Hi!
Some errors (e.g. in in this particular PR in a backend machine builtin)
are detected only during folding and the recursive cp_fold* call can then
return error_mark_node. Passing that to fold_build*_loc is undesirable
though, the gimplifiers as well as other places in the compiler don't expect
error_mark_node to be operand of NOP_EXPR and various other trees,
historically the FEs would then just not create the expression at all
and use error_mark_node instead of the whole expression.
The following patch handles those in cp_fold. Bootstrapped/regtested on
x86_64-linux and i686-linux, and tested on the testcase from the PR (which
is in the testsuite already) using cross to darwin; ok for trunk?
Another alternative would be to make sure tree folders don't introduce
error_mark_node (if it wasn't there already), but instead fold the call say
to build_int_cst (returntype, 0). The known cases that would need to change
are at least darwin_build_constant_cfstring and darwin_fold_builtin, but
maybe others.
2016-01-26 Jakub Jelinek <ja...@redhat.com>
PR c++/68357
* cp-gimplify.c (cp_fold): If some operand folds to error_mark_node,
return error_mark_node instead of building trees with error_mark_node
operands.
--- gcc/cp/cp-gimplify.c.jj 2016-01-20 10:55:15.000000000 +0100
+++ gcc/cp/cp-gimplify.c 2016-01-26 11:42:34.966038507 +0100
@@ -1954,7 +1954,12 @@ cp_fold (tree x)
op0 = cp_fold_maybe_rvalue (TREE_OPERAND (x, 0), rval_ops);
if (op0 != TREE_OPERAND (x, 0))
- x = fold_build1_loc (loc, code, TREE_TYPE (x), op0);
+ {
+ if (op0 == error_mark_node)
+ x = error_mark_node;
+ else
+ x = fold_build1_loc (loc, code, TREE_TYPE (x), op0);
+ }
else
x = fold (x);
@@ -1986,7 +1991,12 @@ cp_fold (tree x)
op0 = cp_fold_maybe_rvalue (TREE_OPERAND (x, 0), rval_ops);
if (op0 != TREE_OPERAND (x, 0))
- x = fold_build1_loc (loc, code, TREE_TYPE (x), op0);
+ {
+ if (op0 == error_mark_node)
+ x = error_mark_node;
+ else
+ x = fold_build1_loc (loc, code, TREE_TYPE (x), op0);
+ }
else
x = fold (x);
@@ -2043,7 +2053,12 @@ cp_fold (tree x)
op1 = cp_fold_rvalue (TREE_OPERAND (x, 1));
if (op0 != TREE_OPERAND (x, 0) || op1 != TREE_OPERAND (x, 1))
- x = fold_build2_loc (loc, code, TREE_TYPE (x), op0, op1);
+ {
+ if (op0 == error_mark_node || op1 == error_mark_node)
+ x = error_mark_node;
+ else
+ x = fold_build2_loc (loc, code, TREE_TYPE (x), op0, op1);
+ }
else
x = fold (x);
@@ -2066,7 +2081,14 @@ cp_fold (tree x)
if (op0 != TREE_OPERAND (x, 0)
|| op1 != TREE_OPERAND (x, 1)
|| op2 != TREE_OPERAND (x, 2))
- x = fold_build3_loc (loc, code, TREE_TYPE (x), op0, op1, op2);
+ {
+ if (op0 == error_mark_node
+ || op1 == error_mark_node
+ || op2 == error_mark_node)
+ x = error_mark_node;
+ else
+ x = fold_build3_loc (loc, code, TREE_TYPE (x), op0, op1, op2);
+ }
else
x = fold (x);
@@ -2093,9 +2115,18 @@ cp_fold (tree x)
{
r = cp_fold (CALL_EXPR_ARG (x, i));
if (r != CALL_EXPR_ARG (x, i))
- changed = 1;
+ {
+ if (r == error_mark_node)
+ {
+ x = error_mark_node;
+ break;
+ }
+ changed = 1;
+ }
CALL_EXPR_ARG (x, i) = r;
}
+ if (x == error_mark_node)
+ break;
optimize = nw;
r = fold (x);
@@ -2143,7 +2174,15 @@ cp_fold (tree x)
constructor_elt e = { p->index, op };
nelts->quick_push (e);
if (op != p->value)
- changed = true;
+ {
+ if (op == error_mark_node)
+ {
+ x = error_mark_node;
+ changed = false;
+ break;
+ }
+ changed = true;
+ }
}
if (changed)
x = build_constructor (TREE_TYPE (x), nelts);
@@ -2188,9 +2227,19 @@ cp_fold (tree x)
op2 = cp_fold (TREE_OPERAND (x, 2));
op3 = cp_fold (TREE_OPERAND (x, 3));
- if (op0 != TREE_OPERAND (x, 0) || op1 != TREE_OPERAND (x, 1)
- || op2 != TREE_OPERAND (x, 2) || op3 != TREE_OPERAND (x, 3))
- x = build4_loc (loc, code, TREE_TYPE (x), op0, op1, op2, op3);
+ if (op0 != TREE_OPERAND (x, 0)
+ || op1 != TREE_OPERAND (x, 1)
+ || op2 != TREE_OPERAND (x, 2)
+ || op3 != TREE_OPERAND (x, 3))
+ {
+ if (op0 == error_mark_node
+ || op1 == error_mark_node
+ || op2 == error_mark_node
+ || op3 == error_mark_node)
+ x = error_mark_node;
+ else
+ x = build4_loc (loc, code, TREE_TYPE (x), op0, op1, op2, op3);
+ }
x = fold (x);
break;
Jakub
