PR c/92326 - wrong bound in zero-length array diagnostics

gcc/c-family/ChangeLog:

	PR c/92326
	* c-pretty-print.c (c_pretty_printer::direct_abstract_declarator): Avoid
	printing array bound for flexible array members.

gcc/testsuite/ChangeLog:

	PR c/92326
	* c-c++-common/Warray-bounds-8.c: New test.
	* gcc.dg/Warray-bounds-46.c: Adjust expected format of flexible array
	memebrs in diagnostics.
	* gcc.dg/Warray-bounds-49.c: Same.
This commit is contained in:
Martin Sebor 2020-04-13 15:31:44 -06:00
parent 1dcb779916
commit 09f0413902
6 changed files with 60 additions and 22 deletions

View file

@ -1,3 +1,9 @@
2020-04-13 Martin Sebor <msebor@redhat.com>
PR c/92326
* c-pretty-print.c (c_pretty_printer::direct_abstract_declarator): Avoid
printing array bound for flexible array members.
2020-04-13 Iain Sandoe <iain@sandoe.co.uk>
* c-cppbuiltin.c (c_cpp_builtins): Update coroutines builtin

View file

@ -593,7 +593,9 @@ c_pretty_printer::direct_abstract_declarator (tree t)
expression (fold_build2 (PLUS_EXPR, type, maxval,
build_int_cst (type, 1)));
}
else
else if (TYPE_SIZE (t))
/* Print zero for zero-length arrays but not for flexible
array members whose TYPE_SIZE is null. */
pp_string (this, "0");
}
pp_c_right_bracket (this);

View file

@ -1,3 +1,11 @@
2020-04-13 Martin Sebor <msebor@redhat.com>
PR c/92326
* c-c++-common/Warray-bounds-8.c: New test.
* gcc.dg/Warray-bounds-46.c: Adjust expected format of flexible array
memebrs in diagnostics.
* gcc.dg/Warray-bounds-49.c: Same.
2020-04-13 Patrick Palka <ppalka@redhat.com>
PR c++/94521

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@ -0,0 +1,22 @@
/* PR c/92326 - wrong bound in zero-length array diagnostics
{ dg-do compile }
{ dg-options "-O2 -Wall" } */
extern int a0[0];
extern int ax[];
void warn_global_array (void)
{
a0[0] = 0; // { dg-warning "array bounds of 'int *\\\[0]'" }
ax[-1] = 0; // { dg-warning "array bounds of 'int *\\\[]'" }
}
struct S0 { int n, a0[0]; } s0;
struct Sx { int n, ax[]; } sx = { 0 };
void warn_member_array (void)
{
s0.a0[0] = 0; // { dg-warning "array bounds of 'int *\\\[0]'" }
sx.ax[0] = 0; // { dg-warning "array bounds of 'int *\\\[]'" }
}

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@ -95,13 +95,13 @@ void strcpy_global_array (void)
/* GMA2 is external but because it's an array its definition in another
translation unit may not provide an initializer for the flexible array
member. Verify that a warning is issued for access to it. */
T (gma2[0].ax, 1); // { dg-warning "'strcpy' offset \\\[157, 158] from the object at 'gma2' is out of the bounds of referenced subobject 'ax' with type 'char\\\[0]' at offset 157" }
T (gma2[0].ax, 7); // { dg-warning "'strcpy' offset \\\[157, 164] from the object at 'gma2' is out of the bounds of referenced subobject 'ax' with type 'char\\\[0]' at offset 157" }
T (gma2[0].ax, 1); // { dg-warning "'strcpy' offset \\\[157, 158] from the object at 'gma2' is out of the bounds of referenced subobject 'ax' with type 'char\\\[]' at offset 157" }
T (gma2[0].ax, 7); // { dg-warning "'strcpy' offset \\\[157, 164] from the object at 'gma2' is out of the bounds of referenced subobject 'ax' with type 'char\\\[]' at offset 157" }
/* IGMA_ is internal and provides on definition for the flexible array
member. Verify that a warnin is issued for out-of-bounds accesses
/* IGMA2_ is internal and provides no definition for the flexible array
member. Verify that a warning is issued for out-of-bounds accesses
to it. */
T (igma2_[0].ax, 1); // { dg-warning "'strcpy' offset \\\[157, 158] from the object at 'igma2_' is out of the bounds of referenced subobject 'ax' with type 'char\\\[0]' at offset 157" }
T (igma2_[0].ax, 1); // { dg-warning "'strcpy' offset \\\[157, 158] from the object at 'igma2_' is out of the bounds of referenced subobject 'ax' with type 'char\\\[]' at offset 157" }
T (igma_3.ax, 0);
T (igma_3.ax, 1);
@ -134,7 +134,7 @@ void strcpy_local (void)
T (lma.a17, 16);
T (lma.a17, 17); // { dg-warning "'strcpy' offset 157 from the object at 'lma' is out of the bounds of referenced subobject 'a17' with type 'char\\\[17]' at offset 140" }
T (lma.ax, 0); // { dg-warning "'strcpy' offset 157 from the object at 'lma' is out of the bounds of referenced subobject 'ax' with type 'char\\\[0]' at offset 157" }
T (lma.ax, 0); // { dg-warning "'strcpy' offset 157 from the object at 'lma' is out of the bounds of referenced subobject 'ax' with type 'char\\\[]' at offset 157" }
}
@ -191,11 +191,11 @@ void strcpy_ref (struct MA17 *pma)
array. The warning assumes that PMA doesn't point to the last element
of the array which could in theory have nonzero elements without
overlapping other objects. */
T (pma[1].ax, 0); // { dg-warning "'strcpy' offset 314 from the object at 'pma' is out of the bounds of referenced subobject 'ax' with type 'char\\\[0]' at offset 314" }
T ((pma + 1)->ax, 1); // { dg-warning "'strcpy' offset \\\[314, 315] from the object at 'pma' is out of the bounds of referenced subobject 'ax' with type 'char\\\[0]' at offset 314" }
T ((pma + 1)[1].ax, 2); // { dg-warning "'strcpy' offset \\\[471, 473] from the object at 'pma' is out of the bounds of referenced subobject 'ax' with type 'char\\\[0]' at offset 471" }
T ((*(pma + 2)).ax, 2); // { dg-warning "'strcpy' offset \\\[471, 473] from the object at 'pma' is out of the bounds of referenced subobject 'ax' with type 'char\\\[0]' at offset 471" }
T (pma[3].ax, 9); // { dg-warning "'strcpy' offset \\\[628, 637] from the object at 'pma' is out of the bounds of referenced subobject 'ax' with type 'char\\\[0]' at offset 628" }
T (pma[1].ax, 0); // { dg-warning "'strcpy' offset 314 from the object at 'pma' is out of the bounds of referenced subobject 'ax' with type 'char\\\[]' at offset 314" }
T ((pma + 1)->ax, 1); // { dg-warning "'strcpy' offset \\\[314, 315] from the object at 'pma' is out of the bounds of referenced subobject 'ax' with type 'char\\\[]' at offset 314" }
T ((pma + 1)[1].ax, 2); // { dg-warning "'strcpy' offset \\\[471, 473] from the object at 'pma' is out of the bounds of referenced subobject 'ax' with type 'char\\\[]' at offset 471" }
T ((*(pma + 2)).ax, 2); // { dg-warning "'strcpy' offset \\\[471, 473] from the object at 'pma' is out of the bounds of referenced subobject 'ax' with type 'char\\\[]' at offset 471" }
T (pma[3].ax, 9); // { dg-warning "'strcpy' offset \\\[628, 637] from the object at 'pma' is out of the bounds of referenced subobject 'ax' with type 'char\\\[]' at offset 628" }
T (pma[-1].a1, 0);
T (pma[-1].a1, 1); // { dg-warning "'strcpy' offset -152 from the object at 'pma' is out of the bounds of referenced subobject 'a1' with type 'char\\\[1]' at offset -153" }

View file

@ -17,7 +17,7 @@ void test_a0 (void)
// The first three elements fit in the tail padding.
a0.a2[0] = 0; a0.a2[1] = 1; a0.a2[2] = 2;
a0.a2[3] = 3; // { dg-warning "array subscript 3 is above array bounds of 'short int\\\[0]'" }
a0.a2[3] = 3; // { dg-warning "array subscript 3 is above array bounds of 'short int\\\[]'" }
}
@ -27,7 +27,7 @@ void test_a1 (void)
{
a1.a2[0] = 0; a1.a2[1] = 1; a1.a2[2] = 2;
a1.a2[3] = 3; // { dg-warning "array subscript 3 is above array bounds of 'short int\\\[0]'" }
a1.a2[3] = 3; // { dg-warning "array subscript 3 is above array bounds of 'short int\\\[]'" }
}
@ -37,7 +37,7 @@ void test_a2 (void)
{
a2.a2[0] = 0; a2.a2[1] = 1; a2.a2[2] = 2;
a2.a2[3] = 3; // { dg-warning "array subscript 3 is above array bounds of 'short int\\\[0]'" }
a2.a2[3] = 3; // { dg-warning "array subscript 3 is above array bounds of 'short int\\\[]'" }
}
@ -47,7 +47,7 @@ void test_a3 (void)
{
a3.a2[0] = 0; a3.a2[1] = 1; a3.a2[2] = 2;
a3.a2[3] = 3; // { dg-warning "array subscript 3 is above array bounds of 'short int\\\[0]'" }
a3.a2[3] = 3; // { dg-warning "array subscript 3 is above array bounds of 'short int\\\[]'" }
}
@ -57,7 +57,7 @@ void test_a4 (void)
{
a4.a2[0] = 0; a4.a2[1] = 1; a4.a2[2] = 2; a4.a2[3] = 3;
a4.a2[4] = 4; // { dg-warning "array subscript 4 is above array bounds of 'short int\\\[0]'" }
a4.a2[4] = 4; // { dg-warning "array subscript 4 is above array bounds of 'short int\\\[]'" }
}
@ -67,7 +67,7 @@ void test_a5 (void)
{
a5.a2[0] = 0; a5.a2[1] = 1; a5.a2[2] = 2; a5.a2[3] = 3; a5.a2[4] = 4;
a5.a2[5] = 5; // { dg-warning "array subscript 5 is above array bounds of 'short int\\\[0]'" }
a5.a2[5] = 5; // { dg-warning "array subscript 5 is above array bounds of 'short int\\\[]'" }
}
@ -78,7 +78,7 @@ void test_a6 (void)
a6.a2[0] = 0; a6.a2[1] = 1; a6.a2[2] = 2; a6.a2[3] = 3; a6.a2[4] = 4;
a6.a2[5] = 5;
a6.a2[6] = 6; // { dg-warning "array subscript 6 is above array bounds of 'short int\\\[0]'" }
a6.a2[6] = 6; // { dg-warning "array subscript 6 is above array bounds of 'short int\\\[]'" }
}
@ -89,7 +89,7 @@ void test_a7 (void)
a7.a2[0] = 0; a7.a2[1] = 1; a7.a2[2] = 2; a7.a2[3] = 3; a7.a2[4] = 4;
a7.a2[5] = 5; a7.a2[5] = 5; a7.a2[6] = 6;
a7.a2[7] = 7; // { dg-warning "array subscript 7 is above array bounds of 'short int\\\[0]'" }
a7.a2[7] = 7; // { dg-warning "array subscript 7 is above array bounds of 'short int\\\[]'" }
}
@ -100,7 +100,7 @@ void test_a8 (void)
a8.a2[0] = 0; a8.a2[1] = 1; a8.a2[2] = 2; a8.a2[3] = 3; a8.a2[4] = 4;
a8.a2[5] = 5; a8.a2[5] = 5; a8.a2[6] = 6; a8.a2[7] = 7;
a8.a2[8] = 8; // { dg-warning "array subscript 8 is above array bounds of 'short int\\\[0]'" }
a8.a2[8] = 8; // { dg-warning "array subscript 8 is above array bounds of 'short int\\\[]'" }
}
@ -111,5 +111,5 @@ void test_a9 (void)
a8.a2[0] = 8; a8.a2[1] = 7; a8.a2[2] = 6; a8.a2[3] = 5; a8.a2[4] = 4;
a8.a2[5] = 3; a8.a2[5] = 2; a8.a2[6] = 1; a8.a2[7] = 0;
a8.a2[9] = 8; // { dg-warning "array subscript 9 is above array bounds of 'short int\\\[0]'" }
a8.a2[9] = 8; // { dg-warning "array subscript 9 is above array bounds of 'short int\\\[]'" }
}