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re PR c++/84463 (Supposedly-incompliant "error: '* key0' is not a constant expression")

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PR c++/84463
	* typeck.c (cp_build_addr_expr_1): Move handling of offsetof-like
	tricks from here to ...
	* cp-gimplify.c (cp_fold) <case ADDR_EXPR>: ... here.  Only use it
	if INDIRECT_REF's operand is INTEGER_CST cast to pointer type.

	* g++.dg/cpp0x/constexpr-nullptr-1.C: Add -O1 to dg-options.
	* g++.dg/cpp0x/constexpr-nullptr-2.C: Expect different diagnostics
	in two cases.  Uncomment two other tests and add expected dg-error for
	them.
	* g++.dg/init/struct2.C: Cast to int rather than long to avoid
	-Wnarrowing diagnostics on some targets for c++11.
	* g++.dg/parse/array-size2.C: Remove xfail.
	* g++.dg/cpp0x/constexpr-84463.C: New test.

From-SVN: r259458
This commit is contained in:
Jakub Jelinek 2018-04-18 08:57:45 +02:00 committed by Jakub Jelinek
parent a56e2f69fe
commit 715dd933bd
9 changed files with 72 additions and 21 deletions
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8
gcc/cp/ChangeLog
View File

@ -1,3 +1,11 @@
2018-04-18 Jakub Jelinek <jakub@redhat.com>
PR c++/84463
* typeck.c (cp_build_addr_expr_1): Move handling of offsetof-like
tricks from here to ...
* cp-gimplify.c (cp_fold) <case ADDR_EXPR>: ... here. Only use it
if INDIRECT_REF's operand is INTEGER_CST cast to pointer type.
2018-04-18 Alexandre Oliva <aoliva@redhat.com>
PR c++/80290

23
gcc/cp/cp-gimplify.c
View File

@ -2215,6 +2215,28 @@ cp_fold (tree x)
goto unary;
case ADDR_EXPR:
loc = EXPR_LOCATION (x);
op0 = cp_fold_maybe_rvalue (TREE_OPERAND (x, 0), false);
/* Cope with user tricks that amount to offsetof. */
if (op0 != error_mark_node
&& TREE_CODE (TREE_TYPE (op0)) != FUNCTION_TYPE
&& TREE_CODE (TREE_TYPE (op0)) != METHOD_TYPE)
{
tree val = get_base_address (op0);
if (val
&& INDIRECT_REF_P (val)
&& COMPLETE_TYPE_P (TREE_TYPE (val))
&& TREE_CONSTANT (TREE_OPERAND (val, 0)))
{
val = TREE_OPERAND (val, 0);
STRIP_NOPS (val);
if (TREE_CODE (val) == INTEGER_CST)
return fold_convert (TREE_TYPE (x), fold_offsetof_1 (op0));
}
}
goto finish_unary;
case REALPART_EXPR:
case IMAGPART_EXPR:
rval_ops = false;
@ -2232,6 +2254,7 @@ cp_fold (tree x)
loc = EXPR_LOCATION (x);
op0 = cp_fold_maybe_rvalue (TREE_OPERAND (x, 0), rval_ops);
finish_unary:
if (op0 != TREE_OPERAND (x, 0))
{
if (op0 == error_mark_node)

13
gcc/cp/typeck.c
View File

@ -5893,19 +5893,6 @@ cp_build_addr_expr_1 (tree arg, bool strict_lvalue, tsubst_flags_t complain)
return arg;
}
/* ??? Cope with user tricks that amount to offsetof. */
if (TREE_CODE (argtype) != FUNCTION_TYPE
&& TREE_CODE (argtype) != METHOD_TYPE
&& argtype != unknown_type_node
&& (val = get_base_address (arg))
&& COMPLETE_TYPE_P (TREE_TYPE (val))
&& INDIRECT_REF_P (val)
&& TREE_CONSTANT (TREE_OPERAND (val, 0)))
{
tree type = build_pointer_type (argtype);
return fold_convert (type, fold_offsetof_1 (arg));
}
/* Handle complex lvalues (when permitted)
by reduction to simpler cases. */
val = unary_complex_lvalue (ADDR_EXPR, arg);

12
gcc/testsuite/ChangeLog
View File

@ -1,3 +1,15 @@
2018-04-18 Jakub Jelinek <jakub@redhat.com>
PR c++/84463
* g++.dg/cpp0x/constexpr-nullptr-1.C: Add -O1 to dg-options.
* g++.dg/cpp0x/constexpr-nullptr-2.C: Expect different diagnostics
in two cases. Uncomment two other tests and add expected dg-error for
them.
* g++.dg/init/struct2.C: Cast to int rather than long to avoid
-Wnarrowing diagnostics on some targets for c++11.
* g++.dg/parse/array-size2.C: Remove xfail.
* g++.dg/cpp0x/constexpr-84463.C: New test.
2018-04-17 Bill Schmidt <wschmidt@linux.ibm.com>
* gcc.target/powerpc/undef-bool-2.c: Add -mvsx.

22
gcc/testsuite/g++.dg/cpp0x/constexpr-84463.C Normal file
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@ -0,0 +1,22 @@
// PR c++/84463
// { dg-do compile { target c++11 } }
struct S { int r; const unsigned char s[5]; };
static constexpr S a[] = { { 0, "abcd" } };
struct T { const unsigned char s[5]; };
static constexpr T b[] = { { "abcd" } };
constexpr int
foo (const unsigned char *x)
{
return x[0];
}
constexpr static const S *j = &a[0];
constexpr static const int k = j->s[0];
constexpr static int l = foo (a[0].s);
constexpr static int m = foo (j->s);
constexpr static const T *n = &b[0];
constexpr static const int o = n->s[0];
constexpr static int p = foo (b[0].s);
constexpr static int q = foo (n->s);

2
gcc/testsuite/g++.dg/cpp0x/constexpr-nullptr-1.C
View File

@ -6,7 +6,7 @@
// c++/67376 on gcc-patches for additional background.
// { dg-do compile { target c++11 } }
// { dg-options "-fdelete-null-pointer-checks -fdump-tree-optimized" }
// { dg-options "-O1 -fdelete-null-pointer-checks -fdump-tree-optimized" }
// Runtime assert. Used for potentially invalid expressions.
#define RA(e) ((e) ? (void)0 : __builtin_abort ())

9
gcc/testsuite/g++.dg/cpp0x/constexpr-nullptr-2.C
View File

@ -192,12 +192,11 @@ constexpr bool b11 = ps >= (S*)0;
constexpr S* ps1 = ps;
constexpr S* ps2 = ps1;
// The following aren't diagnosed due to a bug.
// constexpr int* pi0 = &((S*)0)->i;
// constexpr int* pi1 = &((S*)nullptr)->i;
constexpr int* pi0 = &((S*)0)->i; // { dg-error "null pointer|not a constant" }
constexpr int* pi1 = &((S*)nullptr)->i; // { dg-error "null pointer|not a constant" }
constexpr int* pj0 = &((S*)0)->j; // { dg-error "not a constant expression" }
constexpr int* pj1 = &((S*)nullptr)->j; // { dg-error "not a constant expression" }
constexpr int* pj0 = &((S*)0)->j; // { dg-error "null pointer|not a constant" }
constexpr int* pj1 = &((S*)nullptr)->j; // { dg-error "null pointer|not a constant" }
constexpr int* psi = &ps->i; // { dg-error "null pointer|not a constant" }
constexpr int* psj = &ps->j; // { dg-error "null pointer|not a constant" }

2
gcc/testsuite/g++.dg/init/struct2.C
View File

@ -15,7 +15,7 @@ void saveOrLoad() {
};
SaveLoadEntry trackEntries = {
((long) (__SIZE_TYPE__) (&((Track *) 42)->soundName[0])) - 42,
((int) (__SIZE_TYPE__) (&((Track *) 42)->soundName[0])) - 42,
0, 1
};
saveLoadEntries(&trackEntries);

2
gcc/testsuite/g++.dg/parse/array-size2.C
View File

@ -15,6 +15,6 @@ void
foo (void)
{
char g[(char *) &((struct S *) 0)->b - (char *) 0]; // { dg-error "constant" }
char h[(__SIZE_TYPE__) &((struct S *) 8)->b]; // { dg-error "constant" "" { xfail *-*-* } }
char h[(__SIZE_TYPE__) &((struct S *) 8)->b]; // { dg-error "constant" }
bar (g, h);
}