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re PR c++/71537 (GCC rejects consetxpr boolean conversions and comparisons on the result of pointer arithmetic.)

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PR c++/71537
	* fold-const.c (maybe_nonzero_address): Return 1 for function
	local objects.
	(tree_single_nonzero_warnv_p): Don't handle function local objects
	here.

	* g++.dg/cpp1y/constexpr-71537.C: New test.

From-SVN: r244333
This commit is contained in:
Jakub Jelinek 2017-01-11 21:10:36 +01:00 committed by Jakub Jelinek
parent 88df7964b5
commit eae63d784c
4 changed files with 32 additions and 8 deletions

6
gcc/ChangeLog

@ -1,5 +1,11 @@
2017-01-11 Jakub Jelinek <jakub@redhat.com>
PR c++/71537
* fold-const.c (maybe_nonzero_address): Return 1 for function
local objects.
(tree_single_nonzero_warnv_p): Don't handle function local objects
here.
PR c++/72813
* gcc.c (default_compilers): Don't add -o %g.s for -S -save-temps
of c-header.

17
gcc/fold-const.c

@ -8171,7 +8171,8 @@ pointer_may_wrap_p (tree base, tree offset, HOST_WIDE_INT bitpos)
/* Return a positive integer when the symbol DECL is known to have
a nonzero address, zero when it's known not to (e.g., it's a weak
symbol), and a negative integer when the symbol is not yet in the
symbol table and so whether or not its address is zero is unknown. */
symbol table and so whether or not its address is zero is unknown.
For function local objects always return positive integer. */
static int
maybe_nonzero_address (tree decl)
{
@ -8179,6 +8180,13 @@ maybe_nonzero_address (tree decl)
if (struct symtab_node *symbol = symtab_node::get_create (decl))
return symbol->nonzero_address ();
/* Function local objects are never NULL. */
if (DECL_P (decl)
&& (DECL_CONTEXT (decl)
&& TREE_CODE (DECL_CONTEXT (decl)) == FUNCTION_DECL
&& auto_var_in_fn_p (decl, DECL_CONTEXT (decl))))
return 1;
return -1;
}
@ -13276,13 +13284,6 @@ tree_single_nonzero_warnv_p (tree t, bool *strict_overflow_p)
if (nonzero_addr >= 0)
return nonzero_addr;
/* Function local objects are never NULL. */
if (DECL_P (base)
&& (DECL_CONTEXT (base)
&& TREE_CODE (DECL_CONTEXT (base)) == FUNCTION_DECL
&& auto_var_in_fn_p (base, DECL_CONTEXT (base))))
return true;
/* Constants are never weak. */
if (CONSTANT_CLASS_P (base))
return true;

3
gcc/testsuite/ChangeLog

@ -1,5 +1,8 @@
2017-01-11 Jakub Jelinek <jakub@redhat.com>
PR c++/71537
* g++.dg/cpp1y/constexpr-71537.C: New test.
* gcc.dg/tree-ssa/flatten-3.c: Add quotation marks around dg-options
argument.

14
gcc/testsuite/g++.dg/cpp1y/constexpr-71537.C Normal file

@ -0,0 +1,14 @@
// PR c++/71537
// { dg-do compile { target c++14 } }
constexpr bool
foo ()
{
constexpr int n[42] = { 1 };
constexpr int o = n ? 1 : 0;
constexpr int p = n + 1 ? 1 : 0;
constexpr int q = "abc" + 1 ? 1 : 0;
return p + p + q == 3;
}
static_assert (foo (), "");