\\[5]\\\[7]\\\[9]'" "pr97425" { xfail *-*-* } .-1 }
// { dg-warning "subscript 315 is outside array bounds " "" { target *-*-* } .-2 }
p = &a[0][6][0];
p[0] = __LINE__;
p[8] = __LINE__;
p = &a[4][6][0];
p[0] = __LINE__;
p[8] = __LINE__;
}
void warn_access_cst_idx (int a[5][7][9])
{
a[0][0][9] = __LINE__; // { dg-warning "subscript 9 is above array bounds of 'int\\\[9]'" }
a[0][7][0] = __LINE__; // { dg-warning "subscript 7 is above array bounds of 'int\\\[7]\\\[9]'" }
a[5][0][0] = __LINE__;
// { dg-warning "subscript 5 is outside array bounds of 'int\\\[5]\\\[7]\\\[9]'" "pr97425" { xfail *-*-* } .-1 }
// { dg-warning "subscript \\d+ is outside array bounds" "" { target *-*-* } .-2 }
}
void test_ptrarray_access_cst_idx (int (*pa)[5][7][9])
{
(*pa)[0][0][0] = __LINE__;
(*pa)[0][0][8] = __LINE__;
(*pa)[0][0][9] = __LINE__; // { dg-warning "subscript 9 is above array bounds of 'int\\\[9]'" }
(*pa)[0][6][0] = __LINE__;
(*pa)[0][7][0] = __LINE__; // { dg-warning "subscript 7 is above array bounds of 'int\\\[7]\\\[9]'" }
(*pa)[0][8][0] = __LINE__; // { dg-warning "subscript 8 is above array bounds of 'int\\\[7]\\\[9]'" }
(*pa)[4][6][8] = __LINE__;
(*pa)[5][0][0] = __LINE__; // { dg-warning "subscript 5 is above array bounds of 'int\\\[5]\\\[7]\\\[9]'" }
}
void test_ptr_ptrarray_access_cst_idx (int (*pa)[5][7][9])
{
int *p = &(*pa)[0][0][0];
p[0] = __LINE__;
p[8] = __LINE__;
/* The following access should trigger a warning but it's represented
the same as the valid access in
p = a[0][1][0];
p[1] = __LINE__;
both as
MEM[(int *)a_1(D) + 36B] = __LINE__; */
p[9] = __LINE__; // { dg-warning "\\\[-Warray-bounds" "pr?????" { xfail *-*-* } }
p[315] = __LINE__; // { dg-warning "\\\[-Warray-bounds" "pr97429" { xfail *-*-* } }
p = &(*pa)[0][6][0];
p[0] = __LINE__;
p[8] = __LINE__;
p = &(*pa)[4][6][0];
p[0] = __LINE__;
p[8] = __LINE__;
}