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re PR c++/17913 (ICE jumping into statement expression)

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2005-05-10  Gabor Loki <loki@gcc.gnu.org>

	PR c/17913
	* c-typeck.c (build_conditional_expr): Remove reducing cond_expr.
	* fold-const.c (fold): Expand the condition of reducing cond_expr.
	(contains_label_1, contains_label_p): New functions for checking
	labels in a sub-tree.

testsuite:
2005-05-10  Gabor Loki <loki@gcc.gnu.org>

	PR c/17913
	* gcc.c-torture/compile/pr17913.c: Computed jump test for PR17913

From-SVN: r99514
This commit is contained in:
Gabor Loki 2005-05-10 13:47:05 +00:00
parent 27e928edee
commit 8c9004573a
5 changed files with 59 additions and 7 deletions
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8
gcc/ChangeLog
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@ -1,3 +1,11 @@
2005-05-10 Gabor Loki <loki@gcc.gnu.org>
PR c/17913
* c-typeck.c (build_conditional_expr): Remove reducing cond_expr.
* fold-const.c (fold): Expand the condition of reducing cond_expr.
(contains_label_1, contains_label_p): New functions for checking
labels in a sub-tree.
2005-05-10 Joseph S. Myers <joseph@codesourcery.com>
PR c/21342

5
gcc/c-typeck.c
View File

@ -3105,10 +3105,7 @@ build_conditional_expr (tree ifexp, tree op1, tree op2)
if (result_type != TREE_TYPE (op2))
op2 = convert_and_check (result_type, op2);
if (TREE_CODE (ifexp) == INTEGER_CST)
return non_lvalue (integer_zerop (ifexp) ? op2 : op1);
return fold (build3 (COND_EXPR, result_type, ifexp, op1, op2));
return fold_build3 (COND_EXPR, result_type, ifexp, op1, op2);
}
/* Return a compound expression that performs two expressions and

41
gcc/fold-const.c
View File

@ -9905,6 +9905,37 @@ fold_binary (enum tree_code code, tree type, tree op0, tree op1)
} /* switch (code) */
}
/* Callback for walk_tree, looking for LABEL_EXPR.
Returns tree TP if it is LABEL_EXPR. Otherwise it returns NULL_TREE.
Do not check the sub-tree of GOTO_EXPR. */
static tree
contains_label_1 (tree *tp,
int *walk_subtrees,
void *data ATTRIBUTE_UNUSED)
{
switch (TREE_CODE (*tp))
{
case LABEL_EXPR:
return *tp;
case GOTO_EXPR:
*walk_subtrees = 0;
/* no break */
default:
return NULL_TREE;
}
}
/* Checks wheter the sub-tree ST contains a label LABEL_EXPR which is
accessible from outside the sub-tree. Returns NULL_TREE if no
addressable label is found. */
static bool
contains_label_p (tree st)
{
return (walk_tree (&st, contains_label_1 , NULL, NULL) != NULL_TREE);
}
/* Fold a ternary expression of code CODE and type TYPE with operands
OP0, OP1, and OP2. Return the folded expression if folding is
successful. Otherwise, return NULL_TREE. */
@ -9958,12 +9989,16 @@ fold_ternary (enum tree_code code, tree type, tree op0, tree op1, tree op2)
so all simple results must be passed through pedantic_non_lvalue. */
if (TREE_CODE (arg0) == INTEGER_CST)
{
tree unused_op = integer_zerop (arg0) ? op1 : op2;
tem = integer_zerop (arg0) ? op2 : op1;
/* Only optimize constant conditions when the selected branch
has the same type as the COND_EXPR. This avoids optimizing
away "c ? x : throw", where the throw has a void type. */
if (! VOID_TYPE_P (TREE_TYPE (tem))
|| VOID_TYPE_P (type))
away "c ? x : throw", where the throw has a void type.
Avoid throwing away that operand which contains label. */
if ((!TREE_SIDE_EFFECTS (unused_op)
|| !contains_label_p (unused_op))
&& (! VOID_TYPE_P (TREE_TYPE (tem))
|| VOID_TYPE_P (type)))
return pedantic_non_lvalue (tem);
return NULL_TREE;
}

5
gcc/testsuite/ChangeLog
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@ -1,3 +1,8 @@
2005-05-10 Gabor Loki <loki@gcc.gnu.org>
PR c/17913
* gcc.c-torture/compile/pr17913.c: Computed jump test for PR17913
2005-05-10 Joseph S. Myers <joseph@codesourcery.com>
PR c/21342

7
gcc/testsuite/gcc.c-torture/compile/pr17913.c Normal file
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@ -0,0 +1,7 @@
/* Test for computed jump into cond_expr: bug 17913. */
void f (void)
{
void *p = &&a;
1 ? 1 : ({ a : 1; });
goto *p;
}